If I'm not mistaken, the MD Trucks (LLY/LRX) use the VVT as an exahust brake. Would it be possible to read the program from a MD truck equipped with the Exahust brake feature and adapt it to our "Light Duty" trucks? Seems to me that might be a good way to get an exahust brake, since (basically) the same engine can come from the factory that way.

Got a VIN from one?

Cheers,
Ross

I believe it is an available option only with the 06+ models. Up to 05, there was an air operated brake valve in the exhaust pipe. I do not know if there is any differences in chargers or not, but if not it should be possible to figure it out.

Did some investigating on 06 exhaust brake operation and found a way to get exhaust brake operation on LLY motors. Need to max out turbo vane position to 100% at 0mm3. Set desired vane position to 100%, max to 100%, and min to 99% but only at 0mm3. Will come on during decel fuel cut-off only that way. Works fairly well for me. Slows truck down fairly well in T/H mode.

06 exhaust brake description from GM.
The exhaust brake system is used to provide additional braking when the vehicle is decelerating. The engine control module (ECM) controls exhaust brake operation based on various sensor inputs. The ECM commands the turbocharger vane position to maximum boost for exhaust brake operation.

Thats what i was thinking, i'm going to try it and i'll let ya know how it works on a stick truck.

do you think 100% will cause to much back pressure at the cyl head????

Later
Caleb

Not if that is what GM is doing for exhaust brake. Does build about 6psi boost while on though.

This really works great, the only thing i noticed is the really harsh spool down sound my turbo makes when shifting with it setup this wayand thats just on my tow tune, on my hot tune it will bark the turbo if you shift at just the right time!

I only have the braking activated from 1400 rpms up on the 0mm3 line, it works really well but im gonna mess around and see if i cant get the harsh spool down sound calmed down when shifting!!!!

Later
Caleb

Good Job! :cool2:

When I get EFILive, I'll have to play with it.

Did some investigating on 06 exhaust brake operation and found a way to get exhaust brake operation on LLY motors. Need to max out turbo vane position to 100% at 0mm3. Set desired vane position to 100%, max to 100%, and min to 99% but only at 0mm3. Will come on during decel fuel cut-off only that way. Works fairly well for me. Slows truck down fairly well in T/H mode.

06 exhaust brake description from GM.
The exhaust brake system is used to provide additional braking when the vehicle is decelerating. The engine control module (ECM) controls exhaust brake operation based on various sensor inputs. The ECM commands the turbocharger vane position to maximum boost for exhaust brake operation.