if you were making an intake...would you get 2.5" tubing or 3" tubing for a b18c1??? i heard 2.5" has higher air velocity..but people tell me to go 3" but never why...i need some pros n cons on 2.5" and 3"


[Modified by tr4il, 8:22 PM 1/9/2002]

 

can anyone post why 3" over 2.5" or vise versa?

 

I would like to hear more two since I want to change my whole intake system to somethitng that's actually gonna make power, from the manifold to the filter. Anyhow, I've been hearing that if your car is making power around 200whp and above, then you want 3in. Other than that, you want 2.5. But the thign that confuses me, is that you see these turbo cars with like 2-2.5in intake as well so

 

someone car smart...please help...3" or 2.5" for a b18c1?

 

You want an intake with a cross sectional area with roughly 25% greater cross sectional area than the TB. I don't have time to calculate this for you, just keep in mind that 25.4mm=1". Area of a circle=radius x radius x ~3.14

For this application (because the intake and TB are both circular) you can just multiply the TB port diameter times 1.25 and convert it into inches.

 

here is why 3", and motor was only a B16

 

What setup are you running,B16's usually pull 135WHP so there must have been more mods than just an intake?

 

is it hard to join 3" tubing to the intake mani on a b18c1, b16a2, or a skunk2?

 

?????

 

no