Disc Rotor Confusion..

[Aust162]

Can anyone tell me if st165/185 gt4's ever came with 258mm diameter front rotors?

The DBA catalogue tells me st185 came in 278mm. I'm assuming thats for the Aust delivered. Was there a difference with the jdm (Yo) gt4 disc's?

I have disc's on the front of my St162 that measure 258mm, but have the thickness of gt4 discs and the same hat height as gt4 ones as well...

The stock st162 rotors are thinner than these (21mm minimum not 23mm), and the hat height is about 5mm taller on the st162 rotors.

Any ideas?

[Aust162]

No one knows??

Bump

[TooF]

the st165 comes witgha twin piston caliper that works on the 258mm rotor.. the other one to look at if you want to replace witha thicker then the 21mm st162 is the 23/258mm aw11 rotor although you will need to redrill it to 5x100 from the 4x100 it comes in,.

[Aust162]

That's whats strange. I've got twin piston calipers with "st185" written on them with a paint pen, and the rotors are 258/23 already in 5x100. they havnt been drilled

Did any other models come out with 258mm/23mm rotor in 5x100 from factory?

[TooF]

yes.. early model st185's had the same calipers and discs as the 165. they changed after only a few months of production to the larger single piston and 278mm rotor. i am currently running the early 185 twins on my aw11.

[Aust162]

when you say same disc's, you mean they where the same thickness as well?becuase st162's are 21mm min. gt4's being 23mm.

If you could clarify this for me,that would be much obliged

[TooF]

yes the early 185 with the twin piston was a 258/23 disc. they then upgraded to a 258/26 disc witha single piston caliper. i wouldnt be using the twins on the 21mm disc it is probaly a little too anorexic. also it risks the pistons not remaining captive.

[Aust162]

Thanks for that. yeah, i've been running the 258/23mm with my twin spots, its just that they are due for a machine and they are going to be undersized. So i got to get info to the DBA people. they dont list the 258/23, only the 278/23. and i want some slotted ones

[matt86sx]

yes.. early model st185's had the same calipers and discs as the 162. they changed after only a few months of production to the larger single piston and 278mm rotor. i am currently running the early 185 twins on my aw11.

Sounds like Toof has answered all your questions correctly, except that the above comment should say that early model ST185's had the same calipers and discs as the 165 (not the 162), although I'm sure that's what he meant These twin piston calipers use DB1181 pads in them, 162s are single piston and use DB308 pads.

All Aus-delivered ST185's had the 278/25 disc and single caliper front brakes (with DB1129 pads), hence the DBA catalogue does not list the disc that suits the twin piston caliper as no model with those brakes was ever sold here. However plenty of people have used the twin piston caliper with the 22mm standard ST162 discs before.

I have read that the 165/early 185 disc is 25mm thick, not 23. (23 is probably the minimum thickness for them.) The ST162 disc is 22mm wide and the 165 disc was made thicker to cope with the extra heat etc that would be generated by the heavier GT4 version of the car. I think they would have made it more than just 1mm thicker though.

There are some good pictures at this site, showing the differences between the three generations of GT4 discs and calipers:

http://www.gtfours.co.uk/

In the left hand menu, go to Modifications > 165 > Brakes, and click on the "Pictures" link in the first box.

Cheers,
Matt

[TooF]

Sounds like Toof has answered all your questions correctly, except that the above comment should say that early model ST185's had the same calipers and discs as the 165 (not the 162), although I'm sure that's what he meant These twin piston calipers use DB1181 pads in them, 162s are single piston and use DB308 pads.

All Aus-delivered ST185's had the 278/25 disc and single caliper front brakes (with DB1129 pads), hence the DBA catalogue does not list the disc that suits the twin piston caliper as no model with those brakes was ever sold here. However plenty of people have used the twin piston caliper with the 22mm standard ST162 discs before.

I have read that the 165/early 185 disc is 25mm thick, not 23. (23 is probably the minimum thickness for them.) The ST162 disc is 22mm wide and the 165 disc was made thicker to cope with the extra heat etc that would be generated by the heavier GT4 version of the car. I think they would have made it more than just 1mm thicker though.

There are some good pictures at this site, showing the differences between the three generations of GT4 discs and calipers:

http://www.gtfours.co.uk/

In the left hand menu, go to Modifications > 165 > Brakes, and click on the "Pictures" link in the first box.

Cheers,
Matt

*oops* yeah that would be the 165 not 162.. typo..


if you need a 258/23 disc like i said the aw11 rotor suits and has the right offset and centre bore just needs redrilling. and avaliable in slotted

[Aust162]

Thanks for the heads up toof. the dba catalog reckons that the aw11 discs are 21mm minimum thickness though, same as the st162 celica..

I sent the dba guys a tech email, so hopefully i will hear from them soon, and that they can get me some 258/25mm jdm sized rotors

[TooF]

they are 22mm. 21mm is the minimum thickness. sorry i thought they were 23

[TooF]

it is unlikley that they will source you anything as they make their rotors in house.. if they sont currently make one they will not whip you up a custom one off. sorry mate

[AndyTTR]

They might be able to make you up a hybrid out of the two piece rotors they sell. The hats are already available and the rotor could easily be machined from a blank. I spent the whole day at work sussing out brakes too. Surely there have to suppliers other than DBA that manafacture a rotor for the GT4.

While we're on the topic, does anyone know if the aus delivered ST185 calipers are different to the ST184 parts? The DBA catalogue has the same rotor (DBA743 - 278mm dia.) listed for both the GT4 and the ST184, so I'm taking a punt that the calipers are likely to be the same too? Or did toyota whack some other pov-pack brakes on the aus. delivered ST184's?

[Aust162]

I think they're different calipers andy. they have different part no. for the brake pads, so i'd assume they're different. they'd both be the single piston ones..