This may be a stupid question but...

[Turbo Hearse]

If I'm reading correctly, I can purchase HPT and upload the GMS1 tune as a starter upgrade. Can I do this without the MAP upgrade?

And also, can someone just confirm that the GMS1 tune is available for free after in the HPT tunes list for each vehicle?

[shabby]

Since you can alter the map scaling you don't need the 3bar maps.
Finding a gmpp tune in the repository is no guarantee, which car do you have?

[cobaltssoverbooster]

I don't think there are any in the repository. Hpt wouldn't allow it when it was released so we pass them around privately

[Turbo Hearse]

This would be for a 2008 HHR SS

[Iam Broke]

Stock base file modified for the 3 bar MAPs is the way to go. Less turbo nanny in the stock base file than GMPP in tables we cannot access.

Or you can boost above the control range of the 2.5 bar MAPs on the stock file & run 'out of control'

You cannot run the GMPP file without changing the sensors and if you modify it to match your stock sensors you will most likely see less boost above 5k rpm but I never tried it personally.

[lsxrx7]

So if I had the dealer flashed the gmpp calibration in my ecu would I be able to access it with Hp tuners?

[Iam Broke]

Yes, but why?

The info to run the 3 bar MAPs on the stock file and tune it is already in this forum.

You can do better than the GMS1 base file with the stock base file.

Buy the sensors & pigtail adapters from Performance Autowerks or CED and do it yourself.

[lsxrx7]

I just received this car and apparently it has a custom os in it with all the map sensors installed. So I'm trying to figure out if I should have the dealer flash it back to stock or
Have the gmpp tune put in it or if I can plug in a tune that l already have and do a write
entire but I was told that I couldn't do that so I haven't tried.

[Iam Broke]

Post the tune after you do a read entire. It may be already a stock file OS and 3 bar MAP data.

Some tuners (like me) prefer this combo.

If you are uncomfortable posting the tune at least post the numbers from the ECU OS and the MAP sensor data.

Need to know the model year and vehicle also to see if it matches.