I was thinking of buying a CAI and began looking around and after looking and looking and wondering what the difference between all the aftermarket items were I started to think more of what was in my car already. So this is what I would really like to know and as always I appreciate all your input.

• Does anyone know what the air flow metrics are on the OEM intake?
• Is there another filter that works with the OEM that would increase the air intake and if so by how much?
• For any aftermarket CAI that you may recommend do you know what the air flow is for that particular model?
• Googling CAI in general seems that replacing has no or minimal affect on fuel consumption and just a mild gain of 10+ HP

2010 Grand Sport
LS3

 

• Does anyone know what the air flow metrics are on the OEM intake?What engine are you talking LS2or LS3, your question is very vague.
• Is there another filter that works with the OEM that would increase the air intake and if so by how much?Yes, there are a couple of options here K&N there is a blue Attack one and a few more that I'm forgetting.
• For any aftermarket CAI that you may recommend do you know what the air flow is for that particular model?This question depends on who you ask, I have a Halltech(LS2) but others like the Vararam, Airraid, Callaway and the list goes on.
• Googling CAI in general seems that replacing has no or minimal affect on fuel consumption and just a mild gain of 10+ HP

I would say this figure is about right depending on your modifications.

 

OEM air system already out flows the motor needs on a stock motor.

A true cold air intake will pull air from the out side of the engine bay, not still from the front of the engine bay like the stock system. Hence KN and Airaid type systems are not CAI systems. Bluntly, for the system to be a CAI, it has to draw air from the other side of the lower shroud.

Hence if the car is standing still, no new cool air coming into the engine bay to cool the bay back down, and the OEM system that pulls it air in from the engine bay will start to pull in the hot engine bay air instead. The hotter the air drain into the motor, the more the motor will retard the timing, hence less HP.
Note:If you are drag racing with a hot engine bay and the stock system, then it take a few second for the car to take in cool air to cool the engine bay back down once the car starts moving, and adjust the timing back to no retard/no HP loss.




So a true standard CAI does not make more powder, But holds the possible power that the engine can make, if it was not pulling in the hot engine bay air to cause a timing HP lose instead.
To add here, some after market system wreak havoc on the MAF sensor, since they flow air through/past the MAF less than ideal. So some much in fact, that you have to have the car re-tuned to just deal with turbulent air flow problems past the MAF sensor.

Now the kicker, and CAI can be resolved with the stock system, by just wedging the lower shroud open with a gap so the Stock system can draw in out side air instead.



And to take it one step farther, the intake manifold on the LS-3 engine is pretty good, while the intake manifold on the LS-2 is not so good due to the way it was produced/is robbing the stock motor of about 10HP.

So you can either have the stock LS-2 intake ported for around $350 to clean up the flaws/ solve the turbulence problem and gain back the 10HP it is robbing, or you can go with something like a Fast 102 for over a grand, to gain back the same 10HP on the stock motor instead.

Again, the heads on the stock motor are only sucking in so much air, so with the turbulence problem solved, only about 10 HP to gained. I bring this up since on mod'd motors where the air needs are higher and both the stock air filter systemand the intake manifold become choke points instead, then higher flowing air system and something like the fast 102 will make large numbers over the stock system that became a choke point instead.

As for a tune on a stock LS-2, LS-3 stock motor, will pick up around 15hp (not matter what air filter system is on the car). On a LS-2, with the intake ported to clean up it flaws, and a tune, then will pick up around 25HP instead.

So again, the stock air filter system is already out flowing the stock motors needs, and getting a system that flows better, does nothing for the motor since the stock air filter system is not a choke point.

 

A real cold air intake is ALWAYS a Plus. Even if you are sitting still you are pulling in air that is cooler than the air under the hood. I would rather put 70 degree air into my motor than 220 degree air any day of the week.

 

Simply put, the Vararam with no filter will produce the most power and the stock intake with the Donaldson filter will produce the cleanest air. Everything else is a compromise between those two.