I decided to try the new RSS plenum out. It's a very nice piece and the finishing work is excellent. It looks like something porsche would have or should have designed themselves.

Just for some background, I have a 2002 996 cab. It's a 3.6 liter with suncoast headers, cargraphic mufflers, and the evo supercharger kit. The car has approximately 23Kish miles.

I've had the car dyno'd numerous times while testing the headers and the supercharger kit. All my previous dynos were on a dynojet dyno.

I found a new shop (well new to me anyway) in town and decided to give them a try. They've been there for four years but the owner has been tuning porsche cars for many years.

http://www.heritagemotorcar.com/

This place was amazing. They offer complete engine builds and vehicle restoration. I've never seen anything like this in a tuner shop. They had a cnc lathe, flow bench, engine parts balancer, and all sorts of other really high tech stuff that I had no idea what it's used for These guys actually design their own connecting rods and studs, valve guides, etc etc. He also builds custom turbos. He even cracked the porsche motronic software and can custom tune anything up to a 996. He said he just doesn't have enough 996 business to justify the programming time. Hopefully that changes soon as I'd love to get a custom map.

Anyway, the install went very smooth. It took him approximatley 45 mins to install the plenum. It fit perfecty with no need to adjust or fabricate anything. Straight bolt on.

The actual dyno was really impressive. He is using a dynapack dyno. It's about three times as expensive as a stanard dynojet, but it's far more accurate and is the closest thing you can get to actually pulling your engine out and using and engine dyno. The rear wheels are removed and the dynos are mounted to your wheel hubs. This type of dyno eliminates dynojet variables such as tire pressure, strap tension, drum water volume, etc... It does read much lower than a dynojet, so it's a big of an ego killer My numbers read much much higher on the dynojet.

Here are a couple shots of the place and this thing in action. Notice the specially designed fan for rear engine porsches.

 

Here's a couple cool things he had around the shop.











This is some crazy custom alignment tool he fabricated. He does the alignment off the wheel hubs for greater accuracy.

 

Wow, my camera phone was really blowing today. Sorry, the lighting was kind of wacky in there...


I don't have a scanner, so I gave my wife the dyno raw data and she is plotting it on an excel sheet right now. I should have the chart up any minute so you guys can see the results.

 

Those are some nice fans!

 

I should mention that we never took the car off the dyno. We did put some mileage on the dyno after the install to let the ECU adjust some. However, a solid 20 or so miles of aggressive street driving would have been preferable. The results may have been a little better had I drove it around some.

It was kind of hard to quantify the results intially as there was a ton of raw data listed in columns. The dynapack overlap graphing just didn't really tell the story and the dynapack graphs can't be manipulated at home without their software. However, after plugging in the data in 300 rpm increments, I'm pleasantly surprised with the results. Gains across the entire band. Not too shabby for a simple bolt on. My car is supercharged so results may vary. I'd say this is a better, less intrusive mod than a chip. And it's less expensive.

I picked up 20 rear wheel max HP and around 12 peak rear wheel HP. It should also be noted that we only ran the car up to 7200. I think my evo software may allow it to run a bit higher, but the dyno operator was hesitant and cut it off there as opposed to letting it bump off the rev limiter as I suggested

 

I must give props to my wife for making such a kick *** graph

Just for a reference point, my last dyno after my header install put me at 423 rwhp on a large drum dynojet. As you can tell from this, there is a big difference with the dynapack readings. I'll still use my dynojet numbers for bragging rights though

For those looking to get dyno work done, I highly suggest the dynapack units. No straps, better accuracy, less noise, no tire wear. If you can't get to one of those, check out the mustang dynos. They use a resistance roller mechanism, while not as good as the dynapack, it's much better than the dynojet. You still have to contend with tire pressure and strap tension variables though.

 

so the rss advertised numbers are legit, yeah, this is prob the best bang dollar to HP wise, bolt on too! ....oh wait your SC.. Can somebody do this on a NA car...Thanks for posting!
Though you could of went with the smaller pulley for $100... just messin with ya

 

Forget the plenum. I want a supercharger! Nice gains.

 

Wow, all that and only two replies. Ingrates

 

Well, I appreciate all the time & effort & cudos to your wife, too!!
Very impressive gains everywhere.



Your car looks sharp as well!

- Cam

 

Great info! Thanks for sharing.

 

Deputy, first let me thank you fo going through the effort and providing this information to the community. Also, thanks to your wife for the excel work. Hopefully you don't mind that I took the liberty of reformatting in graph slightly for my own benefit. Here's my version for others that might be interested:

 

Dog, Very nice work, especially your wife's graph! While I'd like to see NA numbers too, can you tell a diif in the seat-of your-pants driving? Is there any sound diff?

Thanks, bro!! Great effort.

 

That looks pretty cool too. Where did you get the torque figures from?

 

That’s quite impressive for such a bolt on part. Dog, do you know if they had a baseline from another NA 996 done on their dyno? Since the numbers are much lower that you expect to see on a dynojet or even a mustang it would be nice to know a relative baseline.

I used to have to explain the differences in dynos all the time when I had my bimmer and had it done on a mustang. It helped to show the stock baseline vs my car.

That is a very nice facility they have there by the way.