6G Celicas Forums

I was going to do just that, but I decided against it because:
a.You will need to cut the mounting holes (areas) completely off as shown in the pic above, other wise the difference is too small to make a bracket.
b.You will not lose much (if any) surface contact even if you trim the rotor down to 297mm.

Heres why:




The outer circle is of course the original 315mm rotor and the inner circle is the 297mm trimmed rotor.
Now the surface contact between the pads and the rotor is in red, even if you extend the diameter and use the bigger rotor the surface contact will pretty much remains the same.

...and there is an advantage to the trimmed rotor, it weights less

let me know if my logic is wrong.

isn't that a bad idea cutting the crash bar?

Here is the rest of the ST25 front brake conversion.

I could have trimmed to the rotor to 300mm but I went with 297mm and you will see why later.
Trimmed and resurfaced, just like new.



Ive heard that for the ST185 conversion the rotor hits the lower balljoint so 4mm spacer is needed but...lucky for us, it clears the lower balljoint by a few mm.



The OEM bolt is too short now so I went and buy 4 new nuts (with nylon tips) and bolts, it really doesn matter how long they are just make sure that they cover everything and you are good to go. The only thing that you need to be aware of is the threading of the nut, be sure to buy smaller thread mine is 1mm, so that the nut doesnt vibrate and lose-off. The capliper now mounts the opposite way meaning that it goes behind the mounts on the knuckle and the mounting procedures becomes extremly difficult. Because first irst you'll have to put the rotor on and then the capliper goes on, and by now there is really no way to slide the nut in from the front, you could go and slide it in from the back to make thing easier but you cannot hook the nut into place due to the tight space. (if you thread the mounting holes on the steering knuckle then everything will be easier)
I had to chopped mine off abit so I can manneuver them later.


So the capliper went on and we can see that there is a slight offset, I needed to bring the capliper out by a few mm, the offset is actually worst than whats showing in the pics.


I had no choice but to grind down the capliper mounts...this is the most time consuming part because at the start I dont really know how much I should grind, so I started grinding mm by mm and test it after every mm so see if it centered and from 16.5mm down to.....10mm..YUP you got that right a whole 6.5mm off.


At this point its about 6pm and I started at 3pm, 3 hours of pure back-bending, stomach aching and god knows how many times I swear...LOL but the show must goes on so now I need to reassemble everything. To do this I let the rotor lose and pulled it out all the way to just before it drops off, now I put two pre-cut bolts into place but didnt let them protrude to the other side just level with the other side will do. Next I slided the capliper, carefully to the rotor and positioned so the mounting hole lined up. Next I used a flathead screw driver to push them out to the other side.


There is another way of doing it, you will need to part the caliper into two halves then bolt on side to the knuckle then slide the rotor in and bolt the other side on.
If you did everything right the rotor whould align itself to the center of the cap, just a matter of bolting the nuts tightly into place. I used two wrenchs, one for the nut and the other to keep the bolt from rotating.
...and here it is, yes I do need some new brakelines. Bleed the brake and there you have it, the ST205 brake conversion.



Just a quick note on azian_advanced's post, as you can see the contact between the pads and the rotor is excellent, all of the area on the pads are contacting the rotor so dont worry abt sacrifying that 18mm (its actually 9mm but it counts as 18mm when you measure it as diamter's)





NOTE: Im dead tired so if any of the above is not clear let me know and Ill try again.

This post has been edited by lubu: Aug 9, 2008 - 9:54 AM

good post... i understood pretty much everything you wrote. what you did is the best way to go about it. threading the knuckle and getting bolts with threading that go all the way up to the head of the bolt would be something i would do if i were to do this brake conversion so that the knuckle and caliper are more secure.

if, and only if, you had kept the original diameter of the rotors and extended the caliper with a bracket (or whatnot), and although the contact surface of the brake pad to the rotor remains the same, you gain brake force due to increased leverage (but gain in rotational mass from the larger rotors). but certainly that would be the more difficult way to do this conversion.



so basically, the minimum steps are:
-get new caliper bolts and nuts to mount the caliper to the back of the knuckle (get ones with more threads so the nut is less likely to loosen itself)
-trim the rotor from 315mm to 297mm (might as well get them resurfaced if you get used ones)
-grind the inside of the caliper mounting locations from 16.5mm to 10mm
-get st205 brake lines (might as well get braided ones) and bleed the system


doesn't seem so bad. i might even try this some day..

Im looking to buy one of this set..Can someone tell the the model of these, all I know is that they are racing hart's.

To sum everything up.
For the rears:
Pretty much bolt-on except the 5.5mm spacers for the caplipers.

For the fronts [quote from az_ad]:
so basically, the minimum steps are:
-get new caliper bolts and nuts to mount the caliper to the back of the knuckle (get ones with more threads so the nut is less likely to loosen itself)
-trim the rotor from 315mm to 297mm (might as well get them resurfaced if you get used ones) + you can probably trim them down to 300mm if you wish.
-grind the inside of the caliper mounting locations from 16.5mm to 10mm
-get st205 brake lines (might as well get braided ones) and bleed the system

One more thing and this is the most expensive of all, you might (most probably) have to get a new set of rims as the old ones wont clear the caplipers.

amazing stuff

FYI if you just get some spacers (15-20mm) you should be able to clear the calipers with your rims.

I need new brakelines and ATM I cant afford any decent ones as they cost a fortune and no point buying crap ones. The good thing is when you get ur ST205 brakes chances are you will also get the brakelines as well, if you do then you will find that with little mods you can make them to work on ur ST204

I tested the connection between the hardline and the brakeline and they are perfect fit, which is a good start and here are two brakelines side by side, the shorter is of course the ST204's. You will need to cut the brackets off as the mountings are completely different between the two. For me I used an angle grinder for the job, gloves, safety galsses and earmuffs are a-must.




After some cutting and grinding you should have something that look like this, remember not to cut or grind into the rubber line or you're going to have problems later. You'll then need to round the hexagon heads and make a smaller grove so that the holding clip can slide across like the ST204's, so they can fit through the mounting plate.



Another 15 mins...



to be cont....

Here is the rest of the brakelines conversion. Ill let the pics speak for themselves.



It will have to be like that for now.....

Damn nice work! Rear spacers are finally on their way [$47 later - that's just redicualous for a 1lb package IMO]!
Anybody else wants to do this I can post up the drawing I made for the spacers and/or I can make the spacers for you - just allow me a week or two to get them done and shipped.
Badass Lubu - I will def be tackling this with your info in the very near future [Gotta get the $$$ up and order me some parts]

If the bumper is still giving you a hard time... heat gun!

$20aud bucks and 30 mins to spare most of you guys know how to do this, so again Ill let the pics speak for themselves.







I couldnt be bothered so I sticked it between the adjustable spanner and yanked them out..



Taaadaaaa.....

Nice - she's coming along well. No spacers yet? They are taking twice as long as anything else I shipped but of course they have alot farther to go LMK when they get there and what you think of them.

Will do bro.

A small update as Ive just received the spacers from DEATH, Im very impressed with the quality and dimensions of his work.





If anyones doing the conversion and wishes a set for their rear caplipers I suggest contacting DEATH, his work is top notch

Sweet!!! They look like the were a perfect match up and you didn't need the shim kit I included. That paint should outlast the metal around it I'm told but you can LMK about that a few years down the road. I roughed up the spacers just enough for the stuff to take root so you shouldn't have any chipping or anything. The material is e4340 so plenty strong enough for this application.
So the full brake conversion is finished then right? Guess I better start gathering parts for my own

This post has been edited by DEATH: Aug 26, 2008 - 9:54 AM

please update pictures in 2nd page (brakes install)
p.s.
what is the thickness of blue spacers?

This post has been edited by VinT: Jun 6, 2010 - 7:02 AM

Yes it is.
The more stopping power is not given by the surface contact (the resistence will be preety much the same if you have 1mq or 1cmq in contact), its given by resistence x half diameter. If you have the same caliper, with the same pads and different rotors the more powerful one will be the one that byte the rotor farther for thehub centre.

So, using bigger rotors with the same brakets is useless, but making a braket that make you use the full potential of a bigger rotor with the same caliper is the better option, giving the better result.