I don't know if this means something, but I do remember to get the Plenum to work properly, you had to drive about 50 miles so the ECU could adapt to the increased air flow.

If this is correct, has AWE considered/driven these miles between the dynos?

 

[quote=C2S4ME;1805172]I will give it a try. Go back to post number 71 on page 5 of this thread and look at the third chart down titled Mass Air Flow Rate. It clearly shows that the RSS plenum does not flow air as well as the OEM plenum, particularly in the midrange you talk about. We all know that an internal combustion engine is nothing more than an air pump and one of the best ways to increase power is to increase the amount of air and fuel that can be passed through the combustion chamber.

quote]

I went and looked and your explanation above seems to imply this but I am stumped on some things.

Look at this back to back photo post which was on the 997tt board which shows the stock part next to the plenum . This BTW is what led me to buy the plenum.
https://www.6speedonline.com/forums/...ghlight=plenum

How can this design restrict the flow?

 

[quote=yrralis1;1805234]I believe it is deputy dog that has posted a dyno showing improvement in his TC'd engine installing plenum.

 

Awe states in their comments that the engine adaptation at full throttle takes place in a few runs on the dyno. They say it takes longer at partial throttle on the street.

 

I don’t know the answer to that but the test results says that it does.

It may not be the plenum per say that is restricting air flow but the intake/exhaust that remains OEM both before the plenum (air box/air filter) and after the plenum (intake manifolds, air flow meters, cylinder heads and exhaust headers). I can’t explain why a part that looks as well made and supposedly well engineered as the RSS plenum flows less air than the cheap looking OEM plastic plenum but the test results says that it does. It never made any sense to me that a modification midway through the induction system would net substantial power gains unless the OEM plenum was a purposeful restriction much like a restrictor plate used in some sanctioning racing bodies to help lower power output.

I would bet that when Porsche makes modifications to the engine no matter how trivial they run both before and after dynamometer runs and other forms of testing to make sure the changes are actual improvements. I seriously doubt they would let their engineers use the infamous “butt dyno”!

 

I would consider doing an experiment on my car also, but for the expense and hassle/time. I have the headers and the x51 box. I never dynoed my car before. Are the results repeatable? If I went back to the same place, same operator, similar conditions are the results gonna be the same? Even if the are off 3% that could translate to 10hp. If it is 10 hp more than you would be elated and assume the product made the difference. 10 hp less or the same and you would be upset.

 

The Porsche "stock" parts are aimed at balancing performance and warranty . A few bolt on parts have the Turbo flying at a very different rate than stock and even when I had the NA car I found that modding was the way to go over stock .

I speculate that Porsche could have released an 11 second Turbo quite easily but wasn't ready to have doctors and CEO's crashing them on city streets so they left room to grow.

The plastic part is acheaper part too . In fact it's even cheaper to exclude a limited slip differential and other components on the car so cost effectiveness plays arole too.

As for substantial power --I agree with you that one part by itself would be hard to notice . The key with modding for me has been to pick each part carefully and ask a lot of questions .

Ultimately I have only one goal --to have a unique and personalized supercar .

 

No matter which side of the discussion you stand on, it has been interesting and thought provoking to say the least. My respect for AWE has gone up one notch.

 

I was one of the first to do an independent dyno on a normally aspirated car and had great results with the product. In my opinion the product lives up to its claims.

I'll stay tuned for more results!

 

What about the comment from Todd @ AWE that engine temperature needed to remain constant? Could this have influenced the results, or was this a constant?

 

Re Ericdee
Here is a replication of the RSS claims. It is hard to know what to make of this. Others have also shown positive results w this installation. AWE says these are invalid results due to poor control of test conditions. RSS will respond further next week. When this whole thing started I stated that dynoing for what are small performance increments was not always definitive. Peeps cried "copout" and "snake oil"... If RSS is able to produce a new series of acceptable results on a stock car under unbiased conditions there will be an issue over who is right. At that point I am going to trust my subjective impression, shared here by all but one board member (and his impressions do not truly coincide w AWE's graphs), say "to hell" with it and drive the sucker. In the past 2 weeks I have run away from an e39 M5 and pulled slightly on a SL 55 AMG Merc through 3rd gear. How slow can a plenumed 997S be?
[/quote]
Stock up on popcorn for next week folks. Gerry

 

As someone who makes their living in the product management/marketing world, I will merely say this: it is fairly easy to make test statistics "show" whatever you want, which is why vendor-supplied results "proof" should always be viewed with at least some suspicion, "independent" or not.

 

I think at the rpms where this is happening you'll find it has to do with the plenum's interaction with the resonance valving in the intake and the ram-air effect it is supposed to harness.

 

I agree with Ian.
The design of most modern inlet manifolds (particularly performance cars) use pressure waves to aid in cylinder filling. Changes to the inlet system, with flaps or moving parts can allow the pressure waves to add benefits at different parts of the power band.
Maybe the plenum is having an adverse effect at a certain rpm range!
Simon

 

Here's my dyno run. I was also one of the early pioneers that took a chance on this product. I was very pleased with the results. Same day, same dyno. As a matter of fact, it never even came off the dyno or had an ECU reset. Bear in mind my car is supercharged with headers. I've found that the results were very similar for other dynos I've seen on NA cars with the plenum.