grade-braking/dmax-vs-8100

[bluenote]

I read a claim from an 8.1 owner that the Allison grade-braking is better with the gasser than with the Duramax. While I understand that engine braking is better with a gasser, I think his claim is BS due to the grade-braking being a function of the tranny.

What say the experts here?

[tysmith]

I would be of the impression that a diesel would grade-brake better than a gasser simply because of the higher compression of the engine.
Also, I would bet that the ECM and TCM work in unison functioning the grade brake, so there could be some differences there.
Food for thought.

Ty

[FirstDiesel]

I would agree that a gas engine is going to grade brake better than the Diesel. The compression has nothing to do with it. The Diesel never develops the back pressure a gas engine does when grade braking. There is no closed throttle plate for it to develop back pressure against.

That is why there are exhaust brakes for Diesels. Closing off the exhaust to the engine allows the engine to build up a backpressure for grade braking.

Read this:

http://www.dieselpage.com/usgeb.htm

[tysmith]

Nevermind. :rolleyes: As soon as I read it, the lightbulb went on...

Ty