Thought I'd plop in an update on my 2008 HHR SS (stnd). I had the turbo upgrade put in 60,000kms ago.

At that time, I had a dyno test done very soon after. Best numbers were 274whp, 280 wtrq. That was more than advertised!

During this winter, I noticed some clutch slippage in 5th on the highway when the temperature was below freezing and the car hadn't warmed up too much. Thought that was rather weird. This spring, clutch slippage disappeared again.

I took the car in for another dyno test to see the health of the engine after 60K of the upgrade.

Ready?

289 whp, 298wtrq. Now, this was a different shop, so +/- 10hp, but it was fairly consistent on the two pulls.

The power curves were VERY different this time compared to last, so yes, things had re-taught themselves and were running much better than before... which also may explain a bit of the clutch slippage this winter.

And I still fair decent gas mileage even with a full car. Two recent trips to the US fully loaded down with four travelers still got 26-28mpg. By myself last fall on a long trip, 31 mpg!

So, I'll be curious to check out the engine again in another 60K. So far, I'm impressed, and no issues (knock on wood)!

 

I've had a vacuum canister crack and now a sensor & Vacuum valve have failed. First bill was 50% picked up by GM, now I'm looking at $500. Really liked the car until these things happened. Power is still great. MPG is 30-34 hwy. Still have OEM tires and they are not down to the wear bars yet. Front rotors are now warped after a pad change at 54K. I have 66k miles on it now. Still a reasonable car, but wish this stuff wasn't happening, since GM has nothing to replace it on the market now.

 

Wow amazing whp numbers
I am going to have my dealer install my kit soon
I told tje service writer it should take right around
1.5 to 2 hours.
Now I am getting a little nervous where I read above that one dealer wanted 4 hours and that the dealer can charge what they want?
Is that true?
I guess if I had to pay for three hours u would be fine but 4 hours or more is crazy?

 

With the adapter the download from GM will take longer that the install. My dealer had the car two days when they did it.

 

Fellas, I purchased my 2010 HHR SS last year at a dealership in Ohio brand new. I had the GMPerformance kit installed at a dealership in Troy Michigan and I also installed a charged piping system, a free flow cat down-pipe, both sold by Hahn Racing, plus a CAG performance axle back exhaust. My car runs great, but the subjective performance does not seem that much different than stock. A bit better. I talked to a tech at GM Tech Center in Warren Michigan who helped develop the Bosch Performance kit. He said our 2.0 liter four banger was developed with "Algorithms" which mitigates other performance upgrades you add. Like the car rights itself to stock performance no matter what you do. Sounds absurd, but it has kept me from installing a larger turbo. He told me to disengage the battery, re-engage and then drive. At first the car will go like hell, but the engine/computer will right itself sort of back to stock. Does anyone have any information verifying this or is it bull crap? timothy_kozak@comcast.net

 

Great? Timothy I am sure someone will be along to explain this better than I can.
Stock the ss has a learn down mode another. Words add all the Bolton's you want and the Computer will still only allow the car to put out the same power.
But with the gmtu Turbo upgrade kit.
It should pickup power very noticeably right away.
Plus Any bolt ons that are beneficial will add hp.
The gmtu is supposed to turn off the Learn down mode.
What did you guys pay off for the install.
Could my dealer really charge me for a days work.
$90 x 8 hours $720.00
Guess they will have to keep it if they try that since others are only charging 2 hours or so?

 

There is no 'learn down mode', per se. It is all torque based. The ECU has torque targets that it will attempt to meet. If a part is added and the fuel added for stoic causes it to exceed the torque target, it will dial back its calibration to meet the target. If the car is running below its target torque add-ons could increase the torque until the target is met. The GM upgrade has a higher torque target than stock. Two possibilities exist. One, the dealer flashed the car wrong. Or two, the car needs to be driven for a bit to fully realize the new GM calibration. All the adjustments the car makes to meet its targets are gradual.

 

Breadfan thanks for that explanation
you wrote

"the car needs to be driven for a bit to fully realize the new GM calibration. All the adjustments the car makes to meet its targets are gradual."
does that mean it takes a couple days before your really see the difference?

 

If it does not take that long to install why did your dealer take two days to install it?
How many hours did they charge you for?

 

Bigjack. They should not charge you more than 2 hrs. That's what is in their labor book for this work. Get them to look it up and quote it. If it takes them longer, then tough-----. Their loss.
The power increase is there from the start. No learning. The reflash takes care of that. The Vette tech that did mine came back from the test drive with that "SS grin" on his face. Told me I better hold on the first time I nailed it! Well worth the $ and to keep my warranty.