Ae86 4 Wheel Disk Brake Set Up On My Ke70

[KE7T]

GDAY ALL i am in the process of converting my ke70 to blacktop 20 valve and would prefer factory ae86 4 w disk bolt on brake system as it will require less engineering and i would very much like to keep it toyota parts etc . what i need to know is the ae86 t series disk braked diff the same wigth as the original ke70 what i mean will my 14 x 7 ma61 wheels sit further out then rub the guards also will the ae86 rear disks/ calipers fit inside my 14 inch wheels , do the ae86 rear calipers use a caliper handbrake set up or an internal disk handbrake set up (like a commodore), are ae86 rear disks vented ,will it be ok to use the original ke70 booster to run these brakes and do i need to fit a larger bore mastercylnder . any replies would be very much apreciated .thanks for looking

[snot35]

Same width. AE86's came with 13" wheels so clearance won't be a problem. I'm pretty sure the handbrake mechanism is in the caliper, but check that. Rear disks are not vented and you might want to fiddle with the master cylinder. Swapping over to a JDM AE86 would be best, but I don't know how easy that is. Drum brakes generally require residual pressure in the brake lines to operate properly. You don't necessarily need this with a disk brake setup. Having said that it will still work, but can cause the pads to drag. You'd want to check that stuff out.

[parrot]

As above, no issues with fitment inside a 13 inch wheel. Master cylinder is still 13/16 so no issues there and your booster will be fine, but you should consider sourcing the correct proportioning valve. Some people gut the one they have but that worries me. They don't cost that much so do it properly. The calipers have a cable actuated mechanism (not hydraulic) that applies the brake piston as a handbrake. Discs are not vented. The one issue you may have is the caliper brackets. I am almost certain the bolt pattern for mounting to the axle is totally different to what you will find on your drum rear end. Same story if retrofitting to a drum T series axle. No biggy if you are able to have brackets fabricated, but may be an issue with engineering.

 

If I was you I would either buy a AE86 disc brake rear end, assuming you have lots of cash. Otherwise source a late T18 rear end (it's also a T series and the later ones have a sway bar) which are also often pricey due to demand. If you do the latter, you will still need to source some rear calipers and discs to convert and fabricate caliper mounts. There is also write ups around on Toymods for upgrading to a rear Corona disc setup. All engineering issues probably. At least having a T series rear end means you can have an LSD which is a very worthwhile upgrade in my experience. Plus whatever calipers you get will likely need rebuilding at approx $80 for a kit.

 

Discs are available locally from RDA and you can buy them grooved if you wish.

 

Remember the shopping list will include the proportioning valve and handbrake cables.

 

However you do it, it will be expensive. Seriously consider whether you really need to do it. Sensible budget approach would be to install a late T18 rear end, leave it drum which is totally adequate and allows an LSD fitment. Then spend time on your front brakes.

[4k-t]

Brake bias is different between disc and drum brakes. I put disc brakes on the rear of my exa turbo with out changing any thing else in the brake system. They worked well for every day use but under hard braking the rear would lock. Causing the rear the step out on turn in. Worked well when I got used to it. ;D mind you that is a fwd car and the rear wheels are undriven. So may not be such a problem in a rwd.

[parrot]

The proportioning valve is the part that controls brake bias