• Brakes
  • pedal box, setting bias

2012/02/02 18:16:20
Power_Quest
hey there, just wondering if anyone has any advice when setting up the balance bar for a pedal box, im running 0.75 for fronts, 0.7 for rears. brakes are vented wilwoods up front and drums on the rear( not for long)
2012/02/02 19:45:09
Matt75
Have heard you can have a drive on dirt or gravel and then work out when your fronts lock up and then dial it back from there.
 
Failing that ther are places that have brake dyno's.
 
Cheers
 
Matt
2012/02/02 19:55:06
blackmk1cossie
the dirt idea is the way to do it.drive along  hit brakes, until all four wheel lock up at same time then one turn to the front. keep in mind if you are running competition pads on front you will need to get up to temp. if you dont the front brakes will be set wrong
2012/02/03 01:09:32
Paul Dunstan
You also want the bias bar perpendicular to the master cylinder push rods at the fully applied position. It does no matter that one push rod (usually the front) is adjusted longer than the other at rest.
2012/02/03 16:54:44
Matt75
I found this in the Rally Design catalogue if it helps.
 
Cheers
 
Matt
 

 

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2012/03/14 21:29:19
MK1
Shouldnt the smaller master be operating the fronts??
2012/03/14 21:31:58
MK1
Shouldnt the smaller master be operating the fronts??
2012/03/14 22:12:45
Paul Dunstan
Yes - 0.700 on the front and 0.750 on the rear.
Depending on the bore size of the Wilwoods 0.625 may be better.
2012/03/14 23:08:14
John william Hadden
You would be suprised how close you can get it on the hoist good starting point
2012/09/13 21:38:17
rallyrs
This maybe useful.
I cleaned off a years mud and ran my first tar event, a garaged hillclimb, a couple of weekends ago as a shake down for king edward park. This was the first chance we had to test the new rear discs on the tar. 1st, my pedal box has 12 turns end to end. For dirt, 3 off full to the rear is the sweet spot. At this I can jump on the brakes in a dirt khanacross or motokhana and it just buries itself. For the hillclimb, we had to sprint to the top, stop, and then race down. Lucky we got plenty of runs. We figured a bit more front because of the increased grip on the front would unload the rear more so we started with 1/2 a turn to the front, then a whole 1 and more and more until the back stopped wanting to overtake us. We ended up at  4 turns off full front, this had just a tad of rear lock before locking all 4. If my maths is right, thats 5 turns between dirt on rally tyres and semi slicks on tar. Because it ran into the night, I forgot to wind it back for the next days dirt motorkhana and the predictable, locked the front and went staright through the garage on the first event.
Overall a good shakedown and a surprising difference between tar and dirt bias.
 

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