I've got most of the parts togather for bypassing my cat and muffler, and have a few questions for anyone interested in a mod like this. Is it worth bypaassing the cat ? I've got a 4" Y pipe and was going to use 4" flex to get to the dump valve. After the dump valve I was considering a turn down and did not care where the outlet was as it would only be in use when boost pressure stokes the pnematic actuator. The range on the actuator is 8 to 13 psi and after watching my boost during a couple weeks travels 8 psi is very managable for daily use. At least that is where the valve word begin to open. This is all easy to do , including a small selector valve on the dash to block the actuator signal all togather for quiet/low load running. But, where would a good place to run the ,or , tie the dump pipe back into if this mod prves worth while ? I'm talking less than two hours for the y-pipe , flex , valve/actuator assembly and dash mounted valve. Simple tools are all that is needed if a sawzall is counted as simple. The final tie in(if required) would be nice using the factory tailpipe or a drivers side duel exhaust tailpipe. I think this would give the best of both worlds and allow driver control. Anyone have a idea for a simple valve ? This website has a likely candidate but it'pricey.......
http//www.dhmperformance.com/
ON EDIT-EXHAUST CUT OUTS

 

why not just a QT electric cutout?

http://www.quicktimeperformance.com/QTEC/

 

there's a reason people don't run dumps on diesels... the underside of your truck is gonna be a sooty affair!!

 

YES!

 

Just e-mailed Quicktime to see about a valve without an actuator option. I think using a pnuematic actuator is the way to go to follow the EGT thru boost pressure. BTW, I think I found a better test site for the system connection when I was scoping out the room to work with yesterday. The rear of the factory muffler has a protrusion on the back side that aligns with the inlet pipe. I'll open this up and let everyone know if the factory muff' can be converted to straight-thru .The "CAT" is the only other question,does anyone have an approximate flow rate ?
Mark T.

 

Sounds complicated. Just straight pipe. Let us know how it turns out. Sounds interesting.

 

Straight pipe