Hi all,

Wondering if any of you 4500 owners replaced your OEM downpipe, and if so whom makes the aftermarket replacement, or does it have to be manufactured.

If you have the Exhaust Brake, unless you also change out the EB to a 4" you will still have to reduce and enlarge at the EB.

George

OK, thanks for the information. Now did you change out your exhaust brake to a 4"? Let me know in your opinion the best way to go, thanks for your help.

If you want a full 4" Turbo and back exhaust, you'll have to change out the downpipe.

I went with a 4" from the Exhaust Brake and back (see pictures in my garage) and it helped the EGTs a lot. This was by far the easier way to go. There is also a post about the EB flange that you can get to bolt the new exhaust to the EB. Here's a link to that info:

http://www.dieselplace.com/forum/showthread.php?t=75383

Hope this helps.

George

OK George, what company did you order the parts from? Did not catch the name or was it mentioned. Thanks.

I ordered the Adapter from the local Chevy dealer. It wasn't cheap, but allowed me to bolt on everything I changed. Should I need to restore the Exhaust to stock, I just unbolt the 4 bolts at the EB and slip the orginal system back in place.

I built the 4" system with Magnaflow muffler from bits and pieces the local Mod shop had on hand.

I believe (pulling from a very old memory) that the adapter cost was about $85. The Magnafow Muffler was $100 + Shipping. I had a 4" Chrome Tailpiece, and the rest of the exhaust pipe was remnants in the Mod Shop. Welded all joints, and used the original hangars by welding hangar tabs on the system at the location of the original hangars.

I talked to a Magnaflow tech to get a 4" that was as quiet as possible with good flow. They steered me good. As quiet as the original exhaust, but the flow is outstanding. EGTs dropped about at leat 250*


George

Thanks George for all of your help, will call dealer and order though cannot decide on installing an Aurora Turbo, you know just for fun, therfore I might as well do all together once I decide.

Flip :rockit:

I ordered a 4" Pacbrake which, with new weld in brackets, works perfectly with the factory installed electronics and air control. Had a local muffler shop build a 4" turbo back pipe and installed my new brake for $150. My exhaust temps have dropped on average about 250 degrees. I love it!!