Header power results

Hey Guys, new to the forum. Got a 02 996 3.6 and have been researching the header/cats/exhaust debate for a while and seems that you can get some power with a K&N airfilter, 'good' set of headers and exhaust. I still don't think I want to change cats or reprogram the ECU while the car is under warranty. I have herd good things about Techart and Cargraphic as far as quality and non-inflated results. Anybody have these mod's done and have feedback as far as realistic power gains..

You won't get much power gain without the ECU reprogram.

I wouldn't start down this road looking for significant power gains. The 3.6 is a very efficient motor so changing the exhaust isn't going to do much. Fabspeed claims up to 10 hp with their muffler. Can you feel 10 hp? I suspect that many folks feel that their cars are quicker because it sound different. I came over from an e46 M3 and there were many folks trying to squeeze some hp out of the S54 engine by putting on completely new exhausts/intakes/reprogramed ECU's. There many more failures than success's and those that made hp were very disappointed with there gains vs the amount of money they spent. I plan on changing my muffler in the future to get a better sound and lose a bit of weight from the back end of the car. There are many makers out there so it's going to take some time and research to find the right product.

I heard that the ECU on this engine is highly adaptive and is not necessary. Where an ECU reprogram on a 3.4 can yield 12-15hp on the 3.6 there is very little to be gained as the programming from the factory is better. Part of the X51 is better exhaust headers so there is some power to be gained I feel.

I got intake, headers, and exhaust on my car, and felt very little difference until I swapped the ECU. That really woke up my car, and really helped my car use the other equipment. A while back one of the posters synoed his car with & without the headers and got really good results..something like 12 peak hp.

There is a rule of thumb formula that equates effective horsepower gains with weight savings. Aside from any warranty issues, with non-turbo Porsches you are better off getting the performance gains by taking weight off the car, or off you

Who did your ECU upgrade? I think what you felt with the ECU wasn't say a 15hp jump in power, but better throttle response also. The ECU upgrade is probably good for 5hp but much better response with the intake and headers. If you say you can really feel the difference with the ECU than maybe it's worth it. From reading the posts it seems most TT owners do the ECU for obvious reasons to get more boost, but with the 3.6 and it's better coding your really looking for a better responsive engine and a little power. When you did the ECU did you consider sport cats. I have heard that this engine has 250 cell cats, is this true? If so then going to 200 cell cats isn't worth it and the 100 cell cats might trigger the CE light so an ECU reprogram is necessary also. On weight reduction, other than GT3 seats and taking out the back seats that's about all you can do on a street car within reason. It might be cheaper to get the extra 25hp?

You can save 20-30+ lbs with lighter rims and tires (there is a meaningful weight difference between tire brands and sizes) can make a big diffference in performance and handling, esp as they are unsprung weight. While less practical, stereo equipment and sound insulation can also be a source of weight savings. Practical areas include battery and exhaust - while removing the cats is illegal ( )the mufflers are not light and taking weight off the back in particular will also help handling (FYI on my 993 I replace the mufflers with Fabsteed supercups and eliminated over 50 lbs).

my dealer told me i wouldn't get any HP if i changed the Exhaust and Headers UNTIL i had the ECU reprogrammed

That seems a little far fetched. The ECU is adaptive to the point that it will supply more fuel if necessary within the parameters it has. So for instance if you with headers, 100 cell cats and exhaust many people do get the CE light as the 02 sensors are out of range. It has been shown on a dyno that a good exhaust will get you maybe 5hp and better sound of course, not a big gain obviously, but if add an intake say 3-4hp and maybe headers 6-8hp it adds up to 15 hp with the stock ECU. The ECU reprogram can raise the rev-limiter and adjust the powerband downward a little to complement the headers for more mid-range. The only way to get more top-end is to do all the mods with 100 cell cats and the ECU but wre talking more $$ and warranty issues. I know that the factory headers are not the best as if you pull them off there is a weld on the inside of 3-4mm which impedes flow. Just putting on headers will give you more mid-range as the ECU will compensate for it. It just won't pull harder up top unless you do the 100 cell cats also which do require the ECU reprogram. This came from FVD and Cargraphic R&D guys.

far fetched or not, every time i have had an ECU reprogram on any car, it has been a very noticable improvment, but i have yet to do it to my current so who knows

Well I would agree that there is some loss when adding components, that is a given. Whether the ecu is adaptive or not and by how much dunno. I can say that when I rip on it in the caynons it does run much better than running around on the street. From seeing the stock headers and the fvd/fabspeeds I could see the 15/15 they claim. they are equal length and have a much better collector design period. The equal length is what gives you the torque which the collector adds to both and helps the hp. As for the ecu stuff. Claims of about 20/20 seem about right, mufflers maybe 5 I would say, cats unknown how restrictive they are and what you are going to. 250 cell stock seems a bit much I thought they were 200. I would do straight pipes personally if sounds and CEL aren't issues. I think the main issue to consider is sure, if the motronic is adaptive then if you are not letting it know you want to run it hard, then it will adapt to less perfomance with any mod and deter the gain. Mercedes ecu's are notoriously bad with both the motronic and tranny shifting -esp. the tranny ugh! In any event I would say that with the figures if you do all the junk you can get prob a real 25 or more with headers, ecu and intake. This would allow for the overlap of gains which are usually bs.

After talking the Steve at Rennsports he told me that headers muffler add no power. At best 5-10 HP which even may be a little optomistic. The 3.4 ecu upgrade dose improve throttle response and some HP 12 maybe. That probably the best upgrade. He also said the 3.6 is well optimized and a ecu dose not help. If you want more power you might have to step up to the X51 package, but at what cost. Headers will only add 5 HP and that will only be at the top so it might not be worth it. I know andial were doing some cams. This might be worth investigating cams and header will help how much I don't know.

I'm glad to see that Rennsport agrees that the 3.6 ECU is much better than the 3.4. I would do the ECU if I had the 3.4 though..The X51 package as an add-on is way too much $$$. Isn't it like 9-10k wholesale without installation? If you could find a good used 996 3.6 with the X51 that would be the hot number for sure. Anybody know for sure if the stock cats are 250 cell? I know most are now selling the 200 cell cats to be OBDII compliant but the change from 250 to 200 isn't worth it. Maybe too much $$ and BS for a few hp I guess. I'll get the intake and muffler system and enjoy it!!