2004 Duramax

[gregmican]

Has anyone heard or have links of info on the 2004 Duramax Diesel? I heard there is supposed to be a horsepower and torque increase. I have a 02 that has the zf 6 speed and I want to trade off for a allison. I just might wait for a 2004 if they have a performance increase.

[csimo]

GM has not released any "official" information, but we know some of the rumors.

Yes, the 2004 Duramax is supposed to get a power bump. I've heard many things, but here's what I believe to be true:

Redesigned cylinder heads (to better incorporate EGR).
New electronic VVT turbocharger.
EGR - 50 states.
Catalytic converter - 50 states.
Redesigned exhaust manifolds.

My opinion? If you're not in California where they already have EGR and catalyst systems, then you'd be MUCH better off with a 2003 engine and Juice it. The 2004 power increase is supposed to be in the 50 - 60 horsepower range, and the Juice already beats that. With the 2003 engine you don't have all the problems with EGR that will eventually occur.

If you are in California then you would be better off waiting for the 2004. The EGR system is better incorporated in the new engine and the VVT turbo is a much better design.

For those of you with the question in mind (like I did)... NO, you can't change the 2001-2003 exhaust manifolds and turbo out to the new style. They would physically fit, but the new turbo is controlled by the ECM. Unless you're some kind of electronics genius the new ECM is not compatible with the current style ECM. Sorry!

[ 01-12-2003: Message edited by: csimo ]</p>