New front brakes

[Marco Polo]

I've finally got around to fitting a vented front disc kit that is available Down Under. It uses modified Holden Commodore discs and calipers. The Stag drag struts are modified with a cutout and reinforcing plate and swapped across the front of the car. The calipers are at least half the weight of the original items and the discs are about 10mm larger in diameter. The car certainly stops even more quickly now! Front-Disc-2.jpgFront-Disc-1.jpg

[wilf]

Marco - were the original brakes capable of locking the fronts? If they were, I just can't see how you have gained additional braking power. The tyre-road interface is the limiting factor, surely? Never going to complain about a well thought out upgrade though.....

[Marco Polo]

Marco - were the original brakes capable of locking the fronts? If they were, I just can't see how you have gained additional braking power. The tyre-road interface is the limiting factor, surely? Never going to complain about a well thought out upgrade though.....

Yes they were when cool, there are a few mountain ranges nearby and I have experienced brake fade on one or two occasions, fitting the Monarch rear disc kit helped but with the new set up at the front it has made the car feel more sure footed and improved the feel of the brake pedal. Plus they look better through the wire wheels! Cheers, Raoul

[wilf]

Understood, brake fade isn't a nice thing to experience.

[Mansfield Martin]

I am currently rebuilding my Stag but am worried about the braking efficiency. Having driven many hire cars over the years I am always surprised about the brakes on the latest models. My car is 40 years old ! I believe Mercedes advertised that many drivers brake too late and too little , hence a new computer enhanced braking system to be fitted to their new models.
Hence my question is what calipers can be fitted with more stopping power with the least alterations required ? It has been mentioned to me that Austin Princess calipers can be used. Does anyone have any comments please ?

[new to this]

just looked (google) and the austin princess is a four pot brake caliper,any one know the weight of one

dave

[wilf]

I am currently rebuilding my Stag but am worried about the braking efficiency. Having driven many hire cars over the years I am always surprised about the brakes on the latest models. My car is 40 years old ! I believe Mercedes advertised that many drivers brake too late and too little , hence a new computer enhanced braking system to be fitted to their new models.
Hence my question is what calipers can be fitted with more stopping power with the least alterations required ? It has been mentioned to me that Austin Princess calipers can be used. Does anyone have any comments please ?

Unless you live at the top of a mountain, I don't think you need worry. I have been pleasantly surprised at the stopping power of Buttercup, on a totally standard (but well maintained) braking system.

[DJT]

Standard setup is surprisingly efficient if working correctly. As part of my rebuild I stripped a pair of calipers and fitted new pistons and seals. Fitted to virtually new disks with EBC Greenstuff pads. With no miles on to bed the pads in, other than a couple of hundred yards outside the workshop with a few applications, the front brakes achieved an efficiency of 85%. Pass level is >=50%. I expect them to improve as they bed in.

FWIW the disks I took off looked perfect from the outside, but the inner surface was quite corroded. These were new disks only a few years ago and had been fitted with EBC Greenstuff pads for the past 3 years. The pads were worn evenly so the calipers weren't seized.

[Marco Polo]

Standard setup is surprisingly efficient if working correctly. As part of my rebuild I stripped a pair of calipers and fitted new pistons and seals. Fitted to virtually new disks with EBC Greenstuff pads. With no miles on to bed the pads in, other than a couple of hundred yards outside the workshop with a few applications, the front brakes achieved an efficiency of 85%. Pass level is >=50%. I expect them to improve as they bed in.

FWIW the disks I took off looked perfect from the outside, but the inner surface was quite corroded. These were new disks only a few years ago and had been fitted with EBC Greenstuff pads for the past 3 years. The pads were worn evenly so the calipers weren't seized.

Hi Dave, I couldn't agree more, your car looks fantastic by the way! I did a little "non scientific" road test with a mate of mine over the weekend we drove the same road at 100kph and did an emergency brake at a marked spot on the road, his car is auto BW 65 with standard brakes, mine manual OD with monarch rear disc kit and the Commodore vented front disks. My car stopped two and a half car lengths before his regardless of who was driving. We used a GPS to calibrate our speedos and each drove both cars. I would of thought an auto would stop better than a manual car because of the drag of the torque converter and box, however I'm willing to be corrected on that one by the resident automotive guru(s)! I guess it is again down to personal choice, just like carbs! But I think the vented slotted discs look better behind my wire wheels!
cheers,
Raoul

[Bob Heritage]

just looked (google) and the austin princess is a four pot brake caliper,any one know the weight of one

dave

Where do you think you are going to find Austin Princess calipers? this was used when they they were regularly being scrapped. Richard Lane's mod used XJ6 calipers. Stag brakes are fine with a srtandard set-up.

[StagnJag]

I seem to recall someone saying that the Princess callipers, whilst being 4 pot had an overall piston surface area smaller than the Stag ones, making them less efficient.

I Could be wrong though.

Rgds

Dave

[new to this]

Where do you think you are going to find Austin Princess calipers? this was used when they they were regularly being scrapped. Richard Lane's mod used XJ6 calipers. Stag brakes are fine with a srtandard set-up.

bob

not sure but didn't the XJ6 calipers rub on fall lock,? and they were heavy

dave

[mjheathcote]

I seem to recall someone saying that the Princess callipers, whilst being 4 pot had an overall piston surface area smaller than the Stag ones, making them less efficient.

I Could be wrong though.

Rgds

Dave

No you are right.

[Mansfield Martin]

Thanks for the replies. I have been busy trying to finish my rebuild, to no avail. My racing friend at A W Tracksport believes I can have custom made 4 pot callipers in aluminium for a reasonable price. However I shall take most peoples advice and keep it all original except the Green Stuff pads.

[martin]

Hi Martin, Wards do a very nice Ali upgrade, vented discs, Ali calipers etc. but it's pricey. Unless you're racing the originals are good, if kept up to spec. Martin. (Mk1)