Vacumn for a trans

[phat46]

Will the vacuumn from the carb base work to shift a Turbo 350?

[wayne petty]

it truly depends on which port...

if it has manifold vacuum yes...

if it has ported vacuum .. nope...  (ported vacuum is no vacuum at idle with the throttle closed..  but vacuum increases with the speed of air through the carb...

a quick test with your finger over the port or at the end of a vacuum hose plugged into it...

or plugging in your hand held vacuum gauge..

one thing....  be sure to use a steel tube and short lengths of vacuum hose..   prebent ends for the modulator are available at most transmission parts houses...  

the vacuum you are applying to the modulator is a signal only moves the modulator parts about half an inch..   steel tubing makes that signal faster.. cleaner..  

if you ran vacuum hose all the way.. the signal will be delayed as the rubber vacuum hose changes diameters when the vacuum changes...


the reason i ask...   i have run into a hand full of vacuum ports that you would think have manifold vacuum .. but don't...

so a 10 second test is required..

[57larry]

I always use manifold vacumn