I can't agree with that necessarily. I've heard Porsche says engines vary in output by as much as 15hp -not surprising- but the other big assumption you are making is that Porsche rates their engines truthfully. Many underrate their output these days. New Z06's are estimated to really produce 530+ hp, not 505.

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996 GT3 lower control arms at all corners
997 GT3 front sway bar
Tarett rear toe links
Quaife TBD
DMC harness bar/G-force harness

I base my statements on facts and not hear say so I'm making no assumptions. They do not vary by 15hp but rather 5hp on the CaymanS 3.4.


Best

Sorry- you have only assumptions, and the big one is that Porsche's horsepower rating is accurate, and the second is the percentage of losses between the engine and the wheel. 12%, 15%, it's all a guess, or an ASSUMPTION.

Secondly I don't buy 5hp- that's only 1.7% variance over thousands of engines. 15 hp is 5% and that sounds more reasonable. But since your info isn't hearsay, I'm sure you have an authoritative document to point me to.

__________________
996 GT3 lower control arms at all corners
997 GT3 front sway bar
Tarett rear toe links
Quaife TBD
DMC harness bar/G-force harness

I think you will find that the variations between the engines are nothing compared to the differences between the all Dynos out there measuring such power.

I wonder if its possible to get statistical data from Porsche on actual engine power and production spread and put this issue to bed finally. Or is that too much to ask? *smacks self over head*

As an engineer who likes verifiable numbers, I'd love to have these three pieces of information- and love to see documents to back it up. If PCA-TECH really has some, that would be a good thing to post.

__________________
996 GT3 lower control arms at all corners
997 GT3 front sway bar
Tarett rear toe links
Quaife TBD
DMC harness bar/G-force harness

I don't have a document to prove it, but at the factory tour they told us all engines are tested and must make the minimum horsepower or else hey are discarded, torn down and they find out why they weren't making the power and if it was the fault of a 3rd party supplier they get a refund from that supplier, in other words they had performance guarantees in their contracts. They said some engine may make more than the minimum, but typically that was no more than 5-10hp more max. Again, this was spoken word at the factory and my recollection. Unless you can get Porsche to turn over all of their testing numbers I doubt anyone outside of Porsche will ever know for certain. Let's not bicker over something so trivial....

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K-Man S
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I'd second what K-ManS just posted above. I was told the same thing on a factory tour in 2003. All engines are dyno'd on a stand at the factory prior to installation in a vehicle. The factory said the engines must make AT LEAST the stated power at the flywheel, or else they get torn-down and rebuilt. The factory allows itself up to a +10% variance in flywheel horsepower on the high-sde, but 0% variance on the low-side. There was something about German law requiring that they designate it as a different type engine if it varies by more than 10% + or - from official specs, and the factory self-imposing the extra requirement that no engines underperform the stated power.

This could all be tour-publicity-hype, but I did see/hear them dyno'ing engines in stands right there on the factory floor and they seemed to have about 6 little rooms all set-up for this purpose, so it seems credible to me.
Q

Just wanted to let everyone know that my Cayman S, an '07, is bone stock along with the Porsche factory sport exhaust. I just had it dynoed with the car showing consistent 276 & 277 hp at the wheels, and, with the IPD plenum the only mod on the car. Since putting on the plenum the car has had an 'awakening' with extremely linear power everywhere along the powerband. It continues to make me smile every time I start it up. I have no complaints with the power to weight with this car. Thanks...

David Mecey
Venice, CA.

meceyman;
Did you Dyno before as well? We would like to see your Dyno charts.

A 10% tolerance window would be too much. 265 to 330? I dont think so.

295 -0HP, +10HP sounds about right. That would then make the mean power of the distribution curve at 300HP with a tolerance of +/-5HP. So less than 295 being a reject. Making the factory spec min power at 295 as it is now. That would make the design target and actual manufacture power at 300HP. A nice round number.

This variance is a result of a european law that states all engines must be within 2 percent of advertised horsepower. That is why Porsche's hp #'s have always been conservative.

Todd

Dear 4X4, I'm not sure how you got the 330 number in your reply to me as I never mentioned that number in my post. When the car was dyno-ed, two runs, the first was 277 the second 276 and change. And to address the hp figures released by Porsche, I'm sure they try to make the motors produce their advertised hp. I've been reading a lot here about the stock motors producing somewhere in the neighborhood of 250 rwhp fairly consistently. If you take that and determine the 295 hp stated by Porsche, that equates to some 18% loss. Sounds plausible to me. Anyway, the plenum works for me very well. Best hp gain for the money I think. I come from a BMW lineage where I spent major $ to get a few hp here and there. The plenum gave me what I wanted out of my motor. More linear pull and felt torque and still with the stock everything else onboard. Love the car guys.

DJM