Thank you for confirming (via dyno) something I've been working on in the conceptual stage, namely the effect of intake cross-sectional area on intake charge velocity, and its' effects on horsepower at various RPM levels.
This is more than velocity/flow. This test also shows the impact on runner diameter and the strength of the pulse waves being diminished as the cross sectional area increases. Super super interesting.
I'm loving all the data you are producing. And the road speed instead of time as an X demention is messing with mysilly selfff. It's a happy little shifty loop de loop.
i read a reasearch paper stating that a bellmouth shaped like the valve cuts (3 angles ) but not full bell mouthed , not rounded over , gave the best flow. thatd be interesting to see also.
I just bought a 75mm length velocity stack and with your informational video. Now i know why i got more acceleration on my 150cc motorcycle. once i got pass at 8.5k rpm the engine just suddenly gains extra power and reaches redline much faster at 5th gear, although my top speed is just 147kmh but hey my bike weighs 135kg and I am 67kg. its a great win in that situation.
@@stoosee no, it is a chinese bike skygo knight 150(carbureted) . But its already upgraded with an 8 stage Racing CDI, 7.0 lift camshaft, 30mm flat carb, stage 2 exhaust manifold, modified pipe and a semi dome piston.
@@zainrei4917 i have mio sporty, engine specs are 59mm chromebore mtrt bigvalve 30/25 regrind cams 28mm carb cvt set: sun df rrgs pulley straight 8g flyball 1500rpm center spring 1200 clutch spring modified torque drive for more top end 17s rim i need to change exhaust cause cause my current pipe doesn't fit to my engine spec
About what I expected to see with the 40mm, more midrange due to increased velocity, but less top end due to restriction of flow. Would be interested to see a test of the tapered versions with different rates of taper. Im sure there is a text book somewhere that has a formula that would allow you to work the ideal rate of taper for a given flow and velocity...but this is more fun!
Will definitely do something trying different tapers in the future. Since the 51-62 was the only one that had a power gain without a loss somewhere else. At very least will bore my normal intake out with a more aggressive taper.
I’ve read before in university research studies on the subject of taper angles that 3 and 7 degrees is the best, 7 being the best over all and 3 close behind it. Angles close to them either side had drastic changes like what we’ve seen in the intake length tests
I'm not sure if its a velocity thing from the taper. thinking maybe airflow. since can clearly see the smaller diameter runners bottle neck at a certain rpm. the 51 and my normal intake are just hitting it right up top
@@Garage4age True, but in all my cylinder head experiments, a 1.1:1 taper has produced best intake velocity at the valve, and best cylinder filling (and best power curve on the dyno). Love your videos!
@@dragonhealer7588 Yeh not saying you are wrong. this thing proves me wrong every time i think i've figured it out. so now i just test stuff and if it works it works. My normal intake does have a small amount of taper in it. the bellmouth is very similar to whats used on these tests. so the 51mm vs normal intake runs in this vid is a good comparison, the normal intake hangs on a bit longer. although the tapered runner maybe acting bit shorter, even though overall length same. at some stage i will bore the normal intake out with a more aggressive taper, see if it does the same as the 51-62. getting the sweet spot may require a few attempts.
@1979Olitsch it would, that's exactly what most if not all production cars do these days, not seamlessly ofc. but with 2 runner lengths adjusted with flaps.
Can you do more dialed test on reducing diameter "taper" runners? Like higher reduction in diameter per distance and lower, what effects will it have? Like 50-45 reduction in 200mm length vs 70-45mm reduction in 200mm, and like 70-45 in 100 mm(steeper angle), you know? Something like that would be greatly appreciated.
Hey, Yes I want to figure out what will work best after seeing what the big 51-62 did. Just need to figure out an easy way to do a fair test. in the meantime my normal intake has a small taper out to either 54mm or 56mm will have to measure to be sure. so the 51mm straight vs normal vs the 51-62 from these tests is worth a look for comparison
@@Garage4age sounds clever to me. Because what I noticed is that straight pipes give that resonance "supercharging" ram effect, torque climbs, then it gets to opposition and destroys it and makes torque dip in the rev range. So nice taper would yield perfect results from low down to up top. Also won't you think tapering down to lower diameter (let's say 45) give more on lower rpm torque?
@@gedas3419 Going down to smaller diameter like you suggest may work. longer the pipe, more restriction. So a short section 45mm may not pose a restriction at high rpm like the 200mm length in this test. should be worth a try!
I'm curious what you know about tuning. All I know is with intake design there certain frequencies that can be targeted. Frequencies corresponding to engine RPM and how pressure waves are created at every valve event. Would love to here your thoughts on the topic!
You are correct. IMO the big tapered runners are the best. No losses anywhere whilst having a gain right up top. I will try to replicated the steeper taper angle on my normal intake
@@Garage4age I’ve been making carby intakes from pvc tapered 50-75mm with a bell mouth 120mm long. Would you like to try these if I send you them ? I could also lengthen them to your normal 185 or 205 so you can see if added length could possibly be better with a taper compared to your already tested straight sections.
@@Garage4age no worries, I’m making more of different lengths over the week end so I’ll get some done in those sizes so you can see exactly what they’ll be. I’ve just been researching the yoshimura double velocity stack, very interesting with mixed results. From what I’ve read a 1mm gap difference between the velocity stacks make or break the gains so for you to test it would probably take to much time setting up and trialing. Love your channel man, I’ve learnt so much and confirmed so many ideas from all your experimenting. Me and my mate were doing similar sort of tests with ic piping and intercoolers but for now everything has had to stop, your channel pushes me to get back to doing it again.
Man this is my favorite channel even though I have no love for the 4age lol. I know on my rx7 I was able to find a good bit of power using taper exhaust runners. Now I know the pulse is much stronger in a rotary but I'd love to see what it does with this.
Really nice channel! After i watched your video i scrub my airbox out ofmy civic ej9 and made the air intake hole bigger with sandpaper... plus bigger airintakte in stock airbox and k&n filter.. it goesreally good now! But was so god damn loud now cause i had no holes for the resonance box.. after i drilled one into the air intake the noise sounds legal under 3000rpm:D
Tanx and congratulations for sharing all these videos! I'd like to suggest a comparison between wasted spark and full sequential ignition, keeping same timing map and voltage and energy output. If you find it interesting I may help you to do it.
The 51-62 mm is the best scenario in this video, but isn't the removal of the air filter contributing a part of this gain? Do you have an estimate, or have you measured in the past the gain of removing the air filter on your engine setup?
@@Garage4age Impressive, especially in such setup that removing the filter makes no difference! I assume your filter is foam based? Have you also tested any fuel additives?
Need a pressure valve to control air volume , too much air good at hi rpm but Low to mid is bad , German technology already tell us , most of the modern car with pressure control manifold to compensate the needs from engine
The intake air resonance (= cyl fill = power) is related to the intake duct volume (it behaves as an air spring). If you test options with same duct volume (e.g. 165x51 ; 120x60; 140x55; etc etc) you should be able to sweep wave and friction effects at same air inertia (air kinetic energy) levels.
Cylinder 1 should have the shortest trumpet working along making each trumpet longer until the 4th cylinder is at full length. Cylinder 3/4 will always have more fuel sprayed into the itb than cylinder 1/2 it won't be much but it's enough to cause a flat spot or lack of power with equal length trumpets due to atmospheric pressure. The theory is cylinder 1 has the shortest trumpet and cylinder 4 the longest. We studied this and documented all data for Motorsport with the engine sat transverse like your motor you should try this and see how it works.
Hi. I have avoided running different length trumpets, as would have to run a different tune per cylinder. A lot of people have asked to see it, so may do it at some point. but cant see the advantage, based on the testing I've done
Hi, very great videos, I think probably unique because never saw so much work documented in this way. Hope you will never get bored and will continue to do this! What is the diameter of the throttle bodies that you're using? Also the diameter is measured at the end/beginning of the body itself or at the butterfly? (sometimes for example it's maybe 38 - 40 mm but the butterfly inside is like 36mm, so I don't know what diameter it's considered really)
So the tapered 51 - 62mm was better than your normal and well designed intake? lol thats kind of funny Have you tried a bigger size than 51mm straight from the throttlebodies? Or even bigger throttle bodies?
I tired them multiple times after this and couldn't get the same results. 99% sure the car wouldn't have had enough runs on it when i done the baseline run. Even though the engine oil and water temps are where they should be and are the same for all tests. car needs at least another 3 full pulls for the power to be super consistent. It will keep making slightly more power up until this point. Likely due to the gearbox and diff temps taking awhile longer to stabilize. my later videos i do more runs before filming an do at least 2 pulls on the baseline to make sure they overlay 100%. unlike in this older one. Throttles are plenty big. it made the same power here on 47mm throttles as the 52mm's in the vid
can you test throttle body "spacer" it has grooves that makes better air/fuel mix, i am a little skeptical about it but when i put full gas pedal on low rpm and let it to rise(3000-4500) when i start to release gas pedal from 100% to 85-80% i regularly feel increase of power, explanation would be that butterfly is too opened for some rpm and if release it, it starts to make some turbulence that helps to mix air/fuel
nice vid, thanks for putting it up. in essence, for your application there was very little downside of going larger, especially if the application lets you stay in the upper rev range. Ive been doing some work with sr20ve engines but would love to have the dyno access to do what you are doing
A larger bellmouth should be equal to a slightly longer stack, but a good bellmouth will increase the effective rpm that you get power gains from. Almost all of the gains that you see are specific to a rpm because it's mostly tuning the frequency for a specific speed For instance look at the design of the factory pro superflare velocity stack design compared to there normal one. You can also try using 2 longer stacks tuned for say mid rpm and 2 shorter stacks for high rpm power, oems use that mix alot. Depends if you are looking for peak power or lifting the whole power curve
In my other video where I tested length and some different bellmouths. the bellmouth pipes act like a shorter pipe. If adjusted the pipe so the effective length is the same, the power curve will look the same, no bellmouth vs bellmouth. But the bellmouth pipe will start to beat the non bellmouth once airflow demand increases. judging from what i've found so far, and ignoring the complexity. A 2 stage setup running a small diameter runner in the correct length at lower rpm's then switching to a big diameter pipe for the high rpm would give the best overall gain
@@Garage4age yep newer Yamaha r6 motorcycles have electronically variable stacks. They have 2 different positions. It causes a 500rpm or so area in the meat of the power band to be down on power during the switch tho. Most other motorcycle manufacturers haven't switched to similar systems because of complexity and they don't feel it was worth the gains. Suzuki still uses 2 longer stacks on 2 cylinders and 2 shorter on the other 2. There is calculations you can run to determine the optimal length, depending on where you where in the rpms you want the power gains, but testing is always good. You are right about bellmouth needing to be longer, I realized when I looked at the factory pro superflares again vs the normal ones. From your testing, it looks like your stock motors design is tuned rather well for your motor. Yamahas factory stacks use the taper you tested, aftermarket typically uses a large bell mouth.rounding the edge of the bellmouth is done on designs I have seen also. I don't recall if you tested it yet, but I would think a bellmouth with a taper would be best. Just gotta get the length perfect. I'll have to rewatch the older video, I would think the airflow demands of your motor would be high enough at the top of the rpms to benefit from a bellmouth
The different length trumpets should be good for smoothing out the powerband. kinda trading power in one place for another. Bit of a pain to tune as have to tune individual cylinders. i could blend 2 of the dyno graphs together from all the tests i have done to show what 2 long and 2 short would do. so not really worth doing it physically. The last runners in this video are tapered. 51-62mm, they are also the only thing that has beating my normal intake without loosing power somewhere else. said normal intake is far from stock (these engines dont even have itb's stock) and also has a taper in it, but less aggressive taper than 51-62. has an elliptical bellmouth. probably some better pics of it in my other vids
Variable is cool and have attempted something in the past. But there is a lot of complexity and engineering feats to overcome for little gain. Going by the tests i did on length in my other video the longer runner beat the shorter ones almost everywhere. Almost looks like variable diameter would be better than length
would need to do a whole new build to get it up to this ones spec, different pistons etc. I do have a near stock 20v in another car i may do some testing on though
Yeah half the reason i made this video. But tbh I had never tired downsizing the runners so was curious. From what i can tell, big gain down in the low/mid range people have got with smaller diameter runners, is fixing a reversion issues by speeding up the air coming in, so the exhaust gas cant get back in the cylinder. my engine i fixed the issue on the exhaust side. which doesn't result in the big loss in power at high rpm. Its very common on these engines to have a big power dip at 4-5000rpm after installing big cams.
@@Garage4age in another video, with the 3D printed velocity stacks, it looked like you solved it with the tapered intake. Having the small end gasket matched to the intake on the head. Both Intake and exhaust runner length make a difference too, which I’m currently trying to wrap my head around all the math.
I’ve basically got to build intake with longer runners and bigger plenum and have shorter shorter extractor? runners so can get the best of both worlds
Nice, I dont think the 51mm is too large though. I would prefer the nicer power curve with that extra up top. Don't like the peaks and dips that the 40 and 45mm's create. but its possible the step down is doing something funny to produce them.
@@Garage4age what size is the runner after the throttle/before the port? Had a play there? I know when I looked into ITB for my SR20VE I gave up, because the only options that would've provided a nice linear power curve were BMW 52mm+.
@@NicPerichon it used to have blacktop 4age throttles with 47mm throttle plates. and manifold to suit. it ran the same trumpet setup as current but the 100mm section between throttle and top half of trumpet/bellmouth had slightly more taper due to smaller throttle size. the power curve was identical when switched to the bmw 52mm throttles. so they are oversized maybe yes. but the bmw throttles do sit a bit further from the head, so its not as big of a change as it sounds. but still had zero effect so havent bothered revisiting it
remember its only a 1600cc. Also the difference between 40mm and 51mm at peak power is over 10% That's a big difference from just a bit of pipe 200mm long in a different diameter.
@@Liveforeever Pretty hard to say. things like cam size and overlap will likely have an effect. The exhaust side can have a big impact on how things work also. but in a perfect world i would assume the 10% would carry over, if everything is relative to the engine size.
@@africankat1 BMW throttles. it used to have blacktop throttles with 47mm plates. Power wasnt any different going to the 52's but stuck with them for a few reasons.
Cool. Love your style. One note tho, I know it's a pain and takes time but you really should re-map every time you change An item. just to see which would be better.
I do at least one run before the runs you see in the vids, to correct afr if required. ignition advance is kept the same. but end of the day, since its alpha n tuned. if goes richer = power loss. leaner= power increase. there are of course a few exceptions to this.
@@Garage4age it's rather pointless, as the torque does not change enough, even with very bad a/f ratios. Afr is important for emissions, engine health ( especially for force induction) and economy, but as is stands for torque, from ~9:1 to ~16:1 is pretty much the same. What's important, is the good enough atomisation and homogeneous mixture, but second to the volumetric efficiency tho..
@@TheSilviu8x yep I have a video showing how little change in power there is within a afr window. If is within a certain range I generally don't bother correcting afr for most tests. But yeah if it's a final tune needs to be right for other reasons
so inlet surface for 2 inlet valves is (pi*D*h)*2 = 1947mm2. Inlet surface of a trumpet is pi*d*d/4. So inlet trumpet should be at least : 1947=pi*d*d/4, so D should be 49mm minimal. Usually should be 10% higher. 1947*1.1=pi*d*d/4 --> D=approx 52mm
This isn’t ideal because your dealing with air transfer over a drop off in the back of the runners. Anything over a 7 degree angle will cause air to tumble so of course at high rpm the size difference the power loss will be greatly exaggerated on smaller runners. You’d have to different runners every time with a proper transistion. You used pipe with the smallest lip on the last run so of course it worked.
It actually doesn't matter as much as you would think. the runners at the end actually have a worse transition that the normal baseline run. Its pretty clear the smaller runners are running out of airflow, even if there is some small "tumble" effect. to fix the transition. would have to modify and fill all the way down into port, but then wouldn't really be apples to apples test anyway.
@@ajisw_324 yeah, this engine will make the same power on 47mm throttle plates, but any smaller no. Ive kept the 52mm ones on there for other reasons, even though they are slightly large
@@Garage4age well then i remember ducati v4 use 52mm throttle body aswell, 81mm piston same with 4age. Make 215 HP on crank. Yeah i think that's not too big
Thanks for doing these tests. Great use of a dyno for R&D.
Yes. Thank you from me too.
Am trying to decide runner diameter. You made my life easier
Guy: What do you have under the hood?
Me: THEM BIG DOGS
Thank you for confirming (via dyno) something I've been working on in the conceptual stage, namely the effect of intake cross-sectional area on intake charge velocity, and its' effects on horsepower at various RPM levels.
This is more than velocity/flow. This test also shows the impact on runner diameter and the strength of the pulse waves being diminished as the cross sectional area increases. Super super interesting.
I'm loving all the data you are producing. And the road speed instead of time as an X demention is messing with mysilly selfff. It's a happy little shifty loop de loop.
i read a reasearch paper stating that a bellmouth shaped like the valve cuts (3 angles ) but not full bell mouthed , not rounded over , gave the best flow. thatd be interesting to see also.
Appreciate your work man 🤙🏻
I just bought a 75mm length velocity stack and with your informational video. Now i know why i got more acceleration on my 150cc motorcycle. once i got pass at 8.5k rpm the engine just suddenly gains extra power and reaches redline much faster at 5th gear, although my top speed is just 147kmh but hey my bike weighs 135kg and I am 67kg. its a great win in that situation.
whats your motorcycle? is it raider 150 fi?
@@stoosee no, it is a chinese bike skygo knight 150(carbureted) . But its already upgraded with an 8 stage Racing CDI, 7.0 lift camshaft, 30mm flat carb, stage 2 exhaust manifold, modified pipe and a semi dome piston.
@@zainrei4917 may i know what brand of velocity youre using or link of shopee
@@zainrei4917 i have mio sporty, engine specs are
59mm chromebore mtrt
bigvalve 30/25
regrind cams
28mm carb
cvt set:
sun df
rrgs pulley
straight 8g flyball
1500rpm center spring
1200 clutch spring
modified torque drive for more top end
17s rim
i need to change exhaust cause cause my current pipe doesn't fit to my engine spec
@@zainrei4917 does it really improve the performance using velocity stack?
About what I expected to see with the 40mm, more midrange due to increased velocity, but less top end due to restriction of flow.
Would be interested to see a test of the tapered versions with different rates of taper.
Im sure there is a text book somewhere that has a formula that would allow you to work the ideal rate of taper for a given flow and velocity...but this is more fun!
Will definitely do something trying different tapers in the future. Since the 51-62 was the only one that had a power gain without a loss somewhere else. At very least will bore my normal intake out with a more aggressive taper.
I’ve read before in university research studies on the subject of taper angles that 3 and 7 degrees is the best, 7 being the best over all and 3 close behind it. Angles close to them either side had drastic changes like what we’ve seen in the intake length tests
Tapered intake, demonstrates gas velocity is important.
Thanks for all the work and uploading!
I'm not sure if its a velocity thing from the taper. thinking maybe airflow. since can clearly see the smaller diameter runners bottle neck at a certain rpm. the 51 and my normal intake are just hitting it right up top
@@Garage4age
True, but in all my cylinder head experiments, a 1.1:1 taper has produced best intake velocity at the valve, and best cylinder filling (and best power curve on the dyno).
Love your videos!
@@dragonhealer7588 Yeh not saying you are wrong. this thing proves me wrong every time i think i've figured it out. so now i just test stuff and if it works it works. My normal intake does have a small amount of taper in it. the bellmouth is very similar to whats used on these tests. so the 51mm vs normal intake runs in this vid is a good comparison, the normal intake hangs on a bit longer. although the tapered runner maybe acting bit shorter, even though overall length same. at some stage i will bore the normal intake out with a more aggressive taper, see if it does the same as the 51-62. getting the sweet spot may require a few attempts.
What is the rest of the intake? What size butterfly in your ITBs and I assume it’s a big port head?
@@mspecvq30det BMW 52mm (i think they measure more like 51.5) Smallport head
Very cool test!!!!!
Really appreciate your time and effort..
👍👍
Any diffusers' job is to change the velocity with minimal loss of pressure, and the long smooth taper is always going to do that best.
variable length next one
@1979Olitsch it would, that's exactly what most if not all production cars do these days, not seamlessly ofc. but with 2 runner lengths adjusted with flaps.
hi mate... ur video helps me a lot to understand carb... mostly my question answers by ur video... tq so much...
This is. .. AWESOME!!! 😻🙊 love how we could see the actual graph and were top end fell off! 👍
Can you do more dialed test on reducing diameter "taper" runners? Like higher reduction in diameter per distance and lower, what effects will it have? Like 50-45 reduction in 200mm length vs 70-45mm reduction in 200mm, and like 70-45 in 100 mm(steeper angle), you know? Something like that would be greatly appreciated.
Hey, Yes I want to figure out what will work best after seeing what the big 51-62 did. Just need to figure out an easy way to do a fair test. in the meantime my normal intake has a small taper out to either 54mm or 56mm will have to measure to be sure. so the 51mm straight vs normal vs the 51-62 from these tests is worth a look for comparison
@@Garage4age sounds clever to me. Because what I noticed is that straight pipes give that resonance "supercharging" ram effect, torque climbs, then it gets to opposition and destroys it and makes torque dip in the rev range. So nice taper would yield perfect results from low down to up top. Also won't you think tapering down to lower diameter (let's say 45) give more on lower rpm torque?
@@gedas3419 Going down to smaller diameter like you suggest may work. longer the pipe, more restriction. So a short section 45mm may not pose a restriction at high rpm like the 200mm length in this test. should be worth a try!
Great tests..love the videos..
I'm curious what you know about tuning. All I know is with intake design there certain frequencies that can be targeted. Frequencies corresponding to engine RPM and how pressure waves are created at every valve event. Would love to here your thoughts on the topic!
maybe I'm missing something... @4:28 I see about 7hp = 5% gain at the very end of the power curve over the stock setup that included the air filter.
You are correct. IMO the big tapered runners are the best. No losses anywhere whilst having a gain right up top. I will try to replicated the steeper taper angle on my normal intake
@@Garage4age I’ve been making carby intakes from pvc tapered 50-75mm with a bell mouth 120mm long. Would you like to try these if I send you them ? I could also lengthen them to your normal 185 or 205 so you can see if added length could possibly be better with a taper compared to your already tested straight sections.
@@1999ekk24 Hey, could be interested. if possible fire me some pictures garage4age@gmail.com
@@Garage4age no worries, I’m making more of different lengths over the week end so I’ll get some done in those sizes so you can see exactly what they’ll be. I’ve just been researching the yoshimura double velocity stack, very interesting with mixed results. From what I’ve read a 1mm gap difference between the velocity stacks make or break the gains so for you to test it would probably take to much time setting up and trialing. Love your channel man, I’ve learnt so much and confirmed so many ideas from all your experimenting. Me and my mate were doing similar sort of tests with ic piping and intercoolers but for now everything has had to stop, your channel pushes me to get back to doing it again.
@@Garage4age I emailed you them pictures yesterday by the way man
Man this is my favorite channel even though I have no love for the 4age lol. I know on my rx7 I was able to find a good bit of power using taper exhaust runners. Now I know the pulse is much stronger in a rotary but I'd love to see what it does with this.
Oddly enough we do the opposite on single cylinders
Really nice channel!
After i watched your video i scrub my airbox out ofmy civic ej9 and made the air intake hole bigger with sandpaper... plus bigger airintakte in stock airbox and k&n filter.. it goesreally good now!
But was so god damn loud now cause i had no holes for the resonance box.. after i drilled one into the air intake the noise sounds legal under 3000rpm:D
Would be nice to see curved velocity stacks that curve towards the front and see how much of a gain there is due to a ram air effect.
Thank you!
Tanx and congratulations for sharing all these videos!
I'd like to suggest a comparison between wasted spark and full sequential ignition, keeping same timing map and voltage and energy output.
If you find it interesting I may help you to do it.
Ive done one on spark here : ua-cam.com/video/Tp7Y11M388c/v-deo.html
Thanks
Big Dog for the win
love it...
The 51-62 mm is the best scenario in this video, but isn't the removal of the air filter contributing a part of this gain? Do you have an estimate, or have you measured in the past the gain of removing the air filter on your engine setup?
zero change with air filter off
@@Garage4age Impressive, especially in such setup that removing the filter makes no difference! I assume your filter is foam based? Have you also tested any fuel additives?
Is the biggest pipercross foam filter i could fit. from memory rated to 300hp. haven't tested any additives
Need a pressure valve to control air volume , too much air good at hi rpm but Low to mid is bad , German technology already tell us , most of the modern car with pressure control manifold to compensate the needs from engine
The intake air resonance (= cyl fill = power) is related to the intake duct volume (it behaves as an air spring).
If you test options with same duct volume (e.g. 165x51 ; 120x60; 140x55; etc etc) you should be able to sweep wave and friction effects at same air inertia (air kinetic energy) levels.
Well well well, how the turntables
PLEASE ATTACH FLESIGHTS. THAT WOULD BE HILARIOUS.
Noice! Love the videos!
Cylinder 1 should have the shortest trumpet working along making each trumpet longer until the 4th cylinder is at full length. Cylinder 3/4 will always have more fuel sprayed into the itb than cylinder 1/2 it won't be much but it's enough to cause a flat spot or lack of power with equal length trumpets due to atmospheric pressure. The theory is cylinder 1 has the shortest trumpet and cylinder 4 the longest. We studied this and documented all data for Motorsport with the engine sat transverse like your motor you should try this and see how it works.
Hi. I have avoided running different length trumpets, as would have to run a different tune per cylinder. A lot of people have asked to see it, so may do it at some point. but cant see the advantage, based on the testing I've done
Hi, very great videos, I think probably unique because never saw so much work documented in this way. Hope you will never get bored and will continue to do this!
What is the diameter of the throttle bodies that you're using? Also the diameter is measured at the end/beginning of the body itself or at the butterfly? (sometimes for example it's maybe 38 - 40 mm but the butterfly inside is like 36mm, so I don't know what diameter it's considered really)
Thanks. it has 52mm throttles. well there is a very small machined step so the plates themselves maybe 51.5mm
Will be posible to do a taper 60 mm runners with dimples (like a golfball) will that improve top rpm power?
Dimples doesnt improve airflow, its only when fuel is in the air
You need help, where can I buy velocity stack to put on a bike.
So the tapered 51 - 62mm was better than your normal and well designed intake? lol thats kind of funny
Have you tried a bigger size than 51mm straight from the throttlebodies? Or even bigger throttle bodies?
I tired them multiple times after this and couldn't get the same results. 99% sure the car wouldn't have had enough runs on it when i done the baseline run. Even though the engine oil and water temps are where they should be and are the same for all tests. car needs at least another 3 full pulls for the power to be super consistent. It will keep making slightly more power up until this point. Likely due to the gearbox and diff temps taking awhile longer to stabilize. my later videos i do more runs before filming an do at least 2 pulls on the baseline to make sure they overlay 100%. unlike in this older one. Throttles are plenty big. it made the same power here on 47mm throttles as the 52mm's in the vid
can you test throttle body "spacer" it has grooves that makes better air/fuel mix, i am a little skeptical about it but when i put full gas pedal on low rpm and let it to rise(3000-4500) when i start to release gas pedal from 100% to 85-80% i regularly feel increase of power, explanation would be that butterfly is too opened for some rpm and if release it, it starts to make some turbulence that helps to mix air/fuel
nice vid, thanks for putting it up. in essence, for your application there was very little downside of going larger, especially if the application lets you stay in the upper rev range. Ive been doing some work with sr20ve engines but would love to have the dyno access to do what you are doing
Nice. The big tapered ones are definitely best IMO. gain up top and no loss anywhere else.
Wait… was that a big lez show reference?🤨
wadiyatalkinabeet
@@Garage4age you faken druggo mate
by any chance have you noticed any low rpm driveability tradeoff with the bigger runners?
A larger bellmouth should be equal to a slightly longer stack, but a good bellmouth will increase the effective rpm that you get power gains from. Almost all of the gains that you see are specific to a rpm because it's mostly tuning the frequency for a specific speed
For instance look at the design of the factory pro superflare velocity stack design compared to there normal one. You can also try using 2 longer stacks tuned for say mid rpm and 2 shorter stacks for high rpm power, oems use that mix alot. Depends if you are looking for peak power or lifting the whole power curve
In my other video where I tested length and some different bellmouths. the bellmouth pipes act like a shorter pipe. If adjusted the pipe so the effective length is the same, the power curve will look the same, no bellmouth vs bellmouth. But the bellmouth pipe will start to beat the non bellmouth once airflow demand increases. judging from what i've found so far, and ignoring the complexity. A 2 stage setup running a small diameter runner in the correct length at lower rpm's then switching to a big diameter pipe for the high rpm would give the best overall gain
@@Garage4age yep newer Yamaha r6 motorcycles have electronically variable stacks. They have 2 different positions. It causes a 500rpm or so area in the meat of the power band to be down on power during the switch tho. Most other motorcycle manufacturers haven't switched to similar systems because of complexity and they don't feel it was worth the gains. Suzuki still uses 2 longer stacks on 2 cylinders and 2 shorter on the other 2. There is calculations you can run to determine the optimal length, depending on where you where in the rpms you want the power gains, but testing is always good.
You are right about bellmouth needing to be longer, I realized when I looked at the factory pro superflares again vs the normal ones.
From your testing, it looks like your stock motors design is tuned rather well for your motor.
Yamahas factory stacks use the taper you tested, aftermarket typically uses a large bell mouth.rounding the edge of the bellmouth is done on designs I have seen also. I don't recall if you tested it yet, but I would think a bellmouth with a taper would be best. Just gotta get the length perfect.
I'll have to rewatch the older video, I would think the airflow demands of your motor would be high enough at the top of the rpms to benefit from a bellmouth
The different length trumpets should be good for smoothing out the powerband. kinda trading power in one place for another. Bit of a pain to tune as have to tune individual cylinders. i could blend 2 of the dyno graphs together from all the tests i have done to show what 2 long and 2 short would do. so not really worth doing it physically.
The last runners in this video are tapered. 51-62mm, they are also the only thing that has beating my normal intake without loosing power somewhere else. said normal intake is far from stock (these engines dont even have itb's stock) and also has a taper in it, but less aggressive taper than 51-62. has an elliptical bellmouth. probably some better pics of it in my other vids
I love your videos! Did u already try with trumpet shape like the BMW S54B32 engine ? seems to be a very good compromise...
Thanks. No haven't tried them, do you mean the ones with the angle cut on the end?
Garage 4age yep!
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@@gegettelaburette2145 Thanks, they look interesting.
Would be cool if you could make the long and slide shorter as the rpm goes up. Vario intake length.
Variable is cool and have attempted something in the past. But there is a lot of complexity and engineering feats to overcome for little gain. Going by the tests i did on length in my other video the longer runner beat the shorter ones almost everywhere. Almost looks like variable diameter would be better than length
Use a 1.8l 7afe block for this 4age set up it fits well and you can get more hp
Rather stick with the 1600
@@Garage4age what about a 20v head on the 16v block?
would need to do a whole new build to get it up to this ones spec, different pistons etc. I do have a near stock 20v in another car i may do some testing on though
The 7afe block don't like high revs as much. More power down low
would different spark plugs(colder/hotter), affect anything with certain stacks?
Yeaahhhhhh nah nah nah watabout dem big dogs gagag
👍👍 great
And there was this guy under the long runner video claiming your runners are too large for this power 🤔
Yeah half the reason i made this video. But tbh I had never tired downsizing the runners so was curious. From what i can tell, big gain down in the low/mid range people have got with smaller diameter runners, is fixing a reversion issues by speeding up the air coming in, so the exhaust gas cant get back in the cylinder. my engine i fixed the issue on the exhaust side. which doesn't result in the big loss in power at high rpm. Its very common on these engines to have a big power dip at 4-5000rpm after installing big cams.
On the tapered runners was the length 165mm?
They were all 185mm from memory.
Simply put, everything is a restriction small then the port entry?
Yeah some people fix reversion issues using a smaller runner diameter, to increase air speed. But isn't the way to fix it since restricts top end
@@Garage4age in another video, with the 3D printed velocity stacks, it looked like you solved it with the tapered intake. Having the small end gasket matched to the intake on the head. Both Intake and exhaust runner length make a difference too, which I’m currently trying to wrap my head around all the math.
I’ve basically got to build intake with longer runners and bigger plenum and have shorter shorter extractor? runners so can get the best of both worlds
long runners on both sides work best. but lengths need to be correct not just long.
I'd say my guess was bang on 😂
Nice, I dont think the 51mm is too large though. I would prefer the nicer power curve with that extra up top. Don't like the peaks and dips that the 40 and 45mm's create. but its possible the step down is doing something funny to produce them.
@@Garage4age what size is the runner after the throttle/before the port? Had a play there?
I know when I looked into ITB for my SR20VE I gave up, because the only options that would've provided a nice linear power curve were BMW 52mm+.
@@NicPerichon it used to have blacktop 4age throttles with 47mm throttle plates. and manifold to suit. it ran the same trumpet setup as current but the 100mm section between throttle and top half of trumpet/bellmouth had slightly more taper due to smaller throttle size. the power curve was identical when switched to the bmw 52mm throttles. so they are oversized maybe yes. but the bmw throttles do sit a bit further from the head, so its not as big of a change as it sounds. but still had zero effect so havent bothered revisiting it
@@Garage4age nice to take note of. Thanks
There's not much between them. Was cam timing, ignition timing and fuel timing adjusted for each?
remember its only a 1600cc. Also the difference between 40mm and 51mm at peak power is over 10% That's a big difference from just a bit of pipe 200mm long in a different diameter.
@@Garage4age yeah I suppose you are right. Do you think the difference would have been more with a 2000cc, 3" exhaust and 8500rpm?
@@Liveforeever Pretty hard to say. things like cam size and overlap will likely have an effect. The exhaust side can have a big impact on how things work also. but in a perfect world i would assume the 10% would carry over, if everything is relative to the engine size.
Did you adjudt AFR too?
@Garage 4age what is your throttle plate diameter?
52mm
@@Garage4age are they aftermarket? i thought u were runnin the blacktop itb...which is 45mm throttle plate?
@@africankat1 BMW throttles. it used to have blacktop throttles with 47mm plates. Power wasnt any different going to the 52's but stuck with them for a few reasons.
Cool. Love your style. One note tho, I know it's a pain and takes time but you really should re-map every time you change An item. just to see which would be better.
I do at least one run before the runs you see in the vids, to correct afr if required. ignition advance is kept the same. but end of the day, since its alpha n tuned. if goes richer = power loss. leaner= power increase. there are of course a few exceptions to this.
@@Garage4age it's rather pointless, as the torque does not change enough, even with very bad a/f ratios.
Afr is important for emissions, engine health ( especially for force induction) and economy, but as is stands for torque, from ~9:1 to ~16:1 is pretty much the same.
What's important, is the good enough atomisation and homogeneous mixture, but second to the volumetric efficiency tho..
@@TheSilviu8x yep I have a video showing how little change in power there is within a afr window. If is within a certain range I generally don't bother correcting afr for most tests. But yeah if it's a final tune needs to be right for other reasons
Hey man give a try on double stack velocity like yoshimura did
I'm getting a little worried. You'll be running out of intake idea's to test soon. Oh the intro nice jump!
Could try different exhaust
@@exiled3503 he did exhaust testing years ago but yes that would be sweet. Itbs and zombies.
maybe adjustable length runners
Ive got some ideas to try on the exhaust side. just a lot more time and $$$ required to fab stuff. will happen sometime though. Yes need more jumps
Wahoo zoomies
Big dogs it is
POV "port cam". Sweet
do you see any relation between inlet surface trumpet (pi d2 /4) and inlet surface from inlet valve diameter/inlet valve lift height (2pi*r *h ) ?
Can't say I've done the math. 31mm 10mm lift is the intake valve size/lift if you would like to
so inlet surface for 2 inlet valves is (pi*D*h)*2 = 1947mm2. Inlet surface of a trumpet is pi*d*d/4. So inlet trumpet should be at least : 1947=pi*d*d/4, so D should be 49mm minimal. Usually should be 10% higher. 1947*1.1=pi*d*d/4 --> D=approx 52mm
Nice, lines up with what is in the video then.
@@Garage4age yes indeed !
Why is there a loop at very low revs?
just the dyno doing a hold before starts the run. it overshoots if roll into the throttle to fast. So yeah ignore below 2000rpm
There is equal length exhausts why not intakes? Try it please
They are equal length
do you adjust the fuel map between each test?
If needed yes. see my video on afr vs fuel
What diameter are your ITB's ?
52mm
What size was baseline?
52mm and tapers out slightly to bellmouth
This isn’t ideal because your dealing with air transfer over a drop off in the back of the runners. Anything over a 7 degree angle will cause air to tumble so of course at high rpm the size difference the power loss will be greatly exaggerated on smaller runners. You’d have to different runners every time with a proper transistion. You used pipe with the smallest lip on the last run so of course it worked.
It actually doesn't matter as much as you would think. the runners at the end actually have a worse transition that the normal baseline run. Its pretty clear the smaller runners are running out of airflow, even if there is some small "tumble" effect. to fix the transition. would have to modify and fill all the way down into port, but then wouldn't really be apples to apples test anyway.
Not so. 7 deg applies only to outlets.
What throttle body diameter?
52mm
@@Garage4age the inner diameter was 52mm ?? wow that's big.
@@ajisw_324 yeah, this engine will make the same power on 47mm throttle plates, but any smaller no. Ive kept the 52mm ones on there for other reasons, even though they are slightly large
@@Garage4age well then i remember ducati v4 use 52mm throttle body aswell, 81mm piston same with 4age. Make 215 HP on crank. Yeah i think that's not too big
450Nm ?
Its torque measured at wheels.
45 mm tapet 62 podria ser mejor
7A GE....
* research spondored by NASA
👍
Maybe then i could afford to upgrade from pvc pipe and insulation tape
its spelt dawg
garage4ag.files.wordpress.com/2020/08/yo-dawg-heard-you.jpg
big dog hahahaha
I've been falling asleep to these videos. I highly don't recommend it!