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bondurch
April 13th, 2009, 10:28 PM
Q: My concern lies with the Desired Boost ECT and Desired Boost IAT tables. Do they set up a max limit for boost?[/SIZE]

My current tune has good power, but my turbo boost never generates more than 24psi. I am tunning with efi on an 08 LMM with ATS transmission so I have room to generate more HP, hoping I don't blow a head gasket. The future calls for new turbos, but right now i want a little more out of my stock turbo.
When i study the tune parameters the Desired Boost Levels parameters should be taking me well over 24 psi. My concern lies with the Desired Boost ECT and Desired Boost IAT tables. Do they set up a max limit for boost? Is that a fair statement or am i missing something with the Boost control settings.

GMPX
April 13th, 2009, 11:31 PM
They aren't limiters, they are adders to the base boost tables for cold/hot weather conditions.
Off the top of my head I don't recall but can you log desired boost on the LMM? If yes, log that as well as the vane positions to make sure everything is as maxed out as you are wanting.

Cheers,
Ross

bballer182
April 14th, 2009, 10:17 AM
B2226 might be the case but even in stock form it allows up to 34 PSI

Remember when tuning the desired boost; if in low altitude subtract 14.5 from the number in each cell to figure out what the boost pressure is actually going to be.

MadMaxx61
April 14th, 2009, 03:37 PM
24psi is like running a stock tune I see a max of 41 psi on most of the tunes I run but anything over 40 I see the EGT go up like mad.

bondurch
April 14th, 2009, 10:46 PM
My turbo gauge is a Bully Dog PMT. Maybe it is not reading the electronic turbo singnal properly? I will try logging first then up the desired boost.

bondurch
April 16th, 2009, 02:42 AM
So I have done some further testing. The PMT seems to max out at 24 psi with either EFI tune or using the smoky PMT "Extreme" tune. So I switched back to the EFI tune and used the scan tool. From that I am reading MAX boost of ~50 psi. From reading an earlier post the 50 psi is really equates 36 psi at sea level?

I can close this thread by summarizing:
What is the PMT reading for turbo boost and why do I still own one?
Idaho Rob has some bad ass tunes!

dmaxfireman
April 16th, 2009, 10:51 AM
look at what the gauges read at idle. the one that reads 0psi is the the psia or psi absolute. the one that reads 13-15 is the psi reading from the map sensor.