Powermaster VS Vacum

[yipekiya]

Ok,,

Purchased the car not running with vacum brakes already installed, I have never run the car. Now the engine and trans are ready to go and I am debating switching back to a powermaster. However I see many people ditching it...
Questions---Is it harder to build boost on launch with Vacum
-Is the Vacum more of a hassle when staging the car..

Appreciate any feedback

Rob

 

[Roc87]

The Syclones, Typhoons and TTA's all have vacuum brakes, as does my Iroc (W/ Turbo V6). The "secret" is right before you stage, rev up the car in neutral, and when it comes down it should create enough vacuum to hold the brakes enough to stage right. But since I havent had the Iroc to a strip since the swap, perhaps somebody with a vacuum converted TR will also respond.

 

[cmokem]

I have NO problems with my vac setup...to further enhance it I have the extender chip with the launch assist. If you race the car alot and want to leave with more than 10lbs or boost you may want to purchase a separate vac motor and tie that in to the brake system. Master Power Brakes sells them...or go to a local bone yard and pick up a vac motor off a late 80's caddy or a Pontiac Sunbird.

HTH's
Bob

 

[Roger]

If not for bad luck, I'd have no luck at all.



I bought a complete unit from the junkyard off an '86 Regal - $50.
I don't trust junkyard parts, so I bought a lifetime warranty master cylinder - $40.
The Casper vacuum block for the TTA wasn't available yet - I bought one of the two GM had at that time - $85.
I installed the assembly & the vacuum booster unit from the junkyard leaked vacuum - lifetime warranty one - $90.

A couple times on the street when pulling out into heavy traffic (read WOT- maximum boost & no vacuum to operate the vacuum brake boost unit), I would have some brain dead about 2-300' up the road also pull out. By the time I would realize the road is totally blocked (by the brain dead in the Toyota or the suv), I'd be over 40 mph & have to use both feet on the brake pedal to stop (also the traffic behind me is moving 40 - 50 mph.

I bought a vacuum booster pump for the early '80s Citation to give me vacuum to the brake booster all the time - $240. Had so much trouble finding the necessary 3/8” check valves, I never did finish the install.

After about a year the vacuum brake booster developed a vacuum leak. The leak was not steady & varied with every application & release of the brakes. Troubleshooting my IAC was a real hair puller, until I figured out the vacuum brake unit was leaking. No problem, lifetime warranty, I got & installed another unit.

The now third vacuum brake booster developed a leak in about a week. My last trip home from work with this vacuum booster unit was a nightmare. The computer was adding fuel to the leak & the TR was idling at approximately 2k rpm or 70+ mph. At the seemed like thousands of RED lights, using both feet to hold the brakes, the TR would not idle & would die unless I fed it more foot feed - however it took both feet to hold the brakes. I guess I was fortunate the seat didn't break loose from the floor.
I got my money back for the vacuum booster & have a Citation unused vacuum boost pump for sale & bought a lifetime warranty PM. My IAC is now adjusted properly & the PM always works (so far). The only problem with the PM install was that the old unit had blown the fuse.
You can do what you want & I have two local friends who have had no complaints about their vacuum conversions. I just couldn't see the difference in price - PM lifetime warranty - $199. Vacuum conversion - $505 & couldn't set IAC.
HTH,
Roger
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[TR Custom Parts]

Bought all new GM parts for my conversion, no problems in over 5 years. I did the conversion when the GN only had 10k on it and didn't want to put junkyard or rebuilt parts on it. No complaints here.