calculating front to rear brake %'s

[uninformed]

hey all,

how do I figure out the front and rear brake percentages for a 98 Def 110. If the total braking area is 100% what percentage is front and rear.

cheers,
Serg

[Blknight.aus]

the easiest way is to put it on a dyno roller and test them.

you can calculate it roughly by working out the piston surface area of the front and rear calipers and then expressing that as a percentage.

if you have a brake pressure modulator of any kind you have to work it out as the overall force that the calipers can exert which is the calipers total piston area multiplied by the fluid pressure. do that for front and rear and then express them as a percentage.

from memory the split is 60/40

[langy]

This is an expansion of Mr BK's dyno suggestion

Safe-T-Stop - Brake, Steering and Suspension Safety Test (http://www.safetstop.com.au/)

One of their reports came with the RR I picked up in Vic. Strange as it seems it was 70/30 f/r, but it was a 20 yo vehicle after all. It even measured variations L/R on each axle. ( 13% FNS, 27% RNS)

[uninformed]

I may well be wrong but werent the orignal RR twin pot twin piston fronts with single pot rears? This would make some sense to the large % difference

Serg

[uninformed]

the easiest way is to put it on a dyno roller and test them.

you can calculate it roughly by working out the piston surface area of the front and rear calipers and then expressing that as a percentage.

if you have a brake pressure modulator of any kind you have to work it out as the overall force that the calipers can exert which is the calipers total piston area multiplied by the fluid pressure. do that for front and rear and then express them as a percentage.

from memory the split is 60/40

Regarding calculating it, would pad size come into play?

what are the piston sizes and number of for front and rear of a 1998 Def 110 trayback

Serg

[Blknight.aus]

yep, thats why I said roughly calculate.

[uninformed]

yep, thats why I said roughly calculate.

cheers,
do you know the front and rear piston sizes?

[Blknight.aus]

not off the top of my head no.

out of curiosity why do you want to know the brake bias?

(send me a PM tonight And I'll dig the raves/rps/emei/partsmanuas and see if I can find enough to give you a close enough to right answer)

[uninformed]

so i can calculate the amount of anti-dive on my truck and play around with some front end designs.

[Blknight.aus]

why is it that this worries me a little?

Ifff your going to be doing what I think your going to be doing might I suggest that you get an early rangie setup for the brakes and on the secondary plug in a proportioning valve?

[uninformed]

why is it that this worries me a little?

Ifff your going to be doing what I think your going to be doing might I suggest that you get an early rangie setup for the brakes and on the secondary plug in a proportioning valve?

what worries you? lost me there

what do you think that i might be thinking of doing???

[Blknight.aus]

setting the vehicle up for some semi serious competition style use

[uninformed]

nope, not competing at all. Just a belief that there are compromises made by LR due to the manufacturing process and running a business, plus the fact that raising the vehilce on the springs even 1 inch changes the dynamics of the vehicle.

it doesnt hurt anyone to play around with ideas on a piece of paper. ;) but that doesnt mean i dont want some accuracy in my calcs.

as an example: look at the anti squat in the rear end. does it need to be so high to maintain a safe onroad vehicle? could it be lower to improve offroad drivability and still maintain road safety?

[Blknight.aus]

fair enough....

have some fun with it and let us know what you find...

since I forgot about the skullers do and didnt get home till late I didnt get to look up any stats.