Thinking about 350-375 H.P. range in my HHR-SS, auto.
Wondering if anyone has found a beefed 4T45T trans, as I'm sure stock trans won't hold that kind of torque, and H.P.
Supposely the rebuilt one from Import Performance Trans will handle that kind of power, but heard one bad thing about their service. Anyone? Suggestions? "Moon"

 

ZZP mentioned here they had an upgraded 4t45e in their pipeline that was good for 100 extra HP, hopefully it isn`t long now as that was 6 months ago.

I`ve done much research, aside from IPT I haven`t found anything. Short of a diy, I`m waiting on ZZP.

 

Not in a real big hurry. Guess I'll wait awhile and see what ZZP comes up with. Got just over 300 H.P. now, but looking to add some more, and don't want to toast the automatic.
Just lining up my ducks. "Moon"

 

someone on here was selling a beefed up auto that they built from NY

 

GrandAmGT.com
60DegreeV6.com - Site News

Those sites have ALOT of information on the 4t45e trans. They've been dealing with them in custom-built turbo cars for years. There are upgraded clutches and some upgraded hard parts. There've even been final drive ratio and chain conversions as well as limited-slip diffs released.

 

talk to Fred from SMG Motoring and see if he can put you on with their builder. Fred is also familiar with IPT and may be able to give some insight on their build as well. I just brought the last trans from the SMG cavalier drag car.

"This is a fully built 4t45e automatic transmission for a cobalt/cavalier. Has Raybestos Z Pack clutches, hardened input and output shafts, Custom Torsen Posi unit with custom gear set with a final drive of 3.90. Valve body modifications for firmer and quicker shifts, also comes with 2,800-3,000 stall converter. Transmission is ready to install and is good for 500+ whp. Trans is fresh and was only bench tested at time of build. Have over $3,700 invested into this trans...."