I was thinking about just installing a cutoff (dump) before the muffler to see if it helped turbo spool up so I was needing the size. It's only about $40 and has helped my past turbo cars. Could be a cheap alternative to expensive exhaust. Thanks for any help.

The stock exhaust is 3.5". Just add a straight pipe. It helps spool up.

Good sound is not cheap.

Fellow at NE Dyno day had this setup..

http://www.uscom.com/~hoot/cars/duramax/dyno_10-25-03/images/DSCN4184.jpg
http://www.uscom.com/~hoot/cars/duramax/dyno_10-25-03/images/DSCN4185.jpg

That has got to drone in the cab. Before I did the straight pipe, I unbolted the exhaust at the flange under the passenger floor... It was loud under a load.

Hoot,


From the pictures that would seem to be an after CAT installation. How much noise is generated doing that?


Would anyone know if a freeing flowing muffler would help? I'm hesitant about purchasing an after CAT exhaust system knowing that I can't legally get rid of it or change it (the CAT). It seems that the system is only going to free up as much as the exhaust tubing dia. would allow it at the smallest section. But I would like to find some way to free up the exhast to help the trubo wind up sooner.

Not my truck. I never heard it run. Maybe one of the NE GTG guys knows.