Do you want to upgrade only the rotors/pads or the callipers as well?

For the rotos and pads just google "xj8 brembo rotors" and you will find lots of places that sell them.

 

from you mentioning new or pre owned i take it you want a complete set of calipers, rotors and pads. i can tell you just for the rotors and pads you are looking at $1500+ without the calipers which could easily double that.

 

Doesn't the 'R' have larger wheels? Better check if the calipers & rotors fit under yours.

 

I am not sure that is going to yield an "upgrade" in the end. Why the change from just keeping it stock?

 

As was mentioned, going to drilled rotors actually reduces the surface area of the rotor, technically reducing braking force.Some of the folks using this type of stuff are doing it for looks, not performance. In order to make measurable use of extra-cooled rotors, you needto use racing pads, which are not nice to live with, not working well until molten hot and then squealing in normal use, dusting heavilyand lasting 5,000 miles and so on. Also, braided lines are not the greatest for street cars, they can wear internally and you cannot see it. Braided lines are made for racing cars that have suspension parts and exhausts that abrade and burn stockbrake lines.They are made to be changed often, not sit there for years. I used to race and we changed them after about every three or four races. You are getting ready to make yourself miserable and spend money doing it. I suggest you get some high performance ceramic pads (my favorite are Akebono as they do not noticeably dust)made for street cars and bleed your brakes carefully with goodDOT 4 fluid, they will be fine unless you are hitting the track. Then you will need the things you mentioned. The brakes on my XJ8 are not spongy at all and have plenty of stopping power for street use, being able to invoke the ABS anytime I want. The best thing you can do in this areaof street performanceis to get really ,reallygood tires, they are more important and more overlookedthan brakes in the scheme of things.

 

I spoke to the engineers at brembo and were told the do not have a kit for 04 xj8. they said that some people have used the 03 kits and that they might work. they quoted me $6300 for a complete front and rear 03 kit. Not worth the money to me!

 

+1 - I agree with oldmots above

A fresh bleed and new ceramics may remove the 'sponge' feel that you have mentioned. Someone said that the Jag rotors are a softer metal too, so if you do choose to swap out rotors, go wtih an aftermarket EBC, Brembo .. solid rotors for even more responsiveness. I think you'll be suprised and quite happy with the results without changing out calipers too.

 

I'm not looking to make anybody angry but there are some wrong ideas floating around here about the usefulness and benefits to be gained from using armored brake cables and slotted rotors.

Perhaps armored cables would give a race car driver an added margin of protection from abrasion but the paramount reason is brake feel and initial bite. When you first get on the brakes the hydraulic pressure uses a portion of it's applied force to EXPAND the rubber brake hose, thereby lessening , initially, the amount available to drive the piston(S) AGAINST the rotor. That slight lag in brake application can be very disconcerting to a driver or moto rider who is driving at 10/10ths and looking for every bit of performance he can get from his/her brakes. These kinds of hoses aren't of much benefit to the 55 mph driver who leaves TWO car lengths for every 10 miles per hour but to individuals who really enjoy letting out the leash every once in awhile they make the experience that much more fun and secure.

On the matter of slotted, or drilled, rotors there is a very sound and solid scientific reason for doing that. Slotting is more effective but even drilled rotors gain some of the same benefits. When racing teams and mechanics are looking for every single 1/4 gram of advantage or decrease in lap times, and when races are often won by fractions of a second these little bits add up. By slotting a rotor you gain two things, possibly three. Each of those slots aids in cooling not only the rotor but also the pad thereby increasing both pad and rotor life. This also probably helps to minimize rotor warping due to the slots acting somewhat similar to expansion joints in concrete. The real reason however is to increase, again, the ability of the brake pads themselves to maximize not only their initial bite but also their effectiveness throughout each braking cycle. As a pad slides over the rotor scrubbing off speed the heat rises very rapidly and ionizes the air beneath the pad and on the surface of the rotor. This degrades, however slightly, the ability of the pad to reach it's maximum capability. By running over the slots these pent-up gases from the ionized air and friction material have a ready escape route through which they can get out from under the pad thereby giving the pad(s) what amounts to a fresh bite at the rotor SEVERAL TIMES IN EVERY ROTATION.

I can't help it if every teenage and older 'tuner' has taken so many of these ideas to the extreme because it does make many people lose sight of the rational behind the initial concept. Putting a loud resonator, some fender and scoops, and a set of dubs on your 1.6 liter naturally aspirated Honda doesn't actually make it faster, louder probably, but not faster. Yet the origin of all of those things served a real purpose when first applied in competition.

 

These are some valid points. I will say that in all my yers, I have not seen a rotor actually warp, even when they have been running red hot for a 500 mile race. What makes them look warped is pad deposition on the rotor from the molten metallic particles in cheap pads. On street cars, drilled and slotted rotors are mainly for bragging rights as it takes high perf pads to make them function as designed and these are lousy on the street, not really biting hard on initial application. I have had some street cars with Brembos including my current XKR usin gHawk HPS pads and all of them have great brakes but they don't run hot enough around town to really matter. I can feel the change in braking force during a hard stop, ramping up as the rotor gets hotter. Its funny that the brakes are working the best just as the car stops moving!

 

Just like H2o Boys says. You're not racing in Singapore! They catch you and its Caning time. For normal driving, high performance parts are not practical. Like snow tires in Singapore. lol

New pads, rotors, a good brake fluid flush and 4 wheel bleed and you'll be factory with all the stopping you can handle. Sounds like your pads and rotors are very worn and you may have air and crud in your system, which slowly leads to a mushy pedal.You my even find a locked up caliper along the way.

Read what I have done in the How To: section https://www.jaguarforums.com/forum/x...ice-how-61323/

Follow this and you will be more than satisfied.

 

Oldmots for the most part your right about most racer applications for use on the street by the average driver in the everyday bump and grind we call life. Having been a involved with new automotive sales both as an employee and eventually the owner of a Chrysler Corp. products dealership for the better part of 30 years I've had my share of interesting experiences with automobiles of all sorts. While there are some on the forum who may never have experienced a warped rotor I can tell you from my experience that they occur quite frequently amongst the under 30 crowd as they often punish there front rotors with their penchant for coming to almost a screeching stop at every opportunity as if they would arrive at their destination faster if they waited to brake until the last second. This constant rapid heating and cooling causes normal mass market rotors to actually warp. This can be easily felt by a rapid pulsation in the steering wheel and brake pedal upon a more normal application of the brakes as the caliper expands and contracts in an effort to deal with the warp in the rotor. However, it is true that the difference between a $70 rotor and a $600 one is extremely unlikly to ever be felt by the average everyday driver that we all probably are, despite our occassional bursts on adenaline and testosterone overload<G><G> By the way, full floating rotors are much less likley to warp but seem to be much rarer on cars then on motorcycles.

As for armored brake lines I've never had a set on any of my cars, including the more exotic ones that have inhabited my garage over the fast 5 decades since I first started driving. Nonetheless I do install them on my motorcycles because the difference is startling and immediate and I feel that given the added danger inherent in riding a motorcycle that every advantage I can have I will gladly take. I'm one of those ATGATT riders (all the gear all the time) but multi-thousand mile forays have taught me the wisdom of such a choice.

What's the upshot to all this. We're individuals, everyone of us, and we have the right to express ourselves in am myriad of ways up to and including what we judge to be the most satisfying and individualizing 'improvements' to any of our belongings from the type and style of clothes we wear to how we go about the care and feeding of the automobiles we so obviously appreciate.