1GMFanatik

Ok, so here is my largest concern. The girly is going to be getting an 09 HHR SS AUTO...I have heard the auto transmissions aren't holding up too well to the added power compared to the manuals, how true is this?? Are there any upgrade options yet??

c2vette

Maybe I am missing something??, but the HP increase is only about half what you get with the basic Hahn/PPC tune (the engine HP looks about the same as the WHEEL hp with the Hahn/PPC basic tune).

bartSS

Well the GM kit puts you at 290hp and 314tq. What does the HAHN put out?

tomw

I haven't heard of any Automatic Transmission failures where as I have heard of several Manual transmissions and clutch failures

c2vette

Since you are talking engine HP the Base Hahn/PPC tune is:

312 Hp (vs 260 stock)

1GMFanatik

This even pertaining to autos with some work done i.e. Tune, I.C. piping, ect.??? Just trying to do all the research I can BEFORE we do any modding. Plan on hittin the ground running once we get her car.

1GMFanatik

To the wheels?? What kind of dyno??

c2vette

There are plenty of dyno charts and details on other threads that show these numbers, and the increase from stock. For now, the GM tune offers a warranty (big plus), but not as much HP as the Hahn/PPC (not surprising). The dyno results show the increase from stock, so the type of dyno is not really that relevant as it would be if you were talking only absolute numbers.

1GMFanatik

I have a guy that will be doing the dyno tuning, but am slightly concerned about the auto trans not holding up as well as the manual. Then again, this is info I have heard through the grape vine hence my added research on here. lol

mightymouse

i got dynoed with just the tune only i put out 261 to the wheels. so stock, should be around 240ish. i never go by crank hp. with that being said,going from 260 to 290 crank on the gm,to the wheels you are looking at about the same.