Anyone running this successfully and have their setup to share? I'm using VSS on the front wheels and rear to compare and using the MS3 to pull timing. Even by setting the slip threshold very low (2%) it seems the spark retard is not enough to stop my car aggressively spinning up the rear wheels to the point I need to let off the throttle.

I can, of course, pull boost but I'd rather not do that (it takes longer to spool up again). Has anyone had much success and care to share their settings?

 

At 20 degrees, you are reducing the ideal engine output by 16-21% which may not be enough, given that you also bump the boost at the same time due to the increased exhaust gas energy. You need about 30 degrees to get in the 45-50% engine torque reduction, however that can't be sustained as the boost will start increasing radically, at that point an air path (throttle body) reduction must be implemented.