LB7 boost limits

[duramaxiskilinit]

I'm thinking about buying a 2003 duramax with the lb7 in it and i have been told that out of all the duramax motors the lb7 can hold the most boost safely. does anyone know if this is true? if so how much is safe to boost?

[Mark Rinker]

Before answering this question - I'll ask one.

What is your intended purpose of adding more boost? i.e. Are you running an otherwise stock engine, pulling a trailer through the mountains, or are you racing a chipped truck in the 1/4 mile?

[dmaxalliTech]

The boost limits are more a derivative of the turbo then the engine itself. A stock LB7 turbo wont live long with more then 32lbs, but I think drive pressure readings show that its not doing much above 29 lbs for the positive.

[duramaxiskilinit]

It will be chipped with the Quadzilla Stealth 2 and a straight pipe exhaust and an intake. And yeah im going to be racing it in the quarter mile.

[Mark Rinker]

I have no experience with that application, but would keep it south of 30psi peak with a stock turbo.

For extended towing duty, I think 25psi max is more reasonable.

Good luck keeping head gaskets in your LB7. You might want to price a set of studs.