0% DC = full advance (park position)
50% - nominal run position (50% retard)about 12*
100% - full retard - 25*
EFI-DIY, so I have questions about the VVT. I have been reading that it is controlled by oil pressure and a solenoid, is the solenoid computer controlled? I have a BMW with VVT but it is all mechanical off of oil pressure. I am looking to use the 4200 and want to keep the VVT, just wondering if it is feasible out of the factory GM car, and does it need to be fairly stock to keep the VVT?
Yes the PCM controls the solenoid.
What are you planning on putting the engine into and are you planning on using the factory PCM or aftermarket (e.g. Megasquirt 3) to run the engine?
DIYautotune makes a standalone VVT controller.
I am wanting to build a cart (death cart, vette cart, dune buggy etc.) I first started looking at the 4200 because I thought it would be cool to have AWD, so I started looking at the bravada's. Will probably use the GM PCM for simplicity. That and I am not trying to squeeze tons of power out of it. If I am able to get 350 or so I would be pretty happy. Weight will be down around 1500 lbs or so, mid 80" wheelbase, AWD, low to the ground with wide tires and a roll cage. My family has been building race cars since before I was born, my brother is an even better fabricator than I am. I'm ok, he is GOOD. Even thinking about using a ford explorer IRS for better handling and to solve short driveshaft problems with such a short wheelbase.
Head porting is key to making power on these engines. Ported head and a header with a tune on a 06 up head should net ~ 30 hp.
I have on 02 Envoy and was able to view the cam phaser desired and actual angle through Torque pro. Mine will max at 20 deg momentarily but regularly will not go past 19 deg.
My buddy has an 05 and I can see 23 deg on his.
Also, I will get 19 deg fairly early, around 2200 RPM and will back off as I apply throttle, maybe to maintain vacuum, not sure.
Is that the norm for the early engines?
Good question - a good person to ask is Jeremy @ lime-swap.com
He does a lot of 4200 tuning.
The 02 (and possibly some 03's) were limited to 20 degrees whereas the later models were 26. I believe they had a different can phaser all together. Mp