stiff wastsgates, preadator, and PCM boost
more torque than you'll ever need.
There a lot of guys fiddling with different waste gates trying to get one or another to run like they want it to on PCM boost. I put together a short list of do's and don'ts and a short intro.
PCM Boost control what is it?
Think of it more as Torque control. The PCM is programmed to deliver a certain amount of Torque at specific times. The PCM measure TIP pressure and compares it to the MAP pressure, and uses the difference to calulated Mass Air Flow. It varies boost to match a preset Mass Air flow in able to reach this preset Torque value. The mechanics of moving boost, is that the PCM has a big table stating that if it applies X duty cycle to the waste gate solenoid then it “Should” deliver X amount of manifold pressure. These tables are made for their respective wg(Stock, S2, S3) There’s two key points here pertaining to swapping wastegate around.
1) The preset Torque goes up and down from its base value(aka Desired Torque, yes you can log this) Don't expect it to be the SAME EVERY TIME
2) When you swap in a different WG, the WG duty cycle vs Torque tables don’t match up anymore. So, the PCM gets a bit befuddled. BUT there’s a sneaky deal provided to the PCM. Waste gate Adaptives. The PCM will “adjust” the WG duty cycles to get the manifold pressure it wants., but they have limits. If the PCM hits the Adaptive limits before it reaches the proper manifold pressure then you’re stuck. This is where MINDMELT has come in and “manually” adjusted the WG tables make up the gap.
What does this all mean to the average guy
When you increase the boost in the Predator you're only upping the Desired Torque and not overwriting any of the WG dc table.
All the above will only apply: if the WG DC learning is activated. SInce the Learnig is turned off in the 93tune, if the WG performs eracitally or otherwise "poorly", the PCM CAN NOT adjust it. It will require a CMR tune to manually adjust the WG DC Table to better match the WGA being used.