Rear brake upgrade

[Ross Nicol]

Here is a pic of the rear brake upgrade on my car. The old rotor is reversed
and sitting on the wheel studs to show how much fatter the new rotor is. You can also see the 3mm spacers I made and fitted to the calipers to allow use of my original AP calipers.
Original Spec
Rotor- 280mm Dia, 20mm thick, one piece
Caliper- AP 4 piston
Pads- Ferodo FRP219H

New Spec
Rotor- 304mm Dia, 32mm thick, two piece
Caliper- AP 4 piston/ with spacer
Pads- Ferodo DS 3000

They work so well now I've had to shift the bias back to the front.
The 2 piece front rotors will be fitted over christmas.
Ross

 

[John]

Ross,

Given how light the GT40's are, where you having trouble stopping with the original rotors?

John
epper:

 

[Ross Nicol]

Only had trouble stopping after overheated rotors also overheated the pads.
The glazed pads had almost zero bite. The small rotors weren't able to get rid of the heat during racing which was the cause. As you can see the new rotors have much larger vents and ability to sink heat, also enlarged surface area for cooling. I had 4 of those small rotors crack over a 3 year period, they are however quite adequate for the road.
Ross

 

[Trevor Booth]

Ross,
keep a watchfull eye on those caliper spacers , hopefully they are not aluminium and preferably ground tool steel stock. Aluminium will not last long, ordinary mild steel flat suffers creep over time.
Trevor

 

[Ross Nicol]

Made them out of aluminium.Is it a problem with heat Trevor? I assumed because the calipers were alloy this would be ok. I'll keep an eye on them.
Thanks.
Ross

 

[Jac Mac]

Ross,
Obviously time is at a premium, but would it not be better to get the front rotors etc fitted asap and deal with the balance issue once rather than possibly have to cure a problem now that may not exist when the new front rotors are fitted.

Jac Mac

 

[Ross Nicol]

Yes your right Jac Mac but time as you say is against me. With the race meeting next weekend I will run with what I've got. However I will take accurate note of where the balance bar is now, so I can restore it to this point after the front brakes are done. Actually I have found I have to constantly check my memory (not easy these days) after a race meeting, to remember all the things I need to do to improve the car. For example tomorrow I will be fitting different throttle springs as the throttle body butterflies are not returning to my liking.Also the Anti roll bar adjustor is annoying under my left elbow and I'm going to shift it forward.Just one of the reasons I don't want to rush the front brakes is that I want the rotor hat to be made deep enough so I can eliminate a silly little wheel spacer I've had to use for caliper clearance. Apart from the balance the brakes at the Island were pretty good but Sandown is harder on them. And the final reason for holding off is that my wets are on 16" rims, so when the 340mm rotors are fitted to the front they will no longer fit and I will be forced to invest in 17" wet rubber and wheels, not a small investment and I'll need time to recover from the financial trauma. I don't want to get you boys too excited but I'm hoping to have some in car video from next weekend.
Ross