diesel_guy86 wrote:
I believe it is the same turbo but not 100% sure. The turbo i have came off a 2010 Audi q7 with a 3.0L TDI. Im gonna order a new center section and bearing kit (mine is at the machine shop) tomorrow to start assembling so i can test how well the new vanes and turbine work in our housings.
Ive also been thinking of contacting a couple master truck tuners to see how much work is involved in creating a tow tune that can use the new vanes for exhaust braking. It would be neat to use the o/d button on the gear shifter to turn this tune on/off. I love this feature on my truck, but I dont know if the same idea can be carried over to our application.
funnyman06 wrote:
In our Liberty we could have a similar exhaust brake function simply by closing the vanes in the turbo. This would create a restriction in the exhaust just like an aftermarket exhaust brake does. This is how all modern pickup truck diesel engines do it. Being that the turbo is controlled pneumatically, its possible you could create a mechanical system that would close the turbo vanes on call. The other side to this would be to force the transmission to keep the TC locked so really take advantage of this.
I was actually planning on trying to tune an exhaust brake myself and I dont think it would be that hard to set the turbo vanes to close in the tune. There are 3 N75 maps which are there to kinda calibrate the PWM that is sent to the vacuum system so that the turbo does not over or under boost. By changing these three maps at 0% throttle and only when the engine is above a certain RPM(IE, it you downshift using the OD Off button), then you should be able to get the VNT to close only in situations where you are trying to engine brake. My only concern is that at high RPM you could spin the turbo too fast with an aggresive VNT.
The Chevy Colorado/GMC Canyon Dmax trucks do this via a switch on the dash, but this is how they work as there is not standalone engine brake.
If I get a chance I will try this this weekend. I've got some nice hills around here that I can do some before and after testing on. I think that datalogging the boost should be a good indicator if it works.