Re: Adding an engine brake to U320
Reply #15 –
The disk brakes are somewhat cold blooded especially if the coach has not been driven recently. Rotors I think get surface rust on them. Need to be warmed up and deglazed before they can be relied upon if really needed.
Hence the factories wider adoption of the retarder versus only the 6v92 U300's originally.
Especially as the D2 seems to slowly lose pressure from oil buildup in the valving, at least in my case.
Adjusting the D2 to the max of 130/110 gives much stronger braking. Lessening the need for the retarders input.
The brakes obviously have a certain limit of heat absorption as does the retarder.
As Wolfe mentions downshifting the engine/trans increases the natural ability of a four stroke engine to hold back any vehicle.
Helps. Mixing the retardation and the brakes and keeping the revs up maximizes their abilities.
Driving hard like I am used to doing and living where everywhere out of our area involves hills I tend to be probably closer to the coaches limits.
Trained a lot of customers of the coaches actual limits versus they got concerned(panicked) if the temp gauge moved off its nominal minimum position.
The jake addition I put on similar displacement marquis with 3176 cats made the coach a true up and down interstate grades at 65 at 37,000 pound combined with both heels in front on the drivers seat.
2,4 or 6 cylinder jake panel on the left drivers wall(which was hollow to allow this placement) allowed the driver to control their downhill speed.
The 8,3 can have an exhaust brake if the engine has the correct valve springs which I think all the Foretravels have oem.
Which actually worked fairly well if you kept up the motors revs.
Rocky Mountains and high loads and increased speed users might consider the m11 jake option. I have.
The cat marquis had an optional after delivery customer preference software update available that allowed the jake to work with cruise control.
Like my 97's retarder. Works with the cruise. Marvelous.
If I added a jake it would have to be able to operate separately from the retarder and work on cruise control.
If possible....
Pipe dreams so far but the idea is there