Hi, new to this forum I post my first thread. I know that there are multiple similar posts since before. Reading through them didn't give me the answers I am looking for.

My car is a Xkr coupé year 2000. The car is in decent condition, 120 000 km has passed. I've had it for almost two years now. I'm looking to improve a few bits on it, so far exhaust is changed to cat-back Milltek, and the intake tube has been changed to an aluminium Mina tube. Otherwise it is still standard.

Now, I want to upgrade the brakes. The discs are getting worn so it's about time to do something, and at the same time I want to have beefier brakes. I looked for some time at Ebay for the bigger Brembo calipers for the front wheels, but none showed up. Eventually, instead I bought a pair of front end Brembo four pot calipers from a Xjr 2003. Yes, I'm aware of the threads already covering the issue but none of them gave me the answers. Some contributors write it is possible to use Xjr calipers on Xkr, others deny it.

My questions are:

1. Is it possible to fit Xjr front end four pot calipers on a 2000 Xkr with standard brakes fitted from factory without changing spindles, hubs etc?
2. If answer on 1 is no, would it be possible to do if also changing other parts like spindles, hubs etc? If so, what parts do I need to buy together with the calipers?

In the pictures showing the Xjr calipers, you can see that the distance between the mounting ears is 90 mm. Of course also the offset between the ears and the disc centre might be different between Xkr 2000 and Xjr 2003

Thanks,
Higgins

 

My understanding is that they are compatible. The X100 XKR brakes are compatible with X308 XJR with the R1 package (big brakes).

If you search "BREMBO" on this site, there are a handful of conversion threads. The short version is that you need to tap the uprights for new bolts, source brake lines, source the calipers and rotors. Dust shields are reputedly NLA, so the existing (smaller) ones have t be reworked (outer edge lip cut off). The rears are easier, I believe, if you want to bother.

Beware that the S-Type-R brakes come up a lot on eBay (and cheap) but are NOT compatible.

Best of luck, keep us posted.

PS: brembo-conversion-111642/

 

Great, thanks for the advice. A little worried that the calipers might be late 2003, and from X350. Anyone with knowledge on the different distances between mounting holes (mine Xjr calipers got 90 mm) and perhaps difference in appearance of the calipers between X308 and X350?

 

Also, double check your wheels. Some do not have the backspace for the bigger calipers. What wheels do you have?

There is also a ready-made kit at a good price here: Brembo_Performance_Front_Brake_Kit

 

Nice kit! Have to check my balance..

 

I use double five 18". But would like to get a set of Detroits

 

Those are rear calipers, not fronts. If you are sure they're from an XJR, than it was an X350. By chance they might be from the rear of an 03+ XKR (X100) as they have the same paint scheme, and would fit the rear of yours.

Otherwise the answer to your question is yes, XJR (X308) calipers are interchangeable with XK8/R (X100).

 

Can you tell from the color scheme alone that they are rear calipers? Strange, they were sold as Xjr front calipers at Ebay. But of course that might have been incorrect info from the seller. Can you tell from the distance of 90 mm between mounting holes if it is X308 or X350?

Regards,
Higgins

 

Not from the color scheme, but from the shape, size and 90mm distance. X350 rears have 90mm mounting spacing but the front spacing is higher. X308 (and X100) spacing is 90mm front and rear. Rear calipers also have the same diameter pistons, whereas the front are different diameters.

Not sure if these will fit your rear as the X350 uses a different size rotor so I don't know if the offset will work. Maybe if you use the X350 rotors but then you'll have to re-drill them for the correct bolt pattern.

 

Great info, thanks. Lets see if I can use them rear , or I sell them and buy other ones for front. The complete front kit at Welsh is tempting,.

 

To use rear X350 rotors on my x100, would it help to use X350 hubs rear? Or impossible without re-drilling rotor? I understand high risk of cracks when rotors are drilled

 

I don't know if you can just swap the hubs, as the spindles/hub carriers on X350 are a completely different design.

 

No, not possible, its a complete different design as Stevem mentions, there are no upper arms connections on our cars, that is controlled by the axle/hub combo.

 

Thanks Avos for the additional info on differences in the rear suspension between x100 and X350. From the pictures of my calipers, can you tell if they are from a X308 or X350?

Regards,
Higgins

 

No, you would need to have 2 more measurements to make an educated guess, one from the bolt holes to the center of the pistons, and one from the bolt holes to the middle of the pistons/caliper (so where the disc centers).

 

Great, I will try to measure as specified. Thanks!

Regards,
Higgins

 

Pistons are marked by the two thick red circles. Distance between pistons are 55 mm (centre to centre). Distance between mounting hole centre and piston centre is approx 17.5 mm

Hard to measure exactly, but rotor centre should be around 12 mm from mounting hole surface

 

This helps already, though for 1 measurement it was not between the pistons, but between the center of the bolt holes and the center of the piston. On mine that's roughly 53mm.

But one thing is already very different; mine have a about 36mm wide gap for the disc, and the position from the bolt holes is about 18mm.

I take it our discs (28mm) are thicker then the xjr/str versions, so it looks like this a no go.

 

Thanks Avos, that should be enough to decide I need other calipers for my XKR. Lets raid Ebay again..

Regards,
Higgins

 

Hi,

an update in this thread, I decided to go for the Brembo kit from Welsh. Got the shipment a few days ago but to my surprise it just contained the calipers and pads, no rotors or brake lines as specified. Welsh shipment dept had messed up, they will ship the rest tomorrow.

Now I'm looking for parts for the rear end. Best would be a Brembo kit for the rear as well, but a good enough solution would be matching (with front rotors for looks) drilled and slotted rotors at standard size and new or refurbished standard calipers.