Turbo and Auto Tranny???

[Sand-Maverick]

We build 2 and 4 seater LS1 and LS2 Sand rails. We recently built a LS2 2seater with twin 44 garrets. Using HP Tuners software we got the engine dialed in pretty well. But unless you are just cruising real slow like very little throttle and absolutely NO boost it will shift, when you punch it will down shift into first but never shift out. Even messing with the shift RPM, and shift MPH tables in the software the car still won't shift. We think that it is because of the computer looking to base when it shifts off of manifold vacuum and all it sees is boost???? Any Ideas?????

[got-a-ls1]

i would make sure you have the speed sensor setup correctly and the tps sensor...

Shifting is completely electrical and uses the speed sensor the the throttle pos. sensor if im not mistaken. Pretty positive it doesnt look into the vacuum at all. MAybe the there is a mechanical problem with the tranny?