Chuck Harmon

Porsche uses a cone style filter on the GT-3 race cars

Jay H

Porsche has that stock air box "horn" there for a reason. That horn brings in cooler air from the rear deck lid. Look through your rear deck lid (if you can) and note where that horn is. Porsche doesn't do stuff for nothing...

I have an '84 3.2. The PO put in a K&N air filter (square filter, fits in stock air box). I bought a paper filter (good quality OEM) and replaced the K&N since I'm not comfortable with all I've read on how the K&N lets larger particles in. The K&N had about 1000 miles on it before I replaced it with a paper filter, so it probably was still pretty clean.

I noticed a 1 point drop in gas mileage immediately after changing out the air filter from the K&N to the paper filter. I averaged out the mpg I was getting over several tanks and compared to what I had been getting for mpg for 3-4 months prior.

There is zero change in how the car performs.

Jay
90 964, 84 3.2

Steve Weiner-Rennsport Systems

LOL,..Indeed, they do and as Jay pointed out, its an integral part of the intake system.

Please remember that these engines get totally rebuilt every 50 hours to the tune of $ 24K,...

Jay Gratton

Nice read everyone. I have a K&N on my '85 and that is because the PO put it in. I will really have to try the switch in the spring (the car is away sleeping now). Best wishes - Jay

Jay H

Randy is correct on this point. Porsche didn't cut the factory air box until the 964 models and found only 1-2 hp gains on these specific 964 models. The 993 was the first model with a "motor sound" option available as a regular factory option that included a modified air box cover. So, there is nothing really gained other than increased sound when you drill the 3.2 air box cover.

lewis9113.2

The placebo effect with a K&N works for me but the question I feel is dust particles.

If you drive in an overly dusty environment (eg, freeways or on a race circuit even) then use the paper stock filter (as this does the better filtering job vis-a-vis K&N, BMC et al).
If you drive in a clear air envirmonment, no reason why you can't use the K&N.

Just don't over oil it; this can lead to a mucky AFM.

Stick to the stock air box with the panel filter you were asking about.
But for more fun, drill said air-box with a series of inch and 1/4 holes which will give you a more pronounced induction type roar. However some say this will reduce the effectiveness of the stock air box....

As usual with Porsche, stock is usually best.

J. Brinkley

if you want to use a K&N type filter I suggest attaching one of these to it as well.
decent power, decent sound

Tetra84

nice bit of info here, i guess my next question would be, where could i get a spare airbox cover should i want to try and drill holes in it? I dont want to drill up the only one i've got.

Jay H

You might want to try to source one from the aftermarket or eBay. Porsche will sell only the entire air box assembly and that's over $250 the last time I checked...

r911

or a junkyard

use a hole saw - cheapest ones will be fine

KC911

You might want to post a WTB (want to buy) over on Pelican...I picked one up (already nicely drilled) for $40 a while back.

Keith
'88 CE coupe

Tetra84

nice, thanks.

ron mcatee

Partsheaven in Hayward CA, Oklahoma Foreign in Moore Okla, and other salvage lots sell them.

Tetra84

I just did a drive around town with just the airfilter duck taped to the filter house w/o the filter cover on to kind of get an idea of how it would sound, and it was great! I dont know if it was just me, but I also seemed to notice a better throttle response, the car seemed to accelerate faster too, but that might just have been my imagination.

theiceman

Red Green would be proud ...