[SupraFiend]

Ah cool. So I assume you have been through a set of pads already then? Any issues when the pads get low? I guess thats only 1mm difference per side of the rotor, the pistons probably have enough extra travel to make up for that.

Update, PT Cruiser stuff is all over hub, not gonna work. I think I may have a solution though. Going to do some experimenting tomorrow night

 

[revvhappy]

I'm on my second set of pads with the Z32 calipers, but I only use the car for endurance races. The Raybestos ST43 pads have been amazing on my Supra; strong, heat tolerant, and easy on rotors. The 1st set went 39 hours (3 races), and the current set has 22 hours and will get 14 more in February. I hope that I never run them down near the backing plates but don't think that the pistons would come out before they hit the rotor. I can see how that could happen with the narrower rotors.

I love that 49 forum pages and 30 years later you're still willing to find a better solution for your needs. The people on this site are amazing.

 

[SupraFiend]

Ha ha, maybe I'm just super picky, or stubborn.

In my research I've looked up the following info, could be useful for others exploring other rotor options;

1990 300zx NA front rotor. The one designed to mate to the 26mm caliper that many of us have gone with.

1996 300zx Turbo front rotor (90-96 should be the same). The rotor for the more common 30mm caliper.

1996 Mazda MPV front rotor. The one that everybody uses.

Outer Diameter:308mm (12.19 inchs)
Normal Thickness:32mm (1.25 inchs)
Jim King mk2 BB Kit front rotor.

Anyone weigh one of those bad boys with the aluminum centerplate and 8 bolts and nuts needed to attach them to each other?

I've been using autoparts warehouse to look this stuff up as they seem to carry standard centric rotors for every application and they always have the diagrams.

 

[rsdeo]

Want to save weight? Drill more holes, also get cross drilled grooved discs.

Please see very first post.

 

[revvhappy]

Wow, the MPV rotors add 6 pounds per side vs OE! My 17" wheels and 255 tires probably add another 10 pounds per corner. That's a lot of additional unsprung weight. Thank goodness Supra suspension parts are stout.

The JKBB kit seems like overkill but looks great!

 

[SupraFiend]

Nope, its worse!

Found the mk2 Supra's spec sheet on the actual centric web site...

With the MPV rotor thats a 7.25lbs increase of pure centrifugal mass per corner, for a somewhat tame sized rotor. No thanks, I have found several better alternatives already. Almost done my research, more to come soon!

 

[rsdeo]

The whole idea for this thread was to build up a swap that was easy to implement by anyone and affordable with what existing parts are out there. Z32 or Q45 caliper, M30 hub, Land Cruiser studs and MPV disc no machining required for basic swap.

Anything is possible if you throw enough money at it.

Looking forward to seeing what you come up with.

 

[revvhappy]

Nope, its worse!

With the MPV rotor thats a 7.25lbs increase of pure centrifugal mass per corner, for a somewhat tame sized rotor. No thanks, I have found several better alternatives already. Almost done my research, more to come soon!

Oh well... at least we can hammer them for 24 hours without a hint fade.

 

[rsdeo]

I weighed the front disc and aluminium hat for the JKBBK on a bathroom scale. The disc is cross drilled and slotted, it's weight is ~13 lbs. The aluminium hat is ~2 lbs. Add another ~2 lbs for the hardware. So that set up is close to 17 lbs.

 

[SupraFiend]

Yeah that sounds about right, good to know. Thanks!

Hey also, what's the width of the JK adapter for the front rotors?

As for the 300zx calipers, I'm trying to find out how far they're going to protrude and if I should go with the 26mm versions. Looking for the distance from the center of the caliper (where the rotor would be centered) to the outer edge/front face. Have people run the 26mm calipers with 28mm rotors? I would think it might be tricky fitting the rotor with brand new pads.

I also would like to know the max rotor diameter we can use with z32 calipers bolted to the stock mk2 caliper mounts. The mpv is only 276mm, I wonder if we can even fit a true 280mm rotor.

 

[rsdeo]

As I've always said both versions the Z32 caliper are very wide and have issues with spoke interference on certain wheels.

It's hard to make accurate measurements on the Z32 calipers. I used a standard ruler and a flat surface.

The Z32 caliper that uses the 30mm wide disc is ~74mm from it's center to it's outside face.
The Z32 caliper that uses the 26mm wide disc is ~71mm from it's center to it's outside face.

Both these calipers have NISSAN cast on the outside face which will be removed so the above dimensions should be ~2mm smaller once these letters are removed.

More dimensions can be seen here.

With the Z32 caliper mounted on a MA6x strut the ideal disc diameter is 280mm which is exactly the diameter of both the Z32 discs, 30mm wide and 26mm wide. A disc that is slightly larger at 281mm to 284mm may fit.

The MPV disc which is 28mm wide will fit tight in the Z32 26mm wide caliper.

If caliper wheel spoke clearance is an issue use the Q45 caliper with the MPV disc redrilled to 4x114.3 (three extra holes) and M30 hub.

If spoke clearance isn't an issue then use the Z32 30mm caliper with the Z32 disc redrilled to 4x114.3 (three extra holes) and a 10mm spacer for the caliper mount. You will lose 10mm of spoke clearance, but the disc will fit perfectly on the M30 hub.

The M30 hub is almost a perfect swap for our cars. It designed for a front face mounted floating disc. It's outside face without a disc mounted sits exactly where the outside face of the stock MA6x hub sits. The studs must be changed out to 12x1.5mm as the stock studs are Nissan 12x1.25mm. The only drawback is the wheel center bore is typical Nissan 66.1mm, but that can be turned to 60.1mm on a lathe to match the Toyota center bore. Not really a big deal.

 

[SupraFiend]

Awesome Raj, exactly what I was looking for.

With the Z32 caliper mounted on a MA6x strut the ideal disc diameter is 280mm which is exactly the diameter of both the Z32 discs, 30mm wide and 26mm wide. A disc that is slightly larger at 281mm to 284mm may fit.
.

Is that from measuring on a Z32 caliper mounted to our struts? If that's correct then peeps with mpv rotors and Z32 Calipers should have 5-8mm clearance from the top of the rotor to the caliper. It's hard to tell from the pics I've seen but it looks lower. The Mk2 caliper mounts aren't necessarily mounted at the same distance from the axel center as the ones on a Zed would be.

 

[rsdeo]

Awesome Raj, exactly what I was looking for.



Is that from measuring on a Z32 caliper mounted to our struts? If that's correct then peeps with mpv rotors and Z32 Calipers should have 5-8mm clearance from the top of the rotor to the caliper. It's hard to tell from the pics I've seen but it looks lower. The Mk2 caliper mounts aren't necessarily mounted at the same distance from the axel center as the ones on a Zed would be.

With the Z32 caliper mounted on a MA6x strut the ideal disc diameter is 280mm. Which happens to be exactly the diameter of the disc the caliper was designed for.

You may be making a common mistake between diameter and radius, unless I'm understanding your statement wrong.

The measurement you require is the radius of the disc for the clearance of the top of the disc to the caliper.

It's been ages since I've looked at all this. If I remember correctly there was a 288mm Jeep disc I thought was slightly too big in diameter to try, but always wandered what if?

Jeep Liberty 2002 to 2007 front disc. Will the diameter be too large?

 

[SupraFiend]

True, I forgot to correct for radius. I'm looking at a 282mm disc and curious if it will fit. Peeps with the 276mm MPV rotor would have to have 4mm or more clearance between the top of the rotor and the inside of the z32 caliper for it to clear comfortably.

Raj, would you mind measuring the thickness of the JK rotor hat? My clearance numbers are really tight. I consider the inside rotor clearance on the JK front brakes the absolute minimum one would ever want. It will be between 5 and 7mm I would say, but the difference will actually affect my selection. I believe there is a washer between the hat and rotor too if you could add that to the measurement.

 

[SupraFiend]

Still looking for answers to 2 questions in that last post, but I have another for the general populace here...

So hats off to Mr Jim King. Going with the calipers speced in his Wilwood kit is a great choice. I have found a large range of rotors that meet my criteria but so far no 4pot monoblock caliper off a regular production car that is slim enough to mount to a rotor bolted to our hub that can clear old school wheels without at least a 5mm spacer. I've found interference specs for several calipers and none, even with modification will do it. Before I spring for a set of 26mm z32 calipers and resign to spacers, can anyone think of any others? My criteria is; must use pads that were available on a production car sold in North America ( I want to be able to get pads on long distance road trips if need be), must be a 4 pot monoblock design, must be designed to work with a rotor between 280 and 310mm in diameter, must weigh 10lbs or less (so aluminum ) and needs to be less then 68mm from the center of where the rotor would sit to the outer edge that would be closest to the wheel spokes.

I have looked at the following front calipers;
Z32 26mm and 30mm.
FD Rx7 (3rd gen)
All calipers from Double wishbone Toyotas and Lexus LS/GS/SC models
Subaru Wrx 4pot (06/07), used on other models and markets too

They are all around 70-75mm and interfere. Any ideas guys?

 

[rsdeo]

The JKBBK hat has a height of ~19mm and is offset by 10mm, it is not a flat disc. If you want to go with this hat you might as well go with the whole JKBBK as I don't think it comes separate.

All the calipers in the above list will require mounting brackets except the Z32 and 350Z/G35/Skyline calipers.

If the Z32 claiper with MPV disc doesn't meet your criteria, I will point you in another direction. The direction I would go in.

Caliper: 2005+ Acura RL front caliper. 4 piston radial mount.

Radial mount caliper is the way to go if you want to make a mounting bracket. Not only is it easier to make the bracket, it's easier to get the offset you want and a more factory look.

Disc hat and disc: This will have to be custom made and Coleman Racing Products just does that here. They can even make an oem style disc to mount on our hubs.

 

[SupraFiend]

Thanks Raj! 10mm, that's what I needed to know, and that has solved my caliper clearance problem! I figured that spacer was more like 5-7mm.

The RL caliper is pretty cool, that might work well for some as its designed for a 12.6", 318mm rotor. Too big for my uses though.

I've ordered my calipers and rotors. I believe I have found a combination that has met all of my criteria. I'll post up my findings once I've played with the hard parts a little more. I have found a large size range of rotors that will work with our hubs.

 

[SupraFiend]

So I am currently in the process of fitting my new big brakes as I find time. It will be a little while yet till I finish them so I'm just going to post the results of my research now while it's still fresh. This information should help others find some new lighter caliper/rotor combinations that may work better with their specific clearance issues, budgets and performance targets. Call it a little Christmas present from the Fiend .

I've been looking into new swap possibilities as none of the existing solutions I've seen so far are quite what I want and I suspect others are in the same boat. A rotor about the size of the MPV one is adequate for most (incl me), but sliding 2 pot calipers are not sexy, light nor ideal for performance. Changing wheel offset isn't terribly appealing either nor is taking an 8lb deficit per corner for such a tame sized rotor. The JK BB kit is overkill for many, is very expensive and its dimensions result in control arm interference with many combinations of steering arms and RCAs (incl mine). My plan has always been to find a rotor that I can mount like stock so I can avoid the weight penalty your average over hub rotor incurs. Unfortunately it seems the only bolt to hub rotors that have been made in the last 25 years are for trucks and are rediculously heavy. So I had the brilliant idea that perhaps I could find some over hub rotors with a low overa height to work as bolt to hub rotors with minimal modification. Adapting calipers is fairly straight forward, finding the perfect rotor I figured would be the trick. Of course it turns out, this method has been done. There was some talk of it early in this thread, but this guy actually did it...

FD RX7 with Peugeot rotors

My problem with his setup is that I can't get Peugeot rotors easily over here and that rotor is a little small for my needs.

So I grabbed a copy of the international DBA catalog from here... and went through the entire thing and came up with a list of rotors that could work with one of the donor 4 pot, aluminium, monoblock calipers I could think of that aren't too hard to find and are affordable. However as many have found out, finding a rotor isn't that hard, but finding a rotor/caliper combo that doesn't foul your wheels can be. It's all about caliper clearance.

Here's the critical dimensions of our hubs and stock setup that you need to be aware of when selecting your rotor;

Stock Rotor:

- Mk2 rotor bolt pattern is 4x100mm. The original rotors wheel stud pattern can cause issues here if it is too similar and 5 bolt.

- The hub center hole is 76mm ("Hub Reg" on Centric diagrams). You don't want to use a rotor with a hole greater then this as you would need a custom centering ring then. You also don't want to trust just the bolts to keep your rotor centered. Not usually a problem though, most rotors are about 64mm.

- Rotor mating surface to wheel mating surface is 32mm. Super important to know when you're calculating caliper to wheel clearance. FYI most old school wheels only have about a 10mm spoke clearance (wheel mating surface to spokes where the calipers sit).

- Rotor mating surface to inner rotor edge is 6mm (with the stock rotor). Calculate this from Centric diagrams by deducting the "Nom Thickness" number from the Height (26mm - 20mm = 6mm).

- Inner rotor edge to tightest point on the unmodified dust shield is approx 3mm. The stock dust shield has a huge recess for the tip of the control arm to fit into. You will need this space if you run Celica gts steering arms without massive RCAs. If you don't, it is possible to cut this recess out and mangle the stock dust shield so that you can gain about 15mm clearance from the stock rotor vs the stock 3mm. The JK kit requires this for instance. That rotor with spacer is approx 42mm in "Height" and I would consider that the absolute tallest rotor you should ever consider. Actually, unless you run an RCA so tall that it pushes the control arm underneath the rotor, I would aim for something thinner or you will have contact problems like people with normal RCAs and JK brakes do.

So your total caliper clearance is Spoke Clearance + Wheel to Rotor mating surface Clearance (32mm) + Rotor mating surface to Rotor Center (which is rotor "Height" - half of Rotor Thickness).

So for example, old school wheels (lets say 10mm Spoke Clearance) with the stock rotor (26mm - (20mm / 2) = 16mm) gives us a total Caliper clearance of 58mm.

To give you an idea, the 26mm 300zx calipers with the letters milled off requires 69mm of caliper clearance. FYI that is the thinnest oem 4pot caliper I have found so far. A caliper's needed clearance is simply the thickness of the caliper from the center point (where the center of the rotor would be) to the outer edge (wheel side). I have provided this number for all calipers that I could find it for (speak up if you can get it for the missing ones!). A calipers needed clearance with a specific rotor is this number with half the rotors width subtracted from it.

Here's the specs on all the calipers I figured were worth considering and the diameter and thickness of the rotor they were designed to work with. Obviously you will need to pick a caliper that was originally mated to a rotor with almost exactly the same thickness as the rotor you are considering and has a similar diameter.


Calipers

**All front calipers unless otherwise specified. All numbers are mm unless otherwise noted.

My shorthand for dimensions: width = width of rotor it came mated to, dia = diameter of rotor it came mated to, rotor = Center to Edge is the distance from the center of where the rotor would be to the outer edge on the wheel side.

- 90-96 z32 300zx 30mm width, 280mm dia. 74mm Center to Edge (Incl 2mm tall letters). Available in aluminum (6.5lbs) or iron (10lbs). Bonus, same bolt pattern as the stock ra/ma6x calipers.

- 1990 z32 300zx 26mm width, 280mm dia. 71mm Center to Edge (Incl 2mm tall letters). Available in aluminum (6.5lbs). Also same bolt pattern of course.

- 92-95 FD RX7 22mm width, 296dia. 72mm Center to Edge (Incl 2mm tall letters). Available in aluminium (5.7lbs).

- "4 Pot Subaru" 06/07 Subaru WRX, 24-25mm width, 294dia. ??mm Center to Edge (Incl 2mm tall letters). Available in aluminum (Approx 10lbs). Made by Sumito, very similar to z32 calipers.

- 92-94 Lexus LS400 32mm width, 296dia. Approx 73mm Center to Edge. Available in Aluminum (Approx 10lbs). At least 3 different sizes of rotors/calipers are used on different LS400 generations/years. Every few years the diameter goes up but the rotor width, and essentially caliper design and pads stay the same. MK4 Supra uses essentially the same caliper (but half iron so heavy and also very expensive) with a 330mm rotor. 2006 LS430 is the last year to use this design, 30mm width 315mm diameter. 2007+ gets crazy, 35mm thick 360mm diameter.

- 05-12 Acura RL 28mm, 319mm diameter. Approx ??mm Center to Edge. Available in Aluminum (Approx ??lbs). Radial mount unlike all the others. Very common for swaps in the Honda world, especially on NSXs.

Possible Rotor Donors

All of these rotors should work as bolt to hub rotors with a little machining (bore out the inner bore and redrill for 4x100mm). Note: I searched for these rotors with the "Height" (outer edge of rotor to hub/wheel mating surface) of the Jim King BBK front setup in mind as my max spec. I assumed the spacer was 5-7mm so I didn't look at any rotors over 39mm. Turns out it is 42mm and I overlooked many in the 40-42mm range. You may also want to go through that catalog yourself if you are in a different region of the world as I ignored all models not available in North America. However, the JK's height is extreme so it's a good idea to avoid rotors in that range if you can (like if you have slim calipers, run spacers or have wheels with awesome spoke clearance).

***All front rotors unless otherwise noted. All numbers are mm unless otherwise noted.

My shorthand for dimensions: dia = diameter, rotor = actual rotor thickness ("Nom Thick" for centric), tall = total rotor height ("Height" for centric), hole = hub center hole ("Hub Reg" for centric)

- 2000-2002 Audi TT front rotor: 312dia, 25rotor, 34tall, 65hole, 18lbs
3.2l 06 v6 model is the same except 334dia, 23.5lbs.

- 2004-09 Chrysler PT Cruiser Turbo/Limited: 280mm, 28rotor, 39tall, 17.5lbs.

- 2008-12 Dodge Journey 2.0td, 2.4, 2.7: 302dia, 28rotor, 38.2tall, 72mm hole 16.9lbs.
2012+ HD JC series are 330dia.

- 91-96 nsx front: 282dia, 28rotor, 36tall, 70mm hole 14.2lbs.
Rear: 282dia, 21rotor, 32.5tall, 64mm hole 13.5lbs.

97+ front: 297dia, 28rotor, 36tall, 70mm hole 16lbs.
Rear: 302dia, 23rotor, 32.8tall, 64mm hole 15lbs.

- 94-98 Golf VR6, 95-98 GTI: 288dia, 25rotor, 28tall, 65mm hole, 15.8lbs.

- 2003/04 Golf r32: 334dia, 32rotor, 35tall, 65hole, 24lbs.

- 99-04 Golf 1zq, 1lq: 312dia, 25rotor, 34tall, 65hole, 17.9lbs.

If you want to see the centric diagram for any of these you can look it up here...

So when thinking about weight, keep in mind that the stock front rotor is 10.5lbs and that the Jim King rotor is 308min in diameter and with its aluminum center hat and extra hardware is nearly 17lbs. Obviously any rotor that you machine material out of the center will lighten up and there are cross drilled options for many too, but you quickly cross a threshold when going bigger in diameter where aluminum center hats start to make a difference. But for smaller diameters, there are some nice options that are lighter. And if cost is a bigger factor then weight for you and you want diameter, there are some good options there. What's also nice with this list is there are a bunch of actual performance cars in there so you get some nice aftermarket rotor options (at a significant cost of course). Many of those models listed are pricy cars and have expensive part prices but I've found that generally the entry level Centric rotor is pretty cheap at least. Happy hunting, I hope this information helps some of you! If you run across any other calipers, rotors or missing info that you think should be added to this post, speak up and I will make an edit from time to time.

 

[SupraFiend]

Raj, if you'd prefer I can post this as a new thread. There is definitely some duplicate info in there and enough new stuff to warrant a new thread.

Put this together on my phone. I will fix up the links and formating issues on my laptop when I can.

 

[gamble]

Raj, if you'd prefer I can post this as a new thread. There is definitely some duplicate info in there and enough new stuff to warrant a new thread.

Put this together on my phone. I will fix up the links and formating issues on my laptop when I can.

Damn you did that on your phone? That is very impressive. Great info for anyone considering a new custom option.