Outer Limits 4x4 Board

thinkin bout fitting slotted or cross drilled rotors to the front of my cruiser just thought they might get filled with mud while wheelin and end up being a nuisance, anyone got any experience with this????

i would of thought that they will help clear the pads, if any thing, plus the slotts arent all that deep that they would clog, as it happens i have a pair of Brand new DBA slotted 80 series rotors, that i bought when doing my widetrack lux diff, but had to go with the 60 series, 80's didnt work. $200 bucks u can have them if interested PN DBA 782 sl and sr

any idea how much improved they would make it?
my 80 diffs have trouble stopping the 42inch tyres and holding the torque from a v8 in double low.

i searched this website for slotted brake rotors and found a large section on this, apparently you can fit 100 series pads straight into an 80 as long as its after 08/92, they have a larger surface area and apparently work a treat, the problem i have is my vehicle is an 08/92 so its right on the change over so i have to do a little more research before i can do too much...

slotted rotors are designed to decrease brake pad fade, after long heavy application of the brakes (at speed). I can't imagine a 4wd would benefit any whatsoever off road. As far as stopping power, i would think there'd be a slight decrease with slotted rotors, as there is technically less surface area for the pads to clamp on.

Everyone on the 80 series forum who have fitted the slotted rotors are happy. None have decreased performance. All agree that they have benefited from them but whether it's from the slots or the 100 series pads I'm not sure as most have upgraded pads with new rotors.

If your 8/92 model came with the 16 inch wheels standard (eg not fitted by previous owner) then it will have the larger disks.

You cna fit the larger front disks to an early model as they will still clear 15 inch rims but the bigger rears will not. So if you want a reasonable upgrade the later fronts would be beneficial as the rears wouldn't make that much difference anyway. However if you have an early model you also need the calipers and backing plate/dust shield unless you want to bend yours up to clear the rotor.

I put slotted rotors on my old 80. They did work better, and with 33"s on it needed a bit of extra help.

Cross-drilled are not recommended for off road as they will fill up with mud.

oldmate wrote:slotted rotors are designed to decrease brake pad fade, after long heavy application of the brakes (at speed). I can't imagine a 4wd would benefit any whatsoever off road. As far as stopping power, i would think there'd be a slight decrease with slotted rotors, as there is technically less surface area for the pads to clamp on.

in relation to surface area and stopping power, thats a myth.
friction force between pad and rotor = normal force(piston force) x coefficient of friction( a friction value for the pad material when in contact with the rotor)

what will make you stop harder is:
larger rotor
smaller tire
smaller master cylinder
larger piston area in calipers
different pads with a higher friction co-efficient.
slotting rotors is used to prevent glazing

what will make you stop for longer without fade is, anything that prevents pads from reaching a temperature where the friction coefficient changes, or even worse, the brake fluid boils, so:
larger diameter rotors(increased surfact area for improved cooling)
Larger pads(increased mass to absorb heat energy with less temperature rise)
better ventilation
Vented rotors (increased surfact area for improved cooling)
Slotting rotors is used to help prevent glazing pads

cheers for that, so if i wanted to fit the larger rotors and calipers off the later model is it a bolt on upgrade or is it a big job, being a larger rotor does the later model caliper just bolt onto the same holes that i have now and accommodate this larger rotor?

BIG PUMPER wrote:cheers for that, so if i wanted to fit the larger rotors and calipers off the later model is it a bolt on upgrade or is it a big job, being a larger rotor does the later model caliper just bolt onto the same holes that i have now and accommodate this larger rotor?

Yup.... about the only downside is your cant run 15" rims anymore.

Slotted rotors F&R, bendix 4wd pads, and braided lines accompanied with DOT3 fluid only! is about the best you can make an 80 without going uber custom. You should only use DOT3 per Toyota specs/recommendations even though legally DOT4 fluid shouldn't cause any problems. DOT3 fluid is availble through supercheap (Castrol) or Toyota, both are about the same price funnily enough .

You can put just the bigger brakes on the front which is where most improvement will come from anyway. It's only the bigger rears that will foul 15's. Yes it's a bolt on the calipers use the same bolt spacing, just the lugs are spaced out to suit the bigger rotors. If you are happy to butcher you back plate a bit all you need is the calipers and rotors but for a factory look the back plates as well.

Cross drilled rotors are not good on any road car. On race cars tehy get changed regularly have a look at any that have been on a road car for a while and good chance you will see cracks forming between the holes. you alos must bear in mind you don't want them to run too cool either as you may not get good braking around town till they heat up to the spec of the pads.

What is supposed to be the problem with DOT 4 from Toyota's viewpoint if they don't recommend it.