Re: To all Charlie Smith spring users

[raf40@oes.amdahl.com (Richard Funnell)]

Jeffrey,

You're right about it being a bleed valve.  I asked when I saw the first
post.  If it had been a true regulator, I would have questioned its ability
to preserve the overboost protection.

>> Whisper air control valve by Second Nature (single) #56001      $3.39
>
>Yesterday afternoon, I bought one of these at the local Petsmart and rigged
>up my own testing system to check it out ... turns out that it's not really
>a regulator but merely a control valve.  As such, it doesn't clamp pressure
>at a given point but bleeds off a fixed percentage.  This effectively means
>the more boost you have, the more timing advance (or less retard, depending
>on how you look at it) you'll get, which sounds backwards to me.

I think this mod is analogous to using a resistive bridge to scale the
output of the transducer.  In this case, the bleed valve is scaling the
input to the transducer.  I would expect this approach would provide a more
aggressive advance curve, with more power but less reserve against
detonation.  See the earlier discussion regarding the bridge vs the Zener
clamp.

>
>Has anyone else looked into this yet or have I overlooked something here?
>
>     _             _
>    / l       l o l  \       l o   Jeffrey Goggin
>   /__l l l / l l l  l l l / l l   * * * * * * *
>  /   l l_l \_l l l__/ l_l \_l l   AudiDudi@delphi.com
>

Richard Funnell,
San Jose, California
'83 urQ
'87 560 SL