poppopbangbang
Nurburgring
- Joined
- 25 May 2015
- Messages
- 480
I'd like to go to floating discs on my car but everything out there in the aftermarket is a bit "meh", mainly because it's all based on off the shelf motorsport discs and the float is via bobbins which work great on a race car where the brakes are always hot but are mostly annoying on a road car because they are noisy and rattle when you pull up at junctions. The Brembo Track day discs are pretty good but are still £1500 odd which is a hell of a lot for two front discs. Alcon do a kit at £1350 but that uses their 360mm disc (as they don't do a 350 in the right thickness) so you need to ***** around spacing the caliper to use them (and there is no real performance benefit from that small an increase in disc size), plus replacement discs are £450 each.
OEMs like BMW and Merc get around it by having pin drive floating discs where the disc sits on multiple pins arrange vertically from the bell which is great but they are single use i.e. the bells can't be reused so it's an expensive way to do it and not viable for small production. Here's an OEM floating pin drive disc:
So I've decided to make my own, using a system with a compliant amount of float in it but with an anti-vibration element to stop clacky arrivals at the traffic lights. As always I've looked to F1 for inspiration where for the past few years a spline drive has been used in place of bobbins. Here's Mercs brakes for example:
This provides the float required but with less deflection, greater wear resistance, lower weight and reduced failure points. Here's the first draft CAD:
It's a 20 fixing system which captures the disc spline within the rotor spline. The inner retaining ring provides an amount of compliance to allow for float without it being noisy. The disc is used in a GT3 application currently so is well proven. Even better is that replacement discs are around £300 each, so 40 - 50% less than Brembo/Alcon replacement discs and although the bell is a complex piece on tight tolerances as there is no requirement for bobbins the cost is not too different to using bobbins.
I should have them made in a couple of weeks
OEMs like BMW and Merc get around it by having pin drive floating discs where the disc sits on multiple pins arrange vertically from the bell which is great but they are single use i.e. the bells can't be reused so it's an expensive way to do it and not viable for small production. Here's an OEM floating pin drive disc:
So I've decided to make my own, using a system with a compliant amount of float in it but with an anti-vibration element to stop clacky arrivals at the traffic lights. As always I've looked to F1 for inspiration where for the past few years a spline drive has been used in place of bobbins. Here's Mercs brakes for example:
This provides the float required but with less deflection, greater wear resistance, lower weight and reduced failure points. Here's the first draft CAD:
It's a 20 fixing system which captures the disc spline within the rotor spline. The inner retaining ring provides an amount of compliance to allow for float without it being noisy. The disc is used in a GT3 application currently so is well proven. Even better is that replacement discs are around £300 each, so 40 - 50% less than Brembo/Alcon replacement discs and although the bell is a complex piece on tight tolerances as there is no requirement for bobbins the cost is not too different to using bobbins.
I should have them made in a couple of weeks