Why 2" is better than 3", Intake diameter wars...

[David Coleman]

that's pretty muchly my setup. works well

[RayRay]

I've got the same setup, it works pretty well, reduces the "heat-soak" effect.

[fuzzyboy]

will the ractive filter fit on the vaf with out a coupler ? [img]shrug.gif"%20border="0[/img]

[David Coleman]

yes

[Ramdao]

Mine is working fine w/3" tubing so far, I feel a drop of power when the engine heats up the aluminun intake tube do to the cooling fan when it blows all that hot air. what I´m about to do is to wrap it with an a/c insulating foam tube, those ones used on the low side of all home A/C´s + an intake by-pass valve because is the rain season here in Venezuela.

[Geezer000]

Whats wrong with having the VAF vertical? Just askin.....<BR>Gravity I'm guessing. Prolly less power a higher RPM's due to thinking less air is comin in.<BR>Am I close?

[Shades]

One day I will understand all this tech talk to install something on my stock car. I've seen all different air intakes and such... cone filter, ones that go down to the bumper... confuses me which one is good.<P>All that stuff sorta makes sense, me thinks that if I keep reading this it'll make sense one time around.

[tk1138]

This post has some interesting concepts. <P>Someone was mentioning a venturi; I would NEVER put one in an intake. This will only slow the air down. An intercooler is a much better idea if you want to cool the air, but it's probably net zero power unless you're boosting. <P>The calculations are for just a 3" vs. 2" section of pipe. If the pipe sections change then a lot is dependant on the shap of the transition, the new section diameter, etc. It's probably hard enough to model that only a proper test would be accurate.<P>Also, the caclulations don't take into account the length of the pipe. Since the flow of air into the engine is not a simple volume per time, but has an oscilating part, it would be benificial to have the length of pipe such that the resonant frequency is just above the botem of the power band. This is very dependant on the air density and a number of other factors, so I won't even tempt people with a calculation. <P>The velocity stack sounds like a good idea. I'd like to see a dyno of something like that.<P>Physics is so cool<BR>tk1138

[ZUNE MX-3 Gs]

For what I know, I always supposed that a venturi just before the throttle body helped to speed the air entering to it. What´s your point on saying that it slow them down? What is a velocity stack? it is half a venturi?

[pelado]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by ZUNE MX-3 Gs:<BR><STRONG>For what I know, I always supposed that a venturi just before the throttle body helped to speed the air entering to it. What´s your point on saying that it slow them down? What is a velocity stack? it is half a venturi?</STRONG><HR></BLOCKQUOTE><P>A velocity stack may resemble half a venturi and that's the point, it's not a venturi if it's not complete. A velocity stack's mouth is wider than the TB or port it is attached to and therefore the air will speed up.<P>A venturi is only used when you need a low pressure point, such as in a carburetor to cause fuel to flow or as a measuring device for air flow, water flow, etc. Venturis have a a short converging part where the interior necks down to the smallest diameter. It is here in the throat of the venturi where the air is moving fastest and the pressure is lowest. After the throat there is the longer diverging part where the diameter gradually enlarges and the air velocity drops back to the same speed as before the venturi. Thus, the venturi would neither speed up the air nor slow it down.

[fuzzyboy]

is it necessary to reset the ecu when you do a custom intake to accomadate for the changes in air flow. [img]shrug.gif"%20border="0[/img]