Definitely Sharky. I think it is a very personal sort of choice. I'd recommend actually listening to each exhaust that you are considering first, if at all possible.

 

sharkster,

I believe the car was tuned for the Fabspeed while the others were added without benefit of a retune. This might make a small difference. Are we going to go through this again? In my tests where the afr's were maximized for each exhaust, the Fabspeed did make more maximium power ..... it spiked at 6700 rpm's. Average hp over the full rpm range the Europipe prevailed in my tests on my car. That is why I bought the Europipe. At the time I tested the Europipe Stage II Quiet.

 

I also think that there's a tremendous amount of variability on the dyno. Just the variability between runs for the same car on the same day is very problematic for assessing power. It's almost like you'd need a random sample of 100s of cars, taken on different days, etc. to get a really robust result.

Bottom line, if you took an otherwise identical 996TT, excpet one had Fabspeed and one had Europipe, and raced the two cars, it would come down to who's the best driver. (Whether on a road course or a 1/4 mile...) So, pick the one you like and enjoy!

 

racer63,

I understand Stephens tests were done on the same dyno under like conditions. Yes, the same dyno can vary a little bit, but all in all Stephens tests were about as accurate as you are going to get. I understood the car used was tuned with the Fabspeed exhaust. I am not taking anything away from Stephen. He did an excellent job. Another piece of information to go along with the rest. The work involved in adjusting the afr's for each exhaust would have been extreme. My opinion is Fabspeed had the luck of the draw in this test. My opinion is worth exactly what it cost you.

 

That right there is the BEST thing said in this thread. I believe the gains from the exhaust whilst decent aren't the be all and end all in any case. We're talking about 20hp differences here that can more than be made up for with much "better HP" gains like an ECU, turbos etc... Primarily buy an exhaust based upon the sound that you like best. And take the extra 15-35hp you get from any of the exhausts and I garantuee you'll have a hard time noticing that small delta unless of course you are driving a car with 70 hp and adding 35hp Most of us here are not...

 

Takes a deep breath...

I not going to discredit Stephen's tests because I trust him and value his views tremendously. Let's face it, he is an honest guy and simply published his findings based upon our requests. Of course "benchmarking" (which is what I do everyday in the PC world and write analysis etc..) can always be more thorough and under ideal controlled environments you want to be able to compare apples to apples- where possible. Based upon resources, time, money etc... I'm not sure what else Stephen could have done. I understand that the tests were done on his car with GIAC tuning. However at the time I believe his car was running the EP exhaust as well as him selling his various tuned packadges with the EP exhaust as part of the packadge? I think he still sells any of the exhausts in the test, which I think is a good idea anyway. It gives people the option to do whatever is best for them in terms of sound etc... I'm not saying the EP is bad, I like the sound too, and it performed the best on your car (the 85MM one) as did the RuF and Fabspeed which you had before (I'm not sure if the car was retuned each time?).

I'll just wrap up by saying once again, in my opinion, 996TT owners should pick their exhaust based firstly upon what kind of sound they like. Loud, boomy, ricey, high pitched, low-pitched, Porsche-like, un-Porsche-like etc.. After that they can then be happier in the knowledge that their car "breathes" a little better.

PS I also use mine the way I do because it saves so much weight using just the straight pipes. I know that can't be beat

 

Also I'm not sure why this kind of thread is a common trend on so many other car forums. I don't know why people get so emotional about fart cans to begin with

I'll be completely honest when I say this. I've heard pretty much all of the exhausts (except a GHL one) available for the 996TT and I have to say they all make a great improvement in terms of sound over the stock POS heavy Boysen-blockadge special...

 

And before we get carried away here again let's all have a group hug:

 

HEY ALEX! I THOUGHT WE ALL AGREED NOT TO LET THAT
NIGHT'S PHOTOS GET OUT TO THE PUBLIC! WHAT GOES
ON IN VEGAS STAYS IN VEGAS!
Joe

 

Sharky,

That photo makes me nauseous. That and the fart can comment. I think I'm going to excuse myself to the restroom!

 

Chad,

I hear what you are saying. I agree with you that tuning is probably the no. 1 explanatory variable in Stephen's results. But, I don't think that random variation should be overlooked. My background is in experimental design (not automotive, but experimental design is experimental design, whether widgets or fart cans).

I am not saying that dynos are off by 10% between runs, or anything like that. I'm saying that there are small measurement errors that are not accounted for in a dyno run. You just simply can't control for all variables fully. You can't exactly control air temps, engine temps, air density, charge temp, etc. etc. between runs. So, there will be some small variaion, maybe on the order of 1-2% variation in dyno runs. When looking at exhausts that dyno within 20HP of one another on a 600 HP car, that 1-2% *could* make the difference between the winner and loser.

Ok. Enough theory. On to pure anecdotal evidence (a good joke if you're an empiricist. If not, ignore the prior sentence). Admittedly, my dyno experiences are limited to three different cars on three different dynos. But, what I noticed in each case was lots of random variation. Take my 996TT on the Technodyne dyno. On the exact same day, same time of day, same dyno, same car, exact same setup we got four very different HP figures. I say very different. They varied by about 10 HP. Maybe that's not much on a 530-540 rwhp car. But, that's what we are saying here in this thread. That Fabspeed is 10-20 HP better than the Europipe (depending on whether you measure at peak, or average, more on that later).

So, any way, take the fact that the GIAC unit in Stephen's car was not tuned for the EP, and some small variation on the dyno (although it is small in pct terms) and I think you need to take the results for what they are, ONE test. Not the only test. But, one good data point.

OK. Here's two other good data points. Todd dyno'd a stage 4gt with the Europipe (and Todd's new intake) at 560 HP. That's 20 more HP than my stage 4gt with stock intake and Fabspeed loud. Chad's car has 700+ HP at the flywheel. Now, if everyone posted their dyno charts, we'd have some really rich data and could maybe start to make conclusions about which exhaust is better. But, for now, I don't think we have conclusive data.

So, bottom line, I think what Sharky says is right. Buy the exhaust that sounds good to you. Don't worry about 10-20 peak HP on a dyno run. And if you are going to make the decision purely on power, then (1) tune your car for each exhaust system when measuring it on the dyno, (2) take a number of dyno runs for each exhaust and take the middle data point (DON'T take the best one) and (3) look at the area under the curve, not the peak HP. Stephen's "average HP" and "average torque" tables do a decent job of summing up area under the curve, and there's not much difference there to be noted even in his tests. Your butt-o-meter won't be able to tell the difference. Only your ears wil know.

Just my $0.02, given out for free today.

 

ROFL.. well we won't let anyone in the on the secret of who the short guy is in the pic

 

go with the EP II quiet. It will exceed your listed requirements and your expectations. Are any of us really that concerned about the cost of an individual mod if it is the one that gets the blood going?

 

This forum is a place to talk about cars...Not to argue...."cant we all get along"?

 

I used to think that too. Boy was I mistaken!

Not to make light of the situation. I'm sometimes bothered by the same thing. But, I just try to roll with the punches now because amidst all the arguing I usually learn something.

Yours in speed.