ok i know you can go to 300mm on the rear with the mikeR kits (or whoever makes em )

but what about the fronts? i assume 1st things 1st is 2wd calipers yeah, but what size bolts straight on with spaces? 300+?

nout wrong with the brakes on my car, best ive ever driven... but they LOOK small against the 16inch esccos rims, and i dont like that

 

what kind of wheels do you have. it is hard to get big brakes on a 4wd saph. there are not many wheels which can get big brakes behind them.

do you have the same wheels as on the pic. (escort cossie wheels).
you can go for a 300mm set up from hi-spec for example. and using the same calipers.

cheers

 

yep theyre escos wheels

but the front hubs are normal 2wd boggo base model sierra ones.

getting 2wd cos hubs aint a big issue if necessary tho

 

Jim you currently got 4x4 Cos calipers on your Saff?

Fooking give em to me you plank!!!!!

 

thruh, then i'll have no brakes... how will i stop?

 

i got 350 mm discs and ap 6 pots on my saff ..... 18" split compomotives too thanks to godspeed for makin em fit

 

eagle, unfortunately i do not have easy access to automatic rifles in order to rob a bank to pay for your setup i was thinkin more along the lines of a few hundred, not a few thousand

 

if you can afford to get a big disc with an ally bell .. then you can get the kit made up for your exact setup ... like mine was .. mine was cheap ish .... just sayin .. get 2wd fronts .. then go from there

 

Jim - Get some 2WD Cos hubs, then bolt up a set of 2WD 4 pots and discs - then sell me your 4x4 callipers and discs!!!!!!

 

Jim,

I think you'll find that the 4x4 set up is actually more efficient than the 2wd.

Remember your physics from school - P=F/A.

 

rich, im confused

they apply pressure to a larger area (4 pistons instead of one)

also discs ar same size etc. etc.

also i always thought the 2wd was better just becasue, well, everyone says it is

 

Think of the size of the individual pistons in a 2wd caliper, versus the size of the single pot 4x4.

The 4 pot pistons in a standard caliper aren't very big at all.

 

Nah don't listen to him Jim - get some 4pot calipers and sell me your 4x4 ones

 

PMSL

 

so why do people always say the 2wd brakes are bettr then?

or is it just pubtalk bullshite?

anyway, i just want them to LOOK nice...

 

Hmmm. I wonder because if you walk on snow in high heels (work with me here) you'll sink, but if you have clowns shoes on you exert less the same force over a larger area hence you actually produce less pressure)

So I thought Id do some rough guessing

Now I dont know specifics, but I would imagine that actual pad size is fairly similar single vs 4 pot.

Some examples (and Im guessing the single calipers piston at 50mm diameter, I checked another site and the m16 caliper has a piston diameter 19mm or so.)


(not to scale obviously)
a = 9.5mm
b = 25 mm

Contact area of the piston is (pi)r squared

so

4 pot is 3.142 x (9.5 x 9.5) = 283.566mm squared
Single is 3.142 x (12.5 x 12.5) = 490.938mm squared

Lets assume that the pedal exerts the same force. Say 500. (joules (no not Spadge) I think )

Pressure = force / area

So on a single caliper its 500 over 490.938mm squared = 1.018
on a 4 pot its twice that of course so 500 over 567.132 mm squared = 0.882

So presssure exerted on a pad in a single is 1.018

an in a 4 pot its 0.882

Is that right?

If its a 6 pot caliper with the same piston diameter as the 4 pot its 0.588

I dont know what that proves

 

but surely the single pot has to then be divided by both sides of the disc , so the effort exerted by the one piston is split to both sides of the disc , whereas the 4 pot has the same effort 4 times over ???

the formulae looks teh bollox tho !!!

 

Thrush the 4x4 discs will be no good to you, you need 2WD discs....

 

Im not sure

500J line force is 250 per side on a single caliper

or

125 per piston on a 4 pot.

Im trying to simplify it to pad pressure as thats the important part not how its divided up inside the caliper piston(s)

but like I say Im no expert.

 

Wes - yeah I know - I jsut wanted Jims calipers

BTW - does anyone know why on a 4x4 cos, 2WD discs are too big for the caliper, yet on the ERST, 4x4 discs are too small if used with 4x4 calipers? Surely being 5mm bigger the 2WD disc *shouldn't* fit?????????????

Or is it that the mounting points on the ERST hub sit 5mm further out than on a 4x4 hub?

 

jim,i got some 2wd brakes here if ya need?worked ok with jb fletchs old 400 bhp motor!and i had escos rims too!let me know,not after the earth!

 

Disc's are actually smaller on a 4wd.AFAIK. But they do have better vented disc's on rear.

 

Correct...

4x4 discs = 278mm

2WD = 283mm

Std laws of physics says that the bigger the rotating curcumfrence(sp) the more the stopping power

 

Force is in Newtons Rich, not Jewels, that is for energy!

 

Nah Jewels is for my bitch's innit, aye

Think you mean jules - and no I don't mean Spadge

 

Also, for what it's worth, I think that the multi piston arrangement of the 2wd 4-pot caliper is better than the single piston sliding carrier arrangement on the 4wd, and the change was made purely as a cost saving measure!

 

Actually I mean joules!

 

 

Yes, this is true. Hence Nm when you torque something up. Im such an idiot

Think? or proove? I tried and look where it got me

 

Educated 'think' Rich. All uprated brakes are of a similar multi-piston design.. can you imagine a touring car team thinking "Right we'll upgrade these 6-pots for a single piston sliding caliper"?? I certainly can't. AP racing don't make any single piston calipers as far as i'm aware! Learn from the brake experts, not the penny pinchers at Ford. I work for Nissan in the design centre, and 70% of the work is costing down saving 1% on a particular part, so imagine at Ford changing the caliper design over to one used elsewhere, and has to be a huge amount cheaper to make and then fitting a single piston with a single bleed point etc.. then it allows them to use a common 4wd sierra front hub etc etc.. It would probably cost them over 50% more to use a 2wd style caliper! That wouldn't get signed off in a million years!

 

Agreed, what you are trying to do is like saying that a pinto is better than a YB because it has bigger valves
How much are those 2wd brakes BigWig?

 

Phil

Oh I know cost comes into it and like you say why would people like AP bother with 6 pot conversions if not for a point.

I was really just trying to see what Pon said above. was right or wrong. I think that the Ratios I got out of the end although right are inversely proportional. In that the closer it gets to 0 the more power it must be.