what does the vaccuum mod do?

 

Vacuum mod takes the line pressure out of the hands of the PCM. It uses vacuum to determine how much boost pressure is needed (more throttle = harder shift) so you can get a smoother daily driver and excellent shift performance when you need it.

Vince -- I think he said he had the ball check valve.

Ogkev -- when there was a mistake installing my check valve by my engine builder, I blew out the vacuum modulator (basically he put the check valve in backwards so the tranny was seeing boost pressures and then not ever bleeding it down. Needless to say, the first couple of times I went to boost were the last...) I now run two one-way check valves of the ball bearing variety in the line the taps my brake booster line, and connects to the tranny.

 

what values do you put in the PCM then?

 

Makes absolutely no difference. I just left mine as they were.

 

ok so should i remove the check ball valve and put a 2 way ill get some pics for u guys tomorrow to show what i have. im just getting annoyed of this damn thing surging

 

No no -- you need a one way check valve (mine is a ball type valve and frankly that has worked best for me). Just make sure it's one way, and will unplug on boost (blow the ball out and bleed off the boost). Oh and make sure it is in the right way.

 

ok sure will do!!! do u think that tranny will hold at 10-12 psi im usually light on it but if i want to get on it will it hold? and do u think their is a leak in the line on the vac mod?