Intake track length and size

[BlitZ]

All i know is this :

you'll actually make more hp if you rev high enough. longer tubes will make more power at mid-low rpms, but the shorter ones will make more high end.

anymore info .. better yet online calcualtor?

[Jingers]

longer pipes = less response?
shorter pipes = high response?



i would have thought longer pipes created more high end.

Case in hand on the dc5 aem cai/etc is more focused on high end whilst grouppem and mugen is more focused on mid

I think if i was going to spend trouble to do my intake again i would first make sure i have a MUCH larger airbox. This provides a larger amount of readily available air for the car to suck in and then enough piping to provide the box with fresh supplies of air. If you are handy with fiberglass this might be a good option? Alternatively abit of sheet steel work would help too.

[GoldCoastDC5R]

Its more so to do with the Intake Manifold, longer runners give you better low-mid range while shorter runners give you more top end.

I guess the theory is the same for intakes as well???

[BlitZ]

yeah.. i see the contridiction... The above comment was ripped from honda-tech, i got no idea hahah

[GoldCoastDC5R]

longer pipes = less response?
shorter pipes = high response?



i would have thought longer pipes created more high end.

Case in hand on the dc5 aem cai/etc is more focused on high end whilst grouppem and mugen is more focused on mid

I think if i was going to spend trouble to do my intake again i would first make sure i have a MUCH larger airbox. This provides a larger amount of readily available air for the car to suck in and then enough piping to provide the box with fresh supplies of air. If you are handy with fiberglass this might be a good option? Alternatively abit of sheet steel work would help too.

I wouldn't say ITB's are high response, they are very good for making high end power tho, and they are the shortest of intakes

[Jingers]

yes but it also has 4 openings instead of one. Id rather perfer to compare apples to apples.

Also intake/exhuast side of things isnt that a different matter all together?

Instead of comparing exhuast headers lets compare all the intakes and draw an approx conclusion from that

[BlitZ]

quads give more mid end than top end from understanding.. could be wrong ehre though

[Jingers]

But also from understanding changing the velocity stack length on the quads give powers in different powerbands. You might want to consult eric as his done alot of research on this.

[chuck]

There was a thread on Ozhonda where DynoDave and Adrian from Toda talked about verified dyno results from changing intake pipe length. I know the longer intake pipes were making more power... but can't find it...

Here is a semi useful one.
http://www.ozhonda.com/forum/showthr...=intake+length

Kinda related, in this thread in Type R forum on honda-tech velocity stacks added to intake arms (AEM CAI etc) were adding 5+HP at the wheels.
http://www.honda-tech.com/zerothread?id=1864717&page=1

[GTR RECARO]

the longer the pipe the smoother the delivery shorter piping causes turbulence in extreme cases

[wonton]

longer the pipe (injen) cause less response on low RPM

[tinkerbell]

depends entirely on dynamic compression ratio and engine breathing ability, eg headers/exhaust/cam timing...

the only way to know what *perfect* inlet tract length is is on the dyno...

then it will only be *perfect* for a particular RPM range...

won't it?

[TODA AU]

longer the pipe (injen) cause less response on low RPM

That's actually a myth. The opposite is true.

[Howie]

I think the intake runners are supposed to act like tubes that carry air. Like musical tubes these air carrying tubes can set up standing waves, i.e. like a musical organ. The air flow to the cylinders are interrupted at a certain frequency from the opening and closing of the valves.

Each length of pipe as its own resonant frequency, and a frequency in which the longest wavelength of the standing wave can fit in the tube. The setting up of the wavelengths is advantageous to the aspiration of the cylinder because when the valves are opening at that right frequency, the air pressure wave comes into the cylinder at that precise moment, aiding in the filling of the cylinder.

So like musical tubes the longer the tube the longer the wavelength and thus the lower the frequency. The lower the frequency means the slower the valves open and close for this standing wave to occur. The slower the valves means slower RPM.

The reverse occurs for shorter tubes. Short wavelengths -> high frequency -> high RPM.

This is why variable intake length geometry is employed on engines from BMW and Ferrari. I can't remember which exact engines use it, but I did read a article where the intake runners were spiral shaped and the internal core was moved up and down its axis to create the desired length at fast enough speeds to match the climbing speed of the engine RPM range.

This is not considering other things such as the cam timing and exhaust.

That's how I understand it anyway....

[CK1]

this has nothing to do with the length of an intake pipe.... but an intake pipe with the ID of say "x" square centimetres and a airbox with the internal volume of "y" centimetres cubed, would produce more topend (based on the hondata airbox mod) compared to an intake pipe of the same ID, but with an airbox which had the internal capacity of "1/2y" centimetres cubed?? i would image that an airbox of half the internal volume would give greater response but compromise on topend power... with that in mind, if you had an intake pipe that had the ID of "2x" and the internal volume of the airbox was "1/2y" centimetres cubed, would that mean that at the same time u would get better response as well as better topend???

does any of that make sense? and if it does, would any of you agree? i have a feeling that i could be way off though....