Need help with cat back

**DIRTY JERZY** · 07-13-2009, 12:47 PM

Well this is the 4th time I will be getting my Corsa muffler welded Im thinking about the lm2 but its only a 2and 1/2 inch pipe and my corsa is 3 or 3and1/2 will the lm2 be a power cork down the road should I look for a 4inch or 3 or 3-1/2.

**cammed goat** · 07-13-2009, 06:01 PM

IMO downgrading in pipe diameter will cause a restriction.

**DIRTY JERZY** · 07-14-2009, 05:13 AM

Yeah but the lm2 is not the same type of muffler its like a bullet

**V8MUSCLE** · 07-14-2009, 07:05 PM

too big a pipe can hurt you the same as too small a pipe.

if you have a 1 inch pipe you will be trying to cram all that hot gas out a itty bitty pipe.

3 inch is more than enough unless your trying to get in the 10-11's

with each exhaust stroke your piston is pushing all the air out of your cylinder and exhaust. if its say 8 inch diameter, the hot not so dense gasses will have time to cool and become cooler more dense gas, so you will be pushing more weight from the cooler heavier gas out robbing power.