you guys running dual calliper set up? if so what companies

anyone run passthrough? what are your experiences.

thanks

planning on ASD hydro brake

 

I have a CNC staging brake that I've run in both pass-through and dual-caliper configuration. Both setups worked well for me.

For the pass-through I just intercepted the rear brake line after the proportioning valve on the fire wall. Ran braided lines to the hydro and back and left all the existing hard lines intact. This may not be completely applicable to an OEM FC setup though, I'm running a larger honda master cylinder, have 4 piston stoptechs in the front, and use an adjustable wilwood proportioning valve on the rear brake line. This was super easy to set up, weld in some mounting points, run the braided lines, and bleed the system... worked like a champ, locking the rears with great feel from day 1, run 1. I liked the feel of this setup more than the dual-setup that I'm running now - The handle was stiff, there was very little lever travel before rear brake lock up, and I did not experience feed-back to the front calipers, the handle getting ripped out of my hand when on both the foot brake and pulling on the hydro, or any of the other strange things that people tend to complain about with an inline pass-through hydro.

I'm currently running the Racefab dual caliper kit in the rear which mounts a second set of OEM sliding rear calipers to the rear hubs. It works well but took much longer to get "set-up" properly to work like the pass-through. I ended up keeping the CNC staging brake but picked up a small motorcycle brake fluid reservoir and some braided line as a remote-mount reservoir to convert it to a stand alone system. I ran new hard lines through the car and then braided lines out to the calipers. This new system ended up being super tough to bleed as someone always needed to keep an eye on the fluid levels in the reservoir and the calipers needed to be held upside down while bleeding for proper bleeder screw position. I ended up getting all the air out of the lines/calipers and achieving decent feel, but you have to pull the lever much further than you did with the pass-though to get the wheels to lock. I also had to swap the hawk pads I started with to the cheapest "part-store" pads for good initial bite at low temperatures since I could never seem to get or keep enough heat in the hawks to have them reliably lock both rears on command. Between the complex bleed procedure and having the "wrong" pads I wasted a ton of time in the pits at events trying to sort out the new dual setup. Once I got the right pads and the air out of the system it works well and is very consistent after the first few runs (still have issues with inconsistent locking on the first or so runs if it's cold out - and I try my best to get heat into the brakes with either a brake stand while holding the hydro or dragging the hydro down the entire front straight).

Cliff notes - used both, like both. I would start with a pass-though and see if it works for you. If you encounter strange braking/handling issues that some people encounter, you can always convert it to a dual caliper. I'd check out Stu Kelly's bracket set if you want to go dual right out of the gate. It uses a fixed Nissan caliper vs the sliding Mazda caliper that Racefab requires. I'd think the fixed caliper would give you better handle feel so long as there isn't a ton of pad knock-back with his design.

 

thanks for this, I am going with the passthrough, its mainly just to have a little fun I am not planning to be a pro drifter or anything

 

I have a pass through, this is the way rally cars are built, it just works and doesn't create needless complication.

I sometimes get a long pedal after using the handbrake so I'm thinking of putting a 2psi pressure hold valve between the master and the handbrake master.

If you "get the handle ripped from your hand" using the foot brake, there is something seriously wrong with your setup. handbrake should be .625 bore with a minimum of 10-12:1 motion ratio. Use a finger to work the rear brakes if you want. I use the handbrake more for varying the brake bias than locking the rear wheels, when it is muddy my front brakes lock extremely easily so I foot brake lightly and apply some extra braking with the handbrake, works just fine.

 

I ordered the ASD pull back 5/8"

 

bumping this.. Im currently putting together a dual caliper setup. got the racefab kit, with reman OE calipers. They have 2 bleeders on them, an upper and a lower. the upper bleeder hits the knuckle, and the caliper will not line up to the bracket without removing it. I could easily just block off the upper bleeder and be done, but that will make it nearly impossible to bleed the air out of the caliper right? anyone else have this issue?

 

I don't remember that being an issue with my racefab kit, but I put speed bleeders in that position when freshening up the calipers before the install so that might have given me extra clearance in that area.

 

I'm planning to do a passthrough set up on my FB, I have done plenty of them on offroad trucks before, always need to pump the hand brake as well when bleeding