I've heard exhaust brakes in the big rigs but I haven't heard them in a pickup truck. How do they sound with both stock exhaust and aftermarket ?

 

It's pretty quiet with the stock exhaust.

 

Nothing like the big rigs. It's just a kinda hissing noise.

 

The exhaust brakes in a semi are totally different. They are a part of the engine/cylinder head itself. They open the valves and shut off fuel causing the engine to be a giant "air compressor" hence the loud bellowing. This is a true "jake" brake. The brakes on Dodges just shut off the exhaust and cause alot of backpressure, hence the "hissing" sound.

 

WhiteSport is correct, the Jake for ISB is an exhaust brake- big butterfly valve in the turbo elbow, where big trucks use compression brakes, that essentially open a valve open near TDC to release compression pressure so the engine has to push the piston up the compression stroke, but doesn't gain the force back from the pressure on the following downstroke.

Mine hisses at idle, but when in actual operation with some back pressure built up, it does make a kind of chug, chug, chug sound...

Can you post a sound clip on these theads? (I think my digital camera can record one).

Jeff