Adjusted the VacAmp to fully CW.

Downshifting became a bit too harsh and vacuum was reaching 0 inHg close to 3/4 throttle. Afterward, I backed it off about 10*-15* CCW on the VacAmp.

I think its safe to say all fine tuning can be made on the '85 as you suggested, Brian. I am very satisfied with the results.

In glorious addition to the shifting benefits, my brake pedal finally stiffened up -- now that the VacAmp is consuming less. The whole time I thought I was prepping for a new Brake Booster.

Sam - when its warm out I will post pics of the components involved.

thanks again.

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jt20,
IF your vacuum "reaches 0 inHg close to 3/4 throttle" this could be caused by either:
(a) the orifice size you have in the vacuum line coming off the main vacuum pump -to- brake booster vacuum supply line,... this orifice is too small... or
(b) the VCV needs to be adjusted

My belief is that you should first change the orifice size and in your case make it larger by one or two sizes. This allows the pump to draw a stronger vacuum from the tranny-shifter system and this means the VCV will NOT bleed off as much the vacuum being seen by the tranny's vacuum modulator valve. Remember this vacuum control system is very "dynamic" with air flowing through it primarily because the VCV purposely allows air into it in order to do it's job of modulating the vacuum seen by the tranny's vacuum-to-hydraulic modulating valve!

The other alternative to adjust the VCV is a bit more abstract and thus tricky!

Regards,

You have a unique combination of a vac amp coupled with the VCV on a 617. That's the only year where it exists.

The effect that you got was much greater than what we usually get with the 603's using similar adjustments.

Glad it worked for you.

BTW, you might want to disregard the irrelevant posts on this thread..........

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