I have an SS auto and I am just curious if the numbers that are posted on crateenginedepot.com website are correct. Here is what they have posted:

HHR torque ratings:
MT 315 lb,-ft of torque @ 4,800
AT 315 lb,-ft of torque @ 4,800

and 290HP @ 5,200 for both.

Is the MT going to have more HP and torque or will they actually be equal after the upgrade? Are these hp and torque numbers correct for the auto and are they the same in all four gears? Or is it going to be like the original tune where it is more restricted in first and second gear and then more power in third and fourth? And also if the torque rating is correct will this tune void my warranty, because if i remember correctly I believe that the input shaft of the auto transmission is only rated at something like 222 ft/lbs of torque and 315 is obviously going to be a little overkill.

Thanks for any possible help.

Dave

(I also sent this message as a PM to chevymgr to since he seems to have inside info.)

 

yes..
MT = AT

No reduced power in any gears...

FULL warranty too.....

 

So in simplistic terms if you've ever kicked yourself for not getting a stick because of the power difference, here's your redemption. Almost 25% power increase for $550 + tax and labor? No question, what a deal.

 

From my understanding, the auto transmissions are not as strong as the manuals, hence less power. My tuner tells me that once we get our HHR SS, (the girly wants an auto) he will make sure the tune is mild compared to what he would do with the manuals. Am I mistaken here??

 

any good tranny shop could beef up the auto if you want

 

Do a search on this forum on trans issues. I know of one guy here that has a auto and a hefty tune. Loves it. No Problems. I heard of quite a few sticks without a tune when shifting into 2nd or 3rd, clutch goes bye bye and cracks the trans housing. New tranny time. Be at the dealer for a few months waiting for it to come in. Go with the auto and put the tune in. GM rated the trans for 225lbft. Now they are going to 315lbft. They have to take care of that trans for 100k. That trans will handle more that 315 for quite a long time. But they wont tell us that.

 

They will cover it if we go with GM's stage kits, NOT if Tune Time dyno tunes it for me. I will do some more research. Thanks for the input so far guys.

 

The SS auto trans is rated for
325 lb-ft of gearbox torque Maximum
221 lb-ft of engine torque Maximum

don't ask me what the difference is though

 

Your mixing your issues here....

The cracked tranny issues is due to excessive wheel hop. I know of no one who has had a slipping clutch cause a cracked tranny.

Why do you think Chevy is limiting the torque to 315? Could it be that the clutch can't handle much more than that? Could it be the HP Tuner based tunes are pushing MORE than the HP and torque that Chevy is releasing with their new kit?

I'll probably be getting the Chevy kit but not because it is more powerful than current tunes, it is not, but because as others have correctly stated because of the new OS and the possibilities it open up for higher boost rates.

 

The cracked trans issue is not due to the slipping clutch. It is caused by the clutch itself coming apart. I may be wrong, but what I have heard about the manual trans issues with the trans breaking is in the clutch, which is also the weakest link in the system, whether you have a tune or not. And I believe you are right on the fact that the GM program will open the system up for better breathing.