Quote:
Originally Posted by Got_The_Benz
Is the wastegate hose a pressure hose or vacuum type hose?
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MB didn't use vacuum wastegate actuators in US cars before the 1990 300D 2.5 and 1992 300SD.
Quote:
Originally Posted by Got_The_Benz
Is the pressure (if it is) in that hose the same as what would read on a Boost guage?
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In steady state the boost readings will be the same. The boost signal to the wastegate is right at the compressor outlet whereas typically a boost gauge is hooked up just ahead of or just after the overboost switchover valve. The distance between those two points and that huge chamber in between that is the intake manifold will introduce some lag in the downstream signal. You're probably more interested in manifold pressure than compressor outlet pressure. In fact you're probably most interested in what the ALDA sees since in a sense that's the only usable boost.
Quote:
Originally Posted by Got_The_Benz
if I put an adjustable restriction in-line of that hose would I be able to adjust the boost capability of the Turbocharger without having to adjust the wastegate?
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A restriction will increase the time it takes for the wastegate to open but it won't change the point at which the wastegate if fully open. The big downside is that since the wastegate can't respond quickly to compressor output, you risk interim boost spikes. Under hard acceleration you might see 16psi before the wastegate opens to limit boost to 12psi, vs in factory form the wastegate creeps open at something like 5psi and is fully open by 12psi. I pulled these pressure numbers out of the air. I don't know what the numbers are for your car.
You have much tighter control and predictable behavior with a ball and spring boost controler like ForcedInduction recommends.
Sixto
93 300SD