gotturbo?

I just had a local shop install a exhaust on my car, from the stock sleeve points back....no muffler, just straight pipe. Power just dies after about 4-4.5 thousand rpms.
i was under the impression that the turbos were all we needed for backpressure on our engines....have i spent money on a mod that decreases performance?
If it isn't the backpressure, i feel it might be because the bends are too tight on the exhaust....but i just want to make sure

tia
joe

EkSiPd

hrmmm i thought the same thing??? well in any case how does it sound???

Prodigy

something else is wrong, it's not the exhaust

LCP

...it could be something else besides the exhaust OR the exhaust could make the car so much faster below 4000rpm that it now feels slow above 4000rpm OR the exhaust's flow characteristics suck.

gotturbo?

then the exhaust sounds like it is gonna come off the manifold....
the car was running FINE before i went and had this put on. it is aft of the sensors, just like a tuners model would be...the only difference here is that there is no muffler, and there is a more adjacent bend than normal where the two pipes y into one pipe on stock exhaust. they needed to bend this more to make it fit they said, and at the time i did not think it would hurt it that much (at least not hurt it more than the mufflers would)
anyway, the power drop is incredible, not just a illusion of greater power. i thought the same thig at first...that it was so smooth that i could not feel the actual power, but the more i drove it, the more i saw...the power just dies.

Thrust

On a turbo car the less backpressure the better. Your problem is elsewhere.

gotturbo?

but then why would the car perform better on a stock exhaust before the new one is on?

esfor

and your car has less power above 4,000 RPMs that means you have MORE backpressure with the new exhaust. what size pipe? stock Y-pipe? did you use small pipe w/o mandrel bends?

--or there may be some other problem unrelated to the exhaust.

How are you quantifying the power loss? its pretty hard to feel the difference in power between exhaust only changes.

As far as backpressure -- less is always better with a turbo car. If it were normally aspirated, there are cases where you would get less power -- but that'll only happen at low RPM anyway....

Singletrack

have more high end power. Auto Union Jack ran them on an A6 2.7T, and that was basically what he found.

-st