On a duramax, a turbo back system actually doesn't bolt onto the turbo on a duramax right? It bolts onto the pipe that comes off the turbo which is called a front direct pipe??? I keep reading different things.

Yes that is correct it.

Brian

So what size is the stock front pipe on a LLY and LBZ? How much is benefited if you actually were to change that out also when changing exhaust out?

for a lly and up you can get the diamond eye turbo direct pipe and have a real turbo back exhuast

for a lly and up you can get the diamond eye turbo direct pipe and have a real turbo back exhuast


Whats the benefit? I seen the pipe online. Just lower egt?

Lower egt's, and faster spool up.

Tyler
MPF

How big is the stock size vs the aftermarket diamond front pipe?

I think the aftermarked downpipe is a 4".

So what size is the stock front pipe on a LLY and LBZ? How much is benefited if you actually were to change that out also when changing exhaust out?

The stock front pipe is 3.5" and the aftermarket units are 4" or 5" (Magnaflow). You can drop as much as 150° EGT's with the removal of your front pipe.

How big is the stock size vs the aftermarket diamond front pipe?


The Diameter of the stock pipe is roughly the same, but is rectangular and doesn't have smooth bends. The Diamond Eye Direct Pipe is 3" constant diameter, mandrel bent pipe. On my truck while towing, it dropped my EGT's a constant 100° when towing in PPE level 3 vs. the stock pipe.

The Diameter of the stock pipe is roughly the same, but is rectangular and doesn't have smooth bends. The Diamond Eye Direct Pipe is 3" constant diameter, mandrel bent pipe. On my truck while towing, it dropped my EGT's a constant 100° when towing in PPE level 3 vs. the stock pipe.
Is it a pain to install? Looks like it would.

It is a little challenging......:D

Some people have issues, others say its easy. If you are half way handy with a wrench, you will be fine.

Good to know! Im getting one asap. But when purchasing a exhaust system do you buy the cat back system or turbo back system with the diamond eye pipe??

I was thinking you would order cat back system?

The stock downpipe sucks. It has a bunch of bends and kinks in it. I put the diamond eye downpipe in. By the way the downpipe bolts up to the front pipe which bolts up to the rest of the exhaust. The downpipe is what bolts up to the back of the turbo.

You would need a turbo-back system or as they are correctly called by some manufacturers, down-pipe back. They will bolt up to the v-band flange under the firewall. The Diamond Eye turbo direct pipe uses that flange as well and goes up to the turbo.

Anyone every dyno'd a hp increase in the Diamond downpipe vs the stock one? Or is it just a EGT drop? And slightly faster spool