Just want to say thanks to this forum in advance. Im my noob t00ning journey Ive learned so much from this group as well as trial and error. As part of the journey I'm running into a situation I've never seen before and Im hoping for advice to resolve. Ive been helping a buddy out with his trans tune on his G8. The tune worked out fine when he was at 6psi (build list below), nice strong shifts at WOT and firm around town, now that hes upped the boost, 15psi, its having 2-3 shift issues and part throttle surging. attached is the current tune and a log (one at wot where the 2-3 seems to drop all torque before the shifting, doesnt happen in any other gear, and part throttle where it surges. Hoping to get ssome tips to remedy. THe trans tune update file has the current trans tune, and the other file has the current engine tune. sorry its broken up. THanks again!


P.S. ignore the DC... the ECM limits the flowrate scaling after 400kpa, theres no fuel pressure drop nor lean conditions. Spoke with a local tuner and ID about it.

G8 WEIRD TRANS SHIFTING.hplJosh G8 cog 21deg_1050x_H_C_e85_SMooth Maf 1.hptg8 newest.hplJosh G8 trans tune update 1.hpt

2009 G8GT
408 LS3
BTR stage 3 PDS cam
Maggie 2300 cogged to run 15psi
6L90E
E85 with aux pump
ID1050x injectors
heads (not sure spec)