TT B4 Exhaust note dies off toward high revs

[Guest Eastwolf]

Hi,

Man TT-B4, BOV, but otherwise standard engine.

This is not a new diagnosis:

Under primary boost, exhaust sound delicious: deep rumble with the flutter of the turbosmart BOV.

BUT when revving toward rev line, the deep burble disappears almost sounds like the sound the car makes when inside the VOD. Then the BOV just squeals.

It goes like the clappers, but just sounds weird in the high range.

Comments please?

[Guest keltik]

Yeah when the secondary opens up you lose a lot of the rumble as the exhaust headers become relatively balanced.

[RSB]

 keltik said:

Yeah when the secondary opens up you lose a lot of the rumble as the exhaust headers become relatively balanced.

+1

[Guest Eastwolf]

er. don't really understand, but will have to take your word for it as being normal. =) Thanks

[Guest keltik]

The rumble exists because the exhaust gas from the one bank has to go all the way around the front of the motor to meet up with the other - then out the turbo. Theres a big difference in length.

When the secondary turbo spools up, both banks exit straight to each turbo - the distance traveled is about the same - the headers are then balanced and the rumble goes away.

Or at least thats my understanding of it.

[Guest Eastwolf]

Thank you =). SOunds good to me.