The best I could tell on the bench, it held up fine at the 15 or so lbs i tried it at. I just thought that if the diaphram sprung a leak, it would make a mess with the boost blowing into the trans! I think it will shift the same under boost as it does with no (or very low) vacuum. The vacuum pulls the modulator plunger in, but pressure does not push it out.
I'm thinking it will work fine at very small throttle openings, but at half throttle when it's making a little boost, it's not going to shift untill the governor makes it. I'll try disconnecting it and see what it does. The turbos are on the way:beer ..
This appears to be out of stock, but does anyone have any idea how it is supposed to work??? Obviously there are more parts needed..
http://books.google.com/books?id=pe...onepage&q=vacuum modulator with boost&f=false Any thoughts on the setup on page 29 like Nitro71455's? ...anyone? ElectraJim
I'm just using a one way check valve to isolate the modulator valve and vacuum ball thingy whose name escapes me at the moment.. It works fine like that. It probably could work better.. At half throttle where the vacuum reaches zero the tranny winds all the way out.. It happes so fast that you really don't notice. At soft throttle it drives around perfectly like a baby..
If you put a small bleed off hole, the tranny won't wind out at no boost. I'm still running the setup your asking about Jim, and my SP TH400 is still happy!
