Porsche Enthusiasts Club Forum

Hi,

What's the feeling about air filters, should I stick with stock or are the K&N or Pipercross ones any better ?

Thanks

Don't know about Pipercross but K&N is a no-no.

Many cases of oil from the filter contaminating the MAF hot wire. Apart from the running problems this causes, the cost of rebuilding the MAF is much more than any saving from longer change interval of filter (a trivial saving anyway).

I expect there will be people leaping to defence of K&N here, but it's been de-recommended by some of the real experts on 928s/MAFs which is good enough for me.

I now run a standard paper filter. I used to run a K&N for years. There is no performance difference apart from maybe being quiter with the standard one.

The only think I miss about the K&N was the black seal looked better than the orange one.

For sale SH K&N to suit 928 (needs re-oiling) 20 pounds plus post.


Stephen

Hi

I run a K&N and have for years....

The problem with them about damaging MAFs is caused by RE-Oiling AFTER 50,000 miles...its not caused by the normal oiling which they come with....

So....do not reoil and just change every 50,000 miles....

Its a matter of personal preference, but personally I like them....

All the best Brett

What performance gains are there from a K&N filter. Is it possible to fit an actual induction kit, such as one like a K&N 57i?

There are some impressive looking 928 induction kits availiable from the states.
Expensive though.
I would send you a link but my internet is playing up.

Stephen

Hi

Performance gains...maybe just maybe 1 to 2 hp.....

Induction noise sounds better to me personally, plus you can leave a K&N in for 50,000 miles or say 5 to 6 years and save £30 plus a year for that time....

Induction kits...hmmm to be honest I am not a fan of them on our 928s as we have MASSIVE twin air intakes already...to find any major gains you would have to get rid of the air filter casing etc....

You will find a LOT more extra power in the exhaust system....X-Pipes for example are worth around 10 to 20 hp.....

You could always try Nitrous lolllll.....

Pick your increase figure....50 hp....100 hp....150 hp...etc

All the best Brett

These photos show the shark charger induction kit from 928 Specialists.
https://www.928gt.com

There are lots of bits to be had from the states,

Stephen

The rest of the information from the site showing the claimed gains backed up by dyno graph.
Darn expensive but looks pretty. There are many more cheaper ways of getting that power as Brett mentioned.




Prototype Dyno test run info:

928S4 with X-pipe with high flow cats, RMB, AFR. No tuning or changes made between stock filter dyno run and our TwinAir Filter System dyno run. 11.4 RWHP Gain and 15.8 Rear Wheel Torque gain!! Even more gains can be had with Fuel Tuning via remapping LH computer or adjusting fuel pressure.

Testers report noticeable Throttle Response Improvement, especially in the lower RPM ranges.

Also, what's the little cylindrical air filter at the front of the engine for ?

Good question .. I havent found mine yet, but bought one on-line in error and dont know where it goes.
Havent looked that hard to be honest yet, but its not jumping out at me!

Hmmm, on mine it is the first thing you see when you open the bonnet.... between the air intakes, directly inline with the oil filler cap

Black circular thing at very bottom right of this pic http://www.20thstreetauto.com/cars/car267/engine.jpg (no not mine )

I know where it is, but not what it's for

you know i dont think i have one .... will look in the morning

Hi Guys,

I think you will find it is a pollen filter.
If changing it watch the 'lid' it can fly off and fall into the fan blades.

Stephen

Can't wait to go and check it out now!