Springs and Shocks on Contemporary

[Eljaro]

Originally Posted by kdavies3

Thanks Stefan,
I had to junk the pads that were the Wilwoods I got from you.
They were just too hard without a servo.
I've gone with EBC greenstuff pads now which is better but still not as good as I'd like the front brakes to be.
I may try an even softer pad or fit a remote servo in the longer term.
I had to fit a pressure restrictor in the rear brake line to stop the rear end locking up first.
I'm going to replace the restrictor with an adjustable valve so i can optimize things.

I am running Polymatrix E type compound pads , and braking is vigorous without any power assistance.
For the rear i have a Wilwood proportioning valve to limit the pressure to the rear brakes. Takes some brake testing to find the good adjustment. Once set you can leave it like that.

[kdavies3]

Holy thread revival Bat Man!
Hi Stefan, what calipers, discs etc did you end up with?
I've come to the conclusion that the Wilwoods I had from you aren't going to cut it.
As I suspect you found.
I just can't get enough front braking as it is.
I really don't want to fit a servo.
I have 5.98 sq" of piston area with 4 pots, what did you get by going to 6 pistons?
Did you go with bigger diameter discs too or just thicker?

[Eljaro]

Originally Posted by kdavies3

Holy thread revival Bat Man!
Hi Stefan, what calipers, discs etc did you end up with?
I've come to the conclusion that the Wilwoods I had from you aren't going to cut it.
As I suspect you found.
I just can't get enough front braking as it is.
I really don't want to fit a servo.
I have 5.98 sq" of piston area with 4 pots, what did you get by going to 6 pistons?
Did you go with bigger diameter discs too or just thicker?

Hi Kevin, the brakes with the 4 pots worked alright. I am using 3/4" master cylinders (one for front and one for back, with balance bar) and no servo and did not have problems.
What bore size master cylinder are you using?
On some rallies with plenty of curves and lots of hard braking the brakes would get very hot and the brake fluid would start boiling, leaving me with no brakes up front.
I decided to install larger discs and calipers. I have 12.75" diameter vented discs, 1.25" thick and Billet Superlite SL6 calipers with narrowed outer body.
Piston area is actually less than on your calipers (4.04 sq"). I think the 6 pot calipers are smaller and will fit into a wheel where 4 pot ones will not.

I had to do a lot of measurements to make sure it would all fit inside the 15" Halibrand wheels. And it all did. Just one mm of space between one outer edge of the caliper body and the wheel, and no weight can be fitted inside the wheel or it will get scarped off.
Braking is now incredible, almost like having a servo. Easy push and unrelenting deceleration is what I have now.
Pads are Polimatrix E Compound front and back, with a pressure limiter for the rear brakes.
Fitting the brakes needed me making a special hat and adapters to fit the lug mount calipers on to the Jaguar front axle.
I also fed a hose from the front openings to the calipers for cooling.

If you need info on how I did it let me know.
best
Stefan

[kdavies3]

Hi Stefan,
in fact no your calipers are bigger than mine in piston area.
mine are 6" sq. That's for the whole caliper ie. 4 pistons.
Yours are 8.08" sq. over 6 pistons, Wilwood quote the piston area only on one side of the caliper for some reason.
Therefore yours are 25% larger than mine.
I think i see my way forward with bigger brakes, it's just how to keep the cost down is the issue as always.
I want to get them sorted before my run to Le Mans in July.
Ideally I'd like to keep my discs and bells and just increase the piston area.
I've been looking at the Superlite 4120-7568/69.
I'm not sure if I can make them work with the rest of my set up?

[Dominik]

You might consider replacing the 4 shocks with 2 and mount them a bit further out at the lower mount. Of course, that saving only makes sense if the ones you have are long enough and you don't have to buy new ones.

I used a 100N/mm coil, which was a bit hard. I forgot the length.

Drill a hole in the center of the XJ6 bracket which connects the shock lower mounting shaft with the upright (as far up as you can) and bolt it right there.

I took a pic once, but can't find it.

And before anybody says it does not work, I can tell you that 20 years down the line with this setup "it still does not work"... ;-)

Jaguar used 4 because they had a package problem. The exhaust was routed along there.

[Eljaro]

Originally Posted by kdavies3

Hi Stefan,
in fact no your calipers are bigger than mine in piston area.
mine are 6" sq. That's for the whole caliper ie. 4 pistons.
Yours are 8.08" sq. over 6 pistons, Wilwood quote the piston area only on one side of the caliper for some reason.
Therefore yours are 25% larger than mine.
I think i see my way forward with bigger brakes, it's just how to keep the cost down is the issue as always.
I want to get them sorted before my run to Le Mans in July.
Ideally I'd like to keep my discs and bells and just increase the piston area.
I've been looking at the Superlite 4120-7568/69.
I'm not sure if I can make them work with the rest of my set up?

If you do not want to change discs (yours are 0.81" ?)you should look at the Caliper No.: 120-11137. The one you mention is for minimum 1.19" thick discs.
Also make sure you get adequate cooling to the brakes and use a high temp brake fluid (I use Castrol SRF). Pads are important too. I do not know how the EBC pads work, but the Wilwood polimatrix E really grab. I tried also Compound BP-20 , which is not so aggressive but tolerates more temperature.

In the end thicker discs dissipate more heat and your brakes last longer in a race. Maybe you can go that route and get same diameter discs.

BTW, what are you doing in LeMans.? What is going on there? I might be interested in getting there too. Let me know about it.
Best
Stefan

[Eljaro]

Ended up getting new 250 lb springs. The old springs that came out were one shorter (about 1/2 inch) than the other. Probably from a hard landing in a ditch. New springs on old Spax Gas shocks are much better now, ride more comfortable without bumps trying to steer the car.
Will change the rear springs now. Will get one set of 250lb springs and replace ona pair and see. If it is not enough I can replace the other pair.