MG Sports Cars

I got the 86-88(87) 10.7" vented Toyota Cressida rotors! I don't know why no one has tried this yet. If you draw an X through the rotor mounting holes and mill 2MM inside they bolt up to stock hubs. They are a little further out than stock but that is good as it makes room for caliper adapters for the small 86-88 4 cylinder 4X4 Toyota S12-8 calipers or 86-91 Mazda RX7 Turbo II aluminum calipers. I already have a set of the larger S12W 4X4 V6 86-92 calipers,same mounting as smaller S12-8. Tommorow I am ordering the RX7 calipers. Should have prototype caliper brackets soon. Might even fit under Rostyles.



Edited 4 time(s). Last edit at 01/26/2011 07:45PM by mgb260.

Here is a photo with the larger S12W V6 Toyota caliper. The shiny stud is 90's Camaro/Firebird/Corvette(12mm), about 1/4" longer. So with a 1/4" spacer the caliper does'nt stick up beyond the wheel mating surface if you ground the fins down. The smaller Toyota and Mazda calipers probably don't need a wheel spacer. I just ordered the 88-91 Mazda Turbo II aluminum 4 piston calipers for $35 each at a junkyard through car-part.com.



Edited 4 time(s). Last edit at 01/24/2011 05:33PM by mgb260.

There is a straight bolt on conversion for Toyota brakes on a TR4-6 on the VTR website, if you want to compare.

Dan, Here is a picture of the U.S. spec 86-88 Toyota Cressida 10.7" vented rotor with large 86-92 Toyota V6 4X4 S12W caliper on a TVR. And pictures of the newer (92-95)RX7caliper with Mazda name polished off and painted Alfa Romeo. On the TR4-6 and TVR the center hole in the rotor has to be opened up slightly or hub diameter turned down. The caliper bolts on like stock, some have had to use washers to shim to center. As far as I know the MGB has never been adapted. The mounting holes have to be slotted inside 2MM. The center hole is a little larger than stock MGB. A bracket has to be made for the caliper (3.25" spacing on MGB,3.5" on Toyota). The 86-91 Mazda RX7 Turbo II aluminum caliper or 92-95 RX7 aluminum caliper requires a simple bracket to bridge the 3.25" MGB mount out to 6 1/8" wide Mazda caliper mount. Even the Triumph and TVR guys should be interested in the Mazda calipers. You can use the 11.7" Mini Cooper S rotor for big brakes (16-17" wheels). Would require 1/2" wider brackets.






Edited 6 time(s). Last edit at 01/26/2011 01:16PM by mgb260.

Brackets like these would be necessary. First one for Toyota calipers,next one for Mazda.

These pics are on a TR7 and a Volvo but, you get the idea.

86-91 Turbo II calipers(GSL also) aluminum 4 piston that I ordered from wrecking yard look like this. Internally and mounting are the same as newer ones (same rebuild kit). Specify the newer ones for performance pads. The older calipers are more common and cheaper. Remember, you can sand off the Mazda name but leave the ridge on the newer one and the square bump on the older one,there is a passage underneath.




Edited 4 time(s). Last edit at 01/25/2011 06:20PM by mgb260.

Got my RX7 calipers today. About the same size as Toyota but 5 lb instead of 9 lb. Smaller Toyota somewhere in between,probably 7 lb. First pic is of pads, left 2 red ones are Large Toyota,2 on right Mazda. The smaller Toyota pads look similar to the Mazda's.






Edited 3 time(s). Last edit at 01/30/2011 08:00PM by mgb260.

Mazda 86-91 Turbo II calipers with name ground off.

Do you have the measurements from the centerline of where the caliper would sit to the closest mounting surface where the bolt goes through (where it sits against the bracket)? I was thinking about these for the front of my alpine nut can't find any info on the measurements. What size master are you going to use? Wasn't the Mazda disc .81" thick? Thanks

I'll try and get the measurements for you soon. 22mm thick rotor(.88),same as many Toyota,Nissan. 7/8 master, I personally like the aluminum 80 Ford Fairmont. I'm just doing prototype work for those who want to upgrade the stock MGB hub. What wheel bolt pattern is Alpine, I thought it was 4X4.25 like some late Fords and Volvos, should be lots of rotors available 10.5" to 11.5" to fit the caliper simply move the mounting bolt spacing on the center of adapter bracket as necessary.



Edited 2 time(s). Last edit at 01/29/2011 05:56PM by mgb260.

Ive been following this thread to see if i can get any different ideas. Thanks for the info i looked at the Toyota calipers at my local parts house and they appear those would be easy for a caliper swap. How thick and what kind of material is good to make a bracket from? I think if I made a bracket then the Mazda would be good for a cheap front upgrade.

For me as a rule if you need to go 1/2" or more thick use 6061 aluminum. I like 1018 steel bar or flat plate 1/4"- 3/8" thick and use 2 pieces sometimes to offset. Use grade 8 bolts,nuts and washers and Loctite blue threadlock also. Remember to center the caliper to rotor. Sometimes the 4 piston calipers require a wheel spacer for some rims also.



Edited 3 time(s). Last edit at 02/06/2011 11:31AM by mgb260.

Thanks. The sunbeam rotor bolts to the back of the hub, so caliper thickness isnt too much of an issue. When I get around to doing it I think ill use a rotor hat and ring type rotor, bolted how the original one is bolted on, and make a bracket for the caliper.

What's the bolt circle hub to rotor? You might be able to use the Cressida rotor by slotting the holes,use a grade 8 washer under bolt head. Those separate hats like Speedway and Wilwood have multiple 5 lug bolt patterns and would probably work if slotted but might have overlap going to 4 lug.

Im not sure, i never had the hub off the car to look around the back. This is what it looks like. I saw a pcture of an old racecar on ebay where they turned down the Sunbeam rotor, drilled it, and used that to mount a ring type rotor on. I dont know if thats a good setup or not.


If I had to guess, the bolt circle to bolt the rotor on is somewhere in the 3-4" range.



Edited 1 time(s). Last edit at 01/29/2011 10:19PM by socorob.

Robbie,TR6 is 4X100mm same as Cressida,MGB hub looks similar but is 4X96mm. You might luck out or if quite a bit different you could drill the right pattern between the existing rotor mounting holes. If you use the aftermarket rotor/hat you would have to use shims between the pads and pistons(.035 on each side) to make up the difference in thickness (.81 to .88). Here is the measurements from caliper center(piston) to mounting hole centers,Toyota 1 3/4",Mazda 2 1/2". The Toyota stock was a 10.5" rotor and the Mazda was an 11" rotor. Hope this helps you.

The sunbeam has 4x4.25 bolt pattern (4x108).

Robbie, The wheel lug bolt pattern is usually different than the rotor pattern but if that is the pattern,you can slot out 4mm on Cressida or drill new 4X108MM holes between existing holes ,or go on Rockauto.com and search for a Volvo or Ford 4X4.25 pattern 10-11" rotor with a short hat. Then you can bolt behind rotor like stock, similar to TR6 or MGB.



Edited 1 time(s). Last edit at 01/30/2011 07:13PM by mgb260.

Another pic of 86-91 caliper: