jameswrx

iTrader: (4)

Have these AP brakes on my V6 STI. I need some new pads and disc rotors but was wondering if anyone knows the exact model and what I need?

Currently there's something not right. They're pretty noisy so I copper slip them up and they shut up for a while. This time I decided to take the callipers off and clean out the piston seal area etc. When I say something not right, the pad sits about 4mm over the edge of the disc (see pic) and there is a (circa 2mm) spacer between the AP calliper and the cradle. So, I thought why not take the spacer out and move the calliper and (by proxy) pad nearer to centre and reduce the overhang. I tried this but then the pad backing fouls on the disc bell. What I'm thinking is the disc rotor is the wrong size?

I'm sure one of the brake gurus will know the exact model of calliper and what size rotor I can get away with and the pads I need to fit properly?

Godspeed Brakes

iTrader: (259)

The calipers you have are the CP5200's , and can fit up to 330mm discs.

What size wheels are you using , 17's or 18's ? the discs look quite small behind those wheels , so if you have 17" wheels you may have 304mm discs fitted .

We can offer you our own 330mm discs to fit onto 304mm bells , or if you have 330's already then we can also offer direct replacements for them

The discs look like AP ones to me , so don't know why it doesn't seem to fit properly , if you want to discuss you can ring me on 01656 723060

Cheers Ian

banny sti

iTrader: (68)

They look like 4 pot CP5200 calipers which normally use a 330mm * 28mm disc but if you have a spacer then most likely you will have a 30mm thick disc. Best speaking to Alyn at AS

jameswrx

iTrader: (4)

Thanks gents.

The wheels are 17's, rotors do look quite small. I should have measured them when I last cleaned them.

Let's assume they are 304mm.. If I replaced them with 330mm rotors, I'd need a different mounting bracket surely? Looking at the clearance between the rotor edge and the calliper body and pad retaining pin, I'd say there's at most 6mm there. So a 10mm increase in diameter is realistic to have clearance. But disc size seems to jump from 304mm to 325mm. If this clearance doesn't sound right for 304mm rotors, it may be that I actually have larger rotors. I'll have to whip them off again and have a measure up.

Aside from aesthetics, I can't feel a reason to upgrade the rotor size, the brakes are already way too much for the ABS.

One of the main problems I have is the pad fitment inside the calliper, the current pads have too much movement up and down in regards to their length. They clonk up and down against the inside ends of the callipers. I have noticed on the AP site they list the pad length 0.3mm longer than EBC and other manufacturers, 132.3mm/5.20". I wonder if other manufacturers made their pads slightly smaller (as they do indeed list them at 132mm instead of AP's 132.2mm blueprint). Mine are Mintex pads (I think)

AS Performance

iTrader: (4)

for starters from the pics it looks as if the rotors are well past their "best" judging by the radial wear at the inner face where it meets the bell

initially i would suggest measuring the diameter of the rotor, thickness, how many bell mounting bolts there are and also the PCD of the bell to rotor mounts

jameswrx

iTrader: (4)

Rotors are 304mm 28mm thick. 12 bolt fixing 49mm

Guess I'll need the same size rotors with the brackets on there. The brakes are great anyway, I don't feel any real need to upgrade the size apart from a slight desire for the visual upgrade.

AS Performance

iTrader: (4)

to measure the PCD you want the centre to centre distance of opposing bolts e.g. 6 o'clock to 12 o'clock - will be something like 190mm, etc.

Godspeed Brakes

iTrader: (259)

Measure it as Alyn says , 2 opposite bolts , we find they are either 177.8mm or 190.5mm , we make a 330mm x 28mm grooved rotor with the same centre as the 304mm rotors so they will fit your bells , and then supply you 13mm spacers and longer bolts to space the calipers off your brackets so you won't need new brackets or bells to go to a larger disc , and will still fit under your wheels
Cheers Ian
01656 723060

jameswrx

iTrader: (4)

Darn, knew there'd be something else. So the 49mm between mounting hole centres isn't a giveaway to which ones I need? There must be a difference in hole centres depending on bell mounting size (if both fitments are 12 bolt)

Any input as to why the pad hangs over the disc edge like that? The pads must be the right size as the retainer fits snug. Is this just how the 304mm setup goes?

AS Performance

iTrader: (4)

you need to measure the PCD as above between an opposite pair of mounting bolts to get an accurate reference

AS Performance

iTrader: (4)

just to add the 304mm std AP "forumla" kit normally uses a -4mm scalloped pad over the std radial depth one but often people simply fit std parts not realising

Godspeed Brakes

iTrader: (259)

Is the forumla a new kit Alyn

AS Performance

iTrader: (4)

yes its exclusive to those with over-speedy fingers that dis-obey their brains due to over-work or simply dyslexic typing..............