dominant1

I've been looking at aftermarket cold air kits and their hp claims and I'm wondering what makes them so much better then the stock unit. Is it just the fact that they flow more air or is it the tune that goes with them that adds the extra hp or both. The Roush intake claims a 17hp 9 ft pounds of torque increase. Steeda claims their new unit with a custom tune can get you up 25 hp / 20 ft pounds of torque increase..I just ordered an x3 tuner with a custom tune from Brenspeed, they haven't emailed me yet for my setup specs but I will probably have it set up for the stock intake. If i upgrade to an aftermarket unit i will have them email me a tune...I'm leaning towards the new Steeda intake since it has the highest hp claims. Its not much in the looks dept, but with a custom tune its got the guts..

references:

http://www.steeda.com/products/2010-...air-intake.php

http://store.roushperformance.com/detail.aspx?ID=775

Lax07

Roush and a lot of other makers are saying at some point on the horsepower and torque curves you will find these numbers, unless it says peak horsepower. Remember this is also crank horsepower and not what you will see at the wheels. Our intakes in these cars flow pretty well, and as another member said if you throw in a K&N filter into ours with a tune you will see about the same results and spend a lot less money. I know when I had a VW the reason why we upgraded our intakes was because the factory air box was so restrictive. Generally the factory does this to keep the sound down, because when you put on a cold air intake or ram air intake, they both increase the cars sound under the hood.

Nuke

First of all, if you believe the advertised #'s, then you need to go change your diaper and go watch cartoons. Let us know when you're old enough for the real world.

Secondly, you could leave the stock airbox on and load a custom 87 octane tune and STILL pick up about 10-15 RWHP on an '10. It's not the CAI that's doing much; it's the tune. The CAI simply compliments what the tune can add (as do a few other mods).

On the 05-09's, the CAI & tune added 20-25 or more REAL RWHP with the CAI providing only about 20% of the power gain and the tune providing about 80%. With the '10s slightly tweaked stock tune, the CAI & tune combo will only add about 10-20 RWHP with the CAI providing more like 40% and the tune 60%.

Lastly, all of the tune-required CAI's will provide equivalent HP gains. Be more concerned about a quality tune since those from AM, SCT and others that don't write their own tunes typically provide lesser RWHP gains. But since you chose Brenspeed, you're good to go.

Nuke

After rereading your post, I don't believe your question has been properly answered.

Our engines breathing is restricted by the stock air intakes. Adding the CAI helps it breathe but the PCM's programming cannot adequately adjust for the change and will typically allow the engine to run lean w/o intervention. A properly written tune will adjust various engine operating parameters to allow closer to peak performance along with other parameters that enhance the cars overall driveability.

dominant1

First of all, if you believe the advertised #'s, then you need to go change your diaper and go watch cartoons. Let us know when you're old enough for the real world.

Damn nuke that's a little harsh for a guy just asking a question about aftermarket cold airtakes...thing is i'm 46 years old...

Nuke

LOL! Sorry, man. I'm 54 and tend to be a just a LITTLE blunt and mean in my old age. Yeah, it gets me in trouble but I've had bosses back-off because they're too afraid of what I was going to say sometimes so it sort of works for me. hehehehe. No REAL offense intended.

swat 79

Unfortunately for us '10 owners, we get less from the cai. It seems like its closer to 80 percent tune, 20 percent intake than anything else. Where as the 09's could really benefit from the intake/tune, which is much closer to a 50/50 power gain, at most 60/40 tune to intake.

bustacrab

I'd really like to see a data comparison of with and without a tune with the same fuel octane. (comparing a lower octane fuel without a tune is not a fair comparison with a higher octane WITH a tune). Maybe they already have this on this forum somewhere, if there is I'd love to see it.

Also, physically, a CAI can improve flow by increasing the diameter of the pipe HOWEVER increasing the pipe diameter too much will decrease the velocity of the flow and lead to losses. So it's really a matter of optimization and trade off. Which it seems to be the case that FORD optimized their CAI's pretty well based on data presented by a member on here.

Nuke

My comments in red.

bustacrab

"You can put whatever bigger intake on you want only the car can only TAKE so much so more isn't better"

this is why i said that increasing the diameter too much would actually increase losses, so you can't just make a bigger pipe and get gains out of it - this is one of the reasons why I have my questions about adding after-market CAI just because they have larger diameters. so we are in agreement here.

A larger diameter reduces losses due to friction (Darcy–Weisbach), but too much of an increase in diameter lowers the velocity and would lead to losses. A smoother material would help also.. this is all fluid (this includes gases) mechanics