Jim Michaels

I have no reason to suspect anything on your list, and have no reason to question the numbers you got. What I question is the logic in concluding that the 13 additional measured hp must be due to the removal of the plate just because that's the only thing you know about that changed between the first and second set of runs. To ensure that it was the plate removal that caused the gain, one would have to demonstrate that the hp measures return to baseline when the plate is put back in place, and again return to the higher hp figures when it's again removed. This would be the classical ABAB experimental design that should be sufficiently convincing to most. I own a Cayman too, so I'm hoping that your previous findings are replicated, but I won't let wishful thinking lead me to conclude that removing the plate leads to a 13 hp gain without the replication. Does this make sense to you?

PorscheDoc

Oh, of course it makes perfect sense, but when someone does that on a dyno, someone else will still dispute them. I go through it every day, on every single product I test on the dyno. I stay as neutral as possible on performance products, because quite frankly I don't care if they make power or not....if it doesn't make power, I don't put it on a car, and I will find something else that does work. I was a huge pusher of 3" exhausts for the 951, thought it really was the cats meow for performance gains. I tested a 2.5" (no cat) versus a lindsey 3" (no cat) on the dyno last week to finally show people what it would make.....it made a whopping 4hp and 7tq over the 2.5" catless system...for $850 bucks. Turns out most of the gains come from deleting the cat, not from the extra .5" piping. No big deal, I learned something new and added it to the knowledge base. Sompe people were happy with the results, of course, some people were not.

Ken says he can remove the plate in under 20 minutes, so I would be more than happy to do the tests over again with and without the plate on the same dyno, same tank of gas, and within about an hour of each other. And that goes for whatever tests you guys want done, just let me know what you want to see tested, and I will make it happen (of course if Ken is ok with it, since it is his car). And I do so from a completly unbiased standpoint, it is of no concern to me if something makes power or loses power, it is more important to you guys who own the cars as to what makes power, which is obviously what we are shooting for.

Typically I live at the shop 7 days a week, but this month is allergy season so am I pretty exhausted by the time the shop business hours are gone for the day, so I can fit him in, it just make take a week or two to get the testing done.

928Buyer

Doc,
I have no reason to doubt your dyno or your abilities in running the tests and I have no reason to doubt that in this instance the removal of the air baffle plate produced a HP gain as measured by your dyno. There was one other change with the car, it had a clear bra installed. If I were a betting man I would bet that the increase was due to the air baffle and not the clear bra. As you say, people will doubt you no matter what you tell them. No one on the Cayman Club site is forcing anyone to do the modification, the information is simply offered as what it claims to be, the results of one individual's modification and dyno testing of that modification. If others want to do it, great, if not that's great too. I don't see what the hang-up is. If Jim has an issue with the mod or the test shouldn't he be discussing it on the site where the testing was done?

Jim Michaels

Yes, he should have posted his concern where the test results and conclusion were first reported. Unfortunately, due to an incompatible browser, he cannot post there. Ken (K-Man S) is aware of this.

Helo Driver

Download "Mozilla Firefox" for free. It's a web browser. Just type that into google and then download it. It takes five minutes and you can then go to caymanclub.net.

Shane

smlporsche

Jim-

I understand your academic skeptisism and I suggest that when Maury comes back up from Florida we all go to the dyno shop in Salem and do before & after runs on the same day. That would surely put this question to rest.
BTW, after knowing what I had to do on the S2 to get 9 additional ponies I also believe this mod needs futher verification.

pcar964

yeah that's right, Porsche put a restrictor plate that dropped 15bhp just for the heck of it...

NJ-GT

Not to jeopardize 997 Carrera sales and performance figures. Nothing new from Porsche these days.

Just wonder that back in 2000, the same engine without today's technology was running 300Hp.

Doug&Julie

Sadly, that's true...

Jim Michaels

The 3.4-liter engine making 295 hp leaves plenty of room for future hp increases. If Porsche started the 3.4 out with 330 hp they wouldn't have much room to grow, and the aftermarket tuners wouldn't be licking their chops as much either.
Pcar: Someone has already suggested that Porsche put the vent "restrictor" plate on to reduce hp, and that Porsche's first Cayman S hp upgrade would simply be to remove the restrictor plate. I give Porsche more credit than that in terms of looking toward the long haul.

pcar964

I seriously doubt they put a restrictor plate on the Cayman to reduce power. They could have been more conservative with their performance numbers if they were afraid of stepping on the 997's toes, but they certainly wouldn't physically reduce the power with such a draconian device.

Helo Driver

I agree with pcar. Porsche isn't going to simply reduce the power of the engine by placing a restrictor plate in front of the intake knowing that consumers can simply remove it and get an extra 13 ponies. I don't buy that for a second.

I HOPE that removing the plate really does add 13 WHP. I doubt it though. Yes, I've seen the dyno charts. I don't know how to explain it but I do know this: If something seems too good to be true, then it probably is. I'll wait for further testing or for several more dyno results before I remove the restrictor and expect a 13 WHP gain.

Shane

Doug&Julie

OK, I'll agree the restrictor point...but I firmly believe that the 3.4 motor in the Cayman S was engineered to a hp number just to be between the Boxster S and the 997.

Helo Driver

Doug,

I don't think anyone is arguing against you on that. It is a fact that the 3.4 motor was engineered to be exactly between the Boxster S and the 997 base model. Not only the engine but the 0-60 times, top speed, and every-single other performance number. It's so perfectly inbetween it's almost sick. It makes me wonder what the Cayman could have been like even with the same 3.4L motor just with tuning done by Porsche.

Shane

Jim Michaels

My guess is that Porsche's 3.4-liter could have been tuned to make about 330 hp. I assume that if BMW can do it, Porsche can too. But getting more hp out of 3.4 liters was not their aim. As Shane said, their goal was to fit the Cayman between the Boxster S and the 997, and they hit their mark. As long as the Cayman remains the mid-model Porsche, we can expect it's price, power, and performance to remain midway between the other two. As long as the current trend of hp increases continues, all three models can be expected to gain power. There probably has been some talk at Porsche about rising gas prices, however. The last time gas prices spiked this high in constant dollars (1981), Porsche introduced the 944 economy sports car with only 142 hp. But my 295 hp Cayman already gets better gas mileage than my 944 did, so maybe we shouldn't worry about Porsche shooting for better fuel economy over better performance. I wouldn't be shocked to read about a hybrid Porsche, however.