advice on brake upgrades

[Steve W]

>>the caterham AP set-up will not fit my 89/90 car

 

I've seen cars of this vintage with big brakes. What's the problem?

 

Alex

 

Don't know what the problem is but I have been told that it is not available for my car ?

 

Do they only fit certain uprights ?

[Peter Carmichael]

All is clear now.

 

I never had my handbrake adjusted too tight, but the pedal travel was IMO far too long. I was referring to the amount of pedal travel before brake application as *backing the pads off*. If fluid is moving down the pipe but not applying pressure to the pads then that is *backing off the pads* as far as I give a damn. Glad to be rid of it. Self-adjusting handbrake seems to be an over-complex solution for a Caterham. Glad to be rid of it. Agree that fitting an AP master cylinder is just masking this excess latency with an inappropriately high ratio - I still have the standard cylinder. Trap line pressure valve sounds like a good idea for all caterhams fitted with these calipers. Still glad I don't have the bother of working out the correct voodoo line pressure to trap - please publish the correct valve spec if you get it sorted.

 

I have an ideal for brakes of: near zero latency; appropriate hydraulic gearing for reasonable pedal effort; short travel for consistent heel and toe; slight rear bias in the dry, which can be corrected with a click-position type proportioning valve in the rear circuit; no obvious overheating problems. I'm about half way there. Current SLR racer spec is 100% there, or so I am led to believe.

[Graham Perry]

Tony, I don't have the exact figures but I seem to recall that what I did was set the balance valve by feel. ie kept braking hard and adjusting the valve until the car locked the fronts first rather than the rears. I thought that this was the optimum but the pyrometer showed that the rears were about 100 degrees hotter than the front(I had let them cool down before testing them and measuring them again) . I figured that this was far too large a difference to ignore and have now adjusted the bias further to the front, but even so the rears after several applications are still 40-60 degrees warmer. Hot rear brakes seem to be a feature of the seven. If yours are cooler at the rear you may well have a problem as you suggest. I hope this helps.

[Chelspeed]

>>the caterham AP set-up will not fit my 89/90 car

> Dont know what the problem is but I have been told that it

> is not available for my car ?

 

There is only one Alcon set up, if that fits both early and late cars then they must both use the same upright in which case then the AP set-up will also fit all cars. Likewise the standard caliper is the same for all cars.

[V7 SLR]

What's the spec of the current SLR racer then?

[Miraz]

Bigger vented rear disk with an uprated caliper - the catch is that you no longer have a handbrake which you will need to pass an MoT. There are some cars around that have converted to hydraulic handbrakes in order to get around this.

 

Miraz