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ST185 Brake Upgrade? St205 Caliper Avensis Disc
http://gt4dc.co.uk/forum/viewtopic.php?f=13&t=2354		 Page 1 of 2
Author:  Diceman [ Sun Apr 13, 2008 11:58 pm ]
Post subject:  ST185 Brake Upgrade? St205 Caliper Avensis Disc
I am starting to try and prep the St185 for hopefully track use and ideally wanted to upgrade the poor front brakes.

I tried looking at the St205 brake upgrade as I had a set of old bells & rotors in ST205 size from my old ST205.
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It has been reported that the disc hits the bottom ball joint.
I can confirm lol
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Whilst saying hello to Peter Piper at Toyota I stumbled across the parts bin and found some old and knackered Avensis discs. Now the Avensis normally uses similar size discs as the St185 but these looked bigger. The Avensis shares the same PCD & Centre bore as the Celica so fitment should not be too far off.... At this point I should say thanks to peter & he deserves soem credit as he has been looking at a similar idea using these discs. Anyway the discs measure roughly 295mm dia x 26mm on the old very worn one I have so a considerable upgrade on the UK spec discs size at 277mm x 24mm.

So once I managed to pick up some ST205 calipers for a mock up we were off :-)

I had a spare ST185 front hub/upright on the bench which made things a lot easier.

The complete setup bolted together
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Rear view - looking promising.
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Clears the bottom ball joint quite nicely:-
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Centre bore stated for the Avensis is the same 54.1mm as the celica although it actually measures slightly larger than the stock disc by about 0.9mm.
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Unfortunately the St205 caliper & St185 hub/upright do not have any threads at all so you have to use a nut & bolt to retain. The setup in the mock up is not what I will use but what I found lying around.
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Now to have a look at the disc off set:-
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The pad swept area looks good - bloody close to being tooo big!
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seems the disc is offset by 2-3mm toward one side. Whilst evrything rotates freely it is too close and should be central.

So anyone got any bright ideas on the best method to correct this?

The above pictures & text are provided for info only. I am not a brake specialist and cannot verify the above will be safe. Unless you know what you are doing don't touch them!
Author:  Kris [ Mon Apr 14, 2008 6:49 am ]
Post subject: 
Nice work JP :)

What about removing the metal clip that sits over the calliper mounting point, this should move the disk closer to the hub by 1mm or so?
Author:  Diceman [ Mon Apr 14, 2008 10:04 am ]
Post subject: 
Yes It will definitely help, but I suspect not enough.
I should have pointed out that the pads in the caliper are not new. There may be some issue getting the new full thickness pads in and out.

Has anyone got a set of new pads they can measure the thickness of? I Hope it will not be an issue as the disc is thinner than the ST205.
Author:  Diceman [ Mon Apr 14, 2008 11:07 pm ]
Post subject: 
I will get some decent measurments at the weekend and update. Only had 10 minutes to whack it together so far so is very much a work in progress. I will take the clips off and re-measure.
Author:  Homer [ Wed Apr 16, 2008 9:46 am ]
Post subject: 
Interesting work jp, although my car is never going to be a track orientated monster, developments like this might give me the encouragement to lose my trackday virgin tag 8) , after all its good to know slowing it down may not be an issue :lol: .
Author:  Diceman [ Wed Apr 16, 2008 10:16 am ]
Post subject: 
Indeed Clive :-)
How are you finding the ST205 rear conversion on its own? I am not sure if on its own it would unbalance the braking system. Whilst I would like a small braking improvement maintaining the balance is my main goal at present as I have managed to bugger up my ST185 rear brakes and have a ST205 setup spare!

The ST185 will hopefully be lightened significantly but will not have much in the way of engine mods so it is not a monster track spec build. More of a "caca" effort :-)
Author:  Homer [ Wed Apr 16, 2008 11:08 am ]
Post subject: 
Jp i would fit the 205 rear set up if i were you , the only time i have experienced anything untoward with the rears was a emergency brake stop test, when the rear of the car locked up way before the front and ended up out of shape, Thinking about it, its the only time i've had the crate out of shape at all. Under normal/hard braking the car feels stable and straight :wink: yes you can feel the rear sitting down, but thats surely not a bad thing :? . If you need first hand experience before your decision pop over and take it out ?
Author:  Diceman [ Wed Apr 16, 2008 11:38 am ]
Post subject: 
I can see a "watch this" moment coming lol.
Author:  TrackToyFour [ Wed Apr 16, 2008 1:41 pm ]
Post subject: 
JP, if you have trouble with the brake balance after fitting the ST205 kit you can always fit an adjustable brake bias :D
Author:  Diceman [ Wed Apr 16, 2008 1:50 pm ]
Post subject: 
Well, as I hope to ditch the ABS - in for a penny in for a pound.

What is involved in this - any ideas?
Author:  two_OH_five [ Wed Apr 16, 2008 8:02 pm ]
Post subject: 
I **think** don might have the bits JP

Apparently Toyota do a "bypass" pipe which is actually a bit of stock non ABS models
Author:  TrackToyFour [ Wed Apr 16, 2008 11:58 pm ]
Post subject: 
As Steve has indicated I do have an 'ABS removal kit' which consists of OEM brake lines from a non-ABS ST205. Not sure if it will fit an ST185 tho?

Fitting an adjustable bias is not a trivial exercise at least not if its anything like the setup on the FFord which has a twin master cylinder arrangement connected via a fulcrum bar which is driver adjustable via a Bowden cable/knurled knob from the cockpit :mrgreen:

The OEM bias is fixed within the alloy 'spider' on the front bulkhead. :(
Author:  Diceman [ Mon Apr 21, 2008 9:18 pm ]
Post subject: 
Will have an update on thsi very soon as a decent vernier, new set of st205 pads & caliper refurb is underway. Anyone got a spare ST185 drive shaft knocking around I can borrow lol. Would like to tension up on the wheel bearing to get exact dims.

Also downloaded a load of info from www.brakesinternational on alternative disc offsets & sizes.
Author:  Muddy Water [ Thu May 15, 2008 4:46 pm ]
Post subject:  Got an update JP?
Think there should be an update on this soon :?:

If I remember correctly from the other weekend there may be an issue with the calliper alignment, that is, not sitting centrally relative to the disc.
Author:  Diceman [ Thu May 15, 2008 5:42 pm ]
Post subject: 
You are correct nigel, I hope to provide an update soon.

I went out to buy some new pads to test fit and came back with a car! Hence have had my hands full trying to ensure the driveway is not full!

Give me a week or 2 and I hope to have some more info.
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