decel valve

btectonic · Post by **btectonic** » Sun Sep 20, 2009 11:02 am

I vaguely recall Ray mentioning he has the porsche 914 type decel valve on his car. Plumbed correctly this ought to eliminate the need for the throttle dashpot, correct?

Anyone else tried others like the flat pancake type valve found on T2's?

raygreenwood · Post by **raygreenwood** » Mon Sep 21, 2009 5:39 am

Bear in mind, using the decel valve to fix this will require a change in plumbing and some adjustment.

The decel valve will have to plumbed to a differnt vacuum point than it was originally. It should come from the vacuum point that controls the throttle dashpot.
You will then have to figure out with a gauge T'd in before removing the dashpot, what vaccum level the dashpot comes into play. Then adjusst the decel valve waaaaay down. Then install a restrictor orifice in the line much as I do on the PCV valve.

Wait....also before you go any farther....I almost forgot. Check the PCV valve on your engine. It can disturb the throttle dashpot action. If its cracked or does not close all the way....replace it with a 3mm inline orifice. Do a search. Ray

btectonic · Post by **btectonic** » Mon Sep 21, 2009 10:06 pm

PCV valve gone, fixed orifice in place. Fixed at the valve housing.

Planned to put in a clear air supply fitting on the air filter housing right by where the snorkel clamps on and a t-fitting in the PCV line to the plenum.

These decel valves are a bit easier to source than a know good dashpot. Thanks Ray.