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View Full Version : cammed LS3 Surging on auto downshift



dusto82
August 15th, 2013, 04:55 PM
hey all
i have been tuning my ls3 that i have just put a cam in
i think i have the idle pretty good where i want it, it sits nice and flat and when free revved drops right back to where it should be no hunting etc, also if i hold in gear and slow to a stop it will just drop the desired rpm, problem is when in auto mode the box shifts down as i pull up to a stop and the revs drop right down to 500 rpm then flair up it does it on every downshift, the only way i have been able to make it half way acceptable is set the 2-1 and 3-2 down shift speeds 0 and low throttle opening, but this means it wants to take of in 3rd and the rapidly downshifts to 1st or 2nd,
the idle tuning guide dosnt seem to have anything like this in there and i believe i have min idle area good etc as apart from the down shift it always drops and stays where it should without hunting or anything, is this somthing i have to live with having a stock convertor?

thanks in advance, i will get some logs up later on

Regards,
Dustin

Rhino79
August 15th, 2013, 05:10 PM
Try disabling tq mgt on closed throttle downshifts. Also don't over time it with base and coast down timing. Log to see if the timing correction is pulling a bunch after the tq mgt is turned off, then if so, you may need to play with coast down and base timing to make it smoother.