Answer to One of the Re: <VV> Two Questions

[FrankCB at aol.com]

From:  "Smitty Smith" <vairologist at verizon.net>

> Smitty  Says: 
>  Question # Two.  It has been recommended to use  a solenoid controlled by 
> a switch on the throttle linkage  when  using a Vac Adv/ Press Retard unit 
> with a turbo.  What are we  trying to accomplish ?



Smitty,
    The Dale type of vac adv/press retard unit hooks up  to the intake 
manifold so it ALWAYS has vacuum (or pressure) on the distributor  "pot".  This 
means that unlike ALL other Corvairs you get vacuum advance at  idle speed and 
when you accelerate off idle the vacuum advance is reduced.   ALL the other NA 
Corvairs use a vacuum advance port in the carb that shuts off  the vacuum 
advance at idle and only "brings it in" as you open the throttle  plate to 
accelerate above idle speed.  Many of us feel that you will get a  "bog" if you REDUCE 
the timing advance as you accelerate off idle.  The  stock Corvair YH carb has 
NO vacuum advance port, although you can find throttle  bodies from early 
Corvette 6 cyl engines (three YHs, remember) or Nashes that do  have the vacuum 
advance port.  One of those is on my 180 YH carb which is  otherwise stock 
Corvair YH carb.  When I added that vacuum advance my  throttle response improved 
dramatically in street driving and my gas mileage  also improved over 20% on 
my daily trip back and forth to work (both local and  highway driving).
    So I recommend adding some method of eliminating  the vacuum advance at 
idle, whether it is the solenoid controlled by the switch  on the throttle 
linkage (Ray Sedman offers a kit that provides this) OR a vacuum  ported throttle 
body like the Vette or Nash YH that I use.
    Frank "the stock turbo Corvair is a good beginning"  Burkhard 
    



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