shortened exhaust ques. ??

Silv2KGT

New Member
Mar 18, 2008
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California
Hey, I cut out the stock mufflers on my 00' GT and tac welded the tips in place for the mean time until i do a "real" exhaust lol. The exhaust now effectively ends about 15in. after the final flanges after the mid-pipe. Will the rather signifiant decrease in backpressure hurt anything?? I have heard multiple things regarding inadequate backpressure, yet I am unsure. This is definitely not permanent by any means, yet I want to make sure I am not going to hurt the motor.. It seems to has significant less power and winds down quite a bit slower than it did with the stock setup..(If I rev it up, then put the clutch in, it "revs down" if you will, relatively slow compared to stock..)

Thanks for your help!

Tom.
 
Any other advice/input?? Why do I seem to have less power and how come it winds up/down way slower??

If you've eliminated the back pressure and move the power band higher up in the rpms your going to lose the low end grunt. Your top end would be better but now the bottom end loses the power down lower. I don't know how much you would of lost but it will make a diference.
 
Back pressure is completely the wrong word to describe what you are talking about. You don't want or need back pressure ever. However, in a properly designed system, there will be some back pressure.

It has a lot more to do with flow velocity. If you run too large a diameter pipe, the velocity will drop which is what causes a loss of low end torque. It probably isn't a great idea to run an open shorty header, and you will likely loose power because it is too short, but certainly no problem if it's cut off somewhere in the mid-pipe.

Must be painfully loud though....