You create LOTS of vacuum at steady-speed cruise and when you back off the gas. Stock Z/28's only generate 9"-10" Hg. at idle, and they all had power disc brakes. The General wouldn't have put boosters on them if they didn't have enough vacuum to operate them.Originally posted by HwyStarJoe:
I keep reading and hearing that a booster with discs needs 18" of vacuum to work properly. How many Camaros actually have that much vacuum after modifying the engine with bigger cams, etc? Everyone always says "I've got 15-16" of vacuum...." which isn't even close. Where's the extra vacuum coming from while driving?
I don't have an engine built yet but I'm setting the car up for power discs. I want to make SURE I'm sucking like a Hoover at speed so this drum-disc upgrade is worth the money and time. I can always install a auxillary vacuum setup but I don't want that hassle.