Stage 1 kit can go in Automatic. Really????
Member
Joined: 07-12-2009
Posts: 66
From: SoCal
GTPs max output 'safely' on the trans is 280ft/lbs of torque with the 4T65e, hence why the GTP never went higher in torque due to that limitation. Diff is definitely the week point especially on FWD. Do one-wheel peels and your diff will go. Do high stall launches and your torque converter will go.
However, increasing the power/torque will decrease the life and I seen those trans go from 12k miles (with the GXP V8) to close to 150k miles (325whp/ 375ft/lb modded GTP).
However, increasing the power/torque will decrease the life and I seen those trans go from 12k miles (with the GXP V8) to close to 150k miles (325whp/ 375ft/lb modded GTP).
Senior Member
Joined: 07-05-2008
Posts: 5,464
From: Akron Ohio
Well the GXP has 323 FT LBS stock and they have not been failing in great numbers.
On other factor to contend with here is the VVT. The computer can dial in the Torque when it is safe. The computer is what keeps everything alive on these cars engine and transmission.
Many of the Fiero engine swap guys also use this tranny with little issue. Most know you just can't take it to the track week after week with out breaking something. Now in normal performance street driving they seldom fail.
The diffs fail often at the start line at the stip with slicks and a sticky track. I have seen them split the case and parts hit the track.
Either way GM would not have pointed a gun to their heads and put this out if it would not last nor make warranty claims they would have a hard time winning in court.
My Comp G GTP has yet to miss a shift and is still running great.
On other factor to contend with here is the VVT. The computer can dial in the Torque when it is safe. The computer is what keeps everything alive on these cars engine and transmission.
Many of the Fiero engine swap guys also use this tranny with little issue. Most know you just can't take it to the track week after week with out breaking something. Now in normal performance street driving they seldom fail.
The diffs fail often at the start line at the stip with slicks and a sticky track. I have seen them split the case and parts hit the track.
Either way GM would not have pointed a gun to their heads and put this out if it would not last nor make warranty claims they would have a hard time winning in court.
My Comp G GTP has yet to miss a shift and is still running great.
Member
Joined: 03-25-2008
Posts: 69
From: Southern New Jersey
The Grand Prix used the 4T65 transmission which had a published torque limit of 303 lb-ft in 2008. The HHR uses the 4T45 transmission which has an official, GM published engine torque spec of 221 lb-ft in 2009.
There is a bulletin that says your factory warranty is still good with the upgrade kit, but that wasn't my question. My original question was... Is there an official GM website, or can someone produce an official GM published spec sheet that says forget the original specs, with the stage kit these transmissions are rated to handle the upgraded power?
There is a bulletin that says your factory warranty is still good with the upgrade kit, but that wasn't my question. My original question was... Is there an official GM website, or can someone produce an official GM published spec sheet that says forget the original specs, with the stage kit these transmissions are rated to handle the upgraded power?
Senior Member
Joined: 07-05-2008
Posts: 5,464
From: Akron Ohio
The Grand Prix used the 4T65 transmission which had a published torque limit of 303 lb-ft in 2008. The HHR uses the 4T45 transmission which has an official, GM published engine torque spec of 221 lb-ft in 2009.
There is a bulletin that says your factory warranty is still good with the upgrade kit, but that wasn't my question. My original question was... Is there an official GM website, or can someone produce an official GM published spec sheet that says forget the original specs, with the stage kit these transmissions are rated to handle the upgraded power?
There is a bulletin that says your factory warranty is still good with the upgrade kit, but that wasn't my question. My original question was... Is there an official GM website, or can someone produce an official GM published spec sheet that says forget the original specs, with the stage kit these transmissions are rated to handle the upgraded power?
I am sure in the programing they have killed the torque at the shift points. This is how they make trannys live today.
Either way GM would have never released a upgrade that would kill the tranny. Even stock they are over the 221 number you have posted.
Senior Member
Joined: 08-06-2009
Posts: 181
From: Crestview,FL
I think this was the purpose of my question. I realized that having a Stage 1 kit didn't void the warranty, but if you do damage while utilizing all that extra power and torque, would the damage be covered. Even if you weren't purposely abusing the engine.
For example, if you punched it while on a freeway and got her up to 130 MPH or so, and the stress did damage, would this be covered. or would GM say, you did the damage while breaking the speed limit so the damage isn't covered.
but I'm still curious about how the AT on a 2008 SS can handle the extra torque of a Stage 1 kit, when GM said they didn't allow the extra torque for the AT because the trany couldn't handle it. I know they may have beefed up the trany on the 2009 or 2010, but I don't think they have upgraded the trany on the 2008.
I know I'm probably not being clear. But how could an original 2008 AT trany handle the Stage 1 available torque, when it couldn't handle the amount of toque that the 2008 MT could.
For example, if you punched it while on a freeway and got her up to 130 MPH or so, and the stress did damage, would this be covered. or would GM say, you did the damage while breaking the speed limit so the damage isn't covered.
but I'm still curious about how the AT on a 2008 SS can handle the extra torque of a Stage 1 kit, when GM said they didn't allow the extra torque for the AT because the trany couldn't handle it. I know they may have beefed up the trany on the 2009 or 2010, but I don't think they have upgraded the trany on the 2008.
I know I'm probably not being clear. But how could an original 2008 AT trany handle the Stage 1 available torque, when it couldn't handle the amount of toque that the 2008 MT could.
Senior Member
Joined: 11-15-2008
Posts: 1,599
From: Newburgh, NY
Lots of theories about this. Below is an opinion from one of the writers of ChevyMax who asked this very question about the auto SS in 2008:
Understand that this is before the GM Turbo Upgrade was released (along with the factory warrantee for it).
Now for my opinion and for what it's worth (probably -0), I would think that this is subjective. Anyone who first of all would buy and SS, then add a turbo HP/Tqe upgrade has to know how to drive it, since it comes at a premium cost with specific benefits. If it were me, I'd go for it (the upgrade) and argue the fact if the trans blew to hell (I haven't done a neutral drop since the original Camaro days in the late '70's).
I chatted with a powertrain engineer about some inconsistencies. The plant in the F35 5-speed
SS is privy to a 260-horse/260-foot-pound engine whereas the automatic version makes do
with 235hp and 223lb-ft. The sage logic is that the durability of the automatic would suffer
under a real heavy foot.SS is privy to a 260-horse/260-foot-pound engine whereas the automatic version makes do
with 235hp and 223lb-ft. The sage logic is that the durability of the automatic would suffer
Understand that this is before the GM Turbo Upgrade was released (along with the factory warrantee for it).
Now for my opinion and for what it's worth (probably -0), I would think that this is subjective. Anyone who first of all would buy and SS, then add a turbo HP/Tqe upgrade has to know how to drive it, since it comes at a premium cost with specific benefits. If it were me, I'd go for it (the upgrade) and argue the fact if the trans blew to hell (I haven't done a neutral drop since the original Camaro days in the late '70's).
Thread Starter
New Member
Joined: 10-25-2009
Posts: 29
From: Germantown, TN
But the major question was how could the kit be okay for the AT when Chevy said they tuned down the stock engine because of concerns the AT couldn't handle the extra torque and power?
Senior Member
Joined: 02-09-2009
Posts: 3,169
From: Downtown Saint Petersburg, Florida
I been thinking (based on your posts) YOU probably shouldn't install a stage 1 upgrade because your weak AT probably won't handle it.
