EricL

I am starting to get confused about the CAIs.

Before jumping, let me ask a question or three.

1. Has anyone ever tested the HP output of our engine with stock air box, but with the air filter removed (Yes, I know that this is bad for the engine [dirt is bad]) using a dyno?

2. Has anyone ever put a short (like 3 inch straight pipe (or slightly upward bent pipe) with a really top notch/high flow K&N on our engine and checked the HP (then checked the HP with the K&N removed).

3. Do most of the systems use the same size tubing?

4. Do any of the systems use a ram effect by using a non-constant diameter pipe?

I'm asking these questions for the following reasons:

1. I know cold air makes for more power, but the articles I've read in the "popular" compact car mags are testing the CAIs on dynos without cold air.

2. More bends in the tubing makes for more power loss.

3. More restrictive filters lower volumetric efficiency (make it hard to flow lots of air).

BUT,I'm not sure about the effect of length and diameter of a CAI on a engine (like ours) where multiple cylinders are sucking through a single throttle plate/plenum. (I have played and experimented with HP effects of pipes with one throttle per barrel.

So, it looks like we already have a cold air system -- (Yes/No)

Does anyone have any test data or magazines that back up explain how the power was gained with a CAI? (For example, did the reviewer try removing the stock air box filter) *or* did they do any flow tests on the filter that they used on the CAI tested)?


Is there tuning or other factors that come into play?

Experts or others -- your thoughts please!


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2001 Satin Silver Cl-S w/ NAVI

• Mud Guards
• Wheel locks
• Toyo 235/45ZR17-97W* T1S Proxies on Stock 17" CLS wheels
• Gtech 1/8th tank 40F ~=6.1
• Zaino magic

FDao

EricL,

Prbably I can shed some light to questions #3&4. In my days of 4cyl tuning, I've done a fair number of research on CAI systems for my Lude Si. I came to the conclusion that the diameter of the CAI are somewhere between 3-3.5" for all systems. The only system that incorporate some kind of ram-air effect was the ICEMAN intake system that started at 3" and taper down to 2.5" at the throttle body, thus matching exactly the TB opening. Even with this setup, the HP difference between the AEM and ICEMAN was 2-3HP peak. This was shown by SCC as you may have read. This particular article did not test the car on a Dyno, but rather a system similar to GTECH, but more complicated and accurate.

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Frank
01-S White/Parchment
Comptech Sways & Springs