I've had a set of Brembo 17z laying about for awhile which I originally intended for my Corolla*, but got distracted and procrastinated long enough that I thought they'd be a much better fit for the Jag. I spent a good chunk of time researching my rotor choices on the Jag platform and basically discovered the rear rotors from the up-rated X308 are the ticket. I'm using them on all 4 corners. They're 330mm like the stock VW/Audi/Porsche platform my calipers came from.


<Yes, I know that's the wrong sided caliper, but I couldn't wait for the pic.

The front adapters took a LOT of trial and error to cram the giant caliper inside the stock 5 spoke wheel. I have a 3D printer I pressed into service making a total of 15+ iterations. Using a 0.8mm nozzle helped speed things up dramatically. Basically there was a month long war between the 3D printed adapters, the hub, the steering knuckle arm, the wishbone mounts, and the inner wheel diameter. But eventually I got a design that fit, and had it machined out of 4130 steel. Fortunately in my infinite wisdom I took no pictures of it yet.

The rotors fit up but require the centerbore to be machined out to "80mm." For this I took my old x300 rotor and my new x308 rotors to a local machinist and asked him to match the bores. Pro tip: always read your own notes correctly otherwise you'll end up with a set of Z06 rotors machined out to 80mm that don't match the offset of your adapter...ouchie.


The rear went much, much smoother. Firstly, the x308 rotor bolts right on and plays nice with the factory drum parking brakes. No machining required. The caliper adapters are a little funkier but there's more space to work with because the caliper is so much smaller compared to the front ones.

I'm not finished yet but I've reached a point where I'm confident that this is possible. I have a bit of machining left to do on the adapters; and a set of new brake lines to compliment the setup. Then I can give it a try and see how the pedal feel is, I may have to upsize the master cylinder.

 

Fantastic work , I’m following along very keenly :

 

Bit of an update, with pictures of the adapters. Front is an inch thick chunk of 4130, rear are .25" thick 4130 from sendcutsend. Hardware is mostly grade 8 or even grade 10, even the washers. A significant amount of the dust shield has to be cut away. The remaining shield needed reliefs cut in it, and I bent it away from the rotor. I ended up using 4 '97 XJR/XJ6 front brake lines all around. Not too difficult to change although in the rear you have to do it blind. Thank you Jag.

Finished rear caliper, with rotor cleaned and put on, brakes are all bled and not leaking. Unsure how the pedal feel will be, but anxious to test it out.

 

After significant delay, I'm back on this project. The shop that fixed my EGR pipe had more than a few comments about my brakes, none of them good, so I have my work cut out for me here. The brakes did work well enough driving onto the towtruck and parking on the driveway.... at such heady speeds as 1-2 mph.


The rear was made of steel plate with stacks of washers to set the caliper offset. Unfortunately I set the offset wrong and chewed a groove in my new rear rotors. So in addition to correcting the offset, I will be integrating the washer stacks so that taking the assembly apart doesn't unleash a barrage of washers on innocent mechanics. I'm also bringing the pads in 1mm closer to the wheel hub. The pads were just barely over the outer chamfer of the brake discs, and its an easy adjustment in the rear. Might as well.


Up front the shop was unhappy about how much pad was hanging out off the outside of the disc. About 0.25". To bring the caliper in I had to make some big design changes, and I will have to tap the steering knuckle holes. I will be using some grade 12 countersunk bolts from McMaster. Doing this I was able to bring the caliper 4.5mm inward, which isn't the full amount but its the best I can do. I will still have dramatically more swept area than stock, and I'm not concerned about the pad overhanging a small amount.


Now the good news! After trying out the brakes just a little, I confirmed that I need a bigger master cylinder. First I tried a few truck cylinders from the junkyard but they were all too big. The stock Jag master cylinder is really compact and the reservoir is short and shaped to fit a specific spot. But somehow, some way, the Jaguar X300 and the VW Touareg/Porsche Cayenne have master cylinders made by the same company, with similar designs, and the reservoirs are interchangeable. Jag bore is 1", VW bore is 1.0625". The mounting bolts are offset different and the plungers are different lengths, but I'm still pretty thrilled about this find. Hopefully it has a big enough impact.

 

Great work. I'd suspected those rear rotors might work; lots of dimensions the same. Would you share the dimensions of the adaptors you made?

cheers
dave

 

Maybe some day but not until I've tested them myself. I wouldn't feel good sending out my untested design, especially with brakes.