Fabspeed Motorsport

In this video Fabspeed owner, Joe Fabiani, goes over Fabspeed's Cup High-Performance Air Box Cover that improves airflow into your air-cooled 911. These air box covers are for all Carrera 3.2 1984-1989 Coupes and Cabriolets, 964 1990-1994 Carrera Coupes, Cabriolets, and RS Models, 993 Models Carrera Coupes, Cabriolets, and RS Models.

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2swoosh

cool! why not just remove the airbox completely and use a K&N filter? any dyno documentation to prove the 6 hp gain? thanks

tjb616

Have you improved the fitment for 964?

revolve40

I've had no fitment issues with mine. Purchased at the end of last year.

tjb616

I had one 3 or 4 years ago that was given to me because the person who bought it prior couldn't get it to fit. I couldn't get it securely fitted to mine either. Hopefully your experience is a sign of an improvement.

JasonAndreas

If the design hasn't been updated, look at the front of the motor with a mirror and/or camera or when the engine is dropped. The factory clamps deform the FS cover which pinches the air filter. Leaving a small space for unfiltered air to enter the engine.

bb964

I remember reading many years ago that such an open airbox modification by itself on an otherwise stock 964 actually looses few HP due to warmer air getting into the intake. The gooseneck is apparently designed to draw cooler air from the rear decklid opening. Cup cars are tuned differently and there it's by design.

Same goes for K&N filters by themselves - no measurable performance increase and a drawback of reduced filtration/small particles getting into the engine

Fabspeed Motorsport

Hey Jason,

Have you reached out to our customer service department? We have not had any leaks on our shop cars so we'd be happy to look into it.

Shoot me a PM or email Service@Fabspeed.com

Fabspeed Motorsport

We did rework the cover a couple of years ago based on community feedback!
If you're in the area shoot me a PM, I'd love to have you swing by and we can give you an inside look.

JasonAndreas

We tried that 15+ years ago.

spartansix

I don't buy the warmer air theory -- maybe if the car is stationary and you're running it hot on the dyno, but when the car is moving and the engine fan is spinning fast (especially with the engine undertray removed) the turnover of air in the engine compartment is so fast that the air has no time to heat up. I dont think the gooseneck is for cold air; if it were it would reach to a vent, not merely closer to the decklid grille

bb964

Some discussion/Dyno runs here regarding HP:

https://rennlist.com/forums/964-foru...irbox-lid.html

No_snivelling

Seems easy enough to prove or disprove. Get a wireless kitchen thermometer and mount the probe near the airbox air intake and go for a drive while monitoring the temperature in real time.
I will put that on my long list of things to do, once my 964 is back on the road.

JasonAndreas

It has been done before with something slightly more accurate and having a better response time. Same with the undertray...

No_snivelling

Cool. I will have to look that up. Was it published here on Rennlist?