Drilled Air Box Cover??? Bling or Zing?

[hbkramer]

I have a spare airbox cover and was thinking of opening it up.


Does this mod effectivly improve the air flow or is it all BLING? Before I do it (it is a spare),I was looking for the facts and the DATA.

Thanks

[zotman72]

My 74 911S racecar came with one and undrilled cover for "regular" use. I use the opened up cover for my races as part of my "Unfair Advantage" package. But then, there is a KN filter deployed too.... And it is a 2.7.. Next time we have a dyno day in Denver, I will test it for a discernable difference. YMMV

[NoLift911]

Noise only - but a cool noise. Might add a bit little bit if you have a chip and sport muffler - nothing you will notice though...

If you do mod it, make sure you remove the whole face of the cover so that you just have the clips and frame left to hold the filter in. Drilling holes is kinda ridiculous IMO.

Table saw works wonders for this...nice and clean, takes about 2 minutes.

Note this applies to a 3.2 - not sure what motor you are talking about.

-Jeff

[kach22i]

You will hear more sound, and that may be more fun for your ears .

You will have to change $25 air filters between oil changes.

A more interesting project would be snorkeling it to get cooler air from the outside - perhaps from each end.

[sammyg2]

Bling. No benefit besides increased intake noise.

[pgeorgeson]

Not to hijack the thread, but is there any real performance advantage (or any other advantage) to a KN filter over stock?

[livi]

If you remove the major part of the cover, would you not risk a higher level of contamination of the intake air ?? I must have been designed that way for a reason (cover).

Gee, I should have done that BEFORE I changed my rear shocks.

[hbkramer]

The Dyno DATA on K/N(via BMW motorcycles) suggests no appreciable hp increase and a greater risk to the throttle bodies due to k/n letting larger particulates get through the filter.

[dfink]

I tried the holes in a spare cover I bought. Could tell no difference not even really a noise difference. I put the original cover back on to stay stock. Anyone interested in a drilled cover let me know.

[KobaltBlau]

bling.

on the K&N filter, they don't filter as well as a Mahle. any small performance advantage is negated by that, for me. With a CIS car, there is plenty of filter area, so I don't think there is even any performance advantage. Probably the same with a 3.2, but I can't say for sure on that one.

[carnutzzz]

Originally posted by hbkramer
I have a spare airbox cover and was thinking of opening it up.


Does this mod effectivly improve the air flow or is it all BLING? Before I do it (it is a spare),I was looking for the facts and the DATA.

Thanks

I'll buy your spare cover. Then use the money on something that actually adds power! ;-)

[Nine, Frau!]

I have an air box cover from a Club Sport Carrera on my 88 Targa. The sound is awesome. The holes are large, and they're drilled by factory trained Porsche techs's; so they are extra round. he he......

NF

[RickM]

Originally posted by Nine, Frau!
I have an air box cover from a Club Sport Carrera on my 88 Targa. The sound is awesome. The holes are large, and they're drilled by factory trained Porsche techs's; so they are extra round. he he......

NF

Do you have a part number for the CS cover? Also, would you be able to post a pic? Thanks!

[livi]

Yes NF, pics please !

Of both the air filter cover and the rest of the CS.

[sammyg2]

On a CIS engine, completely removing the air filter cover will not increase the power. Neither will a K&N.
According to BA, removing the cover AND the filter will net a couple of HP but running with no filter would not make your engine happy.

On any engine, you need to find the bottleneck and work on making it flow more. the filter on a CIS 911 is not a bottleneck. It will flow air just fine, the air flow sensor and to a lesser extent the throttle body are the bottlenecks on the intake.