JDM Rotors

[grey_nomad]

Thanks all for your help.

To put you in the picture, I'm almost 60 years old and doing hillclimbs/track days/autocrosses etc with my sons (one has a JDM brake equipped AE86, the other has an MR2 AW11) for fun. The car is also a daily drive. It has a stock 4AGE with extractors, and Monroe GT gas shocks(don't laugh - they went on to get the car roadworthy, and will by replaced with some decent springs/shocks in the future). I don't need extra power until I learn how to drive it. I intend to improve handling and add a ROPS before I consider any extra power.

I found at a recent hill climb at Haunted Hills that I could do with an LSD. A T18 rear is pointless as it still has drums. Hence I decided on the JDM rear axle with discs. Bolts straight in hence less hassles. This means an upgrade of the front brakes, hence my question re: calipers for the JDM slotted discs. My son's AE86 has this setup. I don't have bucket loads of money to throw at it. As for brake fade, I haven't experienced any at Sandown track days with the original solid front rotors and drums on the back.

So after some research, the setup I'm looking at is JDM vented front rotors with JDM calipers, and JDM disc rear so I can add an LSD later.

[johl]

as for t18 drum vs jap disc t series, i think your being too harsh on the drum option. there is nothing wrong with this option, it is just as much a bolt in job as the disc setup and is alot cheaper and can be found at alot of local wreckers out of several different cars.

i have jdm front brakes that have been completely re built ($280 later) been sitting on my car for almost 2 years without being used. prior to this i ran them on my ke70 for almost a year and had them rebuilt just before transferring them to my project car, thats why they havnt been used. i'm only getting rid of them as i have upgraded to wilwoods. if your interested let me know

[Sam-Q]

the problem with JDM brackes is they are not much of an upgrade over the original. Due to my ignorance of that track can you explain how much heat does the brakes have to deal with on that hill-climb?

[xero]

no problems grey_nomad, sounds like you have a good plan.
anyway, i agree for your weekend outings JDM brakes with slotted rotors and decent pads will be very sufficient. on my car i run a rather large set up of AU falcon calipers and rotors and if given and oppurtunity the car will do endo it stops that well.
i was at a track day (wakefield, which is pretty harsh on brakes) with a mate (matt mead, when he had his car running) and he had the JDM calipers and slotted rotors. i rode with him for one sessioin and even thoiugh he threatened to steal my set up it was very surpsied at how well the JDM brakes held up and did not fade at all.
certainly for hillclimbs and motorkhana's the JDM brakes will be more than sufficient for you mate, but on the track the RX-7 brakes would be more suitable given the 4 piston caliper and larger rotor, which in turn would make then just as good in a hollclimb or motorkhana.

the reason a lot of the guys here recommend the RX-7 brakes as it is an upgrade over the factory (which at times has been lacking) but also the RX-7 brake upgrade will often cost about the same as getting a set of JDM caliper and rotors.
if your worried about engineering the RX-7 brakes using a AJPS adapter will pass no problems.


theJDM brakes will bolt right up and take a couple of hours to fit up, and the RX-7 using a AJPS brakcet will bolt right up too and take about the same amount of time.




EDIT: some quick ebaying turned this up grey_nomad:
ae86 JDM cailpers


RX7 brakes


now even if the RX-7 brakes needed a rebuild its still going to be cheaper than the JDM calipers and it will be a major upgrade in the long run! (going on the assumption that pads and rotors are roughly the same price, well they were when i got my g/f mx5 pads and rotors not long ago..)

[grey_nomad]

Think I'll go with the RX7 front brakes. AJPS have a complete package that bolts straight on. For the rear I think the drums will be sufficient, so I'll go for the T-18 rear axle if I can't get the disc JDM.

I have 2 more questions...



Once again thanks for all the help and suggestions.

[grey_nomad]

Brakes on hillclimbs don't get anywhere near the use/heat than at a Sandown track day, and since I do more hillclimbs than track days, I don't think I need a massive brake upgrade.

[mild seven]

if that is the case, i question as to whether you will notice a difference between the ADM and JDM brakes at the hillclimb.

[blair]

Make sure you find a T-18 rear diff that has swaybar mounts! (early modles came with no swaybar or mounts, later did) or have facilities/abilities/shanilities to weld some on!

I run the JDM Vented (but not slotted/drilled - even more to be gained!) brakes with Decent pads, fluid, and maintanence and you'd be surprised what cars they can keep up with remember she only weights around a tonne!

[xero]

from what i understand rx-7 brakes dont fit under 13" wheels, im pretty sure they fit under 14's but feel free to correct me.
nope, wont need to upgrade the master cylinder, it works well with this set up.

[ke_70]

rx7 brakes work best with an upgraded 15/16 master cylinder. they can work with a standed 13/16 brake master, but have pretty shit feel apparently. (from what ive read)

and yes they will only fit 14s mininum