Intake vacuum characteristics of a bridgeport
 

With the overlap of a bridgeport what happens to the intake vacuum at idle?

I'm putting a 12a bridgeport into a RX3. I'm trying to select a upgrade master brake cylinder to go with the 4 piston drag brake kit from the Racing Store and the RX7 rear disk brakes conversion. The original vacuum brake booster is a limiting factor. If vacuum at idle is poor, eliminating the booster may be the solution!

Anybody out there with a bridgeport have any data on vacuum at idle?

My 12A 1/2 bp pulls about 8" Hg. Brakes work fine, removing the booster will not increase vacuum, if that's what you're asking. As far as the big brake kit working properly, the brake master will make more difference than the booster.

In the other rotary section, there is a thread on master up grades for the early RXs.

Thanks for the the info.

I was more thinking that with low vacuum at idle the booster may not provide much boost but I now understand that with the check valve on the booster, vacuum will be stored in the booster for proper operation.

One option is to eliminate the booster for more MC options.

The stock MC bore is 7/8" but I can only get a 13/16" replacement. would like to move upto 1" or better