HI-Spec Brake Kit

[davettf2]

Peeps, I've just fitted the HI-Spec 283 mm standard kit to my chim with standard pads as supplied (Volvo 120 / 140 series) and find that the brake pad is slightly above the edge of the disc. Is this normal? It does not feel right as I would normally expect the pads to sit just inside the outer diameter.
regards, dave

[Pupp]

Varies with different pad sets but mine was like that. Won't cause a problem as the 'lip' that forms will crumble away.

[GTRene]

so the discs could also be 300mm say about 8mm wider?
or is it just say, 2mm or so over it.

[davettf2]

2 mm or so over, 300 mm discs would not fit. Also the adapter between the original mounting and the Hi-Spec caliper is marked 283 with the disc running quite close to the caliper. It would be difficult to get the caliper much closer to the disc. Thus i suspect that it is a pad issue.
regards, dave

[SILICONEKID345HP]

I noticed this and the pads do not cover the whole disc . The pads cover the same amount over the 300mm kit .

HiSpec told me that is normal .

[davettf2]

Gentlemen, many thanks for confirming that this is normal. However, as you say the pad does not cover the full disc. Although I will leave it fitted for now I am generally not entirely comfortable with the pads 'overhanging' the disc edge. When engineering 4 pots on my Ducati F2 a considerable effort was put into ensuring that the pads were fully on the disc, something which I would expect a manufacturer to achieve.
regards,dave

[SILICONEKID345HP]

davettf2 said:

Gentlemen, many thanks for confirming that this is normal. However, as you say the pad does not cover the full disc. Although I will leave it fitted for now I am generally not entirely comfortable with the pads 'overhanging' the disc edge. When engineering 4 pots on my Ducati F2 a considerable effort was put into ensuring that the pads were fully on the disc, something which I would expect a manufacturer to achieve.
regards,dave

Why don`t the pads cover the whole disc ? do the WMS brake kits cover the whole disc ?

[QBee]

Sitting reading this thread and I have to comment as follow:

Why upgrade your disks to those 283mm beauties, and then only use what sound like pretty basic pads? Volvo 120/140 doesn't remind me of a high performance vehicle.....

I got a lot of stick when i first had my car for replacing my front pads with the cheapest i could find - a set of Ford Escort pads I bought for £13.99.
Alex took my car down the runway at RAF Marham at over 160 mph and came back into the pits as white as a sheet muttering something about "no brakes".
The stick was of course absolutely correct, and i have seriously upgraded all the elements of my brakes.

Someone please correct me, but aren't the 283mm brakes off a Sierra of some description (?Cosworth)? Your brakes will only be as good as the weakest part. Shouldn't it be possible to find some, say, Mintex 1144 pads that will fit properly, complete the package and give much better braking?

[Pupp]

The reference to the Volvo model is the form of the pads - ie the model type to fit the Hi-Spec calipers

[Keri]

SILICONEKID345HP said:

do the WMS brake kits cover the whole disc ?

Yup, well in as much as they are designed to. 280mm swept on 283mm and 298.5mm swept on 300mm.

The reason is so that standard 280mm and 298.5mm rotors can be used as future upgrades without replacing the customer's brackets etc.

[SILICONEKID345HP]

Keri said:

Yup, well in as much as they are designed to. 280mm swept on 283mm and 298.5mm swept on 300mm.

The reason is so that standard 280mm and 298.5mm rotors can be used as future upgrades without replacing the customer's brackets etc.

Is the pad and caliper larger on the 300mm kit ?

[Keri]

SILICONEKID345HP said:

Is the pad and caliper larger on the 300mm kit ?

Nope, same caliper/pad on differing brackets and discs (on these two kits).

[SILICONEKID345HP]

Keri said:

Nope, same caliper/pad on differing brackets and discs (on these two kits).

So the pad only covering the same area on both kits . You are gaining a little more leverage but no more pad cover .

[Keri]

SILICONEKID345HP said:

So the pad only covering the same area on both kits . You are gaining a little more leverage but no more pad cover .

Correct, this is standard in race brakes, you also get more thermal mass and cooling area. Every 10mm taller the pad is you lose 5mm of leverage (the force is in the centre of the pad).

To put it another way, 50mm tall pads on a 300mm kit are the same torque (or effective diameter) as a 280mm disc with 30mm tall pads.

This is also why drum brakes have far more torque than disc brakes!

[SILICONEKID345HP]

Keri said:

Correct, this is standard in race brakes, you also get more thermal mass and cooling area. Every 10mm taller the pad is you lose 5mm of leverage (the force is in the centre of the pad).

To put it another way, 50mm tall pads on a 300mm kit are the same torque (or effective diameter) as a 280mm disc with 30mm tall pads.

This is also why drum brakes have far more torque than disc brakes!

Apart from aesthetics the 283mm disc with a good pads and four pot caliper like your`s or other top brands will cope with anything you can throw at it .

[Keri]

SILICONEKID345HP said:

Apart from aesthetics the 283mm disc with a good pads and four pot caliper like your`s or other top brands will cope with anything you can throw at it .

Well...........most things that most people can throw at it anyway. The fact remains that with more grip and more power you can put more energy through the brakes and there's not really an upper limit on that.