Downshift or exhaust brake?
I was just thinking after reading a post about gas vs diesel trucks where somebody mentioned they liked diesel because of the exhaust brake. I've never had a diesel, always gas. If I come up to a long...
Forum Discussion
Grit dog wrote:
So the Load leash doesn't run the exhaust valves the same as a Jake and props them them open "permanently" while engine/exhaust braking to work in concert with the turbo/exhaust brake? Whereas a Jake only opens at the top of the compression stroke momentarily, but with a "free flowing" exhaust path out of the engine? (No vgt or exh brake downstream)
Very interesting. Thank you for the explanation.
Yes the Load Leash opens the exhaust valve slightly and holds it slightly open permanently (although, I'm going to guess the exhaust valve might still fully open on the exhaust stroke?).
With the "Jake" the engine braking is generated during the compression stroke, however, there is a variable gain turbo downstream which does build boost pressure to a very significant level (I can't remember off hand exactly what the boost pressure goes to while "Jaking" on our Pete but I think it's between 30 and 40 psi.) This boost contributes to much higher cylinder pressure (engine braking) on the compression stroke than what would otherwise be generated.
