Dual master cylinders OR dual master Cylinder? thart is the question!

[67cougnut]

Im currently running 13" Baer front setup with the T-4 caliper and running the mustang cobra single caliper out back with a 12" rotor. I have been looking around at masters and I really like the Dual master cylinder setup from CNC. But I cant stop debating what to do.I've been doing some research and I found quite a few guys that are using the dual master cylinders and really like it on their street car where as others are advocating its not safe. The 67 will primarily be a street car with some AUTO X time and a couple of track days here and there. was just curious to see what everyone is running?

[cheapthrillz]

Why is it not safe? Are you talking about the CNC balancebar assembly?

[funcars]

If everything is sized right and your pads have enough bite the pedal force is reasonable on the street. Dual masters give you a more adjustable linear response for both channels and you get better feel on the track. Safety wise not relying on vacuum for a power booster or a power steering pump for a hydroboost seems more reliable to me.

[parsonsj]

People who say a properly engineered balance bar/dual master setup isn't safe just don't know any better.

[67cougnut]

thank you everyone for validating!

Cheap thrillz- A lot of people are saying its not safe for low speed stopping as it applies too much pressure to quickly(atleast this is what Im getting from it) there are a bunch of threads and the arguments are the same. here is one thread for example I found:http://mustangforums.com/forum/classic-mustangs-tech/599994-gorilla-performance-bal-bar-balance-bar-dual-mcs-no-booster-required.html . Yes I was going to go with the CNC balance bar setup.I looked at the gorilla performance setup and yes it does save more space, but I have no plans to go traditional big block for extra cubes, So the CNC will work better for me.

Funcars- This is true,I gave up vaccum assisted brakes due to my current camshaft and after watching the goodguys giveaway Nova, along with an Elcamino that had Hydra-boost fail and both of them cause major damage at the Auto X. the CNC Dual master setup seemed like it was the way to go. by the way my masters will be sized accordingly since CNC will not sell you the setup without them knowing ,What calipers your running,# of pistons and size of pistons.

parsonsj- If you look at the thread link I posted looks to me like everyone who actually had it,Likes it. The other well who knows.LOL

[David Pozzi]

The guy in favor of proportioning valves is correct, the dual master cyl setup cannot produce more rear pressure under light braking. BUT the amount of forward weight transfer is only around 200 lbs if I recall correctly, - it's not a huge difference in the requirement. Also factory brake calibrations will always favor the front brakes locking in ALL conditions. AND not all factory brake systems have true proportioning. Most 3rd gen Camaros have rear brake pressure limiting valves and once the rear brakes get up to a specified pressure and that's all you get. It was said no cars came with dual master cyls, but many English sports cars did like Triumph, and the Lotus 7's used dual Girlings and a cast aluminum pedal bracket that was copied by most US manufacturers and sold for racing applications.
You can still have an efficient single master cyl braking system if you carefully match front and rear caliper bores to the needed sizes. Dual master cyls allow extra compensation for mismatch of caliper sizes by changing MC bore sizes or balance bar settings.
The classic mismatch is a guy with a Camaro using single piston front calipers with 2 15/16" bore and adding a Ford Crown Vic rear axle and brakes using a 3" bore single piston master cyl. You can reduce rear line pressure with an adjustable prop valve, but the 3" bore is going to require extra volume of fluid and that will use up extra pedal travel, a LOT of pedal travel. The perfect manual single master cyl system would not require an adjustable proportioning valve, the calipers would be sized to achieve best F/R balance, BUT there would be no way to adjust for changing conditions or weights, even tire compounds or sizes would require some adjustment, so the "perfect" practical system using a single master cyl is to only need the proportioning valve to do a small amount of pressure reduction & the rear caliper bore to be slightly larger than "perfect". Any more than that means you have an excessively large rear caliper bore and extra pedal travel is being wasted pumping extra fluid volume to the rear. A dual master cylinder would be mismatched if the rear master cyl was too small, extra pedal travel would be used up, or the bias bar would need to be adjusted too much to the rear side and waste travel.
David

[parsonsj]

I checked out that product being offered by Gorilla... and it looks like a quality piece. I'd bet it could be adapted easily to a variety of OEM pedals. The trick would be to get the pedal ratio and height right.

[67cougnut]

thanks for the input guys!the CNC setup has been ordered. hopefully between what Tilton suggested and what CNC suggested I will get what I need out these brakes with minor tunning.

[Flash68]

thanks for the input guys!the CNC setup has been ordered. hopefully between what Tilton suggested and what CNC suggested I will get what I need out these brakes with minor tunning.

How you like the CNC dual master?

[67cougnut]

looks great sitting on my shelf. LOL currently cleaning up the engine compartment and will be bolting this in and plumbing. hopefully i'll be ready for the 2014 season.

[jtwoods4]

looks great sitting on my shelf. LOL currently cleaning up the engine compartment and will be bolting this in and plumbing. hopefully i'll be ready for the 2014 season.

What size bores did you order on the CNC Dual master? Have you installed yet?