John Miles

no, no def 25hp....
...ok...ok... I don't always remember to use a tongue in cheek smiley in my posts
J

Smokin

Better airflow = Less HP???

AJKOK1

John, i think you are being conservative. Surely not only do you get the benfit of at least 25 bhp, but you alse get a significant weight loss with all the holes instead of plastic. I reckon the net effect has got to be 30+ bhp.

I also find if you make a "Whooosh" sound just as you press the accelerator, the car definitley feels more responsive.

Al.

btw. seriously for once, great website John.

joey bagadonuts

I have a cone filter on my car and was aware of the over-oiling issue. So, the last time I cleaned and oiled it, I stuffed the inside with newspaper to catch any excess. Then I gave it a thorough spray with oil and let it stand overnight.

The next day, I noticed that excess oil had run down the sides of the cone's exterior. However, when I pulled the newspaper out I did not find any oil stains on the paper. For those unfamiliar, the K&N oil is red and would've been easily to detected.

I won't offer any conclusions but I'm not quite certain that over oiling one of these filters is all that easy to do. $0.02

JasonAndreas

Even if you over-oil the K&N filter there are no consequences if you are running the stock air meter (AFM), there is no sensor to foul. Aftermarket MAFs and 993s can have the problem but not a stock 964.

Chris M.

Well here's my version. I opted for the possibly reversible approach ala Garrett but after hearing that howl I won't be reversing anything. I tried it with and without the "snorkel" and there's no difference so I just left it on.
There's no change in first gear even up to redline but once you get moving, all other gears past 4000 sound great. It seems you've got to be going at least 50 to get good sound. So if you're cruising around 70 in 5th and stomp on it you'll really hear it. Same goes for going 60 in 4th, etc...what a growl!



c

IrocMan

We did precise acceleration tests with airbox modifications. Air box is not so restrictive on the 964 and there is only a few thing to wing using a more direct system (invert throttle and do something similar to the 993 heater inlet).
Making holes in the airbox just helps the engine to breath hot and low pressurized air instead of fresh air from the upper grid. We measured that the acceleration is a bit lower with the holes !

So, OK to use a 'high perf' filter (ie K&N) but holes just offer a nicest sound.

JasonAndreas

IrocMan

something I agree with