Help - Search - Members - Calendar
Full Version: The GT-Four Brake Upgrade
6G Celicas Forums > 6th Generation Celica > Suspension/Handling/Braking
Pages: 1, 2, 3, 4
Tigawoods
This is a GUIDE not a HOW TO and is a thread in progress. Its going to take me a bit to properly organize this load info into a visually pleasing manor.

If anyone has any input from their own experience post or PM me and I will add the info in! There is alot of info in here and I am sure it will get very convoluted



**Be aware that the ST205 Brake upgrade will require at least a 16" wheels and possibly spacers to adjust the offset and avoid contact between the face of the caliper and the backside of the rim face. **



Torque Specs
Caliper halve bolts (four bolts that hold the caliper halves together)
14-17 ft/lbs *Have an even torque value on each bolt (add a dab of red loctite to the bolts thread ends)

Caliper Seal Part Numbers:

Stephen at GT-FourPlay UK sells a rebuild kit. You can still get the kit lsited below from rock auto but Stephens kit is alot more straight forward and youd be supporting Local (UK) business!
https://www.gt4-play.co.uk/shop/brake-calip...ce-kit?___SID=U

Caliper Re-seal Kits (Centric Brand From Rock Auto)
Front Seals X4 #14344031 (kits are used for the small crossover seals for all 4 calipers/the piston seals in this kit are too large so the rest is unused)
Rear Seals X2 #14342021 (Each Single kit services 2 calipers. These piston seals are used for the front too)
(I need to re-confirm that the rear piston seals fit the front pistons)
This will cover the crossover seals/piston seals/piston boots/piston retaining rings

Caliper Hardware Part Numbers
(Need to add the Pad Pin retaining wire #'s & toyota diagram)

Front pin clips: #04947-14010
Front pad pins: #90240-06019
Front shims: #04945-14110 (EBC pads come with stick on shims)

Rear pin clips: #04948-14010
Rear pad pins: #90240-06017
Rear shims: #04946-14030 (EBC pads come with stick on shims)




Front Hub/Caliper Preparation:
(These part#'s correspond to the McMaster-Carr Catalog. I highly recommend ordering hardware from them: www.mcmaster.com as they have VERY fast shipping and exceptional products)

Caliper Prep:
For the rotor to sit center in the caliper, the mounting tabs on the caliper will need to be shaved a slight bit.
Use a DREMEL and shave 7-8mm off of the mounting tabs. START OFF SMALL and shave say 5mm and check clearances, it is quite possible that with whatever spec rotor you use or just slight differences in hub thicknesses may not require a 7-8mm shave

(keep in mind that if you plan on powdercoating the calipers, that will add 1mm or so on top of the mounting tabs, unless you leave them uncoated.)

Use a Micrometer to make sure that the mounting tab is an even #mm across the entire area you shaved.





Hub Prep:
_____________________________________________

The stock hubs are thread-less and will need to be threaded. Below are the specs I prepped my hubs to but also a small description of what Culpable did with his hub. The way I did it requires a bit more drilling, and it is possible to just re-tap the thread-less hub holes rather than drill them out and re-tap. If you drill the hubs you will possibly need to drill out the caliper holes to match. The tap information is listed below.


CULPABLES THREAD (link at bottom of this post):
take the knuckle off the car and thread tap them thread taps are available anywhere, buy matching bolts for the thread you are tapping ( grade 8 bolts please ) use a 1/2 x 20 tap or finer thread. ( the one used on the pictures is 9/16 x 20 but no need to go that big as that will require to drill the hole to make it a little bigger)

______________________________________________

Carbon Steel Hand Tap, 9/16"-18, 4 Flute (I will add the kind of tap wrench that is best for tapping the hubs)
#26035A216


Drill for Tap
33/64
http://www.mcmaster.com/#catalog/119/2432/=oglxb8
8947A217 - 118 Degree Point High-Speed-Steel Short-Length Drill Bit, Black Oxide, 33/64", 3-7/8" Length Overall - $18.92
(CALIPER HOLES WILL ALSO NEED TO BE RE-DRILLED IF USING THIS SIZE, MAKE SURE TO DRILL TO MATCH THE DIAMETER OF THE BOLT YOU ARE USING TO MOUNT THE CALIPERS, THIS DRILL BIT WILL BE TOO SMALL)

Grade 8 Alloy Steel Hex Head Cap Screw, Zinc Yellow Pltd,9/16"-18 Thrd, 1-1/4"l,fully Thrd
#92620A779


(Large washers are used in between the Front Caliper bolts and Hub and one washer has to be trimmed per axle, I will add their sizes later)

The Brake dust shield will fit and no modification is needed other than pushing it back a bit to avoid contact with the rotor (WITH 300mm Rotor).


Rear Hub Preparation:

I was fortunate enough to get the oem caliper bolts with the calipers in the kit from Culpable. I will get their specs since those are the bolts you will need to mount the caliper, the oem ST204 bolts are too short.

The rear dust shield will need a good amount of trimming (use a small dremel) for the caliper to fit. Its hard to really explain where it will need to be cut exactly, but just hold up the ST205 caliper to its mounting mount and you will be able to judge where it will make contact with the dust shield. Both around the top and bottom mount holes on the hubs will need to be trimmed. (If you plan on powdercoating your calipers make sure to do this before, I scratched my newly powder coated calipers holding them up trying to judge how much more I needed to trim)

When mounting the Rear Calipers, there needs to be a 6mm spacer washer between the caliper holes and mounting bracket.
This will correct and center the caliper to match the lower rotor height of the ST205 disk (The ST205 disk is 6mm smaller than the GT disk). As a temporary solution I used 2 washers (2.5mm thick) per hole that when stacked added up to about 6mm. Washers usually have a thickness tolerance of +/- .3mm so I had to sort through a whole bunch to finally find a combination that added up to the right spec. Anywhere between 5-6mm will work fine but the closer to 6mm the better

The better solution, as discussed with ricochet1490, would be to get a custom made 6mm thick washer.

McMaster sells extra thick high strength steel washers, I am ordering a few to test them out, supposedly the thicknesses of the washers arent consistent but we will see



Rotors:

OEM Celica Dimension Specs


Front:

Be aware of the hub diameters. The OE Celia hub diameter is 54.1. Most of our options for the front will be larger than that.
I personally like to have hubcentric rotors but you can run them lug centric if you dont feel like making a shim, I would advise against that though.


Subaru BRZ/Impreza Rotor
Part Number: Centric 121.47021
PCB - 5x100
Hub Dia - 58
Dia - 292mm
Centric Brand Part Number: 121.47021


(additional info on aftermarket solutions will be added soon thanks playr158 for the find!)

93-99 Toyota Supra NON-Turbo
PCB - 5x114.3 (Must Be Re-Drilled)
Hub Dia-60.1
Dia-296mm / 11.811"


****Most OEM and OEM replacement Supra Non-Turbo rotors have service holes on the face of the hat preventing them from being re-drilled to 5x100, Most aftermarket 2-Piece Rotors do not have these service holes allowing the hats to be re-drilled. Always check before purchasing. THIS MAY NO LONGER BE A VIABLE OPTION****




5x114.3 Conversion Front Rotors
93-99 Toyota Supra NON-Turbo
Supra Hub Dia-60.1
Dia-296mm / 11.811"

Rear:

ST205 Rear Rotors
Hub Dia-54.1
Dia-315mm

I highly recommend EBC Brand through this site
http://www.ebcbrakesdirect.com/ (Fast Int'l Shipping with Tracking code!)
Here you have the option of OEM/SlottedDimpled/Slotted

ENDLESS also makes a Slotted and Blank Rear Disk
Blank Rotor (Single) $176
Slotted Rotor (Single) $225
ENDLESS Rotor PDF

5x114.3 Conversion Rear Rotor
***TBD****

Brake Pads:

Supra MK4 Turbo Pads
I recommend EBC brand pads as they come with black 3M rubberized stick on shims. Do Not use both the stick on rubber shim and the metal Toyota/Other brand shim.
Part#
Front
DP31004C
Rear
DP31005C

Some other brands that have both streetable performance and race performance pads that will fit are

-HAWK Pads
-Carbotech Pads
-Endless Pads


I have only ever used EBC pads so I have never needed Shims from Toyota. I am not sure if other brand pads come with some sort of shim. If they don't you will need to order a set of shims

3M Stick on Shims




Brake Lines:

ST205 Lines

ST204 (GT) Lines

Custom Lines (recommended)


Bleeder Fittings

Speed Bleeder #SB1010
Buy them. They work wonders


Caliper High Temp CELICA Stickers
http://www.ebay.com/usr/uber9
Since the sale is re-listed weekly I cannot provide a direct link. Sreach for "celica" and the results will show up. Be sure to message the seller to specify it is for the ST205 Calipers


Brake Bias Controller
One thing that will be immediately apparent with this swap is a different brake bias than what the GT/ST provided.
The bias wont be the same for every car this swap is done for. There are alot of factors that will effect the ration ever so slightly. Worst case scenario your rear bias will be too much to the point of locking up way before the fronts get a chance too. For DD emergency situations, this may be undesirable.
Combat this will installing a Brake BIAS Controller.
I recommend Tilton as the brand to buy but there are other more budget friendly brands.



Brake Proportioning Info
http://stoptech.com/technical-support/tech...rtioning-valves

Additional Links/Reference Links:
ST205 Brake Upgrade Completed (Culpable04)
ST205 Brakes on a ST (Culpable04)
ST205 Brake Upgrade Completed (Batman722)
Toyota Supra Specifications


End Goal?
yellowchinaman
That is really useful.
Im doodling on the idea of adapting a set of Audi Q7 Sline calipers to my faff.
playr158
Thanks TIGA. I was going to do the same with the information you gave me.
I'll probably photograph the whole thing to add to this thread.

Since the supra rotors are 5x114 I'm also thinking about doing the complete 5.x114 hub conversion at the same time..


agian thanks for putting this together!
njccmd2002
but then you have to redrill the gt4 rears... u have to redrill some rotors...
playr158
I believe there might be some bolt on rotors but need to see
Fate
*subscribed.

Tigawoods
QUOTE (playr158 @ Jul 24, 2013 - 3:12 PM) *
Thanks TIGA. I was going to do the same with the information you gave me.
I'll probably photograph the whole thing to add to this thread.

Thatd be helpful. I did not take a single picture of anything when I was going through it

QUOTE (playr158 @ Jul 24, 2013 - 8:48 PM) *
I believe there might be some bolt on rotors but need to see

There are definitely some out there, itd be nice to get a list. And it would be great if they where the right size specs and 5x100! If not then at least we would have some alternatives to the Supra rotors since as noberto found out the hard way...they cant be redrilled, the OEM ones atleast
playr158
Well if we use

FRONT: GEN 1 RAV4 front hubs + MKIV NA Supra rotors + GT4 front calipers = bolt on

REAR: 91-96 Camry rear HUB/Bearing assembly + Camry rotors = bolt on.
The question is here is what larger rotor is needed for the rear GT4 caliper. I thought I had a potential option written down somewhere so now I have to go find it. This might honestly be as simple as contacting adams rotors and having them make a larger diameter rotor based off the camry oem rotor....which would be easy and cheap I thinks.



njccmd2002
well how big are the rear supra rotors?
Tigawoods
300mm I believe
njccmd2002
duh, how thick are the rear supra rotors. thats what i meant sorry...


OH and for those of you that want to buy OEM supra rotors, dont, they have 10 holes.... (arg)

Tigawoods
15mm methinks. Either that or 17mm
Tigawoods
added a couple more things.

I will add the links on how to swap to 5x114 in the OP

Also maybe some tips as to how to remove the pistons from the calipers if you plan on powder coating and/or replacing the piston seals
playr158
Wanted to Toss this in there

http://www.mcmaster.com/#catalog/119/2432/=oglxb8
8947A217 - 118 Degree Point High-Speed-Steel Short-Length Drill Bit, Black Oxide, 33/64", 3-7/8" Length Overall - $18.92
Tigawoods
thanks man!
njccmd2002
Bringing this back from dead. Called adamsrotors, and the guy who was an asshole, pretty much told me not to wast his time all the questions are in his website. They don't do custom rotors, in a sense of different hub pattern, but in a sense of pretty colors and bs. Which leaves me stranded, here in this miserable town, nobody wants to do or even knows how to redrill rotors to 5x100. Lol.
Fate
QUOTE (njccmd2002 @ Nov 25, 2013 - 3:45 PM) *
Bringing this back from dead. Called adamsrotors, and the guy who was an asshole, pretty much told me not to wast his time all the questions are in his website. They don't do custom rotors, in a sense of different hub pattern, but in a sense of pretty colors and bs. Which leaves me stranded, here in this miserable town, nobody wants to do or even knows how to redrill rotors to 5x100. Lol.


Sounds very similar to my email conversation with him roughly 2 months ago.

I have a local place trimming my front st205 rotors to 300mm as my temporary solution for now. The same place I recently found out also does re-drills.
Tigawoods
I will have to update the OP!
njccmd2002
we have to find a source of rotors that will meet our needs, so far, i have only seen racing rotors in the ups of 300+ per rotor, lol.

the problem i have, no one, absolutely no one wants to touch and redrill a rotor here. they are afraid.
njccmd2002
ok, classic example why i need to get my own tools, its stupid, in this town, no one wants to help. Jackson TN. How bad could it be, just need a jig, and a drill press. right?

ive got the jig already.

playr158
That's actually really smart......wheel spacer with proper bore and a drill press. Technically you could get away with a standard drill but press makes life way better.

I'll have a picture step by step of this conversion in about two weeks
njccmd2002
yeah man, im tired of trying to get someone to do this. i have been dying to have a reason to buy a drill press, and this might be it...
njccmd2002
just found this

subaru impreza sti

326 x 30 mm

hub 58

height 52.7

its 5 x 100. so its 2 mm shy of 32. but when we resurface gt4 rotors, thats prolly where they end up at...
Fate
QUOTE (njccmd2002 @ Nov 25, 2013 - 9:00 PM) *
ok, classic example why i need to get my own tools, its stupid, in this town, no one wants to help. Jackson TN. How bad could it be, just need a jig, and a drill press. right?

ive got the jig already.



i like!
Tigawoods
QUOTE (playr158 @ Nov 25, 2013 - 9:53 PM) *
I'll have a picture step by step of this conversion in about two weeks

we can combine to make....the ULTIMATE conversion thread!
njccmd2002
Tiga, do you have a set of brake lines that already dont recommend. I know the slot is empty, i may start to look around, but wanted to see what u have tried.

I bought a wrx sti rotor today, for giggles. ill get it on the third. since no one here wants to redrill, i figure ill work my way with a bracket, if it even works, lol
playr158
326? isn't that too big for the GT4 setup?
I thought we were looking for 300mm?


I just got my Tap and drill bit today, standard from mcmastercarr is overnight for me biggrin.gif
Picking up everything else for my project at fastenal tomorrow am.



njccmd2002
yes i know, but it will be easier to get the rotor reduced in size than redrill to 5x100 in this damn town.
Tigawoods
300mm MAX.

Let me throw that brake line info in, but ST205 lines will work if you can find them, or SS GT lines will fit (I used the rears in the front and the fronts in the rear since the fronts were getting close to stretching when at full lock, when switched they operate just fine)
njccmd2002
Cool, I'll keep looking for those lines. Once I get the rotor in ill post the experience, lol this is the fifth rotor. After 2 supras I can't drill and 2 gt4 I don't want to use spacers on.
Trodai
QUOTE (Tigawoods @ Nov 27, 2013 - 8:20 AM) *
300mm MAX.

Let me throw that brake line info in, but ST205 lines will work if you can find them, or SS GT lines will fit (I used the rears in the front and the fronts in the rear since the fronts were getting close to stretching when at full lock, when switched they operate just fine)


302mm will work also that what i have on my car well its act slightly larger but 302mm works well in mine..(mine are reduced st205 discs) , I would be wary of the pads you choose to use also as some have the braking material located differently on the backing plate and this can have you braking surface of the pad coming out over the top of the disc. have you looked into Vw discs they easily available to you over there? some of those are 300mm, Subaru seem to be the most common for this conversion

I can post pictures of my conversion of the Gt-four brakes on the st202 hubs if you like?
bnr32celica
QUOTE (Trodai @ Nov 27, 2013 - 4:09 PM) *
QUOTE (Tigawoods @ Nov 27, 2013 - 8:20 AM) *
300mm MAX.

Let me throw that brake line info in, but ST205 lines will work if you can find them, or SS GT lines will fit (I used the rears in the front and the fronts in the rear since the fronts were getting close to stretching when at full lock, when switched they operate just fine)


302mm will work also that what i have on my car well its act slightly larger but 302mm works well in mine..(mine are reduced st205 discs) , I would be wary of the pads you choose to use also as some have the braking material located differently on the backing plate and this can have you braking surface of the pad coming out over the top of the disc. have you looked into Vw discs they easily available to you over there? some of those are 300mm, Subaru seem to be the most common for this conversion

I can post pictures of my conversion of the Gt-four brakes on the st202 hubs if you like?


VW makes a disc that's 288mm or 312mm. More than likely, Subaru would be likely to have an 11.9" (300mm) rotor that would fit.
Malek
QUOTE (Trodai @ Nov 27, 2013 - 5:09 PM) *
QUOTE (Tigawoods @ Nov 27, 2013 - 8:20 AM) *
300mm MAX.

Let me throw that brake line info in, but ST205 lines will work if you can find them, or SS GT lines will fit (I used the rears in the front and the fronts in the rear since the fronts were getting close to stretching when at full lock, when switched they operate just fine)


302mm will work also that what i have on my car well its act slightly larger but 302mm works well in mine..(mine are reduced st205 discs) , I would be wary of the pads you choose to use also as some have the braking material located differently on the backing plate and this can have you braking surface of the pad coming out over the top of the disc. have you looked into Vw discs they easily available to you over there? some of those are 300mm, Subaru seem to be the most common for this conversion

I can post pictures of my conversion of the Gt-four brakes on the st202 hubs if you like?


Yes, please post pics haha

What size disc spacers did you use for the front?
Trodai
my conversion (copied from my build trend in another form)
st202 wishbone with Polish bushes
st202 drop links.. (after working on a carlos a while back wondering will the st185 drop link fit? and same dimensions? i need to check this out)Updatewill be fitting Polish drop links when due replacig
st202 balljoint the size of the casting seems to differ in manufacters so some will be tighter than others some just wont fit with the full sized disc in oem fitting position
St202 front strut casing with koni inserts and st202 shock top and st182 spring rubbers( Springs will be changed back to St205 Oem or st205 trd
St205 caliper with mounting point machined to help mounting surface contact and allow disc clearance inside of caliper
1mm spacer made up to fit inside disc to help clear balljoint
st202 hub with the brackets threaded and custom grade 11 bolts(iirc they are same grade as oem anyway) made up so there is a shank that fits inside the st205 caliper hole so it has a good snug fit..., the st202 hub uses the same wheel bearing as the st205 so was happy with that.. i am also using st202 abs sensors,
st205 subframe
st202 ARB with Polish Arb bushings
st205 steering rack with modified st205 inner and outer tie rods
st205 disc reduced to 304mm diameter (would suggest going 1mm or 2mm smaller at this was slightly rubbing the retaining clip fro brake pad pins.
here are the pics

I have more if needed the bolts are grade m14x1.25mm grade 11

here is a picture of 2 different brand of brake pads as you can see one has less material that the other and is also lower placed on the backing plate

are the subaru discs not 295mm and 297mm? i will probably replace mine again with machined st205 discs but if i wasn't i am looking at Volvo discs 302mm diameter and 26mm thickness? even 296 supra discs?, Volkswagen Caravelle models have a 300mm vented disc
99gt3sge
QUOTE (njccmd2002 @ Nov 26, 2013 - 5:32 AM) *
just found this

subaru impreza sti

326 x 30 mm

hub 58

height 52.7

its 5 x 100. so its 2 mm shy of 32. but when we resurface gt4 rotors, thats prolly where they end up at...



yeah that's what i was researching too, the 04 sti is really close to the gt specs but just larger in diameter, i was going to trim it down with my brake lathe. let me know how it works out. i still need to buy a set of calipers before i buy the rotor to play with.
playr158
Just a thought....BRZ rotors are approximately 295x25.5 mm AND 5x100
BonzaiCelica
if you see newcelica.org there is a guy who bolted(without modification) on avensis caliper and 295mm rotor onto his 7th gen celica.

i don't know the thickness of the rotor though
jeffrosie

Only 26mm thick.
playr158
Honestly the 4mm or whatever is not going to make a difference. Thickness is really a marginal issue as it will be compensated for by the pads.
njccmd2002
ok, so the STI rotor sits awesome on the car, but the extra offset of 5 mm that clears the ball joint is so bad that makes the caliper seat not centered.
playr158
More english prease?!

The rotor sits perfect and does not hit the ball joint. But is off center to the caliper is what i'm gathering.

Does it sit too much towards the inside of the car or does it sit more towards the outside?

and your previous post said it was 326mm diameter...isn't it 26mm too large for the caliper as well?
njccmd2002
found this on ebay, bought the last set, what are the chances...

http://www.ebay.com/itm/SET-OF-4-ALUMINUM-...04e&vxp=mtr
Tigawoods
make sure they dont sit higher than the rotor face!!
njccmd2002
QUOTE (playr158 @ Jan 12, 2014 - 8:37 PM) *
More english prease?!

The rotor sits perfect and does not hit the ball joint. But is off center to the caliper is what i'm gathering.

Does it sit too much towards the inside of the car or does it sit more towards the outside?

and your previous post said it was 326mm diameter...isn't it 26mm too large for the caliper as well?



the rotor sits perfect, and the brake surface is excellent.

however i would either have to grind up to 5 mm from the caliper bracket area to even have it centered. i cannot even measure how much that rotor has to be resized, however i will post a pic in a couple of hours.

the rotor sits too much towards the outside, if we could find a caliper for this rotor, it woud be awesome....
njccmd2002
pics...







but.... to keep caliper centered....

lots of grinding..



even trying to bolt caliper outside.. using a 20 mm spacer..

so just keep it simple, and get the supras, if you are able to find some that can be drilled and someone to do it...

or you want this rotor, you need to find another caliper.



lots of grinding....



that puts the rotor and wheel to far away from the center of rotation, and thats a no no...

playr158
Honestly, We could easily have an adaptor bracket made for this. (IE small block of aluminum cut and drilled) So that the caliper sits in the correct place and we have a bolt on rotor.

It looks like the caliper mounting holes are sitting right on top of the knuckle holes. This would be a pretty easy adaptor to fab up.

Then I could get these:
.
njccmd2002
well actually no, because the caliper is not all the way sitting down and grasping the rotor... it still needs to be pushed down at least 10 mm, and still the holes do not align.

i was looking also at a camry spindle, looks alot like our celicas, with the difference of the mounts spaced further, giving chance of a bracket, but then again, too much trouble when u can just drill supra rotors.
playr158
Gotcha.
Well like all you other nuts, I picked up a "X" rotor today. We'll see how she fits and i'll report back, it should fit minus a 7mm offset.
Which is an easy $25 spacer and that's it, much easier than drilling.

PS njccmd2002 I saw your thread about brake rotors and the Subaru. I assume this was your research for the STI rotor.

To add information

CELICA GT OEM ROTOR
_____________________
Outer Dia:.....275mm
Height:.........49.3mm
Nom Thick:....28mm
Min Thick:......26mm
Hub Reg:.......55mm
Bolt Size:.......14.5mm
Weight:.........15lb
njccmd2002
yup sti rotor
playr158
sooooooo.........BOLT ON biggrin.gif biggrin.gif biggrin.gif biggrin.gif

Rotor:
Part Number: Centric 121.47021
292MM FRONT DISC

*I do believe there is a 295mm disc as well*






(NOTE: This is with worn ST205 OEM pads, and unconnected calipers)
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Invision Power Board © 2001-2020 Invision Power Services, Inc.