Brake Upgrade

[djw113uk]

Oh, forgot to say i tried the willwood "lightweight" conversion - it uses the same disks, but the callipers are mounted on special brackets. I absolutely hated them. They were an older type though - with no anti -rattle springs - the chattering drove me nuts (in the saloon) On a convertible it could only be worse! They are on the garage shelf now and I built my own jag conversion as they are no longer available as a kit.

14" stag wheels will go over the jag calipers - it just needed a 3mm spacer.

[KOY 23]

I had a Stag with the Jag 4-pots up front. The car had loads of mods, and came with receipts for all work done by Richard Lane.

The brakes were very effective, but I had a concern that because the rears were still standard, the fronts would lock up quite easily. For obvious reasons I would not recommend doing the front brakes alone, without re-balancing the front to rear bias.

Chris.

Please clarify, did the fronts lock up in practice or were you concerned that they might?

[V Mad]

Yes, as you would expect, they actually did lock up. Very easily in the wet, but in the dry too if you were not careful. The Jag 4-pot setup is very powerful.

[new to this]

I know where there is some so I may well have a look so I can get the part numbers. What vehicle are your vented discs from? I seem to recall you use standard calipers?

James

James

the vented disc i used were from citroen picasso,they need drilling to suit the stag you also need a spacer,to go between the disc and hub,not sure if TR6 calipers are the same as stag,as rimmers now sell a kit

dave

[Stagdad]

Oh, forgot to say i tried the willwood "lightweight" conversion - it uses the same disks, but the callipers are mounted on special brackets. I absolutely hated them. They were an older type though - with no anti -rattle springs - the chattering drove me nuts (in the saloon) On a convertible it could only be worse! They are on the garage shelf now and I built my own jag conversion as they are no longer available as a kit.

14" stag wheels will go over the jag calipers - it just needed a 3mm spacer.

I have the older type and cured the rattle with a light spring slid over the retaining splitpin and pushing outwards against the pads, no problems since

[mjheathcote]

Website:http://www.britishclassiccarparts.com

No connection with the company. Feedback from the owner of the Stag that was used to help perfect the Stag kit is very positive.

I wonder if they are made by HiSpec Motorsport.

[flying farmer]

Brakes need to be balanced front to rear otherwise the stopping distance will be increased under heavy braking.

There are two separate problems with brakes, the amount of force applied to the pedal to give a certain level of retardation, and the heat generated during braking which can lead to brake fade. Increasing the piston area on the front brakes would need bigger diameter rear cylinders to even up the brake force, or a brake proportioning valve to reduce the pressure going to the front brakes, a bit pointless having gone to the trouble of fitting bigger brakes!

Most of my Triumphs suffer from the front pads fading out first. Fitting bigger calipers and pads will give more pad area to absorb the heat, but the amount of force applied by the calipers is proportional to the surface area of the caliper pistons. I have Volvo 4 pots fitted to my V8 Toledo. These have quite small pistons so don't provide a huge amount of extra pressure to the pads, but the larger pad area soaks up the heat better than the small Dolomite pads.

The other alternative is to fit an upgraded pad compound, this will not reduce pedal effort, but will put off the point of brake fade.

After a certain point, the front brakes will continue to work, but the rear brake shoes will be fried. This was the situation on my TR with vented front discs and yellowstuff pads. The rear drums are the uprated finned variety, but the new rear shoes were baked to the point where they looked like shiney plastic, and didn't work when they cooled down. I ended up fitting upgraded rear shoes as well.

Many years ago my V8 Toledo (3.9 litres, 270bhp), used race compound pads front and rear, the fronts were vented discs, the rears were TR7 5 speed axle drums with 4 speed rear cylinders (much bigger diameter for extra pressure), and a brake proportioning valve to get the brake bias correct.
The problem with the rear brakes was the had self adjusters much like the Stag. The heat generated by the rear brakes was sufficient to expand the rear drums sufficiently for the adjusters to click up a couple of notches. When the brakes cooled down, the drums contracted and locked the rear brakes on, and this was just with road use!

I had to resort to welding the self adjusters to stop the brakes locking on!

I intend to fit better pads to the front of the Stag as an interim measure, having found the standard pads were only good for three and a half laps of Blyton Park circuit, but that is track use.
I have never had a problem with the brakes in normal road use, but I tend to be gentle on the brakes having spent so many years driving around the very marginal stoppers on my Toledo suicide machine!

Neil

[DJT]

I wonder if they are made by HiSpec Motorsport.

Make them themselves I gather. Check the About Us tab on their website.

[mjheathcote]

Make them themselves I gather. Check the About Us tab on their website.

Very good.
Looks like when a solid disc is fitted as OEM, the kits have a vented disc replacement. which makes sense.
No Stag listed, as yet..

[bullstarz]

HiSpec don't get very good write ups. Cheap though. Jag Calipers are heavier, more than the Stags. Remember four pot calipers aren't always better than 2. Its all about the total surface area of the pistons, fiction material of the pads and disc size.

Vented disc are the way forward, wilwood calipers are extremely good. They're light weight so that lowers the un-sprung weight on the front suspension. so win win win.

IMAG1399.jpgIMAG1404.jpg

Wilwood set up the old and the new.

[tractorjames]

Thanks for all the replies. Plenty of research to do now so it can hopefully be made a winter project!!

James

[Goldstar]

james, have you considered that the Stag system is good enough if in good fettle? I'm sure you have but I'm just curious (and catching up on a few old threads)

[tractorjames]

Well I have a new set of pads here which i'm going to put in as the current ones are well down, so I will see how it goes. I find the stopping power fine, just shedding heat which is the problem.

James

[new to this]

Well I have a new set of pads here which i'm going to put in as the current ones are well down, so I will see how it goes. I find the stopping power fine, just shedding heat which is the problem.

James

James

check what condition the disc are in,dont know why but stag disc always seam to wear from the back

dave

[V Mad]

Good point Dave, its not easy to spot problems there unless you are looking for it. But I think its more a matter of corrosion which then accelerates wear.