This link ACTUALLY has some pretty good info in it, Andy:

http://en.wikipedia.org/wiki/Brake_fade

Tom Vaught

 

Well the deal with duramax pvc is GM/Isuzu vented the pvc into the inlet side so
any oil residue/blowby and critters go thru your turbo, piping, intercooler and then back to
the engine. I can see and understand how this works, but aren't you putting contaminates
back thru the system (carbon deposits) and getting couplers wet with oil residue (boost leaks).
As for diagnosing problems I can forsee this beeing a shadetree (me) mech's nightmare in the making.

 

I think that's kinda twisting it around. The engine knocks because the control scheme is pre-programmed for EGR to be flowing. If it isn't actually flowing (and unknown to the controller), then those settings are too aggressive such that the engine can knock.

I worked on a diesel emissions project in the late 90's that used a VNT turbo and a common rail injection system. We designed a closed loop control setup on exh backpressure, the goal being of course to try and control/raise backpressure to make substantial amounts of EGR flow (to reduce the NOx). We ran the full EPA emissions test cycle for the class of engine, trying to get the emissions down within a proposed new target box that was quite aggressive (proposed by the CARB/EPA).

The main problem we had with the idea was... closing down the VNT did in fact raise exh backpressure; however, it also spun up the turbo, which raised the intake pressure as well (lol) (VNT is good stuff).

Think the solution for diesel is to have a throttle mechanism to drop pressure enough to make EGR flow.

TurboTR