couple efi quest?s

dracing70

SH--- GETTING EXPENSIVE!
Jun 12, 2007
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mantua, oh
ok first thing i need some clarification on is when logging data what is the difference between turbo boost pressure and boost pressure as well as the diff between fuel rail pressure and actual fuel rail pressure i dont understand these double pids. which ones are best to pay attention to.?
 

LBZrcks

.........
Jun 2, 2007
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SoCal
Are you talking about desired boost/rail and actual boost/rail pressure?

One is what the desired amount that your tune is requesting

The other is the actual amount that your truck is producing
 

durallymax

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Apr 26, 2008
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Under The Hood
^^^^ exactly.

If you have modified the tables or even if it is stock. Go log the commanded/desired and the actual PIDs for boost and rail pressure.

You would be surprised how much it can differ.

The difference in commanded and actual fuel rail pressure is very nice for figuring out what to do with your pulse width.
 

dracing70

SH--- GETTING EXPENSIVE!
Jun 12, 2007
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mantua, oh
ok so what about turbo boost pressure and boost pressure i recieve much higher readings on the turbo boost than just boost what is the difference which is the actual intake boost pressure?
 

durallymax

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Apr 26, 2008
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I would assume turbo boos tpressure is the desired boost pressure and boost pressure is the actual manifold pressure which will walways be lower than the commanded turbo boost pressure.