charchri4

I’ve been debating doing a thread on this because I have no idea if it is going to work and certainly don’t want to encourage anyone else to try it. But I figure you guys might see something I missed so here we go.

The goal is simple, big brakes that are cheaper than the kits and if possible better than the kits. The set up I have now is stock 96 Miata and the plan is this:

Old front rotor 254mm (10”) x 20mm thick with a 45mm offset. Weight 10.3 lbs.
New front rotor 325mm (12.8”) x 32mm thick with a 45mm offset. Weight 18.8 lbs. (2000 Vette front)

Old single piston caliper with a piston area of 3.14”
New two piston caliper with a total piston area of 4.70” (2000 Camaro front)

Old rear rotor non vented 251mm (9.9”) x 9mm thick and a 45mm offset. Weight 6lbs
New rear rotor vented 294mm (11.6”) x 21mm thick and a 44.1mm offset. Weight 15.3lbs (07 Cooper front)

Old single piston caliper with a piston area of 1.22”
New single piston caliper with a piston area of 1.95” (1995 Camaro rear)

Old master cylinder bore 7/8”
New master cylinder bore 1 1/8” (1996 Explorer)
Adjustable purporting valve is already installed on the car.

This is a shot of the rear calipers. Left is stock 96 Miata. Upper right is 2000 Camaro and the bottom is 95 Camaro.

I'm using the bottom one because the mechanical parking brake will allow use of the Miata parking brake set up and it's lighter than the upper one.


I have just about all the parts and will be digging the car out of the snow in the next week or so to get started on it.
The tally so far is:
15 hours research
0 hours wrenching
$283.73 in parts

Estimate to complete 15 hours wrenching and $75 in parts.

Gator Bait

re-drilling bolt pattern on the front rotors?

what are the weights of the calipers?

charchri4

Yeah I fought long and hard not to have to redrill rotors but that's what it came down to. The problem is there is no existing 4x100 rotors thick enough to work with the bigger calipers. The older Audi A4s are 4x100 and close at 29mm but the offsent is wrong and they would run too close to the spindle.

If redrilling doesn't work the whole plan is toast. The good news is I have a couple of junk F body rotors to test with and it should be easy to make a jig with the old Miata rotors.

No weights on the Miata calipers yet but that is a great idea I'll put everything on the scale as I go.

charchri4

Well the first snag in the plan I didn't figure on. The corvette rotor is 3mm thicker than the Miata one where it bolts to the bearing so it will push the wheel out 3mm. I'm already a good 3mm farther out than I want to be so 3 more is a pretty big issue. I could mill the rotor face down 3mm at the bolt area easy enough but I'm not a fan of the idea. I think I'm going to hold the drill and do a little more putzing in with the rest of the car to ponder the situation.


I might just go with cooper parts in front instead of the vette and Camaro stuff. For about another $250 or so I could put matching cooper parts all around and that is kind of appealing.

cvx_20

Thanks for posting your efforts. It all works out in the long run. Some runs are a little longer. Just wanted to mention that the Explorer M/C bore is 1 1/16".

Mike

V8droptop

Keep at it either way Jim. The 11.75 wilwood rotors too small? Little pricey, but will last a long time surely. I'd like to see your rear caliper solution pan out, I've yet to do anything on my car on that front. Good luck, any improvement I'm sure will make a noticeable difference at the auto-x.

charchri4

Nope the wilwood stuff is not too small, it's the pricy part that is the issue. I'd rather spend the money on a wide band or track time and tires.


So I got the rear brackets made over the weekend and they are going to work really well.


It's hard to tell what is going on here but it's 2 pieces of 1/8th inch plate with the spindle sandwiched inbetween them and the caliper bolted through them as well. It should be very stable structure and support the caliper well. But we'll see... (Note the nut is loose and the bottom bolt just catching the first threads because everything is finger tight or less in these shots)



This is the Miata parking brake cable on the Camaro caliper. It works great.




These are suppose to be front rotors so there is a bit more machined surface than needed for the rear application but it shouldn't bother anything and once I paint them they will look normal.


New rotors compared to the old ones.


The master cyl bolts right up and fits perfectly even though it is quite a bit larger.

I forgot to take a photo of it in the car but will do so when I get it in.

I have the design and templates to mount the front rotors done and it will be basically the same design as the back but everything is bigger. With everything going on the Mitty trip I forgot all about the 3mm thicker issue and drilled one of the rotors so I'm just going to keep rolling with it and see how it goes. It's just a matter of making parts now.

The tally so far is:
15 hours research
11 hours fabricating and wrenching (for the back I made 2 mounts before I got one I liked and the front I'm on my 3rd one...)
$291.73 in parts, steel, and fluid

charchri4

I'm on version 3 of the front ones now and I think I'm close. I either need to remake the back bracket out of 1/4 or beef up what I have because even though I'm sure it would be fine the way it is I want to over build this part for sure.

It's the same basic set up as the back with a plate on each side of the spindle mount and caliper mount. The top is spaced back much farther than the bottom and the caliper is rotated rearward which is the only way I make room for the bolts to clear each other. The way the spindle is I should have used a larger rotor and it would have made things much easier. It's probably not the ideal caliper position but I think it will work just fine.




Old and new calipers side by side.


The tally so far is:
15 hours research
16 hours fabricating and wrenching
$291.73 in parts, steel, and fluid

ToySnakePMC

Your brake package is coming along pretty well! I'm just curious about the rear rotors and have a question so I can learn a bit more. Seeing that a fair amount of rotor surface will not be utilized by the pads and caliper, would it be preferable to find smaller diameter rotors that are more fully utilized to shave some unsprung weight or not? I guess bigger rotors can dissipate heat/ energy better than smaller ones... so maybe I'm answering my own question..?

charchri4

True that! Normally rear rotors of this size have a hub in them for the little drum style parking brake so the pad surface is smaller. So for that using F body rotors would have looked more normal but the Cooper ones are 2 lbs lighter and the right drill pattern. Though I think I might drill them anyway to get the right lug size and have them go on tight.

I am a bit nervous about all the unsprung weight going on the car but I'll just see what happens. It's been a project that has taken a ton of brain power so for that it's been fun. And added so much to my parts list too! So now I have parts from:

99 Miata
96 Miata
95 Miata
02 Camaro
00 Camaro
96 Camaro
02 Corvette
00 Corvette
96 Ford Ranger
95 Thunderbird
97 Cavalier
07 Mini Cooper

Not sure how to classify the swap radiator designed for a 68 to 72 Chevelle...

Gator Bait

Franken-Roadster! Are you planning to tack the plates and 'spacer' together on your brackets? ...make it all a bonded unit...?

charchri4

I seriously thought about it but really don't want to put any heat on this steel or make them so they wouldn't clap as tight. I have been thinking about putting a center support in the front one because I'm concerned about flex up there and now that you see the same thing I'm going to do it.

It's been a puzzlement because it's easy to feel like 1/8th plate is not enough but when you look at the cage holding the pads it's a cast form about 5/16 in diameter and not near the beef of these plates.

charchri4

Didn't get much time on it over the weekend and what I did was replace the bent tie rod and all the alignment bolts but here is a couple master cylinder shots.







I never dreamed I would put such a large master in when I made the fire wall support for the old one and it was really hard making it work.

charchri4

Got everything assembled last night and hope to get them bled and road test tonight. I got the new tie rod in and changed all the alignment bolts so had to align it too.



The tally so far is:
15 hours research
24 hours fabricating and wrenching
$303.09 in parts, steel, and fluid

charchri4

I got em bled last night and just like last time I had to reverse bleed them with the vacuum at the top and the hose in the dot 4 in back.




After that I went for a drive and WOW do these brakes ever stop! The parking brake works perfect just like factory and the pedal feel is outstanding.

I only drove for a few laps around the block because there was grinding noises I wanted to check out. On the back I got the calipers a little closer to the rotor than I should have and the outside edge of the rotor was hitting the caliper housing. So I fired up the car, put it in 1st and hit it with the outside edge of the rotor with the grinder till the grinding stopped. :-) The front will come apart tonight but it's probably the same issue.

I'm not calling it a win just yet but am doing an autocross on Sunday to really shake them down. One way or the other I'll post video after the weekend.

The tally so far is:
15 hours research
30 hours fabricating and wrenching
$314.53 in parts, steel, and fluid

charchri4

I ran an autocross Sunday and am going to pull the wheels tonight to inspect everything. So far so good though and I can really feel the difference in performance even in just an autox. As far as I know everything held together just fine and I heard no weird sounds coming from anywhere on course or the way home.

The do a pretty good job of filling up the wheels too.

V8droptop

So, here are my questions:

Do you have the pad area measurements of the Rear Camaro pad? I'm comparing to an FC rear caliper, with its 1.375in bore, and pad 107mmx39mm. I see 110mm wide on the camaro, not sure on width.

What are the differences in >98 and 98+ rear calipers? Change designs so they don't work? Also, would a rear vette caliper likely work? I know C5 vettes and Fbodys had near same front calipers .

Also, on drilling the rear rotors to fit the hubs, wouldn't machining a spacer be easier? Get some tube that is the right OD to fit the current holes, and drill out the ID to fit over your stud. I feel your pain on this, as I have different front and rear studs now, but no choice on that one. You could also redrill the hubs for larger studs, which I would avoid.

I imagine these work really well for you, Jim. You were pretty aggressive on the old brakes, and, well, you are about 4x the hp, why not 4x the brakes! Are you running stock F-body pads or any special compound? Looks like a heavy duty setup, for sure.

jreid1000

Hey Jim,

I used the 96 explorer master as well. Yet to road test it, but it has good pedal feel.

charchri4

[QUOTE V8droptop;14980]So, here are my questions:

Do you have the pad area measurements of the Rear Camaro pad? I'm comparing to an FC rear caliper, with its 1.375in bore, and pad 107mmx39mm. I see 110mm wide on the camaro, not sure on width.

Actually the Camaro pads are not that much bigger than the Miatas. Unfortunately! This is the Miata


and this is the Camaro



What are the differences in >98 and 98+ rear calipers? Change designs so they don't work? Also, would a rear vette caliper likely work? I know C5 vettes and Fbodys had near same front calipers .

You can see the difference between the pre and post 98 in the first post here ^^. The post 98 are a little bigger and heavier but they use much larger pads and that would have been my preference. BUT the pre 98 parking brake uses a mechanical cable set up that takes 5 minutes to adapt to the Miata. I really didn't look very close at other calipers because I had a set from my 95 I knew was good and I knew I could keep the parking brake factory functional with them.

Also, on drilling the rear rotors to fit the hubs, wouldn't machining a spacer be easier? Get some tube that is the right OD to fit the current holes, and drill out the ID to fit over your stud. I feel your pain on this, as I have different front and rear studs now, but no choice on that one. You could also redrill the hubs for larger studs, which I would avoid.

Yep I picked up a set of aluminum hub bore spacers that are the right size for the front and could have been easily machined to work with the backs and I did consider lug spacers too. I may still machine the bore spacers since I have them but it came down to time. In the time it would have taken me to drive one way to my buddies house with the lathe I had both rear rotors drilled. I was really concerned about drilling rotors but it's easy to get them right and adding those 4 holes is not going to weakend them or bother anything.

I imagine these work really well for you, Jim. You were pretty aggressive on the old brakes, and, well, you are about 4x the hp, why not 4x the brakes! Are you running stock F-body pads or any special compound? Looks like a heavy duty setup, for sure.

For now I'm just running cheap rock auto ceramics because I wanted to be sure this was going to work. I'm sure I'll grind most of them away at the track weekend in June and probably look at EBC greens or Hawk HPS on it. Lots of options with Camaro stuff. BTW I owe you beer, gas, dinner whatever for those front calipers yet!

V8droptop

Ah, the photos seem to be shamelessly taken from Rock auto :-D

I am going to do some more precise measuring when I get home. A quick trip to Napa will be in order to get a set of the Camaro rear pads to measure. You see how their measurements take an overall height spec vs a pad area spec. I'm going to check on them. Because you are right, Miata, Camaro, and FC Rx-7 are all really close. Basically 102, 107, 114, so right in the ball park. But I want to get a number for exact pad area, so not including the metal back plate.

On the 98+ camaro, I didn't know they went to the drum-style parking brake. Pretty common on higher hp/higher end cars now days, it would be awesome to have a setup like that on a miata but its rather complex to swap over. Your best option is swapping a whole spindle from something with them from the factory, IMO, which isn't a fun project.

Cheers,

Nick

BTW, I'm thinking of moving to the Camaro caliper very much. There isn't really a lot of option for rear brakes, but this is slightly better than the RX-7 option, which again, isn't really a big upgrade. The main thing for me is my rear is 5-bolt so I needed a rotor, and an FC rotor is a good choice, and ventilated which is a nice benefit. It also fits, which is a plus. The camaro caliper looks like a good fit, with maybe 6-8% increase in pad area, I'll have to get better numbers. Its over 10% larger than the miata one, that's actually not bad.

577nitro

GADZOOKS!!, I need me one of those hands off brake fluid pump thingies....on my desk to look at.....I'll tell people I'm making wine....or something


Brilliant

MRM331

This would actually make a cool thread idea...How many different make/model's parts are on your car...

-Jason

charchri4

LOL it's an old hospital vacuum pump that was obsolete for their use but perfect for mine. It doesn't get used a lot but super handy for sucking oil out of boat engines or the annual brake fluid change.

V8droptop

I think him has a lot of us beat. That's a good list. I'll have to add that to mine, but for sure its
Miata
4th gen camaro
5th gen camaro
Z06 corvette
RX-7 FC and FD generations
Lincoln MK-VIII
Ford Mustang Cobra (99)
Factory five racing AC cobra replica


Probably a few more. Pretty interesting.

charchri4

So after the autocross and about 200 miles of beating them every way I can think of I tore them down and checked everything over. I can't find any sign of stress to the set up at all. Everything stayed in place and lined up just as I had it and the wear is even on both sides of the rotors all around. All the bolts looked good and stayed tight.

I can feel the additional weight in the steering but I actually like the sensation. It feels less like power steering and more connected to the road and responsive. It probably is actually less responsive but it feels good in the steering wheel none the less.

So I'm calling it a win and have a guy coming tomorrow to buy all my old brake parts. After that sale I'll have:

15 hours research
31 hours fabricating and wrenching
$214.53 in parts, steel, and fluid

and really good brakes!

I appreciate all the responses here and the opportunity to bounce ideas off you guys. I know this is not for everyone but I am really happy with the outcome.

Speaking of outcomes I did pretty well in the autocross.

The top 2 came on trailers with race rubber and the GTRs both had NT01 looking 100 treadware autocross tires on them. So for me to come this close on my 300 treadware all seasons means they stink as drivers! The good news is I got all the style points with 100 feet of wheel spin that they can't do!