Please forgive if this has been covered before. I did search around a bit and found this thread. I have a 2009 HHR SS I just got with 84,000 miles and my boost is limited to 10psi. This was a car originally from Michigan and Illinois for the first year and a half, but has spent the last five years in Texas. It is now at sea level in California. Any thoughts on why the boost is so low?

We also own a 2009 Solstice GXP Automatic with the same motor and that car is MUCH faster than the HHR. I know there is a difference in HP for the automatic HHR SS, but the difference is huge. Neither one is upgraded.

Any information would be great. Thanks

 

I started a new thread on this, better than tagging onto the end of a semi-related thread.

Any CheckEngineLight?

Altitude has no effect unless a sensor is bad.

 

Thanks for the administrative help on the thread location.

No check engine light. Cars runs great. Just conservative boost. Car was just smoged in CA and it passed no problem.

 

Even with no CEL present, you could still have a trouble code stored. I would suggest pulling the codes and see if there is something stored.
If it's code free, then maybe a check of all the boost system piping and it's connections. You could have a small leak under boost pressure. Pay particular attention to the intercooler plastic end tanks for any small cracks.

 

I have a friend who has a pro code reader. I will have him check it out. Meanwhile I will look for any cracks and loose connections. Thanks for the suggestions. I will let you know what I find

 

1st gear is limited to 10psi max on the auto higher gears depend on location relative to sea level, temp, humidity. The SS is torque based so if 10psi gets you full torque that's all you'll get get up in the mountains,warm heavy air and boost will go up.

That said usually people see 12-18psi. I was seeing 12-15psi here in NJ close to sea level when I got mine. A after market tune will change all this. I see 24psi anytime now :)


More info

 

if you have the RPD watch the HP numbers and that will pretty much tell you

My 09 Auto hits 12PSI when it was stock (235-240HP) and after it was tuned normally 15-16psi right about (270-275HP) on the RPD meter. Most folks were getting 15 stock and upwards to 20 tuned but mine has always run low but it still hits the projected HP numbers