Originally Posted by TJ555
spark advance is only mechanical, not vacuum advance, i got all advance at 2500-2800rpm like 32°, al sensor are above supercharger
this will not work. The sensor on the TBI body sees a vacuum when the blower is @ WOT pulling hard on the TBI.
The MAP sensor sees this as part throttle cruise engine operation, when the engine is actually WOT full power under boost.
It trims the fuel curve instead of increasing it.
It advances the timing instead of retarding it under boost.
( if it controls spark advance in any way.)
This EFI system is not roots blower motor friendly.
If it was, the MAP sensor would be on the intake manifold under the blower.
its not going to work right on a blower if its for a N/A engine.
The map sensor must be boost referenced just like a boost referenced power valve when using a carb on a blower motor.
Or a second "bypass" "boost" sensor on the manifold or a WOT throttle switch to by pass the false vacuum signal it is seeing at WOT.