blake

Timely thread. Just last week, my mechanic (specialty is GT3 Cups) convinced me to change to a K&N filter in the GT3 because of my altitude at Miller Motorsports Park in SLC (4500 ft.). He noted that the K&N will let the car breathe better...

What do you guys think? (And the last time I hears of "stoichiometry" was in high school chemistry...)

-B

Rob S

I'm interested in this topic too, and will likely be doing some dyno testing of a K&N system on my car later this year. I've read all the threads on this -- there are many who dismiss this as anything from a waste of money to risky for your engine (i.e., filter oil hurts the MAF, dirt gets into the intake, etc.). I have no data yet, and no basis for an opinion. However, the fellow I'm working with on this has done some testing, and he has notes and dyno charts showing that with his custom exhaust, the K&N adds a maximum of about 10 hp to a 996 GT3, especially in the upper rev ranges. If that's true, it's nothing to sneeze at. He said that there are much smaller gains (a few hp, maybe) when the K&N is installed on an engine with a stock exhaust. He said that if the stock airbox is modified (instead of using the K&N), in conjunction with his exhaust, there are gains as well, but they are smaller -- on the order of 5 hp, again in the upper rev ranges. And he has data...

But I'm going to collect my own data and will report on it. If anyone has a K&N system lying around that they'd like to lend to the cause, please let me know. From the press its gotten here, I suspect that there might be a few that have been stashed on the shelf -- next to the snake oil. If the results are favorable, I'll likely buy a new one. But in the meantime, if you have one I could borrow, I'll pay shipping each way and will report on the results. Please PM me if you'd like to participate.

BTW, from discussions with K&N, they firmly stand behind their claim that there is not and has never been a problem with fouling of the MAF from filter oil. They believe that there's no foundation for these concerns and they claim to have done a lot of testing. Again, I have no data, but there are a lot of K&N systems on all kinds of cars around the world, it would seem odd to me that the Porsche GT3 would be adversely affected if so many other cars are (apparently) not affected. Furthermore, there is MAF cleaner that can be used periodically to keep it clean if there are concerns. And as for the adequacy of filtration, it is surprising to me that a K&N fliter would be substantially different from a stock air filter at maintaining intake tract cleanliness. It's a big company that's been around a long time, primarily making air filters. I would think that with proper installation and maintenance, the filter should at least...filter the air.

But let's first find out if the filter adds any performance.

Rob
04 GT3 Track car

SH || NC

If any of you have a Durametric, you can quickly tell I think whether or not this, or any filter, ‘let’s more air in’.

Install stock filter; go for a drive; do a WOT run; log the data; look at the MAF signal while data

Now install the K&N, and repeat is the same drive to the best of your ability, and review the data.

The MAF can only transmit a max signal based on a flow. Even if you let in more air, it’s still only to send the max signal.

I’m thinking in very basic terms – you EEs will get what I’m saying are hear the more technical explanation in your heads.

JohnnyGT3

those filters that eliminate the big ugly black box just look cool.. I kinda want one!!!! but I installed a Mahle filter yesterday. 25 bucks...