Quote:
Originally posted by MBnewB
quick question: you mentioned doing the adjustment
"in the driveway"....i've recently been told to check my turbo's effectiveness using a boost guage at the plenum fitting going to the ALDA...but been advised: check it under LOAD,say climbing a hill above 2500 rpm...vs 2500 running in Park....as I understand the physics involved...spooling at 2500 rpm in Park will require much less fuel burn...said extra fuel burn under hill driving LOAD being different...right?...extra fuel burn = more exhaust gas temp/expansion = faster turbine spin velocity on hot section=more psi cold side boost to the boost guage?....ergo, would a setting dialed in park in the driveway read something very different under load going up the hill?...& most importantly
WHICH is the correct MAX you want to keep from damaging the engine, while preserving your right to make TORQUE & blowing by the factory engines going down the highway....??
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Yes, that is 100% correct...., to a point. Just from experience testing these both under load and in the driveway, there's about a 3/4 psi difference in spread. In the driveway at 10-12 psi, you should be at a good safe boost under load. Remember, this tells the gate when to dump relative to compressor pressure, so even if the turbine is really cranking and under load, there is still a finite pressure that the compressor will be allowed to boost before the gate opens, it will just open earlier under load to dump the pressure, but the pressure should still remain relatively constant, either way.
Of course, this is the DIY quick fix. What a person SHOULD do is have both an EGT and a boost gauge fitted to minitor their changes. Once the car is setup though, the gauges aren't critical anymore (except to give indication of a blockage in the WG sensor line.)