Pad covering the whole swept area?

[McGherkin]

Hi all.

Was dicking around with the Volvo earlier. Some of you may remember I had real issues getting fitment right for my Wilwoods - the setup came with 2 piece rotors (see first pic), which were great apart from the fact that the hats were slightly too big, and hit the edge of the pads whilst braking. I was trying to find different discs and so on, but with largely no success. So I gave up, stuck Focus ST calipers and discs on it, and forgot all about it.

Moving on to today, I suddenly had an epiphany - the OD of the ST discs is the same as the Wilwood discs. Chucked the Wilwood caliper back on the car, and of course it fits perfectly. Great. So that means I could run discs which are easier to get, far cheaper, and it means then that I could run as aggressive as f**k pad and treat the discs as disposable, whilst having a lighter, stronger caliper.

The only issue, though, is that there's a lot of area on the inner portion of the disc that the Wilwood caliper doesn't sweep. I know most cars leave a little, but this is a lot! Would MOT/Plod etc have an issue with this if they saw it?

 

[Gus]

Wilwoods on a volvo? I'll admit I've never seen that before. Usually the only mods are national trust stickers.

 

[JB21]

Shouldn't be an issue as long as it passes the brake efficiency test. Does look a waste though but its still grabbing the same area as the 2 piece presuming they were 320mm OD same as the ST/MPS/T5 discs.

 

[Knuckles]

Didn’t see the issue in the first pic. Then remembered the first paragraph.

Did a lol at the second pic.

 

[McGherkin]

Wilwoods on a volvo? I'll admit I've never seen that before. Usually the only mods are national trust stickers.

100% necessary, I can assure you!

Shouldn't be an issue as long as it passes the brake efficiency test. Does look a waste though but its still grabbing the same area as the 2 piece presuming they were 320mm OD same as the ST/MPS/T5 discs.

The pads in the Wilwoods are a lot longer, and the clamping force is a lot higher, so it does make sense. I loved how the wilwoods felt when I had them on, it was just the fact they were constantly twatting the rotor hats. That was on the gentlest compound they do - the pads I want to run are about half as powerful again on cold bite, and will handle really silly temps before fading.

 

[JB21]

Out of interest what performance pads do you rate in the OE callipers? Got Brembo OE in mine and they are utter shite. Looking at Stoptech fast road pads.

 

[McGherkin]

The Volvo OE or the ST ones? I don't recommend the Volvo calipers at all, I currently run Yellowstuff in the ST ones (and they're actually still OK), but they're still not a track pad. I'd probably go for something like a DS2500 for road or for track a DS3000, something like that.

 

[McGherkin]

Found a photo of the original kit, the setup I bought was new unfitted, and obviously the owner had specced 2 piece rotors instead, looks like it’s the original intention to have that gap anyway.

 

[bloke]

would probably be an mot fail...a braking system component inappropriately repaired or modified.

 

[McGherkin]

But then I could argue that actually it’s as per the design of the system, now that I have evidence for that.

I’m not too worried now I know that’s how it’s supposed to be anyway. Wish I could run those 2 piece rotors though

 

[bloke]

tester could easily argue that the design is flawed as the pad doesn't cover the full area of the disc, may never happen though.

is it just the pad backing that's touching the bell?

 

[McGherkin]

Ground the pad backings back to the friction material and it was still knocking. It’s just way too close. I’d knock up a longer carrier to move the caliper further out, but there’s no more room behind the wheel.

 

[bloke]

i'd either reprofile the pad edge to clear or get the bell machined to clear. looks like the radius is different on them so would probably need a small amount machining off it? pop the pins out of the pad and slide them until they touch the bell and you can at least use the distance the pin holes are out as a guide to how much needs machining off the bell, at least you'll know if it's too much to turn it down by.

have you got a pic of it dead on to see roughly how much it's interfering by?

 

[McGherkin]

Can’t machine the bell as the allen bolts holding the rotor on are using that bit of metal. Rotors are fucked now anyway.

Haven’t got any other pics of the clearance, about 1mm when stationary though.

 

[bloke]

if it's only about 1mm then i'd just do the edge of the pad.

 

[Mr R.]

We had Wilwoods on our Aston race car, tbh they are pretty sh1t and cheap compared to something like Brembo, AP and Alcon.

Our brake set up didn't fit to good, the inner radius of the caliper didn't follow the outer radius of the disc.

 

[PAUL JA]

Not uncommon to radius the inner edge of the pad to clear the Bell. Had to do it on Pagids with AP kit on the focus RS.

 

[JamesBryan]

I read brakes, then Wilwood 😞

Having half the disc unused would be pointless tbh, may as well run smaller calipers with full coverage if you're going to do that.

 

[McGherkin]

I read brakes, then Wilwood 😞

Having half the disc unused would be pointless tbh, may as well run smaller calipers with full coverage if you're going to do that.

They stop better than the ST calipers which are on there, which do cover the whole disc.

 

[JamesBryan]

They stop better than the ST calipers which are on there, which do cover the whole disc.

But they're a different size altogether though aren't they?

Plus single pot calipers and 6 pot will be totally different. You get more even pressure to the pad with 6 pots.