Jaguar brake experts

cobrarkc · #1 (**permalink**) 02-04-2008, 02:35 PM

I have Series II jag brakes on my Contemporary which is a 3 piston caliper and have seen that series III has vented rotors does anyone know what is invloved in converting to them or would it be better to go with Wilwood. If so does anyone have the part#s for Wilwood?

CHANMADD · #2 (**permalink**) 02-04-2008, 04:37 PM

Why do you want to change? The Series 1 Jag rotors are solid discs (I have them too)and work really well in most all driving apps on the Cobra.. The cobra is half the weight of a Jag, and the solid rotors and smaller calipers weigh less than the vented 4 piston brakes. Now I have raced my car on road race tracks and only experienced any heat buildup when I pulled into the pits and sat. The brakes never faded on me on the track.
More is not always better!!!

cobrarkc · #3 (**permalink**) 02-04-2008, 06:31 PM

You can never have to much braking power. From what I can tell looking at XK Unlimited's website series II & III hace the same 3 piston calipers the only difference is the III's have vented rotors but there must be more to it than that because vented ones must be thicker. If I go with the Wilwood superlites I can trim off some upsprung weight but I'd like to hear some opinions.

CHANMADD · #4 (**permalink**) 02-04-2008, 07:35 PM

There is a thicker caliper and /or you can machine a spacer between the caliper halves. But it still beats me why you want to change now,you've had the car since 1980.
the Series 2 jag front end comes with the bigger calipers and vented rotors,but it will change the offset required on the front wheels.

cobrarkc · #5 (**permalink**) 02-04-2008, 07:56 PM

I already have the series 2 brakes they came with solid rotors. I am upgrading things after 28 years and these brakes never impressed me.

CHANMADD · #6 (**permalink**) 02-04-2008, 08:55 PM

As far as I know the Series 2 had the vented, so you must have the Series 1 ,as I do.I did think of doing the swap myself but I decided that it would be too much work.

RoyTheBoy · #7 (**permalink**) 02-04-2008, 10:31 PM

You are right Chanmadd, I have just finished building my front-end and have used Series2 XJ6 components (1976 model) - I have vented rotors and 4 piston calipers. As you have said - more than enough stopping power for a vehicle half the weight of the Jag.

Regards Roy

cobrarkc · #8 (**permalink**) 02-05-2008, 11:41 AM

1969 Series 2 XKE has solid rotors and 3 piston calipers they didn't go to vented until 1971 Series 3. If you have Series 1 there is a conversion out there.
Do-It-Yourself Wilwood Brake Upgrade for Series I E-Type

Not sure if this works with Series 2

767Jockey · #9 (**permalink**) 02-05-2008, 08:45 PM

Rich,
I'm in the middle of the conversion you posted above. If interested contact Mickmate on CC (Nick), he made the brackets for me and some others with CCX's - as usual with anything Nick makes, they're a work of art.

mickmate · #10 (**permalink**) 02-05-2008, 09:09 PM

A couple of local cars with the E fronts just changed to the Wilwood with the vented rotors. The kit bolted right on and works really well although it is pricey. I have seen Volvo calipers used on the Jag front brakes with nothing more than a couple of washers for the spacing correction. We have a couple of cars we're converting to Wilwood calipers on the solid rotors per the above link. We'll be able to tell you in the spring how they work, right Doug?

cobrarkc · #11 (**permalink**) 02-06-2008, 07:35 AM

Mickmate and 767Jockey,
I have seen this conversion but its says it is for Series 1 suspensions and I have a Series 2 so I am looking to find out if this is compatible with mine. I have seen the Volvo conversion also but from what I have read they suggest using the solid rotor ones.

Is there anyone out there that knows the difference between the 3 styles Series 1,2and 3? I know series 1 has dunlop single piston calipers but are there interchangable?

Shelboss · #12 (**permalink**) 08-10-2008, 07:26 PM

The Jag series I front uprights have I believe 3.25" bolt spacing for the Dunlop calipers. Series II uses 3.5" bolt spacing, which works with the heavy 3 piston Jag caliper, or the Wilwood Superlite calipers. Contemporary originally offered this combination with XJ vented rotors as an upgrade. When Series II XKE stuff got expensive, they modified the XJ uprights to change the steering arm to match the XKE (in front). They also machined the front XJ 5 bolt hubs to line the rotor up with the caliper.

mickmate · #13 (**permalink**) 08-10-2008, 09:00 PM

That drawing we used for the caliper upgrade shows a 3" spacing on the series 1, anyone have another series they can check the measurement from? The set up Doug and Jeff are using is per that article and is working super on Jeffs car now. That also is using the master cylinder set up per original geometry and look. We calculated master cylinder sizes to match his calipers.

Shelboss · #14 (**permalink**) 08-12-2008, 08:31 PM

Hi Nick, you are right. The Series I XKE (60-68) uses Dunlop calipers and measures 3". Series II (69-71) uses Girling calipers with 3.5" spacing.
Here are the Series I piston dimensions and comparable Wilwood's
Description Piston Dia # pistons Area
Dunlop Front 2.125 2 3.54
Dunlop Rear 1.75 2 2.40
Wilwood 1.38 4 2.99
Wilwood 1.75 4 4.81

Contemporary used a VW brake master cylinder with a 19 mm (.75") diameter. Is this consistent with what you used?

mickmate · #15 (**permalink**) 08-12-2008, 09:54 PM

I calculated 5/8 front and 3/4 rear masters for Dougs car based on his caliper sizes that gives a 66% front bias. Jeffs car used the same from memory. I put together an Excel spreadsheet that you just input your data and it calculates it for you. If you'd like a copy let me know.