Originally posted by Red Regal T
If holding boost is attainable, as just posted by FlyinGN, and as I have said, what's the problem? Also search the many posts on this subject and you'll find all you need to know. Brakes are for reliable stopping and for me, holding boost, is way down on the list after that. Eventually, you are going to have to change over anyway, unless you hit the lottery to afford fixing PMs. I'm certain there's probably more guys out there with vacuum brakes than with the PM. Join the club!
Excuse me for saying so, but what FlyinGN said about holding "plenty" of boost really doesn't mean much. After all, he didn't specify any amount at all. Maybe 5-10# is a "lot" or "plenty" for some.
Holding boost on the line is near the top of my priority list, as it is with many other that really want to optimize ET and MPH, and need a good launch to do it.
Personally, if I can't hold 15-20# on the line then I would never give up my PM.
BTW, for those that mention it, Just because Pontiac didn't use the PM, doesn't mean a thing. There were reasons why they didn't, and unless anybody knows for sure why they didn't, speculating on why is pretty useless, after all.
Vacuum brakes just aren't "the hot ticket" on boosted (epsecially turbo'd) applications.
On most mild mannered street apps. it's fine, but when there's going to be a lot of boost used, or boost over a consistently long period of time, vacuum brakes would be a dangerous detriment.
Probably why Ford still uses the HydroBoost system on their Powerstroke diesels. Lots of boost and under boost virtually all the time.
If I didn't ever take my GN to the track, vacuums would probably be fine also.