Planet 9

L30N_CS · #1 06-20-2009, 06:07 AM

this is a graph of my before and after having my custom exhaust fitted. ( ive done a write up with pics of it in cayman and boxster mods forum)
my car has no other mods yet apart from de-snork
i used noble motorsport as there rolling road is in a sealed room so temperature is maintained whatever time of year
the first run (standard with de-snork) was very surprising and im sure your all going to say its wrong as the bhp seems very high but after 20ish runs they were all very close average was taken of 314.5 bhp and 246.8lbft torque
my friend who has just brought the new direct injection cayman put his on at the same time and his made 318.5bhp (should be 320bhp) so dyno seems to be reading corrct
after having my custom exhaust fitted i took it back and the new figures came out at 322.5bhp and 255.3lbft torque.
i know the figures seem high but i wanted somewhere that would be consistent to see how the exhaust improved my figures
if my mate hadn't of put his on aswell i would say theres no chance my bhp is this high standard
what do you guys think?

**K-Man S** · #2 06-20-2009, 07:15 AM

Keep in mind your charts are showing an estimated BHP (brake or engine horsepower) not rear wheel horsepower. Since Porsche says BHP should be 295 stock and yours was 314 stock I think you've found as others have as well that Porsche has been sand bagging on the Cayman numbers all along and that the real BHP of the stock Cayman engine is 10-20 hp more than what Porsche advertises.

What is important is your gain and your gains seem to be pretty much across the whole RPM range which is good and were a max of 8hp for a catback exhaust which is actually a little on the low end as I've seen catback exhausts achieve 10-15 hp gain on average.

It would have been nice to get rear wheel hp numbers and compare those, but I don't see anything "wrong" with these results. Enjoy!

**jake** · #3 06-21-2009, 05:24 PM

I think the reason your car in stock configuration makes more bhp than the factory spec (295 bhp) lies mostly in what's happening above 6000 rpm. If you look at most dyno plots on a stock vehicle, the torque starts to roll off at 6000 rpm and the hp flattens out above that point. On yours the torque doesn't roll off until about 6500 rpm and the power continues to increase above 6000 rpm until it reaches a peak up higher over 7000 rpm.