performance brakes
Discussion
Anyone tried cater hams perforce brake kit. Thinking about changing my standard from my 1996 after upgrade (around 180 hp now).
https://caterhamparts.co.uk/other/51-high-performa...
comments and suggestions are highly appreciated
Michael
https://caterhamparts.co.uk/other/51-high-performa...
comments and suggestions are highly appreciated
Michael
I think I might not have the uprated master cylinder which might be causing me a few problems.
Can you confirm it's this one?
https://caterhamparts.co.uk/master-cylinder/29-mas...
Giving the brakes an overhaul next week so good time to switch if I need to.
Also if you know where else one could be sourced it would be good.
Can you confirm it's this one?
https://caterhamparts.co.uk/master-cylinder/29-mas...
Giving the brakes an overhaul next week so good time to switch if I need to.
Also if you know where else one could be sourced it would be good.
Your link is to the uprated AP Racing master cylinder.
I switched to it from a very old standard master. More leg pressure required, firmer feel, quicker better action, less pedal travel. I actually adjusted the brake pedal leverage ratio a bit to match what I wanted from it. Good quality unit.
I also have the AP racing uprated front brakes, but not the rear brakes. The front brakes are excellent. Never any problems, proper pad placement and angles, and a true race brake without dust shields to melt and all that. I've run two makes of full-on track pads in them, and no squeals.
I switched to it from a very old standard master. More leg pressure required, firmer feel, quicker better action, less pedal travel. I actually adjusted the brake pedal leverage ratio a bit to match what I wanted from it. Good quality unit.
I also have the AP racing uprated front brakes, but not the rear brakes. The front brakes are excellent. Never any problems, proper pad placement and angles, and a true race brake without dust shields to melt and all that. I've run two makes of full-on track pads in them, and no squeals.
Thanks!
I have the bigger AP front brakes but the standard master cyclinder which I think is partly responsible for some very strange brake bias experienced on track, notably when braking with some steering input. Without this unit I can't see how the piston ratios would be correct which is probably causing the inbalance (over braked rear).
Turned up this morning, looks good!
I have the bigger AP front brakes but the standard master cyclinder which I think is partly responsible for some very strange brake bias experienced on track, notably when braking with some steering input. Without this unit I can't see how the piston ratios would be correct which is probably causing the inbalance (over braked rear).
Turned up this morning, looks good!
Edited by griggsy2 on Saturday 19th August 12:49
Edited by griggsy2 on Saturday 19th August 12:49
I'm assuming the standard unit is balanced for the single piston front and rear sierra brakes. If adding the twin pot AP callipers up front there has to be an issue with piston ratios doesn't there? Maybe I'm missing something, I prefer less travel anyway so not a total loss if no change.
Edited by griggsy2 on Saturday 19th August 17:10
Looks like I'm talking b
ks and you're right, in which case I need to trace down why I'm having oversteer issues under braking (beyond expected) and therefore can't see how I would be over braked at the rear with my setup.
Will start another thread as my rear camber figures look outside tolerance and would appreciate some thoughts.
ks and you're right, in which case I need to trace down why I'm having oversteer issues under braking (beyond expected) and therefore can't see how I would be over braked at the rear with my setup. Will start another thread as my rear camber figures look outside tolerance and would appreciate some thoughts.
Well, you aren't total bullst - just confused as to how a master cylinder may be made and what it can do. :-) (Maybe a bit hopeful that it will help fix things)
The master is just one single bore size for both front and rear circuits - the AP racing master is a bigger bore size, but still same front and rear. Result is you don't have to push it as far to stop, but it makes less "leverage" so needs more force to stop the same as the stock master.
The bore being the same font and back (as is stock), switching brake masters doesn't have any way to create a change in front/rear brake bias ratios. It just makes the whole package take less pedal travel.
So to balance brake bias the easiest way is with brake pad Mu (co-efficient of friction), the best way - if the rear is too strong - is with a brake bias valve. You can't/shouldn't try to put a brake bias valve into the front brake line to make it a weaker force.
For stock rears and AP racing fronts, the fronts always have a bit more bias than required in ratio to the rears. So it is odd that your rears lock up too early. I would suggest making sure of a few things; that you are running the same brake compounds or what people see as compatible compounds front and rear, that your brake pistons aren't sticking in either end, that you have matching tires/tire ages front and rear. Perhaps even check suspension rake and front/rear spring rates for proper weight transfer behaviour. You may also have glazed rotors or contaminated pads up front, or crazy track pads requiring a lot of heat to work.
t - just confused as to how a master cylinder may be made and what it can do. :-) (Maybe a bit hopeful that it will help fix things)The master is just one single bore size for both front and rear circuits - the AP racing master is a bigger bore size, but still same front and rear. Result is you don't have to push it as far to stop, but it makes less "leverage" so needs more force to stop the same as the stock master.
The bore being the same font and back (as is stock), switching brake masters doesn't have any way to create a change in front/rear brake bias ratios. It just makes the whole package take less pedal travel.
So to balance brake bias the easiest way is with brake pad Mu (co-efficient of friction), the best way - if the rear is too strong - is with a brake bias valve. You can't/shouldn't try to put a brake bias valve into the front brake line to make it a weaker force.
For stock rears and AP racing fronts, the fronts always have a bit more bias than required in ratio to the rears. So it is odd that your rears lock up too early. I would suggest making sure of a few things; that you are running the same brake compounds or what people see as compatible compounds front and rear, that your brake pistons aren't sticking in either end, that you have matching tires/tire ages front and rear. Perhaps even check suspension rake and front/rear spring rates for proper weight transfer behaviour. You may also have glazed rotors or contaminated pads up front, or crazy track pads requiring a lot of heat to work.
Top stuff, thank you.
I prefer shorter travel, harder pressure, and had the AP MC on my previous car so good to change anyway. Going to replace all discs/pads and check caliper function next week so I know where I am, I'm not sure if I have some of the issues you raise given I bought this one used but sounds possible.
Appreciate the help!
I prefer shorter travel, harder pressure, and had the AP MC on my previous car so good to change anyway. Going to replace all discs/pads and check caliper function next week so I know where I am, I'm not sure if I have some of the issues you raise given I bought this one used but sounds possible.
Appreciate the help!
Just a thought for Griggsy... I assume it works on Caterhams, but you can check the bias with the help of a friend. Get the car off the ground all 4 wheels. Then one person in the driver's seat presses the brake pedal with slowly incremental force whilst the other turns the front wheel by hand until the front wheel locks. At this point the brake presser keeps his or her foot still and the wheel turner goes to the back wheel and the rear wheels should be turnable just. Check both sides.
Bert
Bert
Gassing Station | Caterham | Top of Page | What's New | My Stuff