10" Booster or Manual?

[pitts64]

http://www.youtube.com/watch?v=NWm6PUGpfVU

[Apogee]

Are you sure that you have a 9:1 pedal ratio...that's numerically higher than most manual applications (~6:1). Most power brake applications are in the 3.7-4:1 range.

Considering you can try manual brakes relatively easily, I would start there as simpler is usually better if it's an option IMHO. 10" of vacuum at idle isn't enough to properly supply a vacuum booster, so without an auxiliary pump to boost the vacuum levels and accumulator to increase the vacuum volume available, I don't think you'll ever get vacuum assisted brakes to perform like they could or should.

What makes you think removing the metering valve will improve anything? MP brakes doesn't do a very good job of explaining what that valve does in the link you provided, however it just serves to slow down the actuation of the front disc brakes (which is almost immediate) so that the drums can actuate near or just before the fronts. We're only talking about a fraction of a second difference to allow the slower actuating drum brakes a chance to catch up to the discs. Having the rear brakes actuate just before or with the fronts improves the overall stopping attitude of the car with less dive and straighter stops less susceptible to front end issues like worn TRE's, poor alignment, etc.

Tobin
KORE3

[pitts64]

http://www.youtube.com/watch?v=NWm6PUGpfVU

[pitts64]

http://www.youtube.com/watch?v=NWm6PUGpfVU