For quite a few months now I've been looking into an alternative route at a big brake upgrade for the R50,R52, and R53 that is larger then the JCW/R56 brake setup, yet wouldn't set you back a thousand dollars and above like the JCW 4 piston style brakes you find on the latest JCW MINI's , AND all the parts could be picked up at any local parts store, unlike the custom Wilwood or Brembo setup, and I'm pretty close to a setup.

I decided to go with a 316mmX22mm 2007+ JCW rotors, but if people are worried of fitment issues, the R56 294mm rotors could be substituted.

As for the calipers, I thought of using originally jaguar 4 piston calipers, but their width, piston size, and cast iron construction prevented them from being a viable caliper to use. So being a member of the 3000GT community, I remembered the VR4's came with aluminum 4 piston calipers that are used on everything from the Galant,Eclipse, And Silvia communities with nothing but positive results, and because there are thousands out there, they go for less the a couple hundred bucks. Hell I picked my set up for 80 bucks, granted they need to be rebuilt. These are also the same calipers used on the Skyline GT-R, so they've been designed for 3800lbs. Vehicles, so they should be just fine for 2800lbs. Cars!

The other great thing is there was two generations of the caliper with the only difference being the mounting tab length, but the brake pads, width, and everything else is exactly the same. Also the first generation's rotors were 296mm, and the second Gen is 314mm, so they are almost the exact diameter as the MINI Cooper JCW style rotor. now the only downside is the widths of the rotor thickness. The VR4 is 30mm and the MINI is 22mm, but all that needs to be done is have the halves of the caliper machined to compensate the distance between the pads and rotor face.


NAPA auto parts sells the 316mm for $56.00 each, so they are cheap to pick up, so the only major obsticle is creating a caliper bracket to hold it to the spindle/wheel bearing assembly, and find a brake line that will screw into both ends. My goal s to try and keep this under $600.00 for the average Joe, which if you spend 250 for calipers,110.00 for rotors, that leaves 240 for pads, brake lines, and brackets, which seems doable.

 

looking forward to an update. I have also been thinking about using the porsche 911 calipers but haven't looked into it yet.

Good Luck

 

yeah, I originally wanted to go with the Brembo Porsche 944 calipers, but they aren't as easy to get, a little pricey, and were too nice to grind off the Porsche wording on them, the 3000GT's calipers are made by Sumitomo, and since there is an abundance of them, it's not a sin the take off the wording, hell the Dodge Stealth ones didn't come with writing, so if you wanted to skip that step, just buy a pair of those lol.

 

While not such a bad idea....the problem you'll have it that the MINI has a very small and high pressure brake system. Few if any of the calipers you'll find will properly pair with either the rear calipers or the master cylinder. Most will leave you with a long soft pedal and horribly over biased front brakes. And the larger the rotor you put on; the less piston area you'll require compounding the problem.

 

i am interested on this project.

 

That was one thing I looked into, between the R56/R59 JCW master cylinder, and the R56 S master cylinder. Both use the same master cylinder, and considering the R56 stock is the R53 S JCW style setup, it seems the master cylinder may be set up to handle this. I can only assume the bias would be changed internally, but all the part numbers are the same.

The R56/R59 JCW style caliper (4piston) runs on the 12.4/316mm rotors, and considering that the Sumitomo's may be slightly smaller with brake pad area, I need to find out what the diameter of the JCW 4 pot pistons and one of those aftermarket set's pistons, and see how similar they all are, and what displacement they create.

Usually those companies like Wilwood, or Baer, or Brembo create a caliper that will fit a range of rotors. Say a Wilwood would fit a rotor between 280mm to 330mm, and they also make one that would fit from 250mm to 280mm, and so on. When a caliper fits a specific rotor, they either build the caliper to fit the tabs of the existing caliper tabs, or they build brackets to adapt the system to the existing bracket assembly. They don't custom tailor these calipers to each make and model of car, but they'll produce them to fit a large range. They make several versions of the 280mm to 330mm caliper to allow for different bias, and pressure, but in the end they're pretty generic.

I don't see my calipers being off by much, but I also wouldn't build something like this and start handing them out until I fully test them out. my wife may not autocross, but you'll be seeing me burning this setup up when I'm done, and I'll run over to NJMP for a nice test n tune day.

 

You are correct by my way of knowledge; both use the same size mc. The JCW stuff has a larger rotor (R53) and same size rear in that time. The R56 uses the former JCW rotor and small rear rotor then the JCW R56 cars use a larger yet front rotor.

From the technical standpoint when the same rear rotor is used and only the front rotor size is increased the bias shifts some. For the more performance minded cars both rotors were increased in size keeping the bias more in check.

The four pot caliper I'm not certain of the piston size. That's the one you'd want to compare for in your search. The issue of mounting however may well leave you holding the bag. Say it's a 120mm bolt spread (don't recall) and you find a Mercedes four pot with a 120mm bolt spread. Perfect. Not so fast...only if the mount offset is correct, the rotor width matches up AND that 120mm spread is at the right mount height/radius of the caliper to the spindle. While the holes might be 120mm on both one could be flush to the edge of the pad, and the other have 1/2" of pad overhang.

So far in nearly 20yrs I can't think of one of these cross fits that really ended up fitting like someone hoped it would. Just too many variables here. Not saying don't try it, just plan on scouring a lot of yards and buying/searching/returning/ebaying a lot of parts until you hit something that is close.

The brake pad area will only have an impact if you are trying to fit a big pad to a small swept area here. Pad size won't change torque or bias.

 

Subscribed!

 

If that may become a huge factor in the bias, I hear the new JCW rear brakes use a larger rear rotor and caliper, though I believe the caliper is the same construction, but with longer mounting tabs, or they use a bracket to extend it. I'm not sure if that would cure the bias problem automatically byupgrading to the new JCW style, and I would have to find out if the parking brake cables would be compatible with the R53's or just how much modification would be needed to allow them to work properly, but while things are getting big in the front, it's only fair to make sure the rear gets the same treatment.

It's a shame BMW/MINI decided to stay with the external parking brake assembly. Not too many performance calipers integrate that style, and not many companies today do it. I wanted to use the 2nd gen VR4 rear calipers, which are 2 piston (1 on each side) but they used the hat-style setup. Only calipers with that style setup that I could find were Porsche 914 calipers, but they are too pricey, and are very wide due to deep pistons.



Correct, and that is why in another post I asked if anybody had any spare time and a front knuckle assembly, and a few minutes to spare to take some measurements. I'd of begun to take some measurements of the knuckle, but my wife's MINI is still in the body shop, so my research has come to a small halt. I may just purchase a used knuckle assembly, which would allow my wife to drive her car, and allow me to carefully measure everything out, but this will be the biggest hurdle, to create a bracket that will be strong enough not to twist, and accurate to prevent uneven wear, or tapered wear ( was a common problem with the C5 upgrade on the Camaros because people were buying the $100 ebay special that would twist.)

Whatever I finalize as a setup, the bracket will need to be machined out of a single piece of T6061 aluminum, nothing wielded. I know the VR4 calipers tab distance is farther then the MINI's, but I'm concerned at how close they may come, or they even overlap each other, which would really cause a problem, and I couldn't produce a mounting bracket that bolts up behind the bearing because the CV axle is right there. With the C5 upgrade for our Camaro's, we had that style, and just cut the old caliper mounting tabs on the knuckle, so the Corvette Caliper sat right atop where the old tabs were.


I'll certainly put some photos up to show you guys what I'm working on.

 

I agree. If the car hat a drum-in-disc set up that a number of others do today you'd have more options for rear calipers. The requirement to keep the combo caliper for the parking brake hinders it from being more open to custom work.

Ideally you'd like a nice four pot caliper. The two pot opposed you mention above, while looking the part, doesn't offer any more performance or functionality than the single piston combo you have now. (assuming like piston area) For a larger disc like 12" or so a compact four pot would offer much better looks.

 

Not sure if this is any help but the older GM W Platform (Grand Prix, etc) also have the integral parking brake calipers. Just dont get the first-gen design if you levitate towards this project, they suck (88 - 94). Like they had a class-action lawsuit grade suck. I know, my weekend toy has them, and on the fourth (I think, or is it fifth now ??!!???) set of remans. Go 1995 or later and they are fine. They are pretty beefy as that car as well tips in at over 3600 LBS, shouldnt have any issues w/ 2546 LBS.

 

Yes, the LT1 Camaro/Firebirds (4.1 gen) came with those. My Camaro originally had drum rears, and I thought I upgraded to discs, but adjusting them to produce enough clamping force was a pain in the ***, and they never worked right, even after I swapped out the prop/ABS block from a true LT1 car, so I upgraded to LS1 rear brakes, with the integral hat system, and have been smooth sailing since. To me it was a design flaw, and they used that style for 20 years.

I had a friend that owns a 1994 Camaro with the LT1 calipers, and were doing the same thing, they weren't working properly, so I talked him into LS1 brakes, and he hasn't stopped thanking me since. He used to cook the hell out of the front pads, but even before he installed the LS1 calipers on the front, his rotors and pads in the front were lasting longer then before after he swapped the rear setup out.

I know the 3rd gen F-bodies ( Camaro/Firebird) had such a bad proportioning system, as you said, in 1989 or 1990, they changed it, because they found out they weren't allowing for the rear brakes to work enough, some didn't work at all!!!!! and there was a lawsuit because of it. So anybody today who upgrades their 3rd gens with O.E. rear discs, are forced to buy 1990+ brake proportioning valves, period.

 

I whole heartedly agree. I think Acura has a setup for rears with 4 pot, and the Porsche 944 rears are 4 pot, but they look completely different then the Sumitomo :( and once again, that damn hat system is the style they use. I'll do a little more digging, I'm sure a Mercedes somewhere used that style lol.

 

here's some quick pics of the setup. Bonus points if you spot a cat

 

Rebuilt 3000GT calipers are available from rockauto for $60.

Interested in how this works out. I just looked into almost this identical thing last week using 3rd gen RX-7 calipers. They didn't even come close to fitting. There was no way to bolt it in place and have anything line up even with a bracket adapter. Might have worked with a rotor maybe 2" larger but that's not really practical. Also the caliper was so wide it hit the rim spokes. The wheel would have needed to be spaced out at least 15mm.

 

Don't underestimate the potential problems a brake system with altered bias can do. Under hard braking you can find yourself spinning down the road and out of control. Proper brake bias is critical to high performance as well as safety.

Read what Stoptech has to say on the subject:

http://www.stoptech.com/technical-su...alance-matters

Anytime you start playing with different calipers, rotors and the like, it's wise to have some way to adjust the bias front to rear to make sure it's optimized.

 

Noir2005,

thats looking good i want.....

 

Ah good catch for Rock Auto, 120 for a set, you can't beat that!!

Seeing as Sumitomo designed that RX-7 caliper, I'm sure the dimensions are similar. What size rotor did you attempt to use for this setup? It looks like the RX-7 came with 11.56in rotors. The calipers I'm working with will hit the spokes as well, that's it the big advantage that the JCW have over this setup, their pistons are shallow, so the face of the caliper will clear the rims, although I'm not sure how much of the face will stick out after the machining is done. It's to take 4mm from each side, so a total of 8mm will be removed.

 

I am using the 294mm 1st gen JCW rotor. I run 16's on my car so I'm pretty limited as to rotor size.

 

Ah, yeah even using the 294mm, the Mitsu calipers aren't going to fit. This setup will be for 17''+. Not all 17''s will fit with this, so when and if this gets done, I'll try to see if any fellow members have some O.E. 17" rims, and see what fits ,and what doesn't

 

I did a project like this on my 350z. I hope it turns out alright. Maybe we can get somebody to fabricate the brackets if it turns out good. Goodluck on your project. Keep us posted. =D

 

Okay, so last week I took the MINI in to get it up on a lift, and balance/inspect the wheels, so I took some time aside doing that, and threw the rotor, and caliper up on it real quick to get an idea of what I'm working with. I took some pics to just visualize what I'm looking at so far, and I'll post them up on here.

It looks like a lot of grinding will need to be done to massage the caliper against the knuckle assembly, then a custom set of brackets will need to be machined to hold them together, and I would need to make custom shields to help control the incoming air to the rotor, but besides that, I don't see too much modification needing to be done. I'm going to to buy a knuckle sometime in the new year and start to modify the assembly and caliper and see how they will work while taking off the minimal amount of material. So the downside would be that if you guys were to do this modification ( or if I started selling these as a kit if it's successful) you would need a spare set of spindles to modify if you didn't want to change your factory original ones. There are a ton of R50's and wrecked R53's out there to which you could grab their spindles.