Just drove an automatic HHR SS
01-30-2008, 04:57 PM
#13
Member
Join Date: 01-30-2008
Location: Canada
Posts: 59
Automatics and Standards would be programmed differently is all. Also the automatic is detuned. I don't know if that's because it can't handle the extra horses, but that'd be my first guess.
The reason for the faster spool up on automatics is that you are engaged at a lower RPM to start with (launch usually starts off at lower RPMS with automatics because of no clutching in).
I test drove a standard SS (which I'm buying now) and the spool up on the turbo really only kicked in HUGE around 3000 rpms. That wouldn't work with an automatic because most of the time the automatics usually switch gears at lower rpms to save gas, engine, etc.
SO, because the automatics tend to operate at lower RPMS, the programming for a standard tranny turbo engine would leave you in a lot of turbo lag, resulting in poorer performance and worse gas mileage. So, you set up for a faster spool up at lower RPMs, that is compensated for.
On older turbos they were governed by the veins of the turbos with no direct computer control, but isn't the SS equipped with a variable vein system? That would relate to programming.
That's my understanding of things. Anyone out there to support / deny?
I've had two other cars with turbos before (Sprint Turbo standard, and Volvo 940 Turbo auto). On the Volvo auto, later editions were equipped with faster spool up turbos to account for lag.
There's also different control mechanisms for rpm drops between gears or slow down on autos and standards. I know on my old Volvo 940, I had hiccuping with the auto. It was minimal, but it was there.
I'll tell you guys flat out... get the standard unless you have a requirements for the automatic.
1) better control over the use of the turbo
2) more HP
I have a HHR LT 2.4L with a standard that I'm breaking the lease on to get my SS. The clutch on the LT is MUCH stiffer than the SS. The SS's clutch is feather light which is a little odd to adjust to, but in a few minutes, it was quite nice.
Cheers
Rob (not a mechanic, but I have owned a few turbos)
The reason for the faster spool up on automatics is that you are engaged at a lower RPM to start with (launch usually starts off at lower RPMS with automatics because of no clutching in).
I test drove a standard SS (which I'm buying now) and the spool up on the turbo really only kicked in HUGE around 3000 rpms. That wouldn't work with an automatic because most of the time the automatics usually switch gears at lower rpms to save gas, engine, etc.
SO, because the automatics tend to operate at lower RPMS, the programming for a standard tranny turbo engine would leave you in a lot of turbo lag, resulting in poorer performance and worse gas mileage. So, you set up for a faster spool up at lower RPMs, that is compensated for.
On older turbos they were governed by the veins of the turbos with no direct computer control, but isn't the SS equipped with a variable vein system? That would relate to programming.
That's my understanding of things. Anyone out there to support / deny?
I've had two other cars with turbos before (Sprint Turbo standard, and Volvo 940 Turbo auto). On the Volvo auto, later editions were equipped with faster spool up turbos to account for lag.
There's also different control mechanisms for rpm drops between gears or slow down on autos and standards. I know on my old Volvo 940, I had hiccuping with the auto. It was minimal, but it was there.
I'll tell you guys flat out... get the standard unless you have a requirements for the automatic.
1) better control over the use of the turbo
2) more HP
I have a HHR LT 2.4L with a standard that I'm breaking the lease on to get my SS. The clutch on the LT is MUCH stiffer than the SS. The SS's clutch is feather light which is a little odd to adjust to, but in a few minutes, it was quite nice.
Cheers
Rob (not a mechanic, but I have owned a few turbos)
to the site Rob!!! Congrats on your new SS 
01-30-2008, 09:15 PM
#15
New Member
Thread Starter
Join Date: 01-26-2008
Location: NW Ohio
Posts: 28
Automatics and Standards would be programmed differently is all. Also the automatic is detuned. I don't know if that's because it can't handle the extra horses, but that'd be my first guess.
The reason for the faster spool up on automatics is that you are engaged at a lower RPM to start with (launch usually starts off at lower RPMS with automatics because of no clutching in).
I test drove a standard SS (which I'm buying now) and the spool up on the turbo really only kicked in HUGE around 3000 rpms. That wouldn't work with an automatic because most of the time the automatics usually switch gears at lower rpms to save gas, engine, etc.
SO, because the automatics tend to operate at lower RPMS, the programming for a standard tranny turbo engine would leave you in a lot of turbo lag, resulting in poorer performance and worse gas mileage. So, you set up for a faster spool up at lower RPMs, that is compensated for.
On older turbos they were governed by the veins of the turbos with no direct computer control, but isn't the SS equipped with a variable vein system? That would relate to programming.
That's my understanding of things. Anyone out there to support / deny?
I've had two other cars with turbos before (Sprint Turbo standard, and Volvo 940 Turbo auto). On the Volvo auto, later editions were equipped with faster spool up turbos to account for lag.
There's also different control mechanisms for rpm drops between gears or slow down on autos and standards. I know on my old Volvo 940, I had hiccuping with the auto. It was minimal, but it was there.
I'll tell you guys flat out... get the standard unless you have a requirements for the automatic.
1) better control over the use of the turbo
2) more HP
I have a HHR LT 2.4L with a standard that I'm breaking the lease on to get my SS. The clutch on the LT is MUCH stiffer than the SS. The SS's clutch is feather light which is a little odd to adjust to, but in a few minutes, it was quite nice.
Cheers
Rob (not a mechanic, but I have owned a few turbos)
The reason for the faster spool up on automatics is that you are engaged at a lower RPM to start with (launch usually starts off at lower RPMS with automatics because of no clutching in).
I test drove a standard SS (which I'm buying now) and the spool up on the turbo really only kicked in HUGE around 3000 rpms. That wouldn't work with an automatic because most of the time the automatics usually switch gears at lower rpms to save gas, engine, etc.
SO, because the automatics tend to operate at lower RPMS, the programming for a standard tranny turbo engine would leave you in a lot of turbo lag, resulting in poorer performance and worse gas mileage. So, you set up for a faster spool up at lower RPMs, that is compensated for.
On older turbos they were governed by the veins of the turbos with no direct computer control, but isn't the SS equipped with a variable vein system? That would relate to programming.
That's my understanding of things. Anyone out there to support / deny?
I've had two other cars with turbos before (Sprint Turbo standard, and Volvo 940 Turbo auto). On the Volvo auto, later editions were equipped with faster spool up turbos to account for lag.
There's also different control mechanisms for rpm drops between gears or slow down on autos and standards. I know on my old Volvo 940, I had hiccuping with the auto. It was minimal, but it was there.
I'll tell you guys flat out... get the standard unless you have a requirements for the automatic.
1) better control over the use of the turbo
2) more HP
I have a HHR LT 2.4L with a standard that I'm breaking the lease on to get my SS. The clutch on the LT is MUCH stiffer than the SS. The SS's clutch is feather light which is a little odd to adjust to, but in a few minutes, it was quite nice.
Cheers
Rob (not a mechanic, but I have owned a few turbos)
Hell, sounds good to me, you sure you didn't stay at a Holiday Inn Express last night.
I thought the variable vein turbos relied on inertia to open up and make the turbo "bigger" internally as the turbo spun faster. Hence a "smaller" more efficient turbo for low rpm and a larger more powerful turbo at higher rpm. I didn't think the individual veins could be controlled electronically, but I could be wrong. I would have to get an auto due to the HHR SS being the wifes and having to deal with two kids (2yrs and the other is 9 months). No argueing the stick would be faster, just think the auto has a lot of potential also.
01-30-2008, 09:18 PM
#16
Senior Member
Join Date: 01-25-2008
Location: Bergen County, NJ
Posts: 132
I have the automatic in my SS, from what the Dealer told me (I talked to a person who actually knew what he was talking about this time) He said that the Stage kit will be more effective on the Automatics cause it will bring the performance up to the manual's stock numbers and then go up from there to make the two even. He said just what you said, the kit will give you better shift points and better spool time. Its the same engine in both, just different computer calibration. He also said that the automatic tranny was more then able to handle the HP, so its just to get you to buy the stage kit. He compared the two hhrs with the new GTO's, saying that the automatics and the Manuals had the same hp and torque numbers in them regardless of the transmission, its the same with the HHRs. Its the same car, just a matter of wheather you want a auto or a manual (once you get the stage kit)
01-30-2008, 09:38 PM
#17
Senior Member
Join Date: 10-14-2006
Location: So. Cal
Posts: 1,186
Rob those were interesting comments...
From what I understand, the autos are detuned and for the reason you were guessing, yes that tranny will not stand up to 260HP at least not long term.
I've read regarding turbo lag that it's one of the things that GM has addressed with the turbo Ecotec. So anyone let us know if turbo lag is a problem.
From what I understand, the autos are detuned and for the reason you were guessing, yes that tranny will not stand up to 260HP at least not long term.
I've read regarding turbo lag that it's one of the things that GM has addressed with the turbo Ecotec. So anyone let us know if turbo lag is a problem.
01-31-2008, 07:06 AM
#19
Senior Member
Join Date: 01-28-2008
Location: INDIANA
Posts: 355
I wouldn't be surprised to find that the auto cars have a smaller turbo, that's one of the only ways to get a turbo to kick in at a lower rpm, and would also limit overall boost and power, such as in the 235 rating for the auto. The published torque curve shows the auto cars peak starting at like 1650 rpm and the stick at 2000. Those torque curves are taken from an engine on a dyno, not after the transmission, so they do not show the influence of what transmission is behind them, just the power curve and rating of the engine and its programmed operating parameters.