Turbo Talk... & HKS Controllers

[Peter Dufault]

> /// One last time... the SAAB 900t has a analog control box the reads
>     the knock sensor and if the knock is over a preset level that you 
>     can change inside the control box then the unit opens the air boost
>     control valve and then the turbo waste gate can slow the turbine down.
>     If you have good gas and the engine see's no knock then it will alow
>     the wast gate to stay closed untill you have knock.....

One last time eh? Well, you're right.  In my weak memory I was
thinking the turbo bypass valve was being switched by the APC
solenoid.

I did find the manual so using the SAAB terminology - the APC
solenoid vents the waste gate diaphragm (or whatever you call that
pressure bulb the control rod is attached to) from seeing strictly
the intake manifold (the base setting) to an artificially reduced
pressure, so the intake manifold pressure goes higher.  The waste
gate is set to what would be an "abnormally" low setting in another
car and depends on the APC unit to let it go higher.  That is why
the factory SPG units need premium - the base setting is higher.

-- 
Peter Dufault (dufault at hda.com)   Realtime Machine Control and Simulation
HD Associates, Inc.               Voice: 508 433 6936