Exhaust Question

[JAZE55]

Hi fellow members,

I am currently running a 2.5inch catback system into a 2.5 inch twin loop muffler. I have just ordered a Apexi WS2 muffler and the inlet is 60mm or 2.36 inch.

I have 2 options:

1. Chop my twinloop off and weld the WS2 on, using a reducer (2.5 inch --> 2.36 inch) or

2. Have new piping made from the resonator back to the new muffler (resonator output 2.5 inch --> new piping into WS2 2.36 inch)

I am leaning towards option 2, as all reputable japanese catback systems run a 2.36 inch or 60mm size pipe. But I would like the opinion of others with knowledge in this area.

My current mods are I/E and UNICHIP. I will also get my headers ported after new years.

Edited November 11, 2007 by JAZE55

[Northy]

cut the intake to the muffler off and get them to weld on a 2.5" shouldn't be too hard for any half decent exhaust place.

[JAZE55]

cut the intake to the muffler off and get them to weld on a 2.5" shouldn't be too hard for any half decent exhaust place.

But doing so, wouldnt it restrict the muffler?

As the inlet is only 60mm in size, so assume the pipe inside the muffler is also 60mm.

[CHA54]

is your exhaust flanged before the torsion beam?

If so, get a new piece made from the flange back.

For the reduction in diameter, it's very easy for any fabricator to make a nice 75>60mm reducer. Do not just weld a 2.5" pipe to the muffler if it's not 2.5" at the inlet. Steps like that in the exhaust are no good.

[JAZE55]

is your exhaust flanged before the torsion beam?

If so, get a new piece made from the flange back.

For the reduction in diameter, it's very easy for any fabricator to make a nice 75>60mm reducer. Do not just weld a 2.5" pipe to the muffler if it's not 2.5" at the inlet. Steps like that in the exhaust are no good.

Yes mine is flanged after the torsion beam. I will most likey be doing what you have said.

The reason why I was looking at replacing the pipe from resonator back is, I have slightly dented two section of the exhaust pipe (after the resonator), will this be hindering performance dramatically? The dents are not large but they are still noticable upon inspection and when touched.