Duramax Turbo/Engine Damage w/ Aftermarket Exhaust???

[Buffalo]

A friend of mine with an '04 Duramax (LLY) recently told me that his Service Mgr. told him not to install an aftermarket, 4" exhaust because he's been seeing turbo/engine damage with their use. Seems that the aftermarket exhaust allows too many turbo rpm's. because of so little back pressure to slow down the turbo to a safe level. This is on stock trucks.



I've never heard of this, before. Always thought the Duramax turbo's were pretty strong & delivered a lot of air. I'm inclined to not believe this, myself.



Any of you ever heard of this problem? Does it make sense? I could understand this happening with extra fueling but, not on stock trucks.



Thanks.



Joe F. (Buffalo)

 

[Cummins724]

My brother had a 02 & ran a 4" exhaust with 5" stacks & never had a problem... . he also had a edge juice on it set on kill. I think that guy is full of it.

 

[cclark746]

i dont think he knows what he is talking about at all just another way to void your warranty do you know how long people have been running straight pipes on diesels long before diesel performance go big.

 

[rbattelle]

Doesn't make much sense, Buffalo. Turbos are controlled by the wastegate, which prevents over spooling, regardless of what the exhaust system is. Lower backpressure is always better for the turbine, in my opinion.



Besides, most turbos can handle huge amounts of RPM before they fly apart.



Ryan

 

[WUnderwood]

sounds like BS to me also

 

[GButia]

I had that same exact year lly..... Had straight thru 4 inch for 40,000 miles... not a single issue. That truck had a lot of mods too on a stock spinner. He is full of it.

 

[Buffalo]

I agree with you guys.



The Serv. Mgr. also told my friend that when the turbo 'grenades', it loads the engine up with metal parts causing the engine to have to be rebuilt. Costs about $17,000. 00 for the repairs.



Sounds like a lot of manure from the backside of the bull, to me.



Thanks for your replies. Just because I had never heard of this problem doesn't mean that it isn't happening, to others.



Joe F. (Buffalo)

 

[AWise]

Doesnt the backpressure from the compressor side prevent it from "spinning too fast"?

 

[CToney]

Poor Guy driving a DMAX.

 

[rbattelle]

Always remember: whereas facts take time and effort to look up, BS is always right there when you need to sound smart.



Ryan

 

[jwilliams3]

Service manager+Turbo expert=Does not exist.

 

[bmoeller]

Doesnt the backpressure from the compressor side prevent it from "spinning too fast"?

No, it doesn't.



I think the trucks he's seen HAD a box on them. Were taken off for "warranty" work.

 

[nickleinonen]

an aftermarket exhaust won't do any harm to a dmax engine turbocharger. . it may pop a code if it has an egr. but there is the little "fingerstick" avalable to cheat the mass air sensor to allow for an aftermarket exhaust [and blocked off egr system]

Lower backpressure is always better for the turbine, in my opinion.

yep. . mine too. the turbo engines i have at work don't have much of an exhaust system post turbine. . about a 36" stack at the outlet of the turbine casting. . drop a mirror down the stack and you can see the turbine blades. kinda makes them an easy target for bricks/rocks dropped from overpasses. . [pulled out most of a clay brick out of one once. . ]