Hey, don't shoot the messenger! This was the only 3rd-party test I could find and I thought it might prove useful in the absence of anyone having their own cars dyno'd.

I'm as sceptical as the next man when it comes to BS claims from aftermarket tuners. I honestly don't believe that a plenum can make 27BHP (or whatever the manufacturers claim) on a 997S but 11BHP? This is only 3% - a tiny difference - and there is a logic to how the part works. Maybe this is realistic?

Furthermore, why would an 'independent' 3rd party deliberately falsify their results? I'm not familiar with the web site in question (other than I Googled it)! However, if you look at some of the other reviews the site has done, they're not afraid to put in print that a 'performance' mod actually loses power. The results shown for the 997S are an overall increase in power of ~10% (again not much in real terms) from headers, cats, mufflers and plenum - quite a lot of mods. And all catalyser-equipped cars benefit from a freer flowing part - OEM cats are usually 600-cell and very restrictive.

I personally think the results stated are much more plausible than claims such as +39BHP (from a well-known exhaust manufacturer) +27BHP (plenums) and +25BHP (many ECU remappers). These, I agree with you are 'BULL S#$T!!!!!'

Ian

 

very interesting thread...all I know is that for the amount of money people spend on the plenum, headers, ecu re-program, 200 cell cats, mufflers and so forth ...that is a lot of track days were you can improve the performance of your car by starting with the driver.

 

+1

 

I agree that track days are the best way to improve the performance of our cars, but I am curious to see what people had gained from the addition of the Plenum.

 

Which of course has nothing to do with this thread or it's parent thread "RPM plenum sale". I want to thank those who responded to the group buy and provided feedback to those board members who were openminded and interested in a plenum purchase. You were a help to me in making my decision to do the mod. You were instumental in bringing the price down for others. I am happy with my investment. It gives me pleasure to have the car feel stronger and to have individualized my 997. Works better for me than,say, red seatbelts, wings or fairings, etc, but to each his own. To the nay sayers and complainers I say "get your own life". I think these threads have served their purpose. Again thanks Gerry

 

I'm happy that you're satisfied with your purchase. I'd just like to point out, though, that asking for evidence and dyno results is a sign of open-mindedness, not closed-mindedness. It's closed-minded to be angry that people want evidence of improvement or to wish to stifle discussion about the measurable benefits that the plenum (or any bolt-on) truly provides.

 

I regret that your level of proof and that of some others has not been met. It is clear that it never will be met. If you really care, contact the manufacturer, purchase the product, try it youself and report back. The truth, I fear, is that you and a few others really do not care but have found an effective trolling technique. Don't feed the trolls !

 

That would be killer, just picked on up on ebay....

 

+++++++++11111111111 evidence and dyno results

 

I honestly have no idea how you've come to that conclusion. In my view, the expectation for proof of the manufacturer's claims is reasonable and has yet to be met. The goalposts have not moved one inch.

The manufacturer (and by proxy the vendors) make a specific claim about horsepower gains. Absolutely no evidence exists to verify these claims, or even explain how they arrived at the number claimed.

Think how easy it would be for the vendor or manufacturer to end this debate. Then ponder why it has never happened. It's a reasonable concern.

I'm in the market for a Plenum -- if it does what they claim it does. I'm not a troll I'm a prospective customer.

 

You know what I propose the following and I WILL do it if I can get a vendor to agree to the following: I will dyno my 997 c2s with its current mods as a baseline and then dyno it with the plenum. I will pay for the baseline dyno run if the vendor or manufacturer pays for the run with the plenum. If it makes power...even 5whp then I will keep it. If it makes less than 5whp I kindly ask for a full refund. Anyone care to take me up on this offer?

 

Oh I know...me too! I am with ya but this whole thing seems like a big government cover up secret deal.

 

Did Gpjli call the plenum an "investment"? I call it a purchase.

Renhaus in Sarasota has a new Dyno and I know the guys there and my 997S is stock except for Fabspeed muffler cans. Send me the Plenum and I will do the dyno before and after test.

 

I spoke with a sales person today and they gave me a discount on the Plenum to cover the cost of the before and after Dyno runs, if I don' get any gains then they will refund 100% of my money. I have not agreed to purchase it yet, but I was told that I will not get the full HP gains as I have other mods, the full gains will be acheived on a stock car...so I was told.

I am planning on going to a dyno with a freind that has a stock 06 C2S that we would use as a bench mark for my car. I may take the plenum offer and try it. I will definitly post the results if I get to the dyno.

 

Care to share which shop this is in the event that you decide to not go through with it? I would purchase it if I could get the same offer.