18 replies to this topic

[panky]

I seem to recall reading an article on the early works rally cars where they experimented with two standard bore exhausts running parallel with the two pea shooter tail pipes poking out of the back centrally. False memory maybe.

Edited by panky, 15 March 2025 - 11:50 AM.

[Cooperman]

I seem to recall reading an article on the early works rally cars where they experimented with two standard bore exhausts running parallel with the two pea shooter tail pipes poking out of the back centrally. False memory maybe.

 

I guess that might have been tried, but it was obviously no improvement to what they settled on which was a 1.625" I/D bore with a central exit.

On a rally car two separate pipes of small diameter with two silencer boxes, one on each, would be more parts to knock off over bumps and would give no advantage over a single pipe. I guess they might cut the exhaust noise somewhat though.

The centre-exit was used because it removed the transverse silencer box which was easy to damage. On the rally cars the silencer box is in a straight line and has skid plates welded onto each end to deflect stones, etc. The reason the end of the tailpipe is upswept is to reduce the possibility of the pipe getting blocked with earth is the car spins off backwards into a bank.

One interesting question is whether the noise generated by an exhaust actually takes some power from the actual generation of that noise. Something to ponder maybe  .

[m1n1]

I have a maniflow 2 inch but its a twin box side exit with 'mellow' sound.   A nice company to deal with i would recomend them.

[Raggie]

Simple physics says yes. Why I always laugh at cars modified to turn petrol into noise.
I seem to recall reading an article on the early works rally cars where they experimented with two standard bore exhausts running parallel with the two pea shooter tail pipes poking out of the back centrally. False memory maybe.

I guess that might have been tried, but it was obviously no improvement to what they settled on which was a 1.625" I/D bore with a central exit.
On a rally car two separate pipes of small diameter with two silencer boxes, one on each, would be more parts to knock off over bumps and would give no advantage over a single pipe. I guess they might cut the exhaust noise somewhat though.
The centre-exit was used because it removed the transverse silencer box which was easy to damage. On the rally cars the silencer box is in a straight line and has skid plates welded onto each end to deflect stones, etc. The reason the end of the tailpipe is upswept is to reduce the possibility of the pipe getting blocked with earth is the car spins off backwards into a bank.
One interesting question is whether the noise generated by an exhaust actually takes some power from the actual generation of that noise. Something to ponder maybe .