[Rys]

Hi all. I have been contenplating converting my standard NA calipers to TT calipers front and rear. Was just wondering if anyone knew if they will fit on standard diameter discs or if I need to get larger ones? I have aftermarket crossed drilled, slotted and vented discs at the front, but they are still the same size as standard. With stock discs at the rear. I have 18" rims, so clearance shouldn't be an issue.

Any insight into this matter will be greatly appreciated! Thank you very much.

(P.S. I would have put this in the tech section, but it won't let me post there. So here I am. Hope you don't mind)

[IcE]

Hi Rys,

Not being an A80 owner, but having done a bit of reding ont hem, i would imagine if your going a TT brake upgrade you would need to get the bigger rotors as well. And even if you didnt need to, i know that i would want to ;)

Maybe one of the A80 brothers could shed some light on it for you?

IcE

[Reaper]

Hey Mate,

I did the large brake conversion on my 93 TT. For the fronts only as I still want to run small rears in order to keep my oem 16's for drag cross plys.

I'm confused? You want to upgrade the caliper but not the rotor right?

What would be the point in that? You need larger disc using larger caliper on matching pad in order to achieve the complete upgrade ie. = better braking. Without having the additional swept area the larger rotor provides you won't be able to benefit from the larger caliper/pads since they won't be operating on any larger friction surface than before.

Is this idea aimed at staggering costs?

Anyhoo, technically this won't work. For example the front's increase from 296mm to 323mm diameter.

Sooo.. if you now have a large caliper using large caliper pads they are expecting to be able to grip right out to about the 322mm mark. My rotors stop on about the last mm or two say.

IF you are using the smaller rotor @ 296mm then there is some 26mm of rotor diameter missing therefore you'll be ripping into ur pads as they will be 'overhanging' the small rotor.

Also, the diff between brakes is not a NA/TT thing. It is just a small brake, large brake thing. Many TT's came with small brakes for example.

Also, don't assume big brakes WILL clear just because you have 18's, the issue relates to offset and wheel centre design. You should try them on a car with big brakes eg. mine.

Lastly, cheapest source for these is a TRD dealership in NZ. Deal with a spare parts guy called Kevin. Thread is on the national site. Landed my front pair of calis for 570. Rotors cost a boatload, new DBA 4000's all round (large front, smaller rear, slotted) was ~$1K local landed in Adelaide retail shopfront.

Good luck mate,
GEE :cheers:

[ultra_supra]

my first question to someone asking about a big brake upgrade is always "what applications are you looking at?" ie. do you really need 'bigger' brakes?

are you doing circuit racing (repeated heavy braking) or Hills driving (variable braking) ? actually, if you're looking at track work, why aren't you on my track day thread?!!

generally speaking though, bigger brakes means bigger rotors which increases available area/rotor volume to dissipate heat from the pad friction. multipiston calipers (4/6/8 pistons) allow more even (better) clamping of the larger brake rotor, but aren't always essential (eg. performance BMW's still run 2/1 piston setups)

i agree with what Gav said above re bigger 4 piston calipers on standard 296mm rotors. if what you're really after is better braking capability, then you should look at your existing pad and rotor combination.

the slotted and cross drilled rotors that you already have up front allow you better ventilation/heat dissipation, but why are you running stock discs at the rear? do your pads match front and back? all this will affect your brake bias. there's no point having fantastic brakes up front if your rears lock up while the fronts are only moderately stressed. and what about brake fluid? have you boiled your existing fluid by accident

you can get quite aggressive fade free pad combinations for standard rotors. have a look at Project Mu, Ferodo, Pagid, EBC and Endless brands for their solutions. start looking at the links here: http://www.sasupra.c...?showtopic=1646

i personally run the small (16" type) brake setup (2/1) on my Supra with semi-race Endless pads and DBA4000 slotted rotors - i can tell you that these haul up very well with no fade after 8 continuous punishing laps around Mallala. unless you're planning to enter your car into 20-lap race, you won't need a race type pad. my CC-R's are rated up to 800'C

if you really want to upgrade your calipers to the 4/2 'big brake' setup, then contact Kevin in NZ Toyota as suggested by Reaper. but be prepared for some expense (calipers, 323mm+ front rotors, brake lines, new pads, new fluid)

[Hardy]

ill be doing this soon :)

[Darren]

After a bit of research it is also advisable if you do the front upgrade to do the rear one as well as the brake bias will be affected. Also (not neccesary but the Brake master cylinder is different for the bigger brake setup ) you may want to replace the Master cylinder as well for the most benifit. As the others have said you have to replace the brake disc's as well as they wont work with the smaller ones. The cheap job just became not as cheap :o .

I will go down this path in a while after I have given the paintwork a freshen up.

Me getting the bigger brakes is a bit like an HSV add ""I just want them :rock: "" but in the mean time different pad combinations will be tried to make the best of what I have.

Cheers bud
Darren

[Boost Samurai]

I did the big brake conversion a little while back along with some steel braided lines, as did my little bro.

Even if you don't track/race your car it is a worthwhile upgrade. It's not like you are spending $3K on just a pair of front 6pot Brembo's or something.

Put it this way, you may not need big brakes but... I would frequently race Chuck_E (who has big brakes on his 95 RZ) through some twisties on the way home after work. Now, my car was making 216rwkw and his araounf 97rwkw (blown #2 turbo). While I would pull away and leave him for dead, he would out brake me every time and bee back on my backside within the first two turns. After getting my big brakes I didn't have to go out as hard and because I could brake the same as him I would maintain my lead a lot easier ;)

Not too sure about just doing the fronts but I tend to agree with Darren and would suggest you do both front and rear.

I recently had the pleasure of 'test piloting' Reapers car and at the time I didn't know he only had the fronts done. But I did notice that his braking had somewhat of a spongy feel to it and the pedal travel was much longer.

[PK]

Agreed with Darren as per the bias issue. Personally, this is critical.

Also, it would not be a difficult job to do at all, thus saving $$ on labour...

PK

[Boost Samurai]

Yeah, it's pretty easy to do, just take your time and be careful.

Of note, you'll have to remove the front and rear heat shields from behind the rotors as the new rotors will be too big. The rear heat shields are welded on so you "kind of" have to use a chisel to remove them. Sounds pretty hardcore but they come off pretty clean and easy.

[Rys]

Thaks everyone for their input! It has been very useful.

What I had planned on doing was upgrading the calipers front and rear. At the moment, I have the DBA rottors at the front, stock at the rear, Endless pads all round and high temp brake fluid. I do hit the track, hence the interest in brakes. I can't say that my braking performance is bad, but there is always room for improvement. So taking all of your advise on board, I guess for now I'll just upgrade the the rear discs, install braided lines and a brake bias controller.

Thanks again for you help!