Air box up-grade. Opinions.

[96740]

What are your experiences with a particular airbox up-grade?

Factory Motorsound, Fabspeed, Etc..

Any increase in HP? or just better sound?

[Tom W]

HP increase? I really doubt it. The drilled cover does sound better (louder) at wide open throttle.

[meares]

the drilled cover does sound GREAT!!!! i just did it..... it gives about 25 "EAR" wheel horsepower......DAMN does it sound good!!

[Cobalt]

I have the fabspeed cup box and RMB sounds great but I doubt it helps with power. It might open up some mid range response but negligible at best. Did I mention it sounds great.

[Newsboy]

Definitely a nice sound increase. You don't neeed to buy an aftermarket cover, just drill out the airbox yourself. I have approx. 20 1" holes in mine.

[96740]

I'm going to try and find a stock airbox, or at least the cover. And drill the holes.

I've looked on eBay, but none right now. If anyone has one or see's one, give me a holler.

[meares]

call dcAutomotive at 252-977-1430 and order it from them

[meares]

Cobalt....what is an RMB? thanks

[Cobalt]

Originally Posted by meares

Cobalt....what is an RMB? thanks

Sorry "Rear Muffler Bypass" also known as G pipe.

[meares]

is that the little "C" looking pipe? is it loud?

[Cobalt]

Originally Posted by meares

is that the little "C" looking pipe? is it loud?

Yes it is. It is louder than stock but sounds great. Has a nice growl and sounds like it should IMO. It does not resonate like some after market exhausts and is legal even at Lime Rock by a fair amount.

[meares]

is it tough to install?

[Cobalt]

Originally Posted by meares

is it tough to install?

Easy as they get unless the bolts are rusted solid maybe an hour. Once you have done one maybe 25 min. It also saves 25-30 pounds off the rear end.

[meares]

i guess just loosen the bolts that hold the muffler on and replace it with the pipe? is the muffler on the passenger side?

[Cobalt]

Originally Posted by meares

i guess just loosen the bolts that hold the muffler on and replace it with the pipe? is the muffler on the passenger side?

Passenger side. IIRC here are 2 bolts with spacer sleeves towards the back of the muffler that are removed. There is a clamp from the primary muffler with a sealing ring. Loosen this and remove the muffler. Then loosen the clamp and exhaust pipe from the muffler. Attach the exhaust pipe/tip to the G pipe and using the sealing ring from the primary muffler install and tighten. It takes a little playing with to get it adjusted properly. Be sure your about 1/2 inch away from the bumper all the way around.

I know it is a bit basic but once your under there it will become clear.

[meares]

thanks!!

[96740]

Drilled out the Air box today similar to these pics. Very nice sound boost. Not much more than that.

Thanks everyone for the advice and feedback.

[bigchillcar]

i have the k&n air filter..does the same thing..more growl.

[tshih]

It has been documented that drilling the top cover of the airbox does increase the engine's output by 6-8HP in a 993 engine. Bruce Anderson reference. The stock opening where the air goes into the filter is a bit restrictive and the engine has more volumetric efficiency that is achieved by giving the intake more holes to suck air into the engine. The HP claims from K&N and others are mythical in the 964 and 3.2L engines which are restricted by the older barn-door air flow sensor intake after the air-filter intake. Those airbox holes only make more noise and probably has no increased in HP (unless chipped).

[bigchillcar]

don't know of any horsepower gain from the k&n air fllter in my 964 (car is cyntex chipped), but the sound is very nice with it. if that's the only benefit i'm okay with it, and it likely is.