L92 OLDS

I'm building a custom Cold Air Intake for my L92 swap. The factory 90mm throttle body OD is 4" so my entire system including the elbow, tubing and filter are all 4" ID. I plan to use the factory blade style MAF that came from the Escalade but wondering if going with a larger diameter tube will throw off the calibration. I'm pretty sure that the factory intake system is a smaller diameter. Can anyone with tuning experience help me understand if this is something to worry about? Reducing the tubing size and creating a restriction is counter intuitive and I don't want to do it unless I have to.

1989GTA

I made mine out of 4" aluminum tubing. That is 4" OD with .062" wall. How much power are you expecting to make?

Edit: I would also add to use as few bends as possible and using the largest radius bends that will fit. That will help with the CFM of the air flow.

LilJayV10

iTrader: (39)

Anytime you change the location of the MAF or the diameter of the tube the MAF should be recalibrated. Some engines are more sensitive than others.

L92 OLDS

That's encouraging. Did you install the 4" tubing without a tune? My engine should dyno around 430-450 RWHP.

1989GTA

The CAI was part of a package of things I did so I did get a tune. A 4" CAI as you described can supply plenty of air so you have nothing to worry about at your horsepower level. I am at 512rwhp with mine.

L92 OLDS

Thanks for that info. I sent the ECM off for a bench tune and my tuner is using an Express van base program to modify. I hope I can temporarily drive the car without too much trouble.

jmd

iTrader: (4)

The erod instructions call for mount in the middle of a 6" long straight section of 4". No reason that isn't workable.

L92 OLDS

Thanks for that info. I'll start out with the 4" tubing to see how it works.