Boost Pressure at Cruise

[james redman]

I have a Rotrex C38-71 on a 5 liter v8. I have it running and am presently fitting instruments for tuning.

The Rotrex is a ball drive centrifugal machine.

I wonder if you have a similar set up,
e.g.

• blow through MAF,
• centrifugal,
• 5 l,
• V8,
• 10 to 1 CR,
• Normally aspirated cams

...you could tell me the sort of boost pressures your are seeing at what might be

• low cruise 50 to 60 mph and
• high cruise 80 to 90.

My research so far tells me to expect

• 10 inches Hg vacuum at low cruise and
• running just positive boost at the high cruise.

I am wondering if I will have enough vacuum to power the brakes.

Thanks

James

[pavement pounde]

10 Inches hg at cruise should be enough for the brakes.
If you let go of the accelerator during cruise the vacuum goes up even more.