K&N vs. stock filter dyno test results

[chuckr]

As promised I did a back to back test on my 83SC on a dyno.
I got a 174hp\175ftlbs on a stock Porsche factory filter
I got a 167hp\171ftlbs on the K&N
OK... before everybody get overly excited last year I got
183hp\181ftlbs with a K&N.Since last year all I have done is retard my timing.One other member of the club(hcrpca) in a 82SC
got 167hp with stock filter and173hp with K&N in todays testing.
We did the test using our two cars for comparasion, his 82 got better with the K&N my 83 got worse with the K&N.We are at a loss to explain this.I think that my timing has something to do with this and the fact that my K&N is a bit dirty.I believe in the dyno but the operator says that he has seen the same car get different results depending on the weather and other factors.
The Austin Hill Country Region Porsche Club does this once a year,we get a discount rate of $45.00 for two runs on a DynoJet Dyno.This year we had 26 Porsches show up.I think I'll go clean my K&N and maybe re-adjust my timing as see what happens.

[Glasgow 911SC]

Interesting results.

Since stock and original engines can produce both more and less hp than they're supposed to I guess your results aren't that bad.

[jwetering]

I'm assuming that the measurements were made at the rear wheels, and then mathematically corrected to give hp at the flywheel..no?

I sure wish there was a place we could get dyno'd locally (vancouver canada). I wonder if the PNWR Porsche Club does anything like this?

Anyway, thanks for that data...I'm going out on a limb and say that this guys dyno is +/- 10 hp from run to run and that there is actually no difference between the stock and K&N filters. I've been a proponent of K&N for some time, but i never got the seat of the pants improvement in the 911 like i didi in some other cars I've owned. My understanding is that the inlet is not the bottleneck in SC 911's....it's the exhaust.

cheers

[chuckr]

After talking with others that did this, I think the order has a little to do with the results. The owner of the 82SC did his first run with the stock filter and his second run with the K&N.I did my first run with the K&N and my second with the stock paper filter, the second run numbers were higher in both cases.These are at the rear wheel numbers, to get flywheel number add 15% to the rear wheel number.