2.5" tubing for intakes (solution possibly)

[impRSa01]

I am new to the board so obviously I havent read everything you guys have been talking about on the subject of intakes. Reading all of the current talk on intakes makes me think of two things that have made the WeaponR, JC Sports not work so well under 3500 rpms.

1) Tubing was too short to even create velocity.
2) 3" tubing was used in these intakes not helping air velocity also.


My question is, what do you guys think about an intake that eliminated the stock air box, was 2.5" in diameter in tubing size, and sat right behind the front left headlight??

Ya it would still suck in cold air, but the two issues I had addressed that may be affecting good air scaveging could be solved. If this has already been tested or proven wrong, feel free to imform me. I always want to learn something new. Just thought I'd throw this one out there!

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[HondaH8er]

Larry Ganz (www.imprezars.com) has already done a cold air intake in the 2.5" and 3". Here's the 2.5" (on my car ):
<IMG SRC="http://www.i-club.com/ubb-files/image_uploads/GanzFlow.jpg" border=0>
Here's the 3" on Larry's site:
<IMG SRC="http://www.imprezars.com/images/version5/rev5intakeenginebayclose.jpg" border=0>
Great intake, by the way! His retains the stock airbox, preserving the low-end torque, and you can't beat the price!

edit: P.S.- Welcome to the club!


[This message has been edited by HondaH8er (edited February 22, 2001).]

[8Complex]

It's not the velocity that is the concern. Velocity really changes the high end of the powerband more then anything, while the pressure drop is what kills the low end.

With the stock intake plenum you have a small reserve of air that is pulled from first, so you get enough air to run the engine well down low without dropping the pressure too much in the intake plenum causing it to have to pull air harder through the tubing, creating torque. When it does have to pull harder (tube intakes) you get much better high end with a loss of low end because the engine has to put so much effort towards getting air in the first place.

What kinda intake is a good trade off? Larry's is ok. Mine is pretty good too - http://8complex.mwic.org/intake/

[impRSa01]

8Complex

I get what you are saying about the engine having to work harder, but isn't that where the velocity comes into play. Think from my point of view. Either way, the air has got to first start to go into your intake no matter what setup you have. If the engine is sucking it in always, why would air be left around in the intake for under 3500 rpm situations.

Isn't the intake just like the exhaust. I know for the exhaust, that the best exhaust has the lowest amount of backpressure possible without losing it completely. Why would velocity matter for the intake when if the tubing is smaller it will get to the engine faster for low rpm cycles. And I don't mean so small that the engine has to over work to get the air in like you were mentioning. Just a tube size that is practical, yet aftermarket in design.

Thanks for all the help 8Complex.

P.S- I checked out your design. Looks like an N/A intercooler. Wonder if you would see more gains with an aluminum N/A intercooler setup?

[scoobiejosh]

Cobb Tuning uses what looks like less than 3" pipeing on his intake. Maybe for the reason of keeping velocity higher.
<IMG SRC="http://www.cobbtuning.com/images/ct-cai2.jpg" border=0>
judging by the fact that the reducer is right after the filter, and the piping is about the same size as the throttle body, it seems around 2.5". Just an educated guess though.

Josh