My dad has an 04 Duramax, which I think was rated at 320hp and 520ft-lb tq. I read the 05 have 310 hp and 605 ft-lb of tq.
Does anyone know what was done to get such a huge increase in torque, what it a different cam or just a computer modification???
Also, why are the manual tranmission duramax's only rate at 300 hp and 520 ft-lb of tq? Seems weird to detune the manuals.

let me know
UofMN

 

2004.5+ Duramax's are equiped with a variable venturi/vein turbo and it is much more effiecient. The designation different between the older and newer motor is LB7 and LLY respectively.

 

LB7 is alot eaiser to add power because it will not have to have the turbo jacked with...Plus LLY doesnt hold power like the LB7 does

 

Hopefully that will change as more mods become available. But that will lead to other mods like a transmission and converter upgrade.

 

Are you saying the older engine (pre 2004.5) is the LB7 and the newer one is the LLY?
Why does the LB7 hold power better than the LLY, just curious I guess?

Thanks
UofMN