Seems like we're finally getting some good data on this and it is surprising me. I've heard from a couple of seemingly reliable sources that the JR makes 1-2 horsepower and a couple of other seemingly reliable sources that (heresy) the K&N loses 1-2.

What's up? After all of these years is there a new sheriff in town? Why?

 

to me, the problem with that conclusion based on different cars is just that, they are on different cars... not to mention different conditions between dyno and that 1-2 hp is well within the margin of error on a DynoJet.

-Shing

 

This may be true about the JR gains but in the case of the K&N losses the comparisons were made to the same car with the stock filter.

 

I agree that 2 HP is "noise" on the dyno. Try doing back-to-back runs with zero change. You'll see that much variation or more.

 

When I did my dyno runs, I did them all in one session with back to back runs comparing a stock filter that was slightly dirty vs. a brand new k&n. I did three runs with each setup and the k&n was consistantly 1 hp behind. Each group of three runs yielded nearly identical results. The k&n definitely made a VERY slight loss of hp. between .5-1 hp, but there was definitely a slight loss. We did enough runs to verify that.

 

[QUOTE]Originally posted by The Reverend
[B]When I did my dyno runs, I did them all in one session with back to back runs comparing a stock filter that was slightly dirty vs. a brand new k&n.

 

we did over 15 runs (3 different sessions), plus a third party filter showdown by VA S2K with the JR filter, all these runs showed a consistent 2.x HP and torque gains. it's on paper, but it's up to you whether or not to believe it. in a recent German TUV testing, JR filter tested to filtering 2.8 micron particles at 99% flow efficiency. K&N managed 10 microns at 98% efficiency. though numbers never speak for themselves, it's worth considering when shopping for filters.

 

The only noticeable thing after replacing my filter with Comptech's was a bit more noise and the ability to clean and reuse the filter. I will be installing their supercharger soon - need to get the car broke in - and hope this $70 filter will be a replacement for the one that comes with the SC. I've not compared them yet.

 

I think the actual claim is that the filtration gets better (at stopping dirt), not that it flows better.

 

Could someone explain to me how changing the air filter in a car could increase the power that is transmitted to the wheels? The only way this seems possible is that perhaps the aftermarket air filter either restricts or allows more air to pass through the air filter thereby changing the oxygen to hydrocarbon ratio. This would seem to imply that the current air/fuel ratio is not at its optimal point. Perhaps we should proceed in that direction. It appears to me that if an aftermarket air filter increases the amount of air into the engine, it is also possible that it increases the amount of particulates per single pass allowed into the combustion chamber. Please advise.

--Kaptain Insano