what is better dump pipe open or closed?

[wb's87]

I have always raced my car with the dump pipe open. I have had different opinions on this what do you all think, and why?

 

[Slow91z]

Flowmaster exhaust...Open

 

[wb's87]

OK. Thank you. A self reputed TR expert told me that my car may run better with the dump closed because it can overboost due to lack of backpressure. I will keep running the car open. it sounds great too!!

 

[Slow91z]

You boost might go up when you open your dump pipe, this means you exhaust is restrictive and that's not a good thing...Just readjust your boost.

I prefer you have a good flowing exhaust and not mess with opening and closing a dump, but that's totally a personal preferrence.

 

[JP112_89]

I prefer you have a good flowing exhaust and not mess with opening and closing a dump, but that's totally a personal preferrence.

+1 You can hear the motor better.

 

[notacarlo]

Car felt slower with it open. Ran faster with it closed.

+1 on being able to hear the big reciprocating expensive part up front.

 

[Sweet6]

My TTA picks up big with the dump open. I have a 3" cataback with an Ultra Flow. So a little dissappointed in the exhaust. I should have got a 4' catback. If you car picks up with the dump open then your car back is an issue. On a turbo car you want to have zero back pressure after the turbo.

 

[XLR8]

The 2 times I have tried running back to back with the dump open and closed, my car ran 1 MPH faster with the dump closed.

 

[GSX-PKV]

I like the dump closed because as an earlier poster said, you can hear your engine... plus... our engines don't really sound very "cool" with open exhaust in my opinion but they sound awesome through a good exhaust system.