Master Cylinder bore size

[thechad66]

I've got a 66 w/ 4 wheel manual drums and I'm gathering up the parts for the chevy front disc upgrade. I'm planning on running a hydroboost setup. From talking to people and from what I've read,it seams I should use a master cylinder w/ a 1 1/8" bore. I'd like to use a hydroboost system out of another car or truck to save some money 'cuse I'm stationed in Hawaii right now and shipping here is expensive. Does any one know of a hydro setup w/ the MC bore I need? Mabey a Superduty , Astro, Mustang, fullsize van etc. Or an 1 1/8' MC that will bolt to one of these hydro units? Any help would be great.

thanks,
Chad

 

[76Broncofromhell]

Search "hydroboost" and Read Read Read. This has been covered 1000 times and there are a bunch or different ways to do it discussed.

 

[Broncobowsher]

I am running a 1” master cylinder with the Mustang hydroboost. All 1 package, I don’t think I ever unbolted the 2 parts. It has even been approved by the hydro king, Todd Z. himself (after I leave him to go for a test drive and hear howling claws the next block over).

From what I have heard, hydroboost is very tolerant of just about any master cylinder. Although I would shy away from the monster Superduty with the coffee cup bore. Never used one, but the Astro van has been used as a package more then once as well.

 

[bannind]

Coffee cup sized bore? I like my coffee cup sized booster..

Originally I went with my superduty booster I went we a mid 70's Ford MC with 1.25" bore - but after reading some previous posts by both Apogee and Saddleup I did take it back and go with the 1 1/8" bore (forgot that in original post). It all seems to work well, but maybe it will come back and bite me in the ass later on. I haven't had much of an opportunity to really step on it on real hard yet. Either way - MC's are fairly cheap $20 here on the mainland, so I figured if I didn't like mine after a while it wouldn't be a big deal to swap them out.

Edit

 

[Apogee]

It depends on the booster, but the primary reason to go larger with the bore is because you will get better modulation before lockup. Smaller bore cylinders give you less working range and are therefore inherently more sensitive to pressure changes at the pedal. If possible, match the bore to caliper piston area ration to the application that the hydroboost came from for best results.

I've noticed that a lot of folks equate "locking up" the tires with "good brakes". They may be strong brakes, but good brakes should give you the ability to maximize the traction available at your tires in order to stop the fastest. I've never found skidding to be the fastest or safest way to stop, but it can certainly be exciting in a 92" wheelbase rig. ;D