ST185 Brakes

[sergei]

I was wandering exactly what is the diameter of front brake rotor of a ST185?

According to Mr Revhead ALL st185s had the same brakes right through the model run.

So if it is a rumour, that there is a difference before and after facelift,
and that prefacelift 185 have facelift 165 brakes, twin piston callpers with 254mm rotor, and facelift 185 have 265mm single piston calliper, is NOT TRUE.

So what is the diameter of the 185 front rotors, and what callipers they have?
will they bolt on on 165 hub?

Slightly off topic, but I have prefacelift 165 with 254mm rotors and single calliper.

[Malcolm]

According to Mr Revhead ALL st185s had the same brakes right through the model run.

So if it is a rumour, that there is a difference before and after facelift,
and that prefacelift 185 have facelift 165 brakes, twin piston callpers with 254mm rotor, and facelift 185 have 265mm single piston calliper, is NOT TRUE.

It's not rumour, it's 100% fact. Any JDM normal bodied (ie not widebody) ST185 had the smaller disks with twin pot calipers, same as facelift st165s, all facelift JDM models, GT-Four A's, homologation models, and ALL export models have the larger disks with the single pot caliper. Front brakes are 100% interchangable between and model of st165 or st185.

The figures I have for disk sizes are 256mm for the twin pots and 277mm for the single pots.

If anyone wishes to attempt to debate the legitimacy of my claims, I will go and get photos of the brakes of every variant of st185 (several 89-91 st185s, a couple of GT-Four A's, a few GT-Four RC's, a couple of facelift st185s, and maybe an NZ new one) - all of which I have done considerable amounts of work on, and seen for myself the differences in brakes.

[RunningRich]

Don't bother, you are right!

[Mr Revhead]

Any JDM normal bodied (ie not widebody) ST185 had the smaller disks with twin pot calipers, same as facelift st165s, all facelift JDM models, GT-Four A's, homologation models, and ALL export models have the larger disks with the single pot caliper.

your wrong!




ok, ok, ok, im kidding, i was (sorry sergei)
i think i missed checking the NOB jdm model... checked the others though.
so my mistake there

[sergei]

thank you very much
Now what I have to do is find some big brakes for my ST165, current ones are just hopeless...

[Adydas]

I Have a set of these brakes i just need to fit them, mm twin pot. Anyone wanna help?

Just from intrest what are they worth? and is there any upgrade to the rear brakes useing facelifty ones?

OHhh and also do i need bigger rotors? or can i just wack these onto what i have now?



yes yes i know yellow looks naff but better than rust and you cant see them on car anyway.

[Malcolm]

cliff, those calipers should just be a remove your old ones and bolt the new ones on swap, easy as you could hope for. Just clamp the flexible brake hose so you don't lose too much fluid, then give them a good bleed.
If you want a serious upgrade then try and get some ST205 brake disks and calipers. All 4 corners will bolt on (just need to run a tap through the holes on the front hub carriers), also need to machine the front disks down to 300mm diameter (still plenty big). Will need 16" wheels minimum to fit them though.
I think that you'll find that twin pots on the front, with good quality pads (mintex 1166 are highly recommended I hear), and fresh fluid (give the system a complete flush+bleed), should make the braking vastly better.
That is unless you plan to start doing serious track work, in which case definitely go st205 ones

[Adydas]

cheers dude, i can start to fit them then i was under the impression i had to wait untill i had new rotors that fitted these. so sweet.

[flygt4]

on a side note.. allfours may be able to comment on it. theres that guy in oz with the stroked 185rc and the 1uztt st185 that has been bolting STI brakes onto his 185's. in the article i read it said that they required "minimal modification" to fit , tho what that means is anyones guess.

[Malcolm]

well I'm not too sure about that one. I have heard that version 7 sti disks work, but I've never heard anything about how well the calipers go on. To be honest you'd probably be better off with st205 brakes though, as they will be a lot cheaper than sti brakes I imagine

[deaf_rattle]

i priced sti brakes up for a mate that wanted to do that conversion, they were bloody expensive

so he went for 205 brakes in the end

they work bloody well

[gt4mike]

I've fitted a set of 205 brakes to my 185rc, however there is a bit of custom work which needs to be done.

The rear brakes are straight forward, all that needs modifying is the standard guard thing that sits behind the disk. This touches the new disk, so needs to be bent back a bit, or chopped off. Either is easy.

The front brakes are not so straight forward - but are still probably the most cost effective way of getting big brakes.

After weighing up all the options, I'm pretty confident that without serious modification this is pretty much the only way about doing it in a non dodgy fashion.

With this method the 205 caliper bolts to the existing mount points with no modification. The modification that is required is in order to have the disk sit in the centre of the caliper, and fit inside the caliper.

The first requirement is to have the disks lathed down to 304mm diameter. This makes very little difference to the surface area the pad contacts since standard there is some area towards the centre of the disk the pads don't normally touch. As much as I wanted to keep them at 315mm I dont think its possible using the standard mounts for the calipers.

To centre the disks in the calipers I needed to space the disk out 3mm, so needed to fabricate some spacers to sit behind the disk. When I made these I made sure the fit was very tight to ensure there was no chance of movement. Adding the spacer created it's own problem however, and that was that there wasn't enough of the centre locator on the hub for the wheels to locate on. I know some people think its ok for this to be the case, but i wasn't happy with all the force going onto the wheel studs after seeing a few track cars shearing the studs off. To overcome this problem I had to remove the hubs and I had the standard centre locator part machined down slightly, squaring the corner where it meets the main face. From there I had a piece fabricated, which is pretty much a pipe, which was sized to be very tight, heated up and then pressed onto the existing centre locator. The length of this pipe was about 10mm longer than the standard locator. So what's left is the hub with a new centre locator 10mm longer, but also with a bigger outer diameter because its over the top of the old locator. I cant remember what diameter, it is exactly, I think its 60mm. Obviously with this larger centre locator in place the disks and wheels no longer fit, so I had to have those put on the lathe and machined out the centres to fit. The other thing I found was with the extra spacing there wasn't enough thread left of the stock studs to be confident my wheels wouldnt fall off, so at the same time I put some 10mm longer wheel studs in. This may vary depending on the type of wheel, although you'd want to check before reassembling.

I also used this time to do nolathane suspension bushes and replaced the wheel bearings while it was apart.

Hopefully that helps! If you need pics pm me.

[Adydas]

Suppose its to late to request pics on this mike? Ive just got part way into the exzact same modification and its fail big time, Firstly 304mm is wrong i cant clear the caliper unless im 298mm.. the spacer im using is 5mm and i still have sifficent boss that my cert guys is happy where the wheels sitting so i dont feel it needed to press new pipe on and extend that, how ever its good to know i Could if needed..

my issue is clearance of the rotor from the ball joint, i think i might have caused issues by lowering the car, I should wind the height up to confirm this.

Would be good to get it touch if your still avalible to talk gt4...

Ok Party People, Need some help here.. have a smallll issue..

I have installed a 5mm spacer behind a ST205 stock rotor thats had its diameter machined down to 297mm so it fits within the caliper thats bolted onto the hub.

My issues quite simple.. The ball joint on the bottom of the suspension arm gets pushed into the brake disk, How can this be solved so the brakes still operate and the car passes the cert.

If i space the rotor out more i lose access to put the wheel on the boss and therefor fail the cert, if i machine the disk thinner it would be to thin to pass a wof/cert, seems like in usa a subaru wrx imprezza rotor fits on and would solve this problem, Anyone know if this is true?


just to be clear ive had to machine the disks to 298mm not 305mm as it wont clear..

[Adydas]

The only thing we can think of doing is using WRX rotors..

Code: Select all


Diameter  Height  Thickness  Min. Thickness  Center Hole    Bolt Holes
Stock ST205
315       58.5          32          30                        55        5
 
Stock WRX
294         57          24          22                        58         5


The only issue is the size of the boss / Locater, Does this need to be spot on or is it a "guide" only..

[Dell'Orto]

12mm thinner though, thats pretty substantial.

[sergei]

I was pondering on the same problem a while ago, I decided in mean time to go for ST185 brakes in my 165.
I had a few ideas how to achieve ST205 brakes on ST165.. But I did not want to machine ST205 disk (as rotors are consumables, especially when racing, and needed to be off the shelf items). The ST165/185 is almost the same fitments as caldina, and there has been problems with ball joint clearance.
What could of been done is to use custom bearing/spigot combo (say from ST205) and some sort of bracket to offset the calliper, that spaces out the brakes to clear the suspension bits that are in the way.

I have calculated the cost of the hassle and wasted time, and decided it is best just forget about fitting ST205 brakes and trying to reinvent the brakes, and just go with Brembo/Willwood/APracing/Whatever jobbie, that has off the shelf rotors. Although I have not implemented this plan due to financial priorities.

[Adydas]

12mm thinner though, thats pretty substantial.

The surface area remains the same tho..

[xsspeed]

12mm thinner though, thats pretty substantial.

8mm isn't it?

[Adydas]

Yeah its 8mm not 12 but still its the differnce between working and clearing and not.. I just did a dummy fit and its all good.

[Dell'Orto]

Minimum thickness difference is 8mm...thats kind of a misnomer, minimum thickness is actually the scrap thickness of a rotor. IE once it gets that low, turf it.
Cliff - the surface area might be the same, but the calipers are expecting to squeeze on something 32mm thick, but are actually having to bite onto something 24mm thick...I'd just be worried that once your pads are worn, they'll end up pushing the pistons out.
The centre hole needs to be reasonably close, but you ought to be able to make up some sort of 3mm spacer to fix that.