Guys,

Here is my opinion of today dyno test day. First, a special thank you to Greg at RSS and the crew at GT Pro. Greg went all out to show us his wonderful skill of hosting and prove his product is a winner. We, some are volunteers some are guests at the event were treated with courtesy, respect from RSS and GT Pro. Everyone had a great time with the crew and with each others. There were no shortage of food, drink and fun.

Also, I got the chance to meet a bunch of great folks who took the time, energy to be there for the dyno test. There was Simon, who came all the way from Sunnyvale (northern Cali.) to volunteer his 996 SC for the day. And Peter from O.C with his clean white stock 02 996 with 55K miles and pulled a strong 285HP without the plenum and 301 with plenum. Others with their 997S, 997, 996, Cayman were there to do the test. One of the volunteer was so satisfied that he purschased the plenum along with a complete Cargraphic exhaust syst. header/cat/muffler and installed there.

All in all, everyone who volunteer his car was very happy and satisfied. They all purchased the plenum for their cars with special price and free installation. The proof is now in writing and into history book. This will show the critics that the plenum does produced HP gain on 997, 996 like RSS has claimed.

The result for both 997S and non "S" was similar with 18-21HP gains.
The result for 996 is also closely match with 997 with 17HP.

Greg, I am happy to say your plenum is a proven product. Congratulation!

Below is the link to my raw video. Warning, I'm terrible with taking video and editing.
http://www.youtube.com/watch?v=bwiBJt-raYI

 

The video was fine, It was almost like being there

I think the Plenum Dyno Day needs to be taken on the road.

Thanks for the update.

 

It looks like a great deal of time, effort and expense went into making a great day .
I enjoyed watching the video and have been very pleased with the plenum in my Turbo .

 

great to talk to some of the folks there today, although i dont have a Pcar, it was still quite cool talking and meting new people, while checking cool automotive aftermarket products!

 

I am not able to view your youtube video, can you explain the detailsof the test. The AWE test talked about cooling the car to the same temperature as well as a number of other factors. Were the same standards applied?

 

The plenum has proven to be effective at producing nice performance gains...

Case Closed!

 

Congrats to RSS! Outstanding effort to defend your claims and your products. Now I dont feel like an idiot anymore for putting on a plenum!!! Always thought that there was extra power!

 

I thought I saw a thread that said this had no gain???????? I forgot who but I thought it was RSS??????

 

there was a no gain thread. That is one of reasons why rss did the dyno day yesterday.
Congrats to those that attended and bought after proven gains on their own cars.

 

So, did the dyno operator inform everyone that you automatically pick up some added power when you reset the computer.....AND NO OTHER CHANGES HAVE BEEN MADE or did they leave that little bit of info out and just reset the computer AFTER the new plenum was installed?

 

tatally confused I must have missed something on the threads. Please explain. Is it a gain or crafty dyno operation

 

It would be necessary to do a blind study. The dyno operator should not have known what car had what, or the order which they were presented. Still, there would have to be big #s of cars tested to be statistically significant.

Thanks for the effort.

 

Why is that? They dyno'd a 996 that put down 285hp without the Plenum, 301 with.

Christian

 

Peak power gain is non existant as a result of the new plenum. It is an old trick to convince the customer that the computer needs time to learn the new parameters of the mod and therefore the computer must be rebooted. This reboot provides immediate power gains for a short time on most modern engines. Simply rebooting the computer on a stock engine will often show a higher peak hp for a few runs with no other changes.

The intake does nothing to effect the readings of any sensors at WOT from what they were with the old intake. So what is there to learn?

Peak power cannot be changed using only an intake (in any engine) unless the change increases the volume of oxygen to the cylinders. In an NA engine, this new plenum does not increase oxygen volume. The benefit of the plenum is in the change it makes to the power curve and this is what is felt by those who installed it. The driver then uses this change in the powercurve as confirmation that his car has more peak horsepower. Anytime you change the intake system design, whether it is a smaller or larger throttlebody, intake length or diameter or the shape of the intake, you will change the power band. Either moving it upwards or downwards. Obviously, any such change will be felt by the driver. However, peak power will remain unchanged.

You'll notice that the OP showed effectively no gain in peak power after he changed to the new plenum. Dyno runs on the same car over and over again with no changes regularly show differences of as much as 5%. His change was a measely 1.3%. He had a greater chance of recording a larger peak hp increase if he has simply rebooted his computer rather than installing the plenum.

Again, I am not stating that there is not a benefit from the new plenum as changing the powerband is often preferred by the driver. However, there is no increase in peak power.

 

Not to rain on anyones parade, but normally intake and exhaust mods should have time for adaption. As 1999porsche points out that there usually is a gain after the install of intake parts or such and from just resetting the computer. To see what the true gains are, I would go back in a month or so and redyno on the same dyno and correct for enviromental differences.


Dave