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BTW here is a pic
Attachment 3005
Last edited by IZY-10; 01-03-2007 at 09:40 PM.
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Originally Posted by DynoDave
Your smoking crack again dude check your facts before your make such a stupid comment.
Regards Dyno Dave
Why not enlighten everybody as to why?
I will admit it is a generic simplified statement but I am happy to bring out the worksheet for calculating resonant frequencies if you prefer
Last edited by iamhappy46; 23-10-2006 at 01:20 AM.
N14 Pulsar - VQ35 swap, Kelford C spec cams, 12.7:1CR, 6 speed HLSD, BC coilovers & 350Z 12.6" F brakes
Smashed VY SS Ute: Teins, AP Racing brakes, Billet wheels, lazy 481rwKw TT kit - PICS
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Originally Posted by iamhappy46
Why not enlighten everybody as to why?
I will admit it is a generic simplified statement but I am happy to bring out the worksheet for calculating resonant frequencies if you prefer
What does a TOP FUEL engine have to do with a Honda intake system,its a pretty out there statement dont you think.
Regards Dyno Dave
Buddyclub Australia
Member of Master Of Vtec Group
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Originally Posted by iamhappy46
Correct.
Short intake pipes make more torque(and therefore power) at high rpm
Long intake pipes make more torque(and therefore power) at low rpm.
So, please explain why, on the several cars I've experimented on, the whole graph is shifted upwards when going from a short ram to a long ram intake?
We're talking about a torque curve that maintains the same shape, but is shifted upwards from 2krpm to cut out.
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Originally Posted by ginganggooly
So, please explain why, on the several cars I've experimented on, the whole graph is shifted upwards when going from a short ram to a long ram intake?
We're talking about a torque curve that maintains the same shape, but is shifted upwards from 2krpm to cut out.
Slim you know my feelings on these text book tradesmen .All the theory in the world makes jack shit difference when you sit on the dyno for as many hrs as we did testing the intakes and if you think we are going to sit here and tell everything we learned they are dreaming.
Regards Dyno Dave
Buddyclub Australia
Member of Master Of Vtec Group
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Originally Posted by ginganggooly
So, please explain why, on the several cars I've experimented on, the whole graph is shifted upwards when going from a short ram to a long ram intake?
We're talking about a torque curve that maintains the same shape, but is shifted upwards from 2krpm to cut out.
It might help if you detail the test conditions, and how/if any tuning was involved.
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Originally Posted by ProECU
It might help if you detail the test conditions, and how/if any tuning was involved.
That would require effort... and i'm oh so lazy these days.
But anyway-
The engines involved are: 4age 20v silvertop, B18c2, B18c7, B18c2 w/ CTR slugs, pr3 head and ctr valve train.
- Tuning was performed by DynoDave.
- Each car had a short ram style intake
- Each car was tuned with the short ram intake attached.
- Immediately after tuning, each car had several power runs with and without an extension pipe, (approximately 60cm in length).
Whilst the improvements varied from car to car, in EVERY case, there was a definite improvement. At no point was there any overlap in the (power) graphs between long ram run, and short ram run. Peak increases were up to 6kw at the wheels.
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This is very interesting discussion from a tuning & engine dynamic perspective.
I rekon the above method is flawed IF there wasn't further tuning AFTER the extension pipe was added.
You'd expect a higher velocity intake charge so the more power would have been as a result of a leaner mixture.
I dont know where dave tunes these NA hondas in terms of a/f, but I can assure you they like to be lean!
Maybe if Dave feels generous enough, he can comment on my theory, im sure the test was more involved than detailed here.
Originally Posted by iamhappy46
Short intake pipes make more torque(and therefore power) at high rpm
Long intake pipes make more torque(and therefore power) at low rpm.
I agree that the above comment can not be generalised, simply because of crank and rod sizes which govern piston speeds at each rpm and crank angle... so there is more at work here, than just intake charge velocity.
Last edited by ProECU; 23-10-2006 at 09:53 PM.
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AFR depends on the engines compression ratio and cams they are using, I normally use between 12.5 to 13.5 to 1 but again as you know Evan many things will change with different engines.All the testing we did with intakes they where all retuned after the mads to gain the best results but all made gains before tuning as Slim had said.We spent around 60hrs on the dyno over a few months doing testing so he does know what it takes to design the intake on a Honda Vtec engine.
Regards Dyno Dave
Buddyclub Australia
Member of Master Of Vtec Group
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nice, yea i thought there was more to the test conditions and never really doubted the results...
one thing however, ...60mm is that the magic number? what about the turn radius into the throttle body.. was that experimented with also?
Originally Posted by DynoDave
AFR depends on the engines compression ratio and cams they are using
just to qualify this for those who dont understand why, higher compression equates to free "mechanical" octane, which allows a leaner mixture and generally less timing to make power.
The cams govern the dynamic compression ratio of an engine in motion and can either bleed or aid compression, depending on its phasing and cam specs.
Last edited by ProECU; 23-10-2006 at 10:10 PM.
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also tried this to a makes EM1.. lots good throttle response and intake volume lots louder.. but didnt think it made much diff in power.. as his pod was not shielded or nething when it was on pipe.
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Originally Posted by ginganggooly
That would require effort... and i'm oh so lazy these days.
But anyway-
The engines involved are: 4age 20v silvertop, B18c2, B18c7, B18c2 w/ CTR slugs, pr3 head and ctr valve train.
- Tuning was performed by DynoDave.
- Each car had a short ram style intake
- Each car was tuned with the short ram intake attached.
- Immediately after tuning, each car had several power runs with and without an extension pipe, (approximately 60cm in length).
Whilst the improvements varied from car to car, in EVERY case, there was a definite improvement. At no point was there any overlap in the (power) graphs between long ram run, and short ram run. Peak increases were up to 6kw at the wheels.
You forgot 1 engine dude B16B as well was tested and tuned using power FC.
Regards Dyno Dave
Buddyclub Australia
Member of Master Of Vtec Group
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