I know that After Market Exhausts in general reduce back pressure (good) and increase peak power and torque in our Turbo's.

BUT... Is there any possibility that it could cause less low end punch? Am I completely wrong for sensing that? Another owner (of a different brand) feels something similar.

Please don't mention any specific manufacturer's name. I'd rather this thread not turn into a flame war. Would appreciate your opinions, especially from the pro's.

 

It sure could, if your exhaust piping is to large in diameter it will cause you loose too much back pressure resulting in less torque.

 

I feel that if the exahust installation is done poorly it may pose a problem based on improper fitment . As well a defective exhaust may also pose a problem

 

Ive seen the weld seam split on a new aftermarket exaust,notify installer have it checked

 

Thanks for the answers. Please allow me to add: My question is with the assumption that the exhaust system is designed by knowledgeable and reputable engineers, and that is installed professionally and functioning properly.

Is there any possibility that while gaining peak horsepower and torque, low end torque is sacrificed?

I would also appreciate opinions of those who have had their stock Turbo exhaust replaced. After the stock exhaust was replaced, did your car **feel** weaker below 3000 rpm even as it is revving upwards more freely? Thanks.

 

That is a question easily answered... by a before and after dyno. IMHO, it is something that all exhaust manufacturers should provide, especially when selling pricey Porsche exhausts. Properly designed, tested, manufactured, and installed exhausts should not cause problems.

 

Nope . But my car had other mods added simultaneously.
The difference was quite significant in terms of power and midrange pull . Also I noticed that turbo lag was greatly reduced.

 

The best way to get less power out of your 997TT is to trade it in for a Ford Focus. Problem solved!

 

Installed Europipe - actually felt stronger accross the lower rpm band.

 

Cannga, I did the exhaust as my first mod. There was a noticeable improvement in low end spool-up and boost, as if the car was allowed to breath and the exhaust was like an inhaler.

 

Yes, there is some loss of low end TQ.

 

reduction of backpressure should allow earlier spool, boost and torque. AWE's dynos show what should be expected - a shift of the boost and torque curves to the left:

 

Thanks everyone for the replies.

Any more inputs from actual users? Did you car feel less "punchy" in the low range after you change your stock exhaust?
A couple of users have reported a subjective sense of loss of torque with dyno-proven, after-market exhausts that are installed properly. There may be objective data as well.
Question is, in such cases, do we assume something is wrong with the installation or SOP dyno, or is there an explanation for why evidence doesn't match theories?

BTW, I cross posted on rennteam, in case you are interested. http://www.rennteam.com/showflat.php...&page=0#438497

 

[quote=cannga;1821544]Thanks everyone for the replies.

Any more inputs from actual users? Did you car feel less "punchy" in the low range after you change your stock exhaust?
A couple of users have reported a subjective sense of loss of torque with dyno-proven, after-market exhausts that are installed properly. There may be objective data as well.
Question is, in such cases, do we assume something is wrong with the installation or SOP dyno, or is there an explanation for why evidence doesn't match theories?

Interesting observation on lack of punch especially with the cost and trouble putting on one of these exhausts. Seems like offering just the muffler for a better rumble (and different tips for those few who may not like the engineered teardrop design) would be suitable for most, but all after-market outfits seem to want to fuss with the converters which can lead to many porsche-frowning problems. Still hard to accept this so-called 20HP from just changing cats.

 

[quote=johnww;1821678]I don't feel a lack of punch with mine nor is that reflected in the AWE dyno sheets above. Most of the well-engineered systems that use sport cats do not cause CEL problems...and the install is no more difficult than other exhaust installs - in fact a few on this board have managed it as a DIY project.