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Re: Schrappnell Knobben (R)eport


I have seen about 4-5 psi at the W/G for 14-15 psi off boost. Remember
this S-Knob pressure on top of W/G is additional to your mechanical
spring so you may see different S-Knob pressures depending on what
mechanical spring people have.

I ran lines inside the car and mounted my S-Knob on the lower drivers
side package shelf. It is real handy for as you mentioned the valet
adjustment. Although I have found once it is set for (in my case)
14.5-15 psi I rarely mess with it. I do know that temperature extremes
will affect the regulator and it seems that inside the car is a more
temperature stable place.

>Now that I've got the thing installed I'm going to be looking for a 
>one way valve that I can use to allow the pressure to be held on the 
>WG even after the boost has gone down, so that way I'll have the stif-
>fer effective spring before the boost comes back.  This was discussed 
>on the list sometime back, but I never heard if anyone actually did it.

I be the one that brought up that thread. I bought some plastic check
valves from McMaster Carr and put one inline thinking that it would
prevent the engine from applying a vacuum to the top of the W/G during
shifting. It does do this but I cannot tell any performance differences
with or without the check valve. I also put a small pin hole in the hose
between the check valve and W/G to allow the pressure to bleed off
slowly. With a perfectly sealed W/G the pressure could build up and if
you wanted to adjust the S-Knob to a lower pressure you wouldn't be able

87 5KTQ (15 psiofgofastfun)