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 Post subject: Brake Upgrade
PostPosted: Tue Apr 27, 2021 7:02 pm 
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Clubman

Joined: Sat May 18, 2019 9:39 pm
Posts: 58
Location: Herefordshire
Car Model: ST185 CS/RC
I'd like to improve the brakes on the ST185 RC just to make it safer for road use and be able to stop quickly in an emergency(my diesel Audi A3 stops in about half the distance).
There's not much recent info in the arcive so I'd appreciate any guidance about which way to go for under £1000.
My preference would be to fit ST205 set up front and rear but I believe the fronts aren't a direct fit due the discs fouling the upright.
Is there an adaptor/spacer available to overcome this or an alternative disc size?
Are the ST205 brakes significently better then the 185?.
I've found a company called Freaky Parts who offer two front kits for around £800. One is Willwood caliper based and the other is Brembo/Renault.
Does anyone have experience with this company and/or these kits?.
Thanks


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 Post subject: Re: Brake Upgrade
PostPosted: Tue Apr 27, 2021 9:01 pm 
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Joined: Wed Jul 13, 2005 12:14 am
Posts: 3265
Location: Camberley, Surrey
Car Model: ST205
The ST205 brakes are a huge upgrade from the ST185. The ST185 uses a twin or single pot sliding caliper with a 200 and something disc at the front and a single pot sliding caliper at the rear. The ST205 uses a 4 piston alloy caliper at the front and a 2 piston at the rear with 315mm discs.

However the ST205 setup is not easily transplantable to the ST185 and most people would go for a kit of some type. Something to think about maybe, if you are just wanting to make the car safer for general road use and for an emergency stop then I'd have to question whether it is worth taking the time and money. The brakes are poor but should easily be able to lock the wheels during an emergency stop, if the braking distance is excessive then I would be looking at discs, a higher quality pad, better tyres, change brake fluid and are the calipers in good condition. If you are looking at fast road use and are going to be leaning on the brakes a bit then fair enough look at the kits. The other point is that modern cars have more powerful assistance to the brakes, are you properly burying the pedal in the 185?

Hope that gives you some things to consider. :)

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 Post subject: Re: Brake Upgrade
PostPosted: Wed Apr 28, 2021 12:06 pm 
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Clubman

Joined: Sat May 18, 2019 9:39 pm
Posts: 58
Location: Herefordshire
Car Model: ST185 CS/RC
Thanks Sirius.
The current set up is EBC grooved discs and yellow pads, calipers are single pot in good condition and just replaced the fluid. Tyres are 225/45-18 Toyo so probably about as good as it can be for the standard brakes.
I can lock the brakes if I stand on them but they don't inspire confidence, it's that phase between initial breaking and locking up where they're not very good but I know what you mean about modern cars assistance, if I jump in the Audi after the Celica I nearly hit the windscreen the first time I touch the pedal.
Good to know that the ST205 brakes are a big improvement and I'd like to pursue that so would appreciate input on fitting from anyone or any other recommendations.


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 Post subject: Re: Brake Upgrade
PostPosted: Wed Apr 28, 2021 9:24 pm 
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Joined: Sat Sep 02, 2006 3:13 pm
Posts: 3679
Location: Bournemouth
Car Model: None
Puzzled what happened to the reply I spent ages typing last night. Must have failed to post for some reason.

205 rear is a near straight swap. The difference is that the spiggot diameter is 0.5mm bigger on the 205. This means the disk isn't held quite central. The solution is a thin strip of shim metal inserted between the disk inner and the hub spiggot. It's held in place by the wheels once re-fitted.

205 front would be a straight swap except the lower swivel is in the way. Common solutions are audi TT disks and spacer plates for 185 calipers or various spacers on original 205 disks and calipers which leave the front wheels further out. None of these are especially good, I suspect a proper aftermarket solution may be better.

Beware upgrading the front with something which requires less pedal effort. The upshot is that bias will be shifted to the front meaning less assistance from the back at the point of front lockup, meaning less braking overall. False confidence comes from the reduced pedal effort hence all the positive reviews.

Unless you suffer brake fade, I don't see a need to upgrade the front to larger. Braking is limited by tyre grip provided the brakes are capable of getting to the grip limits. from experience, the standard 185 is capable of 2 or 3 hard stops in quick succession row from legal (motorway) speed. Competition pads and dot 5.1 brake fluid will improve this significantly.

I've heard good reports of freaky parts but no personal experience.

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 Post subject: Re: Brake Upgrade
PostPosted: Sun May 02, 2021 6:28 pm 
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Clubman

Joined: Sat May 18, 2019 9:39 pm
Posts: 58
Location: Herefordshire
Car Model: ST185 CS/RC
Thanks for your input Chris.
So the 205 front discs and calipers need to be spaced out by an unknown amount in order to fit. Alternatively brake discs with a smaller "top hat" dimension could give clearance but again this is an unknown measurement.
By fitting an aftermarket kit with four pot calipers plus the 205 rear discs and calipers would the 185 master cylinder be adequate or would it need the 205 cylinder?

Has anyone used Subaru discs and calipers as there re plenty around for reasonable money and they use the same 5x100 bolt pattern?


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 Post subject: Re: Brake Upgrade
PostPosted: Sun May 02, 2021 11:04 pm 
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Joined: Sat Sep 02, 2006 3:13 pm
Posts: 3679
Location: Bournemouth
Car Model: None
The fundamental problem is that the lower swivel is so far out there is only room for a very shallow disk which doesn't really leave room for cylinders on the wheel side without running wheel spacing.
AFAIK the 205 disk / caliper conversion effectively runs the calipers on the other side of the mounting to space it out then runns a spacer of this width under the disk (probably about 20mm at a guess). I haven't actually seen one to confirm.
The TT disk conversion is a shallower disk so no spacers, but there isn't room for cylinders on the wheel side hence using the original 185 calipers which use a sliding caliper. The fact the calipers were made for a smaller disk means a plate to move them outwards as well as adjust for spacing. I have a kit for this but not fitted it yet, I can measure if it helps.
I don't know the details of the aftermarket kits, but I don't see how they can put cylinders on the wheel side without spacers unless they're very short which would bring another set of problems.

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 Post subject: Re: Brake Upgrade
PostPosted: Tue May 04, 2021 6:17 pm 
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Clubman

Joined: Sat May 18, 2019 9:39 pm
Posts: 58
Location: Herefordshire
Car Model: ST185 CS/RC
I don't want to space the wheel out at all as it's flush with the wheel arch so the 205 discs wouldn't work. Interested in the brackets for the tt disc conversion but ideally I'd like a four pot caliper with greater pad area. My car has 8x18 OZ rims so there's more space for a bigger caliper.
I've contacted Freaky parts for more info so see what they come back with.


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 Post subject: Re: Brake Upgrade
PostPosted: Fri Sep 03, 2021 9:36 pm 
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Joined: Tue Aug 27, 2019 10:41 pm
Posts: 28
Location: Gloucestershire
Car Model: ST185 CS/RC
I have only just seen this topic, so where have you got to with your decision-making?
My CS had a brake upgrade 2-3 years ago (so would have been on the car when we saw you at the last Rally Day at CC). We went down the route of using the ST205 brakes because we usually do the Gen 5 N Wales rally drive every year where there are plenty of mountainous routes and good brakes a bonus!


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 Post subject: Re: Brake Upgrade
PostPosted: Mon Sep 06, 2021 3:58 pm 
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Clubman

Joined: Sat May 18, 2019 9:39 pm
Posts: 58
Location: Herefordshire
Car Model: ST185 CS/RC
I didn't get any recommendations for the upgrades I listed and not much info from the companies selling them so I spent the money on a guitar instead.
I'll take a look at yours at Rally Day to see how much the wheels need spacing out as it's something I'd like to do at some point.
Look forward to meeting up again on the 25th.


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