boost

[yonner]

if my car is maped to 15psi will it be safe to run it at a mutch lower boost lets say when its raining or something wihtout it runnign to rich?

[bobster]

It is safe ....just not very manly

[20B_boy]

Your ECU takes references from amongst other things your MAP sensor.

The computers base fuel map is referenced by RPM v boost.

Say the motor is spinning at 4000rpm. If it reads manifold pressure from the MAP sensor to be 5psi it will look up 4000rpm and 5psi on the fuel map and will see that it should squirt the injectors for say 2 milliseconds (for example only!) - which should be enough fuel to maintain whatever AFR you have mapped the car to at the engine speed and load point.

If the MAP sensor tells the ecu that boost pressure is 15psi it will look up 4000rpm again but will look at the 15psi load site and see that it should squirt the injectors for say 4 milliseconds - again enough fuel to maintain the AFR you have mapped that rpm/load site to...

In other words whether u set your boost controller to 7psi or 14psi the car will only run as rich as the ECUs fuel map tells it to. Just cause you have mapped up to 14psi doesnt mean the car will squirt in the fuel needed for 14psi at lower boost levels - they are clever like that! :rollin

HTH?