Wow, I've been trying to understand this for years. To finally have someone draw me a picture (with a simple example and the slow motion video is priceless) FINALLY allowed me to grasp this completely. I can't tell you how much I appreciate it!
Wish i found your videos 2 years ago. Im in the process of redoing my 4 link. This is gonna help me tremendously. You definitely deserve more subs. Thank you!!!
I just found a new channel to check out. I'm a 4x4 guy, but we essentially have the same principles and the more knowledge we know the better we can build. I'll be binge watching!!!
For a solid axle jeep open desert racing…do you aim for more antisquat or less? If i aim for more seperation wont the tires digg alot more into the dirt sand thus make me launch slower? Also on average what do you guys aim for side to side weight bias ?
ive been trying to understand 4 link for the rear of my tacoma just the opposite of what you want for a drag car. this is a great video and I understand it now. no bs, straight to the point. thank you.
When you say opposite do you mean less separation and more squat ? How do you find the sweet spot to avoid excessive digging into dirt/ sand and floatation?
Kevin, Thank you for the explanation on the 4 link bar adjustments . Not knowing anything about 4 links when I hooked the bars up , the car hooked up, I think it would have hooked up in a gravel pit but the car stood straight up at the track. By following your calculations and drawing it out on my garage floor I did the adjustments to the bars to get the bars adjusted to just above the anti squat line. The car launches straight , hard with no wheelies. Very happy. Thanks again.
I would like to say thank you sir. I am a apprentice at a machine shop. My mentor won’t simply give me all the answers, he makes sure I do my homework first. Then after we discuss my findings. I’ve used your videos to help. and they have helped me tremendously.
i always heard knowledge was power ! ... but never thought someone would be kind enough to make a video about it ... great , great information - thank you for your experiences
tonkatoytruck thanks so much for your comments! I would love to have you as a subscriber! I also realize my content needs to provide value so I am going to keep improving the content and channel. Go fast, go straight! Be Safe!!
First, thank you. Second, I got lucky when I put in my ladder bar / coil over setup. I did read the instructions and followed them not knowing what I was actually doing. It isn't perfect but my car is at or just over the anti squat line intersection but can be improved now I know more of what needs to be done. You are an excellent teacher sir. Again, thank you!
Stuart Buckley thanks so much for your comments! This is great news on the installation and I am excited that the videos are helping you be more comfortable tuning your suspension. That is my primary goal of the channel so I always enjoy hearing that part. I have worked with many race cars with some pretty crazy geometry on the bars and chassis mounts. So you are ahead of the game per se' if you started off with good geometry. I will be doing another ladder bar video soon which will give you more insight on tuning ladder bars specifically. Stay tuned! Thanks for the compliments and for supporting the channel. Go fast, go straight! Be Safe!!
At 23:00 mins it really made sense of what Center of Gravity is, hold the car from a cable and it will balance level, push under from the rear it'll wheelie. This video has been the best out there for us that are Challenged at Suspension Math. This is where I know my 63 Nova is having issues just while watching this video and your others ones. I run a 4-speed with a slipper clutch leaving at at 4500-5K and my caltrac bar setup just does NOT like it. Mainly because of the location of the bar. Just by watching your video and me guessing at my Math I could use a extra lower hole or 2 for sure. I had to pre-load 3/4 of a turn which is alot to calm this car down, calvert said 1to2 flats thats all. I bought a used set of badass santhuffs so I have plenty of shock control. Its very likely I'm going to be doing a ladder bar, I can see doing some 38"to 42" ladder bars to get that lower bar to push this car. This is a straight axle gasser so admidityly the front end doesn't have a ton of travel, very stiff front. These cars rely on controlled spin but to push the power from under it and pull the tires instead of what mine does and unload and bounce.
I am so happy that I happened upon your channel I can't express enough how happy I am. The info you are putting out and the way you explain everything is great. Thanks so much.
Shane Mcclaran thanks so much for your comments and support of my channel! My goal is to get racers thinking and understanding more about their suspensions so they can not be afraid to make some changes to try to improve their car! Go fast, go straight! Be Safe!
I was thought a long time ago (Dave Morgan, The Chassis Book) that it is called the neutral line because if the IC is on it it will neither squat or separate. This terminology is in line with automotive physics books, I believe.
Hey Kevin It's me Jeff, I bought your very first rubber upper four links from your website baseline suspensions that were not adjustable you actually made them specifically for me, unfortunately they weren't adjustable like your other setup that you have with the two hymn joints for the Buick Grand National. But I also have the other setup where it's solid. Shortly after I purchased these you came out with the adjustable uppers with the rubber bushing in the front, I wish I would have waited cuz I would have more adjustability out of it. But glad to see you're doing well Jeff 87 Buick Grand National
Faithfully Live thanks so much for your comments! That wasn't me. I have never sold any stuff like that, but I appreciate it. Go fast, go straight! Be Safe!!
steve clayton thanks so much for your comments! My goal is for you, the racer, to have more confidence in understanding and making educated changes to see how your car reacts and maybe why it did what it did. Go fast, go straight! Be Safe!
You bet! Glad it is making sense! I have some refresher videos lately on the Anti Squat line so be sure to check those out also. Go fast, go straight! Be SAFE!!
Thank-you so much for taking the time to leave a comment and for supporting my channel! I don't take your views and support for granted. Go fast, go straight! Be SAFE!! Kevin Wilson KevinWilsonSBC
Now I know everything watch out john force, thanks for your vid I learned a lot and doing my first ever 4 link set up on street car I know it's not a drag car but I do want it to hook and go. MIATA v8 swap
Brilliant, I'm trying to make my 45 year old classic road car into a better sprint / track day car and suspension is key. I'm currently sideways all the time which is entertaining but tbh unnerving and usually results in trying to hard, so thank you
Michael Beacham thanks so much for taking the time to comment! Good luck on your project and I agree with your comment on suspension is key. Go fast, go straight! Be Safe!!
@@KevinWilsonSBC Just fyi really. After watching this several times I've taken all the measurements and I don't have an IC. I have 4 link rear suspension as standard on my 1972 sprint car. I do have upgraded coilovers, springs, bushes etc etc but my trailing arms are perfectly parallel, both pointing down (from rear to front) at 3 degrees. So that explains why now its just rubbish off the line. Axle tramp, squatting on drivers side etc etc. Thanks
Hello along time alignment guy in Kingston Ont Great help going to check my new ride Blown front eng dragster so I guess all new @ least if I scale I will get a 1st hit plan it should 60 in low 90s )
One of the best explanations ever. GREAT JOB. Always good to use knowledge and experience from older and better racers and apply this information to our car. Were trying to hook on a 1971 Chevelle with adjustable uppers and boxed lowers. We do pretty good living on TB at 5000 with a 400 sbc when track prep is good but lauching in over 100 degree weather our 60ft goes to shxxxxt
Thanks for your help in understanding 4 link. I'm looking forward to your videos on ladder bars. Thanks again for your time and I wish you were in Texas
Absolutely great videos... But, I have a set of Intercomp 500 series scales. Their instuctions are very vague on measuring Vertical Center of Gravity. I am not sure which scales you use. But, could you explain how to correctly measure Verticle CG using their scales. That would e great! Or a possible explanation that is better than theres. Thanks,.
DANG!!! I knew by the launch video you where talking about squat and slicks... Was just going on a glimmer of hope you'd talk about antisquat with radials and a stupid short wheelbase like 94" 😂🤘
@@KevinWilsonSBC do you guys offer a "remote tuning" kind of service, for guys like me that live in the great white north? I have a new set up and would like a good base line before towing my car 5 hours to the nearest track, only to start from scratch. It's a 67 Chevy 2 with a parallel 4 link. Small tire car 26x8.5 ".
Absolutely, we offer remote tuning services! In the past 3 months we have helped over 35 drivers improve their 60 foot times via remote services. Goto samsonperformance.com to learn more about us and from there you can start the process (middle ways down on the home page). Email will be the best way to get started as the number of calls we get each day are just too many to answer and get work finished. Getting some key info from you about your car will be necessary to start any remote tuning, so on our website we have a Drag Car Launch Tuning PDF file you will download and that will help us work with you based on data. Go Fast! Go Straight! Be Safe!
Excellent video! In drawing the anti-squat line, it seems that only the height of the center of gravity was used (as you need its intersection with a vertical line through the center of the front wheel.) So why did I need to have the car weighed on scales and determine the front-back placement of the cg?
Thanks! The chalkboard is definitely not to scale. The AS line goes from the center contact patch of the rear tire through through the front spindle centerline at the height of the CG. The location of the center of gravity front to rear is absolutely critical to understanding the reaction of the Instant Center location and height. Take a look at this video to help understand that point more: ua-cam.com/video/_vtb_utqSJM/v-deo.html Go fast, go straight! Be SAFE!!
It’s pretty easy to realize if you run your lower bar up hill you’ll get anti squat if you run it down hill you’ll get squat on initial launch. It’s a fulcrum point, it don’t take all that center squat line calculation to figure that out.
Thanks for your comments! While it is easy for you, my goal is to help break down this stuff for those not as used to making bar changes so they don't have to have 20 opinions from 5 different people get them all turned around. The 4 link is not dark magic or voodoo as you know, but to many it is intimidating. I will check out your videos on it and see if I can pick up some pointers on presenting this better. Go fast, go straight! Be SAFE!!
Great videos…. Coming up with a 230% anti-squat line instant center length 28 inches … height 12 inches . have a factory 4 link 68 GTO running on slick . coil over front and back. Is that Anti-squat line way too high ?1200 hp on spray front heavy no prep car .
Thank you for the awesome video. You wouldn't happen to know how to apply this knowledge to a motorcycle swingarm would you? The part I'm having trouble with is the upper chain run as it's kind of like the top bar but exerting force in the opposite direction
My apologies but that is not something I have messed with... I would think a longer swingarm would improve traction with more weight transfer... Go fast, go straight! Be SAFE!
Kevin, thanks for responding, now I know you're real people trying to help and boy! do we appreciate that. Let me rephrase my question. After you determine that the CG is 44.28" behind the front spindle why don't you move the 100% AS line back to that point which would change the angle of the line? Does AS line go from rear tire patch to cam height over spindle or does it go from rear tire patch to CG? I guess I'm missing something, thanks again and keep the videos coming
Robert Briggs now I better understand your question. The AS line will *always* run from the rear slick contact patch to the vertical centerline of the front spindle and the height of the CG of each car. For the height of this intersect point, it is always best to do the calculation for your car to pinpoint the CG, but not everyone can do all that scaling and jacking around of their race car, so a general rule of thumb to get the height of the AS line intersect point to the front spindles close is to use the height of the camshaft location. The distance of the CG from the front end is just another tool we use in relationship to the IC height and length to help understand how the bars load the suspension at the hit and through the pass. That will be covered more in upcoming videos. So in short, the AS line will ALWAYS be a line from the contact patch of the rear tire to the road/track to the front spindle vertical centerline at the height of the CG of the car, or height of the camshaft as good starting point. Does that help on the AS line?
jvcomet thanks so much for your kind comments! I encourage you to go to samsonperformance.com and checkout the remote tuning services options we setup on our site last night. Due to the large amount of responses to the videos I had to do some to organize it all and set a priority on responses. All the info is on the site on how to get help for sure. I am committed to helping everyone who asks for help. Go fast, go straight! Stay Safe!
Brooksy pointYachtClub thanks so much for your comments! Thanks for taking the time to leave a comment. Good luck in Panama!! Go fast, go straight! Be Safe!!
Thanks Kev for taking the time on these videos. One question though, weather you’re either above or below the neutral line how close do you want to get the IC to the point of COG? Is it better to be closer to the diff or closer to the COG
Great question! This completely depends on so many factors, like, radials, slicks, prep, no prep, weight bias, height of COG, etc... I would encourage you to review this updated video from my channel: ua-cam.com/video/_vtb_utqSJM/v-deo.html Go fast, go straight! Be SAFE!
What do you recommend starting at antisquat wise in a very nose heavy longer wheelbase truck? Its a diesel truck. Makes 1100hp and about 2000ftlbs. Wheelbase Is 117-5/8 I can go as low as 78% or as high as 180 range. Big tire 33/15 stiff sidewalk slick can send a few vids but don’t really have any good test passes yet. Have changed a good bit. And I can send excavation corner weights. Bias is 40.9/59.1 race ready 3940lbs
Iride813 thanks for commenting and some good info already. Go to samsonperformance.com and shoot me an email and I will work with you once we cover a few more pieces of info. Go fast, go straight! Be Safe!
C Ten thanks so much for your comments! Same basic thoughts. The chassis mount point, length and height will determine AS. Generally, on the long trailing arm, getting it shortened is a good move since the stock length naturally wants to just squat. Go fast, go straight! Be Safe!!
Should i do the maths to see how much weight it would take to crush the side wall of my tire. Then base my weight transfer to the rear/ shock compression accordingly? Should i base my max shock compression (in lbs) on the amount of weight it will take to crush the side wall?
Where does the "center of gravity" dot come into play? It looks like anti-squat line goes from rear slick tread to the cam height above front center line. Is the center of gravity dot ever used again? I run a ladder bar so should I try to use the front mounting hole that lies on the anti squat line?
Side to side weigh bias ( left/ right) should we ideally aim for a 50-50% (side to side) with driver in vehicle? How do i know how much weight should be on the rear left side to compensate for engine rotation ?
The link for the AS calculator says that it will give a false reading if you do not use their products, is this something we need to take into account for? Thank you for the info, good breakdown.
Gap Cam TV thanks so much for your comments! That is a just a reference tool. The main goal of the site is to put your measurements in and get your IC length and height. This is representative to your weights entered and CG. It is not perfect, but the goal is a known baseline, then go test and video. Next moves are then more educated versus just throwing things at a wall. Go fast, go straight! Be Safe!!
🏁 ⬆️⬇️Old-timers I've built cars/chassis for in the past have told me they used to try and control this by putting on what I believe they called 90 10 shocks. These were used to transfer 90 percent of the weight to the rear tire. I think this is how the gasser was was created. If you've ever drove a Gasser down the track there a handful. Thank God chassis design has come a long way. Great video good job pretty cool so many people are getting educated from it and actually getting an understanding of how the force's act on or through the chassis. Just the safety alone from setting up a chassis correct is huge!!! You'll probably save some lives or at least keep some cars off the walls through these teaching/educational videos.. 👍👏burn rubber I might not be stating the 90 10 shocks correct so forgive me if I'm wrong it's been a while since I've seen them old dude's!
Kevin, will you please explain something. You go through the math to determine CG front to rear. Weigh the car, figure bias front to rear, 41% on rear, 59% on front, determine it is 63.72" forward of rear, but the AS line still goes to cam height over front spindle which does not change. Why go trough the math to determine CG fore and aft when that never comes into play when calculating % of AS? I'm confused, what am I missing?
Robert Briggs thanks so much for your comments! The camshaft is a good alternative height to knowing your exact CG of location. If you know your CG location, then use that as the intersect height across the perpendicular line through your front spindle centerline. Not everyone can do all the scaling and jacking to understand the exact CG location, so then a good compromise is the camshaft method. Make more sense? Then the relationship b/w the CG and IC is another tuning aid for how your car reacts on the hit and through the run. Also, even in the camshaft method, ride height will impact that calculation, front or rear ride height will move that point. Go fast, go straight! Be Safe!
Still trying to set up a 4 link conversion in my "74 vette. Autofab 9". Some say to start out by adjusting to a neutral setting with the car jacked up, rear hanging . When I do this and let the car down( weight of car on tires) it goes into preload. Should I find neutral with the weight of the car on the suspension and tune from there, as this is the way it will go down the track? Should it make a difference? PS I just hit the subscribe button
Robert Briggs thanks so much for your comments, questions and for subscribing! I generally start out by making sure the bars are the same length with rear end hanging. Then I sit the car down, settle the suspension, roll it back and forth, confirm square and make sure the rearend is centered. Then I check/set pinion angle. Then I move to rear preload with the car on the scales. Hope this helps. Go fast, go straight! Be Safe!!
I also have a ‘74 vette with the Autofab 4-link. A great starting point for your instant center would be around 9.5” high and around 37.5” forward. This should give you around 130% anti squat. I will plant the tire into the track surface. Try and control the rate at which this happens with a quality double adjustable shock. Top bar is going to be in the only hole above the axle bracket and attached to the second from the lowest hole in the top frame bracket. The lower bar is going to be in the center hole on the lower axle bracket and the lowest hole in the lower frame bracket. Corvettes have a significant amount of engine set back and tend to wheel stand. Travel limiters quality front shocks, and maybe a little weight added to the nose of the car might help with this.
So is this a good rule of thumb: Below AS line=Squat (tire lifting from track) control with shock compression Above AS line=Separation (tire forced to track) control with shock extension.
Brian Boles thanks so much for your questions! I try to be careful with doing this but at a high level you are thinking about it in the right direction. Just don't ignore how both Compression and Rebound work together for each car, with spring rates and shock height and wheelie bars and weight transfer. For instance on separation the compression setting is critical after the first .5 second based on the several factors and IS length. Go fast, go straight! Be Safe!
I just got turned on to you and I'm hooked. Subscribed, liked and notifications are turned on. Your videos are very informative and I dig your style. Your timing is actually pretty good as well as I'm getting ready to scrap the 4 link set up that I bought for my 64 Nova. I purchased a four-link kit from a company (I don't want to bash them) but it's a nice set up maybe for the street. Since I've been racing more often, I don't like how my car launches (Squats). The thing that gets me is, all the videos mention the top bar and bottom bar "intersecting" each other at some point. I understand that most setups do and this and is desired so you can manipulate the intersection point depending on your application, but in my current set up both the top and bottom bar are parallel!! There are no adjustment holes on the housing nor on the cross member side. So basically they will never intersect?? Very frustrating. Also the top bar is not on the top side of the rear end housing. It's mounted on the front side of it at about the centerline height. I've heard it's good to have the top bar closer to the centerline of the axle but shouldn't it be at least on the top side of the housing? I have purchased some 4 link brackets that I will install in place of what's on there now. They have 4 hole locations for both top and bottom bars so that should help with my situation. Sorry to write you such a long story but I just wanted to hear what you thought about my "parallel bar" situation. Thanks
Anthony Burgess thanks so much for your comments and questions! Appreciate the nice feedback and support on the channel. Sounds like your current 4-link is more for street or even street rodding. For drag racing, which is my focus, I need to be able to adjust the bar locations for my instant center length and height and I prefer to have the top bar on top of the rear end axle and not out in front the tubes. Good to hear you are taking the steps you are taking to tune your launch and you will not regret it! Nice work and keep us posted on your progress. Go fast, go straight! Be Safe!
Just an update, as I've just watched your video again :). I finally decided to go and cut the old forward brackets out and weld in the new ones. I have yet to make a pass with the new set up since I'm currently freshening up the engine also. It is nice to be able to put some angles on my bars now. I'll keep you posted and thanks so much for what you do for us racers out here that aren't as skilled as you are in this department.
Sorry... I don't have much drag racing experience with airbags other than racers trying to use them vs rear ARBs. The 4 link acts the same so those theories still apply. Go fast, go straight! Be SAFE!
Fred G thanks so much for your comments! Glad these are making sense! Video coming on coil spring selections, spring rates and how they impact the chassis and shocks on the hit. Go Fast! Go Straight! Be Safe!
@@KevinWilsonSBC I took all my measurements tonight so now they are memorialized. Looks like my front springs are too light based on your compression recommendations, 46% compressed! Lots of energy there waiting to cause problems. Rears were closer but a little heavy, 17% compressed. I'l watch for your next video, car isn't turned up yet so she'll stay down for this weekend I hope. Thanks again!
awesome video mate. im in australia. Got a valiant charger and keen on a triangulated 4 link for straight and twisty purposes. but the length of the top bars with most of them look like they delete a lot of the deep analytical explanations you go into. is there any kind of middle ground for such an application ya reckon? cheers in advance. keep up the awesome vids
k1Stung thanks so much for your comments! When I started, I never dreamed people would even care about these suspension videos, especially around the world. Love Australia!!! Definitely watch this video I made recently before making your next step: ua-cam.com/video/eF19sCJxw68/v-deo.html Go fast, go straight! Be Safe!!
Gláucio Duarte thanks so much for your comments and question! I have never worked on a FWD drag car so unfortunately I don't have any experience to help there. I will have to research that one more. Go fast, go straight! Be Safe!!
Have you had much experience with triangulated four link (similar to fox body mustang stuff) I’m looking at options for my Torana (Australian delivered car) that had a triangulated four link but leaning towards parallel four link
David Walker thanks so much for your comments and question! I am absolutely planning a video on leaf springs and how to setup a drag car to launch on leaf springs. Great question!! Go fast, go straight! Be Safe!
Jim Franklin thanks so much for your question! You must mock up your car simulating the race ready ride height, with the rear end height set based on your axle centerline to track and wheel placement in the tubs/body fender, then mock up your bar locations. Every car is so unique, I cannot give you a distance without knowing your car's setup and measurements. Stay tuned for the String Method video coming out soon that will cover squaring a chassis which will help you in this process. Go fast, go straight! Be Safe!!
So I've watched alot of your videos, very informative without a doubt. Fist an foremost, my car and setup are totally street based and for fun. Also, I'm doing what I'm about to explain for fun and to be all the wall different. I have a 2001 Lexus IS300 with a mildly built 2jz, a TH400 and at the moment the stock IRS. I'm in the process of converting it over to a Ford 9 inch. Now you can see the it's quite the different build. I'm leaning towards a triangulated 4 link. The car has a rear subframe and saddle gas tank all of which is being removed for obvious reasons lol. My main question/comment/concern what have you is. Do I build my own frame so speak within the existing frame or can I reinforce the mounting point areas for the 4 link and go with it? The car has integrated frame rails that disappear before the gas tank and reappear after the rear frame. Should I connect those? The car will also have a slight wheel tub increase to accept a 275/60/15 on a 15x10 4.5BS rim. I know it's totally off the wall, but any suggestions would be appreciated, thanks in advance and keep up the great content!!
Rick Shults thanks so much for your comments, info and questions! This is going to be easier via email. Shoot me an email from my profile and we can chat for sure. This is definitely different!! Go fast, go straight! Be Safe!!
I’ve been watching a lot of your videos and I believe I understand quite a bit of it. Im trying to plot the 4 link out on the website link you provided but I don’t think I measuring the “horizontal control arm length”. Do I measure center of bolt going through the heim to center of the other bolt. But it says “control arm length is not the actual length it’s the parrallel/projected length. Do I need to hold a level on the rear bolt and try and measure straight across instead of following the bar angle
This can really screw with you, so in this case, I would want to have the car on wheel scales and confirm what it is doing. You are likely introducing some rear steer more than normal if the adjuster were on the top bar, but this is why I would have my measurements documented and the rear tires on scales before making changes. Go fast, go straight! Be SAFE!
They can mount in front or the rear of the housing. The most common is the rear. Other than a big tire slick, most applications extend on the hit. Go fast, go straight! Be SAFE!!
I'm building a modern day Typhoon (2nd Gen 4 Door GMC Jimmy that has been LS Swapped) Would you want any squat or anti-squat to make the AWD work properly?
Cliff Weatherbee thanks so much for your comments and questions! There is a bunch more info required to help us make more recommendations. Feel free to checkout our website if you want to submit more info at samsonperformance.com Go fast, go straight! Be Safe!
What if the engine is to weak to lift the front wheels (lower class rallycross car). In that case, where would you recommened having the IC? Over or under the anti squat line?
Magnus Göransson thanks so much for your comments! For that I would start as close to neutral as possible, but over the AS line. The AS line is mainly for a starting point. The car will show you what it wants. Go fast, go straight! Be Safe!!
Steve Sutton thanks so much for your comments! I will add that to list of upcoming videos. Though not as common with many of our local racers, it is for real so I will get some content planned for this one also! Go fast, go straight! Be Safe!
Thanks Kevin. Some if/then explanations would really be helpful in creating a mental picture. Something where we can visualize the result. Like our car is squatting on the hit. So I move the upper arms up one hole in the front mount to get ĪC above the anti squat line.
Is it possible to have too much anti squat? Car I'm setting up is 99 mustang stock style suspension. Still have another hole to drop the lower control arms down. Thanks.
hammerdown636 thanks so much for your comments! Absolutely it is possible to have too much AntiSquat. Remember, while necessary to plant the slick/radial, our goal is to apply just enough force for traction and the rest of the energy to move the car forward. It is about a Balance with all the rear components working together. Go fast, go straight! Be Safe!
I believe I figured out I have a ladder bar setup so where it says front upper bolt measurement and front lower control arm bolt measurement I measure the single Bolt down to the ground correct?
Sorry for late response. The main ladder bar measurement is distance of the chassis bolt to the ground. You are correct. For a ladder bar setup, checkout my video on percentage of rise. That is more applicable to a ladder bar with respect to the Anti Squat line.
Marcus Pingitore thanks so much for your question! At high level the 4 link is acting on the chassis under acceleration. I have never, ever, setup a drift car. Go fast, go straight! Be Safe!!
wow man, this video is EXCELLANT !!! Please tell me where to send you some money... just retaired and I'm building a back half 70 Duster with latter bars from COMP. ENGR. I have built the car with a lot of help from the UTUBE community BUT not one good video on SET UP lots of videos on what parts to buy. Thanks for your time I would like to donate to your channel
Thanks for all the kind words and feedback! I am glad the suspension videos are a help to you. By just watching my videos and subscribing to my channel is a big help in keeping the channel alive! I really enjoy helping other racers and I have a dad who poured himself into me on suspension/chassis tuning and engine/transmission building from as far back as I can remember walking around the garage with a baby bottle in my hand. With all I learned, and still learn from him, I just keep learning and building on the foundation which over the past 10 years or so has led to SamSon Performance. My dad's name is Sam and for so many years people would refer to me as Sam's Son, so I just made SamSon Performance from that twist. If you absolutely still want to contribute, you can donate by clicking on the following link that takes you to our shop website and there is a $10 support option and then you can change the quantity which will increment by $10 for each quantity. For any money donated, it is used to purchase more video recording equipment and supplies to keep the channel going. www.samsonperformance.com/store/p7/SupportKevinWilsonSBC.html Hope you have a Merry Christmas and go fast, go straight, be safe!! Kevin Wilson
Wow, I've been trying to understand this for years. To finally have someone draw me a picture (with a simple example and the slow motion video is priceless) FINALLY allowed me to grasp this completely. I can't tell you how much I appreciate it!
Kyle thanks so much for your comments and you are more than welcome! Go fast, go straight! Be Safe!
Ditto, thanks SRC Garage and Kevin Wilson 💪🏼
Thanks a bunch short clean to the point 👍
Kevin you are turning on so many lights for me. Thank you so much for your work.
Just Me thanks so much for your comments and glad to shed some light on this! Glad these videos are helping. Go fast, go straight! Be Safe!
This man is the most knowledgable chassis guy I've ever seen. Thanks to Kevin Wilson for sharing this with us!
Thank you for the 4-link video. You have removed some of the fog I have been fighting for years.
Thomas Burns thanks so much for your comments! Go fast, go straight! Be Safe!
I can't quit watching your video trying to learn more and more thank you for your time sir
Wish i found your videos 2 years ago. Im in the process of redoing my 4 link. This is gonna help me tremendously. You definitely deserve more subs. Thank you!!!
I just found a new channel to check out. I'm a 4x4 guy, but we essentially have the same principles and the more knowledge we know the better we can build. I'll be binge watching!!!
For a solid axle jeep open desert racing…do you aim for more antisquat or less? If i aim for more seperation wont the tires digg alot more into the dirt sand thus make me launch slower? Also on average what do you guys aim for side to side weight bias ?
ive been trying to understand 4 link for the rear of my tacoma just the opposite of what you want for a drag car. this is a great video and I understand it now. no bs, straight to the point. thank you.
wyattreese thanks so much for your comments! Go fast, go straight! Be Safe!!
When you say opposite do you mean less separation and more squat ? How do you find the sweet spot to avoid excessive digging into dirt/ sand and floatation?
Terrific explanation, there are thousands of more people that need to see these videos! I can’t wait to build something serious
Drivin with Drew thanks so much for your comments! I appreciate your kind words!! Go fast, go straight! Be Safe!!
Kevin, Thank you for the explanation on the 4 link bar adjustments . Not knowing anything about 4 links when I hooked the bars up , the car hooked up, I think it would have hooked up in a gravel pit but the car stood straight up at the track. By following your calculations and drawing it out on my garage floor I did the adjustments to the bars to get the bars adjusted to just above the anti squat line. The car launches straight , hard with no wheelies. Very happy. Thanks again.
steve mustaikis thanks so much for your comments! Go fast, go straight! Be Safe!!
I would like to say thank you sir. I am a apprentice at a machine shop. My mentor won’t simply give me all the answers, he makes sure I do my homework first. Then after we discuss my findings. I’ve used your videos to help. and they have helped me tremendously.
Kelvin Jones thanks so much for your comments! Glad the videos help!! Go fast, go straight! Be Safe!!
i always heard knowledge was power ! ... but never thought someone would be kind enough to make a video about it ... great , great information - thank you for your experiences
The best compliment I can pay you is to subscribe. Planning a 275 drag radial build and the rear suspension is my first priority.
tonkatoytruck thanks so much for your comments! I would love to have you as a subscriber! I also realize my content needs to provide value so I am going to keep improving the content and channel. Go fast, go straight! Be Safe!!
Never had a desire to make a racing suspension but loved learning the geometry involved. Awesome video
Glad you liked it! Go fast, go straight! Be SAFE!!
First, thank you. Second, I got lucky when I put in my ladder bar / coil over setup. I did read the instructions and followed them not knowing what I was actually doing. It isn't perfect but my car is at or just over the anti squat line intersection but can be improved now I know more of what needs to be done. You are an excellent teacher sir. Again, thank you!
Stuart Buckley thanks so much for your comments! This is great news on the installation and I am excited that the videos are helping you be more comfortable tuning your suspension. That is my primary goal of the channel so I always enjoy hearing that part. I have worked with many race cars with some pretty crazy geometry on the bars and chassis mounts. So you are ahead of the game per se' if you started off with good geometry. I will be doing another ladder bar video soon which will give you more insight on tuning ladder bars specifically. Stay tuned! Thanks for the compliments and for supporting the channel. Go fast, go straight! Be Safe!!
This was super informative. I can't get enough of this information!
Wayne Edmondson thanks so much for your comments and support of the channel! Go fast, go straight! Be Safe!!
At 23:00 mins it really made sense of what Center of Gravity is, hold the car from a cable and it will balance level, push under from the rear it'll wheelie. This video has been the best out there for us that are Challenged at Suspension Math. This is where I know my 63 Nova is having issues just while watching this video and your others ones. I run a 4-speed with a slipper clutch leaving at at 4500-5K and my caltrac bar setup just does NOT like it. Mainly because of the location of the bar. Just by watching your video and me guessing at my Math I could use a extra lower hole or 2 for sure. I had to pre-load 3/4 of a turn which is alot to calm this car down, calvert said 1to2 flats thats all.
I bought a used set of badass santhuffs so I have plenty of shock control.
Its very likely I'm going to be doing a ladder bar, I can see doing some 38"to 42" ladder bars to get that lower bar to push this car. This is a straight axle gasser so admidityly the front end doesn't have a ton of travel, very stiff front. These cars rely on controlled spin but to push the power from under it and pull the tires instead of what mine does and unload and bounce.
awsomeears thanks so much for your comments and info! Good luck with your build and that sounds like a strong ride! Go fast, go straight! Be Safe!!
Very good I've learned more here than I have all put together prior to this.
David Reed thanks so much for your comments! Go fast, go straight! Be Safe!!
I am so happy that I happened upon your channel I can't express enough how happy I am. The info you are putting out and the way you explain everything is great. Thanks so much.
Shane Mcclaran thanks so much for your comments and support of my channel! My goal is to get racers thinking and understanding more about their suspensions so they can not be afraid to make some changes to try to improve their car! Go fast, go straight! Be Safe!
@@KevinWilsonSBC your suspension series is a big help as I own a third gen fbody and a 87 gbody 442 and an S10 leafsprings
I had no clue about this before I watched the video. You explained it clearly. Thanks.
swatson0061 thanks so much for your comments! Go fast, go straight! Be Safe!!
I just got skooled! 🤯 Thanks for the lesson!!! 🙏🏻
Rock on! Thanks for commenting! Go fast, go straight! Be SAFE!!
I was thought a long time ago (Dave Morgan, The Chassis Book) that it is called the neutral line because if the IC is on it it will neither squat or separate. This terminology is in line with automotive physics books, I believe.
Bill Clark thanks so much for your comments! Go fast, go straight! Be Safe!!
Hey Kevin
It's me Jeff, I bought your very first rubber upper four links from your website baseline suspensions that were not adjustable you actually made them specifically for me, unfortunately they weren't adjustable like your other setup that you have with the two hymn joints for the Buick Grand National.
But I also have the other setup where it's solid.
Shortly after I purchased these you came out with the adjustable uppers with the rubber bushing in the front, I wish I would have waited cuz I would have more adjustability out of it.
But glad to see you're doing well
Jeff
87 Buick Grand National
Faithfully Live thanks so much for your comments! That wasn't me. I have never sold any stuff like that, but I appreciate it. Go fast, go straight! Be Safe!!
This is great been trying to wrap my head around this for a while ,,,, guess what I am doing this week ,,,, scaling and laying out lines !!!!
steve clayton thanks so much for your comments! My goal is for you, the racer, to have more confidence in understanding and making educated changes to see how your car reacts and maybe why it did what it did. Go fast, go straight! Be Safe!
I love the emphasis on what will work and how to get it to work.
Thanks 🙏 for the lesson bruh 😎
You bet! Glad it is making sense! I have some refresher videos lately on the Anti Squat line so be sure to check those out also. Go fast, go straight! Be SAFE!!
Alot of good info here also explain s it well don't forget after the hit things do changes.
Great job. This is exactly what I need. Now that my car is stiffened with a cage and solid bushings I cannot get it to work.
Thank-you so much for taking the time to leave a comment and for supporting my channel! I don't take your views and support for granted. Go fast, go straight! Be SAFE!!
Kevin Wilson
KevinWilsonSBC
Now I know everything watch out john force, thanks for your vid I learned a lot and doing my first ever 4 link set up on street car I know it's not a drag car but I do want it to hook and go. MIATA v8 swap
Brilliant, I'm trying to make my 45 year old classic road car into a better sprint / track day car and suspension is key. I'm currently sideways all the time which is entertaining but tbh unnerving and usually results in trying to hard, so thank you
Michael Beacham thanks so much for taking the time to comment! Good luck on your project and I agree with your comment on suspension is key. Go fast, go straight! Be Safe!!
@@KevinWilsonSBC Just fyi really. After watching this several times I've taken all the measurements and I don't have an IC. I have 4 link rear suspension as standard on my 1972 sprint car. I do have upgraded coilovers, springs, bushes etc etc but my trailing arms are perfectly parallel, both pointing down (from rear to front) at 3 degrees. So that explains why now its just rubbish off the line. Axle tramp, squatting on drivers side etc etc. Thanks
Kevin one of the most helpful videos I’ve watched 👍🏻
Cheers buddy
shaun eckert thanks so much for your comments! Go fast, go straight! Be Safe!!
I’m trying to learn these things at the moment as going to start building a chassis soon. It’s helping, but also confusing 😂
Great explanation, looking forward to re-affirm info thanks
This was a fantastic video! Thanks for breaking this down in a manner that is easy to understand.
Kiel Rosenthal thanks so much for your support and taking the time to comment! Go fast, go straight! Be Safe!!
Hello along time alignment guy in Kingston Ont Great help going to check my new ride Blown front eng dragster so I guess all new @ least if I scale I will get a 1st hit plan it should 60 in low 90s )
One of the best explanations ever. GREAT JOB. Always good to use knowledge and experience from older and better racers and apply this information to our car. Were trying to hook on a 1971 Chevelle with adjustable uppers and boxed lowers. We do pretty good living on TB at 5000 with a 400 sbc when track prep is good but lauching in over 100 degree weather our 60ft goes to shxxxxt
mike balzer thanks so much for your comments and encouragement! Go fast, go straight! Be Safe!!
You have to race the track
Thanks for getting back to me . I also should tell you I don't race at the track. I'm a street racer only , and we do things a lot different ???
Jim Franklin yes the streets are much different than a prepped track! Go fast, go straight! Be Safe!!
I don't have squat... Great info!!
Thanks for your help in understanding 4 link. I'm looking forward to your videos on ladder bars. Thanks again for your time and I wish you were in Texas
Ed Allen thanks so much for your comments! Ladder bar video at ua-cam.com/video/HF9cvi4I_OU/v-deo.html Go fast, go straight! Be Safe!!
Gold. This video is pure gold. Thank you.
Jim Bogart thanks so much for your comments! Go fast, go straight! Be Safe!!
Thank you so much for solid content, no bs! 👌
james Richter thanks so much for your comments! Go fast, go straight! Be Safe!!
Absolutely great videos... But, I have a set of Intercomp 500 series scales. Their instuctions are very vague on measuring Vertical Center of Gravity. I am not sure which scales you use. But, could you explain how to correctly measure Verticle CG using their scales. That would e great! Or a possible explanation that is better than theres. Thanks,.
DANG!!! I knew by the launch video you where talking about squat and slicks... Was just going on a glimmer of hope you'd talk about antisquat with radials and a stupid short wheelbase like 94" 😂🤘
Thank you for putting these together.
1quickchevy2 thanks so much for your comments! I am happy to do these. Hope they make sense. Go fast, go straight! Be safe!
@@KevinWilsonSBC do you guys offer a "remote tuning" kind of service, for guys like me that live in the great white north? I have a new set up and would like a good base line before towing my car 5 hours to the nearest track, only to start from scratch. It's a 67 Chevy 2 with a parallel 4 link. Small tire car 26x8.5 ".
Absolutely, we offer remote tuning services! In the past 3 months we have helped over 35 drivers improve their 60 foot times via remote services. Goto samsonperformance.com to learn more about us and from there you can start the process (middle ways down on the home page). Email will be the best way to get started as the number of calls we get each day are just too many to answer and get work finished. Getting some key info from you about your car will be necessary to start any remote tuning, so on our website we have a Drag Car Launch Tuning PDF file you will download and that will help us work with you based on data. Go Fast! Go Straight! Be Safe!
Excellent video! In drawing the anti-squat line, it seems that only the height of the center of gravity was used (as you need its intersection with a vertical line through the center of the front wheel.) So why did I need to have the car weighed on scales and determine the front-back placement of the cg?
Thanks! The chalkboard is definitely not to scale. The AS line goes from the center contact patch of the rear tire through through the front spindle centerline at the height of the CG. The location of the center of gravity front to rear is absolutely critical to understanding the reaction of the Instant Center location and height. Take a look at this video to help understand that point more: ua-cam.com/video/_vtb_utqSJM/v-deo.html
Go fast, go straight! Be SAFE!!
Will there be a "Finding the CG demonstration video"?
Thanks for getting back to me . I also should tell I don't race at the track. I'm a street racer only and we do things a lot different ???
Jim Franklin thanks so much for your comments! Go fast, go straight! Be Safe!!
It’s pretty easy to realize if you run your lower bar up hill you’ll get anti squat if you run it down hill you’ll get squat on initial launch. It’s a fulcrum point, it don’t take all that center squat line calculation to figure that out.
Thanks for your comments! While it is easy for you, my goal is to help break down this stuff for those not as used to making bar changes so they don't have to have 20 opinions from 5 different people get them all turned around. The 4 link is not dark magic or voodoo as you know, but to many it is intimidating. I will check out your videos on it and see if I can pick up some pointers on presenting this better. Go fast, go straight! Be SAFE!!
Great channel. Great source of info. Appreciate you sharing your knowledge and experiences. Definitely deserve more subscribers
Jason Erwin thanks so much for your comments! I appreciate your support of my channel. Go fast, go straight! Be Safe!!
Great video!
Great videos…. Coming up with a 230% anti-squat line instant center length 28 inches … height 12 inches . have a factory 4 link 68 GTO running on slick . coil over front and back. Is that Anti-squat line way too high ?1200 hp on spray front heavy no prep car .
Fantastic explanation. Appreciate it
Great video. Thank you for sharing.
Thank you for the awesome video. You wouldn't happen to know how to apply this knowledge to a motorcycle swingarm would you? The part I'm having trouble with is the upper chain run as it's kind of like the top bar but exerting force in the opposite direction
My apologies but that is not something I have messed with... I would think a longer swingarm would improve traction with more weight transfer... Go fast, go straight! Be SAFE!
Kevin, thanks for responding, now I know you're real people trying to help and boy! do we appreciate that. Let me rephrase my question. After you determine that the CG is 44.28" behind the front spindle why don't you move the 100% AS line back to that point which would change the angle of the line? Does AS line go from rear tire patch to cam height over spindle or does it go from rear tire patch to CG? I guess I'm missing something, thanks again and keep the videos coming
Robert Briggs now I better understand your question. The AS line will *always* run from the rear slick contact patch to the vertical centerline of the front spindle and the height of the CG of each car. For the height of this intersect point, it is always best to do the calculation for your car to pinpoint the CG, but not everyone can do all that scaling and jacking around of their race car, so a general rule of thumb to get the height of the AS line intersect point to the front spindles close is to use the height of the camshaft location. The distance of the CG from the front end is just another tool we use in relationship to the IC height and length to help understand how the bars load the suspension at the hit and through the pass. That will be covered more in upcoming videos. So in short, the AS line will ALWAYS be a line from the contact patch of the rear tire to the road/track to the front spindle vertical centerline at the height of the CG of the car, or height of the camshaft as good starting point. Does that help on the AS line?
excellent presentation, thank you
Great info in plain understandable English. Just subscribed. Will get all the info together and will be giving you a call. Thanks 👍👍👍
jvcomet thanks so much for your kind comments! I encourage you to go to samsonperformance.com and checkout the remote tuning services options we setup on our site last night. Due to the large amount of responses to the videos I had to do some to organize it all and set a priority on responses. All the info is on the site on how to get help for sure. I am committed to helping everyone who asks for help. Go fast, go straight! Stay Safe!
Wow great presentación learn a lot from your vidio
Racing in Panama, central america
Brooksy pointYachtClub thanks so much for your comments! Thanks for taking the time to leave a comment. Good luck in Panama!! Go fast, go straight! Be Safe!!
Great video, wish there were some similar videos for circuit racing.
Ryan Humfrey thanks so much for your comments! Go fast, go straight! Be Safe!
Wish you had a no bar drag bike version, Lol. But great info, I am just trying to translate it to bikes
I have never messed with drag bikes... but I will take a crack at it. Shoot me an email samsalignmentsc@gmail.com
Go fast, go straight! Be SAFE!
Thanks Kev for taking the time on these videos.
One question though, weather you’re either above or below the neutral line how close do you want to get the IC to the point of COG?
Is it better to be closer to the diff or closer to the COG
Great question! This completely depends on so many factors, like, radials, slicks, prep, no prep, weight bias, height of COG, etc... I would encourage you to review this updated video from my channel: ua-cam.com/video/_vtb_utqSJM/v-deo.html
Go fast, go straight! Be SAFE!
What do you recommend starting at antisquat wise in a very nose heavy longer wheelbase truck? Its a diesel truck. Makes 1100hp and about 2000ftlbs. Wheelbase Is 117-5/8 I can go as low as 78% or as high as 180 range. Big tire 33/15 stiff sidewalk slick can send a few vids but don’t really have any good test passes yet. Have changed a good bit. And I can send excavation corner weights. Bias is 40.9/59.1 race ready 3940lbs
Iride813 thanks for commenting and some good info already. Go to samsonperformance.com and shoot me an email and I will work with you once we cover a few more pieces of info. Go fast, go straight! Be Safe!
Kevin, great video. I was wondering if you had any info on obtaining anti squat with a trailing arm setup as opposed to a 4 link. Thanks so much.
C Ten thanks so much for your comments! Same basic thoughts. The chassis mount point, length and height will determine AS. Generally, on the long trailing arm, getting it shortened is a good move since the stock length naturally wants to just squat. Go fast, go straight! Be Safe!!
Should i do the maths to see how much weight it would take to crush the side wall of my tire. Then base my weight transfer to the rear/ shock compression accordingly? Should i base my max shock compression (in lbs) on the amount of weight it will take to crush the side wall?
Where does the "center of gravity" dot come into play? It looks like anti-squat line goes from rear slick tread to the cam height above front center line. Is the center of gravity dot ever used again? I run a ladder bar so should I try to use the front mounting hole that lies on the anti squat line?
Very helpful 👌
Side to side weigh bias ( left/ right) should we ideally aim for a 50-50% (side to side) with driver in vehicle? How do i know how much weight should be on the rear left side to compensate for engine rotation ?
The link for the AS calculator says that it will give a false reading if you do not use their products, is this something we need to take into account for? Thank you for the info, good breakdown.
Gap Cam TV thanks so much for your comments! That is a just a reference tool. The main goal of the site is to put your measurements in and get your IC length and height. This is representative to your weights entered and CG. It is not perfect, but the goal is a known baseline, then go test and video. Next moves are then more educated versus just throwing things at a wall. Go fast, go straight! Be Safe!!
🏁 ⬆️⬇️Old-timers I've built cars/chassis for in the past have told me they used to try and control this by putting on what I believe they called 90 10 shocks. These were used to transfer 90 percent of the weight to the rear tire. I think this is how the gasser was was created. If you've ever drove a Gasser down the track there a handful. Thank God chassis design has come a long way. Great video good job pretty cool so many people are getting educated from it and actually getting an understanding of how the force's act on or through the chassis. Just the safety alone from setting up a chassis correct is huge!!! You'll probably save some lives or at least keep some cars off the walls through these teaching/educational videos.. 👍👏burn rubber
I might not be stating the 90 10 shocks correct so forgive me if I'm wrong it's been a while since I've seen them old dude's!
Danny A KustomKing USA thanks so much for your comments! Go fast, go straight! Be Safe!!
Kevin, will you please explain something. You go through the math to determine CG front to rear. Weigh the car, figure bias front to rear, 41% on rear, 59% on front, determine it is 63.72" forward of rear, but the AS line still goes to cam height over front spindle which does not change. Why go trough the math to determine CG fore and aft when that never comes into play when calculating % of AS? I'm confused, what am I missing?
Robert Briggs thanks so much for your comments! The camshaft is a good alternative height to knowing your exact CG of location. If you know your CG location, then use that as the intersect height across the perpendicular line through your front spindle centerline. Not everyone can do all the scaling and jacking to understand the exact CG location, so then a good compromise is the camshaft method. Make more sense? Then the relationship b/w the CG and IC is another tuning aid for how your car reacts on the hit and through the run. Also, even in the camshaft method, ride height will impact that calculation, front or rear ride height will move that point. Go fast, go straight! Be Safe!
Kevin, great job on all your videos. Can this technology be used on a F250 four wheel drive truck? Appreciate all you do to help people out.
Matt Antonelli thanks so much for your comments! Yes, same theories apply. Go fast, go straight! Be Safe!!
Still trying to set up a 4 link conversion in my "74 vette. Autofab 9". Some say to start out by adjusting to a neutral setting with the car jacked up, rear hanging . When I do this and let the car down( weight of car on tires) it goes into preload. Should I find neutral with the weight of the car on the suspension and tune from there, as this is the way it will go down the track? Should it make a difference? PS I just hit the subscribe button
Robert Briggs thanks so much for your comments, questions and for subscribing! I generally start out by making sure the bars are the same length with rear end hanging. Then I sit the car down, settle the suspension, roll it back and forth, confirm square and make sure the rearend is centered. Then I check/set pinion angle. Then I move to rear preload with the car on the scales. Hope this helps. Go fast, go straight! Be Safe!!
I also have a ‘74 vette with the Autofab 4-link. A great starting point for your instant center would be around 9.5” high and around 37.5” forward.
This should give you around 130% anti squat.
I will plant the tire into the track surface.
Try and control the rate at which this happens with a quality double adjustable shock.
Top bar is going to be in the only hole above the axle bracket and attached to the second from the lowest hole in the top frame bracket.
The lower bar is going to be in the center hole on the lower axle bracket and the lowest hole in the lower frame bracket.
Corvettes have a significant amount of engine set back and tend to wheel stand. Travel limiters quality front shocks, and maybe a little weight added to the nose of the car might help with this.
So is this a good rule of thumb:
Below AS line=Squat (tire lifting from track) control with shock compression
Above AS line=Separation (tire forced to track) control with shock extension.
Brian Boles thanks so much for your questions! I try to be careful with doing this but at a high level you are thinking about it in the right direction. Just don't ignore how both Compression and Rebound work together for each car, with spring rates and shock height and wheelie bars and weight transfer. For instance on separation the compression setting is critical after the first .5 second based on the several factors and IS length. Go fast, go straight! Be Safe!
I just got turned on to you and I'm hooked. Subscribed, liked and notifications are turned on. Your videos are very informative and I dig your style. Your timing is actually pretty good as well as I'm getting ready to scrap the 4 link set up that I bought for my 64 Nova. I purchased a four-link kit from a company (I don't want to bash them) but it's a nice set up maybe for the street. Since I've been racing more often, I don't like how my car launches (Squats). The thing that gets me is, all the videos mention the top bar and bottom bar "intersecting" each other at some point. I understand that most setups do and this and is desired so you can manipulate the intersection point depending on your application, but in my current set up both the top and bottom bar are parallel!! There are no adjustment holes on the housing nor on the cross member side. So basically they will never intersect?? Very frustrating. Also the top bar is not on the top side of the rear end housing. It's mounted on the front side of it at about the centerline height. I've heard it's good to have the top bar closer to the centerline of the axle but shouldn't it be at least on the top side of the housing? I have purchased some 4 link brackets that I will install in place of what's on there now. They have 4 hole locations for both top and bottom bars so that should help with my situation. Sorry to write you such a long story but I just wanted to hear what you thought about my "parallel bar" situation. Thanks
Anthony Burgess thanks so much for your comments and questions! Appreciate the nice feedback and support on the channel. Sounds like your current 4-link is more for street or even street rodding. For drag racing, which is my focus, I need to be able to adjust the bar locations for my instant center length and height and I prefer to have the top bar on top of the rear end axle and not out in front the tubes. Good to hear you are taking the steps you are taking to tune your launch and you will not regret it! Nice work and keep us posted on your progress. Go fast, go straight! Be Safe!
@@KevinWilsonSBC You rock! Thanks!
Kevin Wilson will do and thank you!
Just an update, as I've just watched your video again :). I finally decided to go and cut the old forward brackets out and weld in the new ones. I have yet to make a pass with the new set up since I'm currently freshening up the engine also. It is nice to be able to put some angles on my bars now. I'll keep you posted and thanks so much for what you do for us racers out here that aren't as skilled as you are in this department.
Nice job
Any good videos with airbags and a good adjustable 4 link
Sorry... I don't have much drag racing experience with airbags other than racers trying to use them vs rear ARBs. The 4 link acts the same so those theories still apply. Go fast, go straight! Be SAFE!
Great stuff, this is really helping me understand.
Fred G thanks so much for your comments! Glad these are making sense! Video coming on coil spring selections, spring rates and how they impact the chassis and shocks on the hit. Go Fast! Go Straight! Be Safe!
@@KevinWilsonSBC I took all my measurements tonight so now they are memorialized. Looks like my front springs are too light based on your compression recommendations, 46% compressed! Lots of energy there waiting to cause problems. Rears were closer but a little heavy, 17% compressed. I'l watch for your next video, car isn't turned up yet so she'll stay down for this weekend I hope. Thanks again!
awesome video mate. im in australia. Got a valiant charger and keen on a triangulated 4 link for straight and twisty purposes. but the length of the top bars with most of them look like they delete a lot of the deep analytical explanations you go into. is there any kind of middle ground for such an application ya reckon? cheers in advance. keep up the awesome vids
k1Stung thanks so much for your comments! When I started, I never dreamed people would even care about these suspension videos, especially around the world. Love Australia!!! Definitely watch this video I made recently before making your next step: ua-cam.com/video/eF19sCJxw68/v-deo.html
Go fast, go straight! Be Safe!!
Very nice video! Can I apply this same idea of want to have Anti-Squat in a FWD Drag Race Car?
Gláucio Duarte thanks so much for your comments and question! I have never worked on a FWD drag car so unfortunately I don't have any experience to help there. I will have to research that one more. Go fast, go straight! Be Safe!!
@@KevinWilsonSBC Thank you for you reply! if you have any information that you could share, that would be great!
Thanks very much. Very informative
Loco Fab thanks so much for your comments! Go fast, go straight! Be Safe!!
Have you had much experience with triangulated four link (similar to fox body mustang stuff) I’m looking at options for my Torana (Australian delivered car) that had a triangulated four link but leaning towards parallel four link
Are you going to do videos on leaf spring setups? Great info here!
David Walker thanks so much for your comments and question! I am absolutely planning a video on leaf springs and how to setup a drag car to launch on leaf springs. Great question!! Go fast, go straight! Be Safe!
Kevin Wilson yes sir! Keep it coming
Building a new car were should I put my 4bar brackets on the frame off the ground ?
Jim Franklin thanks so much for your question! You must mock up your car simulating the race ready ride height, with the rear end height set based on your axle centerline to track and wheel placement in the tubs/body fender, then mock up your bar locations. Every car is so unique, I cannot give you a distance without knowing your car's setup and measurements. Stay tuned for the String Method video coming out soon that will cover squaring a chassis which will help you in this process. Go fast, go straight! Be Safe!!
So I've watched alot of your videos, very informative without a doubt. Fist an foremost, my car and setup are totally street based and for fun. Also, I'm doing what I'm about to explain for fun and to be all the wall different. I have a 2001 Lexus IS300 with a mildly built 2jz, a TH400 and at the moment the stock IRS. I'm in the process of converting it over to a Ford 9 inch. Now you can see the it's quite the different build. I'm leaning towards a triangulated 4 link. The car has a rear subframe and saddle gas tank all of which is being removed for obvious reasons lol. My main question/comment/concern what have you is. Do I build my own frame so speak within the existing frame or can I reinforce the mounting point areas for the 4 link and go with it? The car has integrated frame rails that disappear before the gas tank and reappear after the rear frame. Should I connect those? The car will also have a slight wheel tub increase to accept a 275/60/15 on a 15x10 4.5BS rim. I know it's totally off the wall, but any suggestions would be appreciated, thanks in advance and keep up the great content!!
Rick Shults thanks so much for your comments, info and questions! This is going to be easier via email. Shoot me an email from my profile and we can chat for sure. This is definitely different!! Go fast, go straight! Be Safe!!
@@KevinWilsonSBC lol will do thanks for responding.
What if my willey is bigger than everybody else's? Does that make me the weiner? LOL
I’ve been watching a lot of your videos and I believe I understand quite a bit of it. Im trying to plot the 4 link out on the website link you provided but I don’t think I measuring the “horizontal control arm length”. Do I measure center of bolt going through the heim to center of the other bolt. But it says “control arm length is not the actual length it’s the parrallel/projected length. Do I need to hold a level on the rear bolt and try and measure straight across instead of following the bar angle
Center of bolt to center of bolt. Go fast, go straight! Be SAFE!
how do you know the CG height if your engine dont have camshafts (rotary engine)
I run ladders. My pinion angle and preload is on the bottom bar. Is the adjustment for preload the opposite of adjusting the upper bar?
This can really screw with you, so in this case, I would want to have the car on wheel scales and confirm what it is doing. You are likely introducing some rear steer more than normal if the adjuster were on the top bar, but this is why I would have my measurements documented and the rear tires on scales before making changes. Go fast, go straight! Be SAFE!
So your shocks need to be mounted on the back of the rear end housing? I mean they need to extend at the hit?
They can mount in front or the rear of the housing. The most common is the rear. Other than a big tire slick, most applications extend on the hit. Go fast, go straight! Be SAFE!!
I'm building a modern day Typhoon (2nd Gen 4 Door GMC Jimmy that has been LS Swapped) Would you want any squat or anti-squat to make the AWD work properly?
Cliff Weatherbee thanks so much for your comments and questions! There is a bunch more info required to help us make more recommendations. Feel free to checkout our website if you want to submit more info at samsonperformance.com Go fast, go straight! Be Safe!
I have a question for you I have ladder bar car that wheelie to far out
What if the engine is to weak to lift the front wheels (lower class rallycross car). In that case, where would you recommened having the IC? Over or under the anti squat line?
Magnus Göransson thanks so much for your comments! For that I would start as close to neutral as possible, but over the AS line. The AS line is mainly for a starting point. The car will show you what it wants. Go fast, go straight! Be Safe!!
I would like to see video on f body tork arm camaro's
Steve Sutton thanks so much for your comments! I will add that to list of upcoming videos. Though not as common with many of our local racers, it is for real so I will get some content planned for this one also! Go fast, go straight! Be Safe!
Does this also work with stock style g-body rear suspension? I'm setting up a g-body using aftermarket bars and adjustable mounts on the rear-end.
Mike Blasey thanks so much for your question! Same theory applies at a high level. Go fast, go straight! Be Safe!!
Thanks Kevin. Some if/then explanations would really be helpful in creating a mental picture. Something where we can visualize the result. Like our car is squatting on the hit. So I move the upper arms up one hole in the front mount to get ĪC above the anti squat line.
Is it possible to have too much anti squat? Car I'm setting up is 99 mustang stock style suspension. Still have another hole to drop the lower control arms down. Thanks.
hammerdown636 thanks so much for your comments! Absolutely it is possible to have too much AntiSquat. Remember, while necessary to plant the slick/radial, our goal is to apply just enough force for traction and the rest of the energy to move the car forward. It is about a Balance with all the rear components working together. Go fast, go straight! Be Safe!
Right on
Russell Jackson thanks so much for your comments! Go fast, go straight! Be Safe!!
Hello question I have strut front end so I can't get measurements from upper control arm bolt what do I do ??
Ronald mihal thanks so much for your question, but I am not following you. What measurement are you trying to get? Go fast, go straight! Be Safe!!
I believe I figured out I have a ladder bar setup so where it says front upper bolt measurement and front lower control arm bolt measurement I measure the single Bolt down to the ground correct?
Also when I measure my ladder bars upper bar and lower bar I go from Bolt to bolt correct
Sorry for late response. The main ladder bar measurement is distance of the chassis bolt to the ground. You are correct. For a ladder bar setup, checkout my video on percentage of rise. That is more applicable to a ladder bar with respect to the Anti Squat line.
what category do the pro bracket radials fit in?
Checkout my video: ua-cam.com/video/190DPueS6L4/v-deo.html
Go fast, go straight! Be SAFE!
Love if u could run my numbers and see where I’m at with my 4 link
Rick Granata thanks for commenting. Go to samsonperformance.com and shoot me an email and I will respond. Go fast, go straight!
Would this apply to a drift car?
Marcus Pingitore thanks so much for your question! At high level the 4 link is acting on the chassis under acceleration. I have never, ever, setup a drift car. Go fast, go straight! Be Safe!!
wow man, this video is EXCELLANT !!! Please tell me where to send you some money... just retaired and I'm building a back half 70 Duster with latter bars from COMP. ENGR. I have built the car with a lot of help from the UTUBE community BUT not one good video on SET UP lots of videos on what parts to buy. Thanks for your time I would like to donate to your channel
Thanks for all the kind words and feedback! I am glad the suspension videos are a help to you. By just watching my videos and subscribing to my channel is a big help in keeping the channel alive! I really enjoy helping other racers and I have a dad who poured himself into me on suspension/chassis tuning and engine/transmission building from as far back as I can remember walking around the garage with a baby bottle in my hand. With all I learned, and still learn from him, I just keep learning and building on the foundation which over the past 10 years or so has led to SamSon Performance. My dad's name is Sam and for so many years people would refer to me as Sam's Son, so I just made SamSon Performance from that twist. If you absolutely still want to contribute, you can donate by clicking on the following link that takes you to our shop website and there is a $10 support option and then you can change the quantity which will increment by $10 for each quantity. For any money donated, it is used to purchase more video recording equipment and supplies to keep the channel going. www.samsonperformance.com/store/p7/SupportKevinWilsonSBC.html
Hope you have a Merry Christmas and go fast, go straight, be safe!!
Kevin Wilson