Maybe try a 3d printed design with a Sharrow Propeller inspired design this is really trending at the moment hahah Or maybe a double stacked design with Sharrow Propeller on the external or maybe on the internal or maybe try both hahah
@@mitchellpaterson7062 What for? There is a wonderful article by professor, motorcyclist Gordon Blair, “The Best Bell.” In the article, Blair compares round, aerodynamic and elliptical bells. A bell with an elliptical profile gives a mass air flow rate of 17% more than a conventional pipe.
Usually we see intakes that point up, but in some ocasions there are some that are plenum down like on SR20det, does this curve alters power in any means? only one way to find out
Try a flat plate in front of the trumpets that you can adjust closer and further away and see what happens if you reflect some of the wave energy back down the trumpets it used to work great on twin sidedrafts
I wrote a wikipedia page on Velocity stacks. Read that and you'll know the results of this without doing all the work(although it has been vandalized by a velocity stack manufacturer). There is almost nothing to be had from velocity stacks beyond the length, diameter and some kind of radius. Golf ball dimples are widely misunderstood. They work PARTIALLY on a golf ball under golf conditions. They can be of use on some aircraft wings under certain conditions but they do NOT increase flow what so ever. In fact they can only reduce flow but they alter the downstream conditions that MIGHT be advantageous in SOME situations, like a golf ball in full flight. They are only effective over a small range of speeds even on golf balls(roughly 125mph-250mph) which happens to coincide with the speed of a drive. Above and below that speed range dimples cause MORE drag.
Dimples create vortices that reduce the boundary layer and keep the airflow attached longer. On a surface where the flow cannot detach no matter what you do, like an inlet trumpet, dimples are pointless and merely add flow resistance that goes up exponentially with velocity, as the high rpm numbers show nicely.
Really interesting to see the Golf Ball and Dimples. Was surprised at how the golfball was more even between 3500RPM and 5500RPM than the others. Thanks for another great video.
@@Garage4age right I compared side by side, on the Dyno for a motorcycle, the exact same size, dimensions, etc. velocity stack that had dimples and one without. They performed identical. Well, actually the smooth performed approx. 0.5 better in hp and torque, but I chalk that up to the usual deviation from run to run. I only did two pulls each, comparing the two back to back (4 pulls total)
@@boxcrashmfg9420 yeah that looks to be the same as what happened here. when you compare the red to black. which are the same but red is dimpled. the blue ones where the shorter ones, and different shape to the others so cant really be directly compared. just testing what i've been sent
Yeah Id like to see how much you can move the engines peak torque rpm up or down between a short 4-1 and a very long 4-1 or 4-2-1 manifold. Maybe even try an EXUP valve from a Yamaha FZR/R1?
New wheels on the testcar! Nice job, thanks for sharing! Please try to place some solid full size vertical dividers between the horns. As CFD suggests the cylinders will not interfere.
Dimples only work on round balls to reduce drag on the tail end.Double work to make a stronger vacuum for more fuel intake .I found the Velocity stack design worked on the air intake of my 10kg thrust Pulse Jet engine.Its holds the strength of shock waves & still guides the air in as smooth as possible
I love the craziness and variation of the designs. Working or not it's nice to see what people create. The stupid Golfball texture, i've seen many ITBs on sale with that.
I've got one for you. Ok well, you're gonna need a length of stack that would allow you to turn them up away from the shock tower. But I've always wanted to see if we could adjust the frequency of a large woofer 280-300-350 Hertz, something like that for this engine and see if it either disrupts or enhances power at a resonant frequency. Point it right at the stacks. you've gotta try it!
Increase I.d. as close to the head as you can. Simulate an engine dyno air hat in shape. Keep the trumpet entrance but keep a devider between each port. And last, give the entire port run a slight turn up from the short side of the intake port. 13" rule from valve to opening. This will give you the greatest overall power. A shorter runner will favor peak redline, while an 18" will favor the bottom 50%. The hissing sound at the top end is a tell tale sign the port is hitting exstream velocity. The air needs more room.
An old book i have suggests the biggest increase in flow can be had from like a full radiused disc with no tube/trumpet, imagine cutting a donut in half, sideways, so it's still a full ring but one side is flat. As long as the radius is at least 1/8"/3mm plus, it will have more effect than nothing at all. They tested this on a flow bench and the donut shape on the face of a carb gave the best increase in flow of 5.8%.
Great video. I'd like to see a test of barrel valve throttles against your current setup. I could imagine better fuel atomization and higher airspeed at part throttle and a slight increase in maximum airflow at full throttle. Keep the good work up 🎉
Love watching these and the side by side comparisons! Would really appreciate seeing a comparison of different filtration options for standard or typical velocity stacks and the impact on hp... single/individual foam socks, dual socks, large single foam filter with a backing plate, gauze dual filters, velocity stack "screens" or covers... that would be very helpful! People make all kinds of claims, but nothing beats objective third party data!
For now i can say the big single filter this engine usually runs has no measurable effect on power, Pretty sure i have a video where i tested it. have personally seen individual socks loose a lot of power on dyno. avoid
@@Garage4age thanks for the quick response and info! I currently use foam filters that fit over the two stacks on each TB (Jenvey Heritage EFI TBs that mimic Weber sidedrafts on a 7000rpm Datsun Roadster U20). They do touch the sides of the stack on the outside edges but for the most part are "free" with plenty of room in front. They are very convenient but if they are significantly restrictive then I would likely switch to a "Piper Cross" or "ITG" type set up. Some claim foam is restrictive, others say anything touching the edges of the stack interferes and that things like stack screens are horrible, and other filters are only effective if they are lightly oiled but then become very restrictive... I have not yet found a great, objective side by side test like what you do... I really appreciate whatever info you have or future testing you do!
after watching a lot of your videos, i think its safe to say your intake is not a limiting factor in your engines performance. but fun to watch n learn nonetheless.
Well firstly your setup is unbelievably well sorted. Secondly, I really love that you're product testing for people. It is great to see. I must admit I was surprised the tapered dimple was worse than just the plain taper but you'd never know unless some real world testing confirmed it. Even a homemade flow bench might show the dimples performing better but there's nothing like the real world. I wonder if there's gains in throttle response with the dimples that can't be picked up on the dyno? Great idea dimpling the intake even if it doesn't work but perhaps it needs more or less cross sectional area to realize the benefits. Those dimples have really sparked my curiosity.
Dimples have already been beaten to death in the cylinder head community, and flow benches all consistently reflect poorer airflow with a dimpled surface. What works on a ball doesn't necessarily work on a tube. The ONLY reason to dimple is that it takes considerably more time and you can charge the customer a WHOLE LOT more.
the dimples create a thicker boundary layer effectively reducing the cross sectional area of the trumpet, meaning it can't move as much air through it.
@@seanb250 And this effect is good on a golf ball, because the turbulent boundary layer is more resistant to separation resulting in less drag. But it is not applicable to an intake
@@dannyb9083 correct, the dimple in ports thing has been beaten to death and disproven as a performance gain for a long time, but every 6 months or so it pops up again as some new discovery 😂
Tall taper with elliptical opening with dimples throughout the whole opening plus length of the tube. The elliptical opening seems to smooth entry and the dimples will smooth the pathway.
Wonderful as usual... Continuously variable is the trick... motor controlled... You might shorten them at certain higher revs just to flatten the torque due to the resonances. keep up the amazing work. You are literally killing many people's suppositions with real data.
I made some variable stacks on my motorcycle. Check out the video on my channel. They're not continuously variable, but two step. Determined it needs to move at 9k. Still working on the electronics to have them move at exact rpm.
@@gogocro1 We use an emtron to control all of that on our 24V S38 motor.. Kinsler also makes a high torque radial motor.. But for simplicity the linear motor or motors work best. ua-cam.com/video/YZhSgwYs08k/v-deo.html Keep up the great work!
Did some sotp dyno bellmouth testing in the 80's, on a Ducati 900SS. It was length more than anything else that influenced engine characteristics, even then it was response and power band that were the noticable effects, power was little affected. Short gave better response at top end, long better midrange. SOTP dyno, seat of the pants.
I am probably really late to the party here, but I have an idea that should (in theory, at least) work. Use a Y pipe (one straight leg with the branch pipe coming off at an angle) oriented with the Y branch coming upward and outward (towards the strut tower in your case). The inlet trumpets will be affixed to the Y branch. The end of the straight pipe closest to the engine will attach like the trumpet would normally, the trumpet goes on the Y branch, and the other end is where things get interesting. As the intake valve closes and the pressure wave is formed and "bounces" off the back of the closed intake valve, it would normally travel back up the runner, out of the trumpet, and "bounce" off of the atmosphere- with each time it does this, it loses some pressure (1st, 2nd, and 3rd harmonics)- for two reasons, 1) the atmosphere is not very bouncy, and 2) that's how physics works in this galaxy. We can alleviate one of those issues to some extent by taking advantage of the 1st law of motion ( An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a STRAIGHT LINE unless acted on by an unbalanced force)- the pressure wave which normally travels out to atmosphere will want to travel in a straight line. It will then be directed to the capped end where it should retain more of its initial velocity when it bounces off (think throwing a bouncy ball at a concrete floor vs throwing it at a pillow). In theory this should work, and all it would require to test is 4 of something like this:www.amazon.com/POWERTEC-70228-Y-Fitting-Clear-Color/dp/B07NC6KBQT/ref=pd_lpo_sccl_1/137-6445067-9242329?pd_rd_w=LuuTk&content-id=amzn1.sym.1ad2066f-97d2-4731-9356-36b3edf1ae04&pf_rd_p=1ad2066f-97d2-4731-9356-36b3edf1ae04&pf_rd_r=26BGB0CW7AYEN2VBW244&pd_rd_wg=LW6Yk&pd_rd_r=d0952c71-7d9b-466f-9995-47ff50cc67d3&pd_rd_i=B07NC6KBQT&psc=1 or PVC plumbing
I think the length and diameter are really what's going to effect the way the air bounces back into the cylinder. An interconnected series of intake runners would be interesting.
because it's ITB intake, the flow is close to maximum for what it needs. make them smaller version of all the different shape intake, that will show up a bigger different.
When it comes to intake manifold modeling, runner length has the most dramatic effect on the power curve. The engine speed u want to operate in is hownlong they need to be. The engine displacment determines the diameter
@@802Garage ok now look at the results. No significant changes in power . I didnt comment because im a by stander. I make custom sheet metal intakes for engines. The ideas he is trying wont net him any significant power changes the main reason is the engine is to small and only has 4 cylinders. Not knocking this at all. But out of decads testing. Even 325 ci v8 engines would show no gain with this. Runner length has the most dramatic effect on power
@@davidanderson6706 I thought you were coming at this from the perspective of "Changing length will have far more impact than the design." which I agree with. Just wanted to add that I believe he knows that and this is more for fun and to experiment than anything else. It's very surprising what people find when they are willing to play around in a fairly well established field. Agreed runner length has the most impact, along with diameter of course. Now let's have fun seeing what little tweaks affect! Besides, you are one in a million. Not everyone can do what you have done, nor have you posted your findings on the internet for everyone to see. The entire point of this is so that everyone else who wants to know can see the results for themselves! It's about learning and sharing knowledge. So thanks for sharing yours as well, hope I didn't come off as rude.
A good example BTW is the Fan Showdown by Major Hardware. Everyone knows that Noctua makes pretty much the best fans on the market in terms of noise to flow and with great reliability. Fan science is pretty well nailed down at this point. He has tested over 100 designs now, most of which are worse than the Noctua, but some of which have actually beaten it in one respect or another, and other designs have even gotten companies interested in selling them. Do you get what I'm saying? There could be some useful outcomes here.
This is what i would like to see tested; a custom manifold with long thin tubes that goes all the way into intake port to one side of the valve stem, hopefully creating swirl. Then at a higher rpm, 4 throttle bodies, close to ports, open a larger passage from manifold to port.
Such a cool experiment and well made video thanks. Wounder if you made a good radius bellmouth but with extra large flat 'flange' surface for moving air to creat low pressure over. Obviously witj a large flat area they would merge but still shouls be possible to print
Looks like Golfball normalized midrange the best due to a bit more boundary layer. Looks like a slightly smaller ITB is what this engine is asking for to net area under the curve.
interestingly i think the mouth design is way more important than initialy thought. The dimples do seem to smooth the overall curve, so if you want the power to come on very linear I feel like these would help
Could you try off senter trumpets, so you do not have the trumpets interact with each other. Similar ideas was done in Canam. Uneven length runners as well to avoid interference of each other. @@Garage4age
Haven't watched it all yet but Suzuki used 2 short stacks and 2 longer stacks in their 1000cc engines which produced a broader curve. You could swap to all long/short depending on your track and they were cheaper then aftermarket. Food for though
Great video! It would have been interesting to see what happens with none. There is another detail, at least 2 of the intakes are very close to the suspension support panel, so I think that avoiding that somehow (curved pipes in-between) could change the result of this test. I also think that having a collector would benefit more from the usage of those technics, because the air intake flow would have a better continuity since four cylinders instead of a single one would contribute to the air suction in the same period of time.
Would be nice to try and stick with the best design of those tested, and try and find out narrowest runner with dimples... perhaps if you ended with more narrow runner that flows similar, you would get more velocity and maybe more power? Then compare the new found one to same size but no dimples.
I think its pretty clear that you have enough intake already so trying a bunch of different stuff isint showing any big changes. Id add some more displacement, no idea what your head/cam situation is but i would be going too a stroker and making sure the heads/cam situation is really good then try again.
Mythbusters did not create a myth, they explained how dimples keep flow attached on situations where it wouldn't be. A sphere is a terrible shape aerodynamically, that why it could use dimples to improve its aero wake. People just didn't understand that explanation 😉 It is useless to use dimples on surfaces where the flow would have been attached in the first place.
Nice Comparison. I can recommend to retest the first configuration to see if there are some difference to the first run. sometimes u can see trends for better interpretation the whole results.
I used to, and would if was another car. But have figured out how to get consistent numbers on this car (getting close to 2000 runs on this chassis ) once car is warmed up need to do at least 4 full runs. before starting any testing with the oil and water temps the same on every run. If don't do it right pretty easy to get results all over the shop
The Golf ball seems to have some advantages with a smoother curve. Would be good to see it with different tapers. Have you ever thought of trying one with a bit of a Venturi ?
Conclusion for me - eat noodles and your engine will be happy. In my ride i use audio speaker box tubes. They get the job done. I see performance dont goes up with the price. Thanks for the video 👍
You should try different methods of creating vaccume pressure in the crank case. I've always been interested in those little exhaust gas scavenger fittings, would be interesting. Cheers
Great job and thanks again for your hard work in making a pretty cool vid. Others have mentioned a couple of interesting things. 1. Dave walker done an article 25yrs ago on roller barrel itb’s vs normal butterfly itb’s. I’d like to see that revisited but costly exercise. Lol. 2. Does stand off injectors affect the intake runner length and shape?
Love your videos, i personally believe that a good intake manifold is better than itbs so Can you make a plenum for the itbs and test it with different oppening sizes
probably wasnt the ideal shape but tested a couple plenums in this vid ua-cam.com/video/HbQQc7sq5HQ/v-deo.html everything else ive tried off camera, the airbox/plenum needs to be massive else the open itb's always win. If air temp is the same of course
@@Garage4age i made 268whp on pump 93octane out of a h22 with a custom intake that is basically 2x70mm throttle body on top of a plenum that feeds all runners, i tought that might give you some ideas for videos
@@emmajacobs5575 Yes is a huge difference in the idle and low end running with big cams. a single throttle will idle a lot rougher and stall out easy compared to itb's.
Only real difference will come with variable runner length as long as the general shape is sufficiently allowing the venturi effect to occur (at least the velocity-increase part of it). Maybe try rigging up a pull-tie to make some motorcycle-style 2-stage variable runners that just stack on another trumpet onto the first one.
I'd run the Taper without dimples (latest graph in orange) because it seems to bring the smoothest powerdelivery... If you now optimize other parts, it will bring more benefits then the others.
The problem with the dimples in the trumpets, isn't that air going over air has less friction, which it does, compared to stalled air on the edges, the issue is that the flow of the trumpet isn't even remotely a cause for power loss. It's a huge trumpet and the vehicle doesn't make any horsepower. If there were a lack of power due to flow for it's maximum allowable size, THEN it could help a tiny bit. Right now we're seeing power changes due to air momentum (taper) and resonance. So they will never do anything at this power level with this size of a trumpet.
dimples only create a thicker boundary layer on the surface, this reduces the effective cross sectional area for air to flow through, the dimples made the ID smaller, that is all. Dimples are a waste of time.
@@Christdeliverme dimples create quite a large boundary layer, that’s why we only use a burr finish on cylinder heads, that creates enough boundary layer to keep fuel in suspension and not pool on walls, even the 60grit cartridge rolls produce enough boundary layer. The depth of those dimples would create nearly the same depth/thickness in boundary layer, that is a fair amount of reduction in useable cross sectional area. It’s been tested to death honestly that you would only use dimples if you wanted to shrink a ports useable area by a few %
I would have expected the double stack would have the closer lower one being quite a bit closer to the head making them a combination of a much shorter stack for more lower down power and the second stack being MUCH longer to give you an intake length the same as you seem to be running all of the other stacks... There will be very little difference when the overall length is effectively the same. So having the double stack with one much closer to the cylinder head and one much longer stack (they can even have the same ID as long as you have an air gap around the trumpet when it just overlaps.
Tesla valve intake? Of course with the side that allows flow going towards the engine. Maybe it would help avoid losing air velocity due to reverberation.
The "golf ball phenomenon" does not occur because the ball moves uniformly, with the gas flow close to linear, while the air in the intake sometimes stands still, sometimes accelerates, and these changes occur at relatively high frequency. The creating/stabilization of the "cushion" in the hole itself takes some time. I was interested in this phenomenon before it was commonly known. This myth was propagated on YT by the CNC company that works with the engine heads (i remember the name but I wont write it down). Something else that is interesting - the flow bench test in this case will show false results, because the conditions of such a test (gas flow is unidirectional) do not reflect the actual conditions during engine operation. If it made sense when gas flows in the conditions as in the intake duct - why doesnt any competition engine, including F1 engines, have it? Thank You for antoher interesting video Garage 4AGE. 👍as usual.
Flow bench is a great tool, i'd like to have access too. More work to test things on a running engine, but the power numbers are the end game, so the dyno is the one
I would like to see the test with different angled trumpets. The the back two cylinders must get a different flow of air to the front two because of the strut tower. Tests like 45° angle upsweep or downsweep. Or just straight up 90° badboys.
I believe that a lot of "tuners" in my country only work by placebo effect They use and sell these stuff, iced intake or dimple porting saying that its the big improvement for your car And the argument and proof its "it feels faster and I had no problems with it" Nobody had showed me real proofs like a Dyno chart or drag times
Yeah the classic move is to make the intake runners shorter. which which looses low end power and top end stays the same. feels faster on the butt dyno, but is actually slower
I would like to see a trumpet with a “anti reversion” lip… they make anti reversion plates for square bore carburetors and they even make anti reversion mufflers…
this one compares 45's vs straight ua-cam.com/video/nqYkmCLrlEo/v-deo.html. long as bends arent too tight they are fine. it also shows what a sharp 90 does in that video
I hope in speak for ither with this idea but it mould be sorta cool to see if its possible to create some runners that actually focus on low end torque almost exclusively. You know for science. Probably something that really promotes super high port velocities in the lower rpm range. And if youbdidnfind something particularly good maybe theres room to build off of it
Could you print the tapered one and use fuzzy skin settings in the 3d printer slicer? Both Cura and Prusaslicer has the setting. Seeing how smooth the curve is with both the golfball and dimpled one I think using fuzzy skin would introduce a lot of surface turbulence and therefore minimize the pressure drag.
I wonder if it would be worth making a telescopic variable length set like the 787b or the two stage r6 stacks, I'm planning an itb build on my 2jz and I've been contemplating making something like that to go with.
The taper seems to have more flow right at the top. I wonder if the taper was slightly narrower bore (so faster air speed), what the midrange would do.
People been dimpling turbocharger exhaust outlets thinking they're top engineers when really they're just causing turbulence for absolutely no reason what so ever
Pipe length = drag. Try the shortest runner length possible, while still retaining some bell mouth. The shorter the pipe, the less developed the wall boundary layer. The thinner the boundary layer, the more flow through. The boundary layer works to reduce your effective cross sectional area. Don’t give it pipe length to develop and reduce flow area.
flow is only one part of It. The pipes need to tuned to the correct length. Then size the pipes appropriately at said correct length, so they can support the flow requirements.
Not surprising at all. Many of these things have been worked out during the last 125 years of internal combustion engine tuning. The golf ball dimples are an example of something that helps reduce drag when a shape is not particularly aerodynamic. But seems to be of negative benefit otherwise.
If you haven't seen the first round here it is : ua-cam.com/video/G8L9_XO3iCw/v-deo.html different engine so cant compare to the numbers here
It’s spelt stax not stack
@@garage4k989 hika bro
Maybe try a 3d printed design with a Sharrow Propeller inspired design this is really trending at the moment hahah
Or maybe a double stacked design with Sharrow Propeller on the external or maybe on the internal or maybe try both hahah
@@mitchellpaterson7062 What for? There is a wonderful article by professor, motorcyclist Gordon Blair, “The Best Bell.” In the article, Blair compares round, aerodynamic and elliptical bells. A bell with an elliptical profile gives a mass air flow rate of 17% more than a conventional pipe.
Usually we see intakes that point up, but in some ocasions there are some that are plenum down like on SR20det, does this curve alters power in any means? only one way to find out
I can't believe you're basically doing the Fan Showdown with ITB runners on a dyno. Amazing stuff.
ah a fellow fan fan
@@TheUltimateRanger89lol
Hi fellow fan fan
@@Draecko 🪭🤝🪭
It’s amazing, isn’t it.
Hey thanks for making these dyno comparison videos. Your hard work is much appreciated by many people!
Try a flat plate in front of the trumpets that you can adjust closer and further away and see what happens if you reflect some of the wave energy back down the trumpets it used to work great on twin sidedrafts
Conical satelites with the focus point inside the trumpet.
I'd be surprised if that reflected anything back down the trumpet. I'd guess that it would behave like a marginally longer tube...
I wrote a wikipedia page on Velocity stacks. Read that and you'll know the results of this without doing all the work(although it has been vandalized by a velocity stack manufacturer). There is almost nothing to be had from velocity stacks beyond the length, diameter and some kind of radius.
Golf ball dimples are widely misunderstood. They work PARTIALLY on a golf ball under golf conditions. They can be of use on some aircraft wings under certain conditions but they do NOT increase flow what so ever. In fact they can only reduce flow but they alter the downstream conditions that MIGHT be advantageous in SOME situations, like a golf ball in full flight. They are only effective over a small range of speeds even on golf balls(roughly 125mph-250mph) which happens to coincide with the speed of a drive. Above and below that speed range dimples cause MORE drag.
Dimples create vortices that reduce the boundary layer and keep the airflow attached longer.
On a surface where the flow cannot detach no matter what you do, like an inlet trumpet, dimples are pointless and merely add flow resistance that goes up exponentially with velocity, as the high rpm numbers show nicely.
Really interesting to see the Golf Ball and Dimples. Was surprised at how the golfball was more even between 3500RPM and 5500RPM than the others. Thanks for another great video.
They were a little shorter than the rest. which is most likely the reason for the change in the curve
@@Garage4age right I compared side by side, on the Dyno for a motorcycle, the exact same size, dimensions, etc. velocity stack that had dimples and one without. They performed identical. Well, actually the smooth performed approx. 0.5 better in hp and torque, but I chalk that up to the usual deviation from run to run. I only did two pulls each, comparing the two back to back (4 pulls total)
@@boxcrashmfg9420 yeah that looks to be the same as what happened here. when you compare the red to black. which are the same but red is dimpled. the blue ones where the shorter ones, and different shape to the others so cant really be directly compared. just testing what i've been sent
Great stuff 👍🏻
I wish for a compairson between 4-1 and 4-2-1 header, in best case different diameter and lengh 😁
Yeah Id like to see how much you can move the engines peak torque rpm up or down between a short 4-1 and a very long 4-1 or 4-2-1 manifold. Maybe even try an EXUP valve from a Yamaha FZR/R1?
@@stevenbusk539 about 14" shorter intake tract on my 2.0 Alfa Romeo JTS moved the torque band about 1000 rpm higher and also peak power.
@@projector7141Where does it peak now?
'Compairson' ??? 'Lengh' ???
7600-7700 rpm @@Callagwhan
Cool to see the dimple and golfball actually smooth out the curve
You have no clue how much I LOVE this channel
New wheels on the testcar! Nice job, thanks for sharing! Please try to place some solid full size vertical dividers between the horns. As CFD suggests the cylinders will not interfere.
Respect for taking the effort of fabrication & testing. the science stuff. Cheers
Dimples only work on round balls to reduce drag on the tail end.Double work to make a stronger vacuum for more fuel intake .I found the Velocity stack design worked on the air intake of my 10kg thrust Pulse Jet engine.Its holds the strength of shock waves & still guides the air in as smooth as possible
This is actually the coolest channel on youtube. Project Farm and Torque Test Channel have nothing on the testing you do!
I love the craziness and variation of the designs. Working or not it's nice to see what people create. The stupid Golfball texture, i've seen many ITBs on sale with that.
This is pretty cool. Alot of work to find out different designs have such little different.
The sound changes are crazy!
Well good to see the expected dimple doing nothing for performance… and shutting some people up. Keep it up 👍 another good session of dyno talk
It was worse than stock!! 🤣☠
Your eyes not work bro? The gains were all there for everybody to see
@@garage4k989 What gains? I see a barely perceptible change, with (if anything) a loss of top end power.
Probably above your pay grade mate
@@garage4k989 you just being silly now…
I've got one for you. Ok well, you're gonna need a length of stack that would allow you to turn them up away from the shock tower. But I've always wanted to see if we could adjust the frequency of a large woofer 280-300-350 Hertz, something like that for this engine and see if it either disrupts or enhances power at a resonant frequency. Point it right at the stacks. you've gotta try it!
I’m not going to try it
That's very cool...
I like how your runners were the best. Keep up with the awesome work 👍🇭🇲
Another superb video from you, congrats. That engine won the heaven!!!!! That sound .......
Increase I.d. as close to the head as you can. Simulate an engine dyno air hat in shape. Keep the trumpet entrance but keep a devider between each port. And last, give the entire port run a slight turn up from the short side of the intake port. 13" rule from valve to opening. This will give you the greatest overall power. A shorter runner will favor peak redline, while an 18" will favor the bottom 50%.
The hissing sound at the top end is a tell tale sign the port is hitting exstream velocity. The air needs more room.
An old book i have suggests the biggest increase in flow can be had from like a full radiused disc with no tube/trumpet, imagine cutting a donut in half, sideways, so it's still a full ring but one side is flat. As long as the radius is at least 1/8"/3mm plus, it will have more effect than nothing at all. They tested this on a flow bench and the donut shape on the face of a carb gave the best increase in flow of 5.8%.
👏👏👏👏👏👏
Sounded like the double stack was noticeably raspier than the others. I liked that one.
The crack it makes as it crosses over sounds fantastic
Great video. I'd like to see a test of barrel valve throttles against your current setup. I could imagine better fuel atomization and higher airspeed at part throttle and a slight increase in maximum airflow at full throttle. Keep the good work up 🎉
Great content. Hopefully someone can one day make a comparison between a metal intake manifold with and without velocity stacks.
Love watching these and the side by side comparisons! Would really appreciate seeing a comparison of different filtration options for standard or typical velocity stacks and the impact on hp... single/individual foam socks, dual socks, large single foam filter with a backing plate, gauze dual filters, velocity stack "screens" or covers... that would be very helpful! People make all kinds of claims, but nothing beats objective third party data!
For now i can say the big single filter this engine usually runs has no measurable effect on power, Pretty sure i have a video where i tested it. have personally seen individual socks loose a lot of power on dyno. avoid
totally agree socks kill power@@Garage4age
@@Garage4age thanks for the quick response and info! I currently use foam filters that fit over the two stacks on each TB (Jenvey Heritage EFI TBs that mimic Weber sidedrafts on a 7000rpm Datsun Roadster U20). They do touch the sides of the stack on the outside edges but for the most part are "free" with plenty of room in front. They are very convenient but if they are significantly restrictive then I would likely switch to a "Piper Cross" or "ITG" type set up. Some claim foam is restrictive, others say anything touching the edges of the stack interferes and that things like stack screens are horrible, and other filters are only effective if they are lightly oiled but then become very restrictive... I have not yet found a great, objective side by side test like what you do... I really appreciate whatever info you have or future testing you do!
after watching a lot of your videos, i think its safe to say your intake is not a limiting factor in your engines performance. but fun to watch n learn nonetheless.
Well firstly your setup is unbelievably well sorted.
Secondly, I really love that you're product testing for people. It is great to see.
I must admit I was surprised the tapered dimple was worse than just the plain taper but you'd never know unless some real world testing confirmed it. Even a homemade flow bench might show the dimples performing better but there's nothing like the real world. I wonder if there's gains in throttle response with the dimples that can't be picked up on the dyno? Great idea dimpling the intake even if it doesn't work but perhaps it needs more or less cross sectional area to realize the benefits. Those dimples have really sparked my curiosity.
Dimples have already been beaten to death in the cylinder head community, and flow benches all consistently reflect poorer airflow with a dimpled surface. What works on a ball doesn't necessarily work on a tube. The ONLY reason to dimple is that it takes considerably more time and you can charge the customer a WHOLE LOT more.
the dimples create a thicker boundary layer effectively reducing the cross sectional area of the trumpet, meaning it can't move as much air through it.
@@seanb250 And this effect is good on a golf ball, because the turbulent boundary layer is more resistant to separation resulting in less drag. But it is not applicable to an intake
@@dannyb9083 correct, the dimple in ports thing has been beaten to death and disproven as a performance gain for a long time, but every 6 months or so it pops up again as some new discovery 😂
Im gonna tell about your channel to all my friends!
Man go buy that car a drink after a day on the treadmill like that. Really cool video!
When the bonus title came up I thought it would be the peach cans. But we all know they are king of power delivery.
Tall taper with elliptical opening with dimples throughout the whole opening plus length of the tube. The elliptical opening seems to smooth entry and the dimples will smooth the pathway.
Wonderful as usual... Continuously variable is the trick... motor controlled... You might shorten them at certain higher revs just to flatten the torque due to the resonances. keep up the amazing work. You are literally killing many people's suppositions with real data.
I made some variable stacks on my motorcycle. Check out the video on my channel. They're not continuously variable, but two step. Determined it needs to move at 9k. Still working on the electronics to have them move at exact rpm.
@@gogocro1 We use an emtron to control all of that on our 24V S38 motor.. Kinsler also makes a high torque radial motor.. But for simplicity the linear motor or motors work best. ua-cam.com/video/YZhSgwYs08k/v-deo.html
Keep up the great work!
No you didnt
Did some sotp dyno bellmouth testing in the 80's, on a Ducati 900SS. It was length more than anything else that influenced engine characteristics, even then it was response and power band that were the noticable effects, power was little affected. Short gave better response at top end, long better midrange. SOTP dyno, seat of the pants.
yeah length has the most affect by far, unless i undersized to start with.
I am probably really late to the party here, but I have an idea that should (in theory, at least) work.
Use a Y pipe (one straight leg with the branch pipe coming off at an angle) oriented with the Y branch coming upward and outward (towards the strut tower in your case). The inlet trumpets will be affixed to the Y branch. The end of the straight pipe closest to the engine will attach like the trumpet would normally, the trumpet goes on the Y branch, and the other end is where things get interesting.
As the intake valve closes and the pressure wave is formed and "bounces" off the back of the closed intake valve, it would normally travel back up the runner, out of the trumpet, and "bounce" off of the atmosphere- with each time it does this, it loses some pressure (1st, 2nd, and 3rd harmonics)- for two reasons, 1) the atmosphere is not very bouncy, and 2) that's how physics works in this galaxy.
We can alleviate one of those issues to some extent by taking advantage of the 1st law of motion ( An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a STRAIGHT LINE unless acted on by an unbalanced force)- the pressure wave which normally travels out to atmosphere will want to travel in a straight line. It will then be directed to the capped end where it should retain more of its initial velocity when it bounces off (think throwing a bouncy ball at a concrete floor vs throwing it at a pillow).
In theory this should work, and all it would require to test is 4 of something like this:www.amazon.com/POWERTEC-70228-Y-Fitting-Clear-Color/dp/B07NC6KBQT/ref=pd_lpo_sccl_1/137-6445067-9242329?pd_rd_w=LuuTk&content-id=amzn1.sym.1ad2066f-97d2-4731-9356-36b3edf1ae04&pf_rd_p=1ad2066f-97d2-4731-9356-36b3edf1ae04&pf_rd_r=26BGB0CW7AYEN2VBW244&pd_rd_wg=LW6Yk&pd_rd_r=d0952c71-7d9b-466f-9995-47ff50cc67d3&pd_rd_i=B07NC6KBQT&psc=1
or PVC plumbing
I think the length and diameter are really what's going to effect the way the air bounces back into the cylinder. An interconnected series of intake runners would be interesting.
*affect
you're talking about fuel stand off?
I think you need to go online and read Professor Gordon Blair's article "The Best Bell"
Those golfball runners REALLY flatten that torque curve
Wow! This is kinda research! Well done!
That was very interesting! Thanks for do this!
because it's ITB intake, the flow is close to maximum for what it needs. make them smaller version of all the different shape intake, that will show up a bigger different.
Awesome video. Great work. Original is best in the end.
I like how smooth the golfball intake was.
When it comes to intake manifold modeling, runner length has the most dramatic effect on the power curve. The engine speed u want to operate in is hownlong they need to be. The engine displacment determines the diameter
He has already basically tested the ideal length for this engine so I believe all of these are meant to be roughly equalized to that ideal length.
@@802Garage ok now look at the results. No significant changes in power . I didnt comment because im a by stander. I make custom sheet metal intakes for engines. The ideas he is trying wont net him any significant power changes the main reason is the engine is to small and only has 4 cylinders. Not knocking this at all. But out of decads testing. Even 325 ci v8 engines would show no gain with this. Runner length has the most dramatic effect on power
@@davidanderson6706 I thought you were coming at this from the perspective of "Changing length will have far more impact than the design." which I agree with. Just wanted to add that I believe he knows that and this is more for fun and to experiment than anything else. It's very surprising what people find when they are willing to play around in a fairly well established field. Agreed runner length has the most impact, along with diameter of course. Now let's have fun seeing what little tweaks affect! Besides, you are one in a million. Not everyone can do what you have done, nor have you posted your findings on the internet for everyone to see. The entire point of this is so that everyone else who wants to know can see the results for themselves! It's about learning and sharing knowledge. So thanks for sharing yours as well, hope I didn't come off as rude.
A good example BTW is the Fan Showdown by Major Hardware. Everyone knows that Noctua makes pretty much the best fans on the market in terms of noise to flow and with great reliability. Fan science is pretty well nailed down at this point. He has tested over 100 designs now, most of which are worse than the Noctua, but some of which have actually beaten it in one respect or another, and other designs have even gotten companies interested in selling them. Do you get what I'm saying? There could be some useful outcomes here.
Wow, great stuff as usual man. Well done!
This is what i would like to see tested; a custom manifold with long thin tubes that goes all the way into intake port to one side of the valve stem, hopefully creating swirl. Then at a higher rpm, 4 throttle bodies, close to ports, open a larger passage from manifold to port.
Great video thanks for testing all those.
Such a cool experiment and well made video thanks. Wounder if you made a good radius bellmouth but with extra large flat 'flange' surface for moving air to creat low pressure over. Obviously witj a large flat area they would merge but still shouls be possible to print
Looks like Golfball normalized midrange the best due to a bit more boundary layer. Looks like a slightly smaller ITB is what this engine is asking for to net area under the curve.
Vraiment intéressant toutes ces courbes et tests. Merci.
Спасибо за твой труд.Удачи и добра.
interestingly i think the mouth design is way more important than initialy thought. The dimples do seem to smooth the overall curve, so if you want the power to come on very linear I feel like these would help
Likely find the blue ones changed the power curve, as they were sightly shorter. the red and black were the same
Could you try off senter trumpets, so you do not have the trumpets interact with each other. Similar ideas was done in Canam. Uneven length runners as well to avoid interference of each other. @@Garage4age
@@MatsNorway ua-cam.com/video/nqYkmCLrlEo/v-deo.html
Haven't watched it all yet but Suzuki used 2 short stacks and 2 longer stacks in their 1000cc engines which produced a broader curve. You could swap to all long/short depending on your track and they were cheaper then aftermarket. Food for though
Thanks mate! do tests and spare long theory and discussions.
Great video!
It would have been interesting to see what happens with none.
There is another detail, at least 2 of the intakes are very close to the suspension support panel, so I think that avoiding that somehow (curved pipes in-between) could change the result of this test.
I also think that having a collector would benefit more from the usage of those technics, because the air intake flow would have a better continuity since four cylinders instead of a single one would contribute to the air suction in the same period of time.
Very interesting results!
Would be nice to try and stick with the best design of those tested, and try and find out narrowest runner with dimples... perhaps if you ended with more narrow runner that flows similar, you would get more velocity and maybe more power? Then compare the new found one to same size but no dimples.
Great video with the best symphony 💪 👌 wouldn't mind a set to suit my 45s on my 1700 Ford Xflow one day 💪 cheers for your efforts
I think its pretty clear that you have enough intake already so trying a bunch of different stuff isint showing any big changes.
Id add some more displacement, no idea what your head/cam situation is but i would be going too a stroker and making sure the heads/cam situation is really good then try again.
Thanks for your job!
Mythbusters did not create a myth, they explained how dimples keep flow attached on situations where it wouldn't be. A sphere is a terrible shape aerodynamically, that why it could use dimples to improve its aero wake. People just didn't understand that explanation 😉
It is useless to use dimples on surfaces where the flow would have been attached in the first place.
Nice Comparison. I can recommend to retest the first configuration to see if there are some difference to the first run. sometimes u can see trends for better interpretation the whole results.
I used to, and would if was another car. But have figured out how to get consistent numbers on this car (getting close to 2000 runs on this chassis ) once car is warmed up need to do at least 4 full runs. before starting any testing with the oil and water temps the same on every run. If don't do it right pretty easy to get results all over the shop
The Golf ball seems to have some advantages with a smoother curve. Would be good to see it with different tapers. Have you ever thought of trying one with a bit of a Venturi ?
Conclusion for me - eat noodles and your engine will be happy. In my ride i use audio speaker box tubes. They get the job done. I see performance dont goes up with the price. Thanks for the video 👍
You should try different methods of creating vaccume pressure in the crank case. I've always been interested in those little exhaust gas scavenger fittings, would be interesting. Cheers
The dimple thing is B/S, a golf ball is round, flies through the air and is spinning while it is doing it, nothing like an intake runner.
Great job and thanks again for your hard work in making a pretty cool vid. Others have mentioned a couple of interesting things.
1. Dave walker done an article 25yrs ago on roller barrel itb’s vs normal butterfly itb’s. I’d like to see that revisited but costly exercise. Lol.
2. Does stand off injectors affect the intake runner length and shape?
Few vids back I tested stand off injection. It looked as tho it effectively made the runner longer
Love your videos, i personally believe that a good intake manifold is better than itbs so Can you make a plenum for the itbs and test it with different oppening sizes
probably wasnt the ideal shape but tested a couple plenums in this vid ua-cam.com/video/HbQQc7sq5HQ/v-deo.html everything else ive tried off camera, the airbox/plenum needs to be massive else the open itb's always win. If air temp is the same of course
aside from power considerations, don't ITBs help with drivability if you're running big cams? At least that's what I've been told by people who know
@@Garage4age i made 268whp on pump 93octane out of a h22 with a custom intake that is basically 2x70mm throttle body on top of a plenum that feeds all runners, i tought that might give you some ideas for videos
@@emmajacobs5575 throttle response is greater with itb
@@emmajacobs5575 Yes is a huge difference in the idle and low end running with big cams. a single throttle will idle a lot rougher and stall out easy compared to itb's.
Only real difference will come with variable runner length as long as the general shape is sufficiently allowing the venturi effect to occur (at least the velocity-increase part of it).
Maybe try rigging up a pull-tie to make some motorcycle-style 2-stage variable runners that just stack on another trumpet onto the first one.
I'd run the Taper without dimples (latest graph in orange) because it seems to bring the smoothest powerdelivery... If you now optimize other parts, it will bring more benefits then the others.
The effect of dimples can be improved with circular grooves.
I’ll think you’ll find triangle is the superior shape to increase airflow performance
This car must be so much fun to drive.
The problem with the dimples in the trumpets, isn't that air going over air has less friction, which it does, compared to stalled air on the edges, the issue is that the flow of the trumpet isn't even remotely a cause for power loss. It's a huge trumpet and the vehicle doesn't make any horsepower. If there were a lack of power due to flow for it's maximum allowable size, THEN it could help a tiny bit.
Right now we're seeing power changes due to air momentum (taper) and resonance. So they will never do anything at this power level with this size of a trumpet.
dimples only create a thicker boundary layer on the surface, this reduces the effective cross sectional area for air to flow through, the dimples made the ID smaller, that is all. Dimples are a waste of time.
@@seanb250 but with lower friction. The cross section on these stacks aren't a limiting factor so it's not important
@@Christdeliverme dimples create quite a large boundary layer, that’s why we only use a burr finish on cylinder heads, that creates enough boundary layer to keep fuel in suspension and not pool on walls, even the 60grit cartridge rolls produce enough boundary layer. The depth of those dimples would create nearly the same depth/thickness in boundary layer, that is a fair amount of reduction in useable cross sectional area. It’s been tested to death honestly that you would only use dimples if you wanted to shrink a ports useable area by a few %
I would have expected the double stack would have the closer lower one being quite a bit closer to the head making them a combination of a much shorter stack for more lower down power and the second stack being MUCH longer to give you an intake length the same as you seem to be running all of the other stacks... There will be very little difference when the overall length is effectively the same. So having the double stack with one much closer to the cylinder head and one much longer stack (they can even have the same ID as long as you have an air gap around the trumpet when it just overlaps.
Thanks !! great video!!
Tesla valve intake? Of course with the side that allows flow going towards the engine. Maybe it would help avoid losing air velocity due to reverberation.
your channel has made me drop the turbo stuff and try some N/A fun haha
What i learned is that these are changed out largely as one prefers for appearance or sound because overall performance is so similar
The "golf ball phenomenon" does not occur because the ball moves uniformly, with the gas flow close to linear, while the air in the intake sometimes stands still, sometimes accelerates, and these changes occur at relatively high frequency.
The creating/stabilization of the "cushion" in the hole itself takes some time.
I was interested in this phenomenon before it was commonly known.
This myth was propagated on YT by the CNC company that works with the engine heads (i remember the name but I wont write it down).
Something else that is interesting - the flow bench test in this case will show false results, because the conditions of such a test (gas flow is unidirectional) do not reflect the actual conditions during engine operation.
If it made sense when gas flows in the conditions as in the intake duct - why doesnt any competition engine, including F1 engines, have it?
Thank You for antoher interesting video Garage 4AGE.
👍as usual.
Flow bench is a great tool, i'd like to have access too. More work to test things on a running engine, but the power numbers are the end game, so the dyno is the one
@@Garage4age
Ive been following Your channel for years and I know that building a DIY flowbech, with Your skills, is a piece of cake.
@@Garage4age Building a flow bench is not difficult as long as you understand the simple principals. It will be accurate and affordable.
Good video broski!
I would like to see the test with different angled trumpets. The the back two cylinders must get a different flow of air to the front two because of the strut tower.
Tests like 45° angle upsweep or downsweep. Or just straight up 90° badboys.
COOL VIDEO MAN! Really interesting seeing the differences. Btw, looks like you have ignition miss at high rpm.
no ign problems. just what the dyno does when power rolls over
I believe that a lot of "tuners" in my country only work by placebo effect
They use and sell these stuff, iced intake or dimple porting saying that its the big improvement for your car
And the argument and proof its "it feels faster and I had no problems with it"
Nobody had showed me real proofs like a Dyno chart or drag times
Yeah the classic move is to make the intake runners shorter. which which looses low end power and top end stays the same. feels faster on the butt dyno, but is actually slower
I would like to see a trumpet with a “anti reversion” lip… they make anti reversion plates for square bore carburetors and they even make anti reversion mufflers…
You should
See a set that has a 90 degree bend pointing up I’d love to know what adding a bend to the intake track will do with all els the same
this one compares 45's vs straight ua-cam.com/video/nqYkmCLrlEo/v-deo.html. long as bends arent too tight they are fine. it also shows what a sharp 90 does in that video
The real velocity stacks were the friends and data we made along the way.
I hope in speak for ither with this idea but it mould be sorta cool to see if its possible to create some runners that actually focus on low end torque almost exclusively. You know for science. Probably something that really promotes super high port velocities in the lower rpm range. And if youbdidnfind something particularly good maybe theres room to build off of it
Could you print the tapered one and use fuzzy skin settings in the 3d printer slicer? Both Cura and Prusaslicer has the setting. Seeing how smooth the curve is with both the golfball and dimpled one I think using fuzzy skin would introduce a lot of surface turbulence and therefore minimize the pressure drag.
That took a lot of effort. It is greatly appreciated. Can you enclose the stacks in a pressurized box (a scoop)?
There are cars that do that. BMW, Ferrari, etc. The Hoonicorn before it went twin turbo was setup like that.
I wonder if it would be worth making a telescopic variable length set like the 787b or the two stage r6 stacks, I'm planning an itb build on my 2jz and I've been contemplating making something like that to go with.
I'm currently designing a continuously variable intake for a 2 cylinder engine in a motorbike, made a prototype and its working great
when i get time i will post a video simulating a variable length setup.
dimple before air fuel mixture (itb/trumpet) vs dimple port (intake cylinder head).
I wanna say the goofball lessened the effect of pressure waves
_spicy_
The taper seems to have more flow right at the top. I wonder if the taper was slightly narrower bore (so faster air speed), what the midrange would do.
People been dimpling turbocharger exhaust outlets thinking they're top engineers when really they're just causing turbulence for absolutely no reason what so ever
Pipe length = drag. Try the shortest runner length possible, while still retaining some bell mouth.
The shorter the pipe, the less developed the wall boundary layer. The thinner the boundary layer, the more flow through. The boundary layer works to reduce your effective cross sectional area. Don’t give it pipe length to develop and reduce flow area.
flow is only one part of It. The pipes need to tuned to the correct length. Then size the pipes appropriately at said correct length, so they can support the flow requirements.
Not surprising at all. Many of these things have been worked out during the last 125 years of internal combustion engine tuning. The golf ball dimples are an example of something that helps reduce drag when a shape is not particularly aerodynamic. But seems to be of negative benefit otherwise.
Interesting what if do on inner twisted lines, to twist an air? Do experiment with long and short. And compare with same without twisting