Z4M specific bells for AP Racing Pro5000R BTCC Kit - interest?

Ed Doe

Ed Doe

Veteran
 Ashbourne or Frimley
Hi all,

I'm in discussions with Malc Buck about getting a specific Z4M bell made for his Pro5000R BTCC brake kit.

I'm aware there are at least a couple of bods on here running his e46 m3 kit with some minor adaptions to suit the Z4m (the caliper to disc offset is 2mm different between the Z4m and the e46 m3), so if anyone wants a set once they're made up, let me know so I can give Malc an idea of numbers interested :)

Also I've started a wanted thread but if anyone has a spare z4m hub assembly complete with bearing and dustshield it'd be really helpful, malc needs it to finalise the bells! I can organise delivery if it helps but if anyone has one they're happy to lend or let go for a bit of cash let me know :)

Cheers in advance!

Ed
 
I’m interested, thanks for posting Ed. What disc will you be running? I presume the disc will be different from mine since you’re running different callipers.
Ideally, I’d like discs and bells, but they would need to be available by September so I can bring them back to Aus when we next visit Europe.
 
Thread resurrection! If this helps anyone as far as I can tell the bell has been updated and now sits the disc perfectly centrally in the caliper so no issues for the Z4m any more! I've just done a ring trip on my new setup - the only comments I have are a suggestion to get some spacers off Malc when ordering and to space the caliper radially off the adapter, otherwise the inner edge of the pad material can contact the shoulder of the bell which is a bit irritating. It's more of an issue if you're deciding to run the pad anti-rattle kit as the springs end up pushing the pad material hard up against the bell shoulder meaning heat and wheel wobble.... Ask me how I know (I had to bin the springs off in Dunkirk at 9pm in 30C in the carpark of our hotel on the way out having driven them all the way from Ashbourne wondering wtf I'd done to make the wheel wobble so bad!)

I'm going to give the springs another go at some point now I've spaced the calipers out a bit - will report back!
 
Ed,

Curious to know more about this, i've just had Godspeed make me a direct replacement for the csl disk in a 2piece floating setup. running the Brembo calipers with e46 adapter and have no issues. interesting to hear that there is a 2mm offset as my discs are running in the centre of the caliper.
 
D.Bryce said:
Ed,

Curious to know more about this, i've just had Godspeed make me a direct replacement for the csl disk in a 2piece floating setup. running the Brembo calipers with e46 adapter and have no issues. interesting to hear that there is a 2mm offset as my discs are running in the centre of the caliper.
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Well as far as I can see from my kit now it's fitted is the disc sits bang in the middle of the caliper, so I can only assume it was an early iteration of the kit where the bells or caliper brackets had a very slightly different offset?
 
Around 15 years ago, I tried to fit an Alcon M3 CSL BBK to my Zed. The rears were fine, but the front discs fouled the steering knuckles, despite prior after assurances from the vendor that it would be fine (I got a full refund). I now have E46 M3 AP Racing callipers (as opposed to Z4M fitment) with Z4M-specific discs, and the front callipers need a 2mm shim.
I wonder if the subtle differences in front track and suspension / steering setup are behind this difference. Of note, the E46 M3 front track width is 22 mm wider than that of the Z4M, whilst the difference at the rear is only 8 mm.
 
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i know if you go to 360mm or bigger the disk can foul, i tried to use the e92 disks but was too close for my liking.
where about did you put the spacer ? between the kingpin and the carrier, so making the caliper further outwards ?

the track width also includes the wheels which were larger on the front of the csl
 
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BMWZ4MC said:
Around 15 years ago, I tried to fit an Alcon M3 CSL BBK to my Zed. The rears were fine, but the front discs fouled the steering knuckles, despite prior after assurances from the vendor that it would be fine (I got a full refund). I now have E46 M3 AP Racing callipers (as opposed to Z4M fitment) with Z4M-specific discs, and the front callipers need a 2mm shim.
I wonder if the subtle differences in front track and suspension / steering setup are behind this difference. Of note, the E46 M3 front track width is 22 mm wider than that of the Z4M, whilst the difference at the rear is only 8 mm.
Click to expand...
Literally this was what I thought I'd have to be doing with my kit. I was fairly sure from Tom_K that the disc wouldn't foul the knuckle as he has an older kit fitted, but I was concerned that I might have to shim/space the bell out to centralise the disc. Thankfully its an issue that doesn't seem to have materialised however!


Interesting on the track width, I imagine that's why the Z4m handling is that much spikier than the m3 - combination of track width and shorter wheelbase too...
 
D.Bryce said:
i know if you go to 360mm or bigger the disk can foul, i tried to use the e92 disks but was too close for my liking.
where about did you put the spacer ? between the kingpin and the carrier, so making the caliper further outwards ?

the track width also includes the wheels which were larger on the front of the csl
Click to expand...
I can’t remember now, it was eight years ago. Next time I’m in the wheel arch, I’ll have a look.

Indeed, but the hard bits are wider too.
 
Ed Doe said:
Literally this was what I thought I'd have to be doing with my kit. I was fairly sure from Tom_K that the disc wouldn't foul the knuckle as he has an older kit fitted, but I was concerned that I might have to shim/space the bell out to centralise the disc. Thankfully its an issue that doesn't seem to have materialised however!


Interesting on the track width, I imagine that's why the Z4m handling is that much spikier than the m3 - combination of track width and shorter wheelbase too...
Click to expand...
And it’s simply a more exciting car ;)
 
had a look at majority for e46m3 bbks and there are all saying the are cross compatible with the M. still struggling to see where the 2mm offset comes from ? the e46 m3 csl 345mm disk has the exact same height and the 325mm m3 disk which makes me think theres no offset. could it ust be due to the ap caliper brackets i you are using a thicker disk ? assume 32mm if ap ?
 
It’s been a long time since I looked at the part numbers on AP’s website, but I’m sure I remember different part numbers for the front BBKs for Z4M vs E46 M3 and CSL, but the same part number for the rear kit.
 
Yep I was looking recently at the 5575 kit for comparison as they're both fully listed on the ap website. They are different part numbers

I suspect the original m3 kit was originally dimensioned/ made for a non-csl, as it was he z4m shares caliper and disc part numbers with the csl.
 
D.Bryce said:
could it be due to the ap caliper brackets if you are using a thicker disk ? assume 32mm if ap ?
Click to expand...
Exactly this, with a thicker disk it gets too close to our e36 style steering knuckle and the splash guard than is ideal. Hence AP making a specific kit that reduces the offset of the mounting bell and adjusts the bracket to reposition the disc and caliper further out into the wheel
 
TomK said:
Exactly this, with a thicker disk it gets too close to our e36 style steering knuckle and the splash guard than is ideal. Hence AP making a specific kit that reduces the offset of the mounting bell and adjusts the bracket to reposition the disc and caliper further out into the wheel
Click to expand...
Well now I feel like a thicko 😂 I missed that about the thicker disc, totally forgot the btcc ones were thicker 🤦🏼‍♂️
 
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