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Rear Brakes Conversion Saga - Close


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Morgan,

 

I don't know where you are on your rear brakes but I got the Z32 brakes to work with the bolt on bracket - almost (again no drum parking brake). I mentioned last week that I had one bracket that I made and had it welded on. That turned out just fine but some effort involved. I have a complete spare rear suspension (never really gave up on the bolt on bracket idea) that I experiment on. I just acquired 2 1987 300ZX rear vented rotors. These rotors are 5 lug, just a hair over 11" in diameter, ¾" thick or there abouts and the offset is almost perfect to use with the bolt on bracket (BOB) - key. When I say almost perfect, it barely touches the inside edge of caliper mounting holes. All that one needs to do (and I'm going to do this on Sunday at my friends house - he also has a milling machine) is to remove about 3/32" from the outside face of BOB at the ears. This will provide enough clearance to give the caliper a hair more offset to the inside of the car. Also, the rotor is a tad (30 thousands at the most) too big in diameter as it rubs the top of inside of the caliper ever so slightly. I have two choices here. I could take the rotor to a machine shop and have some material removed or since the caliper is aluminum just use my drimmell tool and remove a little material from it. This might be a better solution because most rotors ware out faster then calipers and it's less expensive process.

 

For the parking brake I'm using the Wilwood spot calipers. I might fabricate a flat bracket and have it welded to the bottom of BOB. Tomorrow I should receive the spots and look into it in depth.

 

This is by far the best fit using the Z32 caliper ('94) and the (Z31?) '87 rotor. I'm certain it will fly all it requires is very minor machining. 11" vented rotor in the rear - yes!

 

Danno74Z

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Guest Anonymous

SWEET!

I got a set of the flat brackets and found a low-offset rotor.... I went to the junkyard to get a pair of 87-89 rear calipers, but they wanted $70 EACH($35 + $35 core) so I laughed and left.

The parking brake thing does kinda blow though. Are you gonna do this instead of the weld-on brackets you did already?

And what about tire clearance danno? I take it it's OK with such a heavily offset rotor? (I have a stack of 87-89 turbo rotors sitting at home already too! smile.gif)

 

SCCA! Make a bolt-on bracket that fits right like danno said(hair thinner and hair larger radiaus for caliper mounting) so it's a bolt-on solution, and incorporate ears for a mechanical parking brake caliper. Bolt-on huge rear brakes for cheap!

Figure the calipers can be had for $100/pair easily at a junkyard, $150 for a pair of brembo replacement rotors, $200 easy for e-brake calipers and brackets, and you're done.

And it's all nissan too smile.gif

 

 

------------------

Morgan

http://z31.com/~morgan/s30

http://carfiche.com

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Guest Anonymous

Hmm. What about a lockable shaft that extends through the holes in a drilled rotor for a parking brake? smile.gif

Or just carry around a coupla wheel chocks? With my luck someone would pull the chocks out and watch my car roll down a hill though!

 

 

Hmm. That hydraulic parking brake thing is like $60.... that would make the brakes super cheap if you only wanted parking brake services and not e-brake functionality. Also figure if you're putting in a proportioning valve that the plumbing is already being re-routed, so no big deal as far as installation goes.......

 

 

------------------

Morgan

http://z31.com/~morgan/s30

http://carfiche.com

 

[This message has been edited by Morgan (edited February 01, 2001).]

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Morgan,

 

This is indeed very exciting at least for me. I will go the bolt on route. Trial and error all the time. I will take some pictures and send them to you as I progress, which I think will be faster. Again, I used the Z32 caliper with a 1987 300zx rotor. I got the rotors from Autogator http://www.autogator.com/ and they came turned (a little dirty - the price was right) and the calipers came from a Z32 salvage yard in GA. (Russell Floyd, ZX Connection, 1313 Old Draketown Tr. Temple, GA 30179 zxparts@mindspring.com 770-562-8668, 770-598-5815.) The one question about the wheels I'm not sure about. Tomorrow, before I head out to work I will check for you but my gut feeling is there won't be a wheel problem. I only have some 14" American Racing rims so this won't be a real good test for fit but you have a valid concern. The caliper did not appear to stick out too far in the trial fit.

 

I used the Nissan B.O.B that nobody seems to be able to purchase or find. I bought them through the dealer here in town and it must have been sheer luck. Morgan, buddy this is going to work but only with a bracket that has the offset, either beg, borrow (and never give back) or take 2 ½" plate steel weld them together and bolt it up to the flange housing. A little more work but very doable.

 

Danno74Z

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I checked for wheel clearance this morning and here is what I found. The caliper housing protrudes 1" from the flat part of the rotor hat and a 6.5 inch radius min is needed to clear the caliper housing. My 7X14 inch AR wheel did not fit as I thought it wouldn't - not a big deal because I'm going to 17" and should have a ton of room. My American Racing rim has ½" clearance around the 4 hole mounting area but this is an ancient flat surface rim. The new rims have arched spokes and will clear the calipers outright.

 

Morgan - I know SCCA or yourself could design a very simple bracket to work - have to run.

 

Danno74Z

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Worked on the brakes a little today and I was mistaken on the rotor machining (outside Dia.). The rotor does not need any machine work at all to work. Just the bracket needs to have a little milling done to the mounting tabs. This will be done tomorrow. Good news.

 

Danno74Z

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Morgan,

 

I have the offset brackets. I machined them today on a milling machine (3hrs) and removed 1/4" of material from the face of the bracket where the caliper bolts up to, this left 1/4" thickness of cast iron for mounting. I bolted up the bracket, put the stub axle back in and secured the caliper - fits perfect. I still have to drill the stub for five lugs and put on the spot calipers but this part is done.

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