Uprating Sierra XR4i 1984 brakes

Uprating Sierra XR4i 1984 brakes

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Richleigh

Original Poster:

11 posts

143 months

Sunday 20th March 2016
quotequote all
Hi All, I have a nice Sierra XR4i, 1984. I'm having the rear end converted from drum to disc, easy so far..... I want to keep the RS seven spoke (15in)which are from mk3 escort/RS era which means they are ET35. I have tried the Mondeo caliper AND Cosworth 2wd options and due to the alloys (which I want to keep) these will not work. The question is has anyone used anything else? Has anyone used aftermarket calipers (for sierra mind?) eg-WMS or Wilwood?? Any help wood be really good, many thanks! Rich

LanceRS

2,182 posts

144 months

Sunday 27th March 2016
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What is catching and where? The Cosworths used 15" wheels, so there should be clearance. Also the 2wd had solid discs and the 4wd had vented with the appropriate calipers.

Richleigh

Original Poster:

11 posts

143 months

Sunday 27th March 2016
quotequote all
Hi LancRS, I have since got a little more info. Basically the 7spoke RS turbo alloys 6x15 are fouling the calipers. I'm told their shape internally doesn't allow for the larger Mondeo caliper, which is a fairly new mod' that folks are using. Any thoughts on upgrading to any other caliper that might fit? If not it's a case of going to the caliper manufacturers to see who makes what to fit? (want better brakes!) Does the sierra 4x4 have better brakes than the standard XR4i do you think?

LanceRS

2,182 posts

144 months

Sunday 27th March 2016
quotequote all
The XR 4x4 also uses rear discs that fitted behind the standard 14" seven spokes. If you can manage to find the back end of one or a Cosworth, it should fit. I'm guessing that the Mondeo thing might be due to a shortage of the older parts. There weren't all that plentiful 20 years ago when I bought mine and the last set of rear calipers for the Cosworth was over 15 years ago.

Richleigh

Original Poster:

11 posts

143 months

Monday 28th March 2016
quotequote all
Hi, Yea I have the rear disc end going in, so that's an improvement I'm looking forward to. It's the front end that's now the problem. Yea Mondeo thing came out of the blue to me also, but it seems due to the alloy choice it wont work (the inside catches on the caliper) Going to go the 4 pot route with a company called HI-SPEC who hopefully will provide me with their compact unit that should help to stop the car pronto!

LanceRS

2,182 posts

144 months

Monday 28th March 2016
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It might be worth considering a set of eibach or similar spacers for the wheels, I'm guessing the calipers are only just catching?

Richleigh

Original Poster:

11 posts

143 months

Tuesday 29th March 2016
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Spoke to Hi-Spec caliper company today, they will email specs etc for their 4 pot caliper kit, fingers crossed.....

Stevenr

915 posts

201 months

Tuesday 29th March 2016
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Any photos of your car with the Escort wheels on it?
Just curious how they look on a Sierra.

Richleigh

Original Poster:

11 posts

143 months

Wednesday 30th March 2016
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They are the RS turbo / RS1600i alloys

s p a c e m a n

10,997 posts

155 months

Wednesday 30th March 2016
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Can't you just slap on a set of 5mm spacers all round, or is that cheating?

Richleigh

Original Poster:

11 posts

143 months

Wednesday 30th March 2016
quotequote all
Hi Spaceman, would love it to be that simple! The calipers foul to the tune of 15mm ish if a spacer is used on the fronts then it will push the wheel out too far and the tyres will rub. Hence the issue and faff :-)

s p a c e m a n

10,997 posts

155 months

Wednesday 30th March 2016
quotequote all
I'm on my phone and the pistonheads search function isn't the easiest but I know that there have been many questions asked of keri from wms regarding chimaera brake conversions, ie... http://www.pistonheads.com/gassing/topic.asp?h=0&a... so maybe a google in that direction may prove fruitful for dimensions as I think they're the same hubs.

Richleigh

Original Poster:

11 posts

143 months

Wednesday 30th March 2016
quotequote all
Thanks Spaceman, it's all good info. I did find WMS a few weeks back and emailed him, I have done so again tonight and hope he picks up my email this time.....

s m

23,510 posts

210 months

Sunday 3rd April 2016
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Richleigh said:
Hi All, I have a nice Sierra XR4i, 1984. I'm having the rear end converted from drum to disc, easy so far..... I want to keep the RS seven spoke (15in)which are from mk3 escort/RS era which means they are ET35. I have tried the Mondeo caliper AND Cosworth 2wd options and due to the alloys (which I want to keep) these will not work. The question is has anyone used anything else? Has anyone used aftermarket calipers (for sierra mind?) eg-WMS or Wilwood?? Any help wood be really good, many thanks! Rich
Hi Richleigh,

I had an XR4i for several years and did quite a few mods. I think you'll need some type of Cosworth-used 15" wheel if you want to stick with standard Ford alloys in 15", either that or look for a later Ford model that came with bigger brakes. The Rwd Cossie calipers are 4-pot fixed and may be a bit bulkier than some of the single pot slider designs. I had the 3-door Cosworth set up on my 4i ( along with the hubs ( different roll centre ) and uprights ) and I ended up using the 2wd lattice alloys off the 4-door rwd to get it all to fit



I also took the opportunity to put on the Ford H14 ARB from the Sapphire ( this was a factory mod for the 3-dr cars ( standard on the RS500 ) if owners complained about high speed straight line stability ) to give more dynamic camber on turn-in. I didn't have the Cosworth rack so the only issue I had was slight rubbing on full lock ( when parking ) because of the extra caster and wider tyres and not having the lock limiters

Later on I went to an even bigger front set-up, Wilwood 4-pot calipers/Hawk pads with 2-piece discs 305mm - Hi spec made me up some brackets to fit these but I had to use 16" alloys ( Momo ) to fit over the brakes. I think I had to use slightly longer wheel studs as well which are quite cheap and easy on Fords ( got them from Demon Tweeks ).

You can't really see the setup in this photo but you may be able to see the bells and discs - sadly I've lost most of the 35mm pics I had of the conversion




I don't think I could have got much bigger discs on it without going up an inch in wheel diameter to 17" alloys unless I could have got some alloys with more clearance for the calipers/stick on wheel weights on inside of rim.

Also changed the back end to an XR4x4 set-up to get the rear discs, thicker ARB and LSD ( I recommend Bara Motorsport to upgrade/re-rate the rear diff )

Just a thought, if you want to use the std Rwd Cosworth set up and have the RS alloy look, have you thought about a set of RS 16" alloys? I'm not definite they'll fit but sets do come up reasonably often as people usually want the 17s You'll probably offset some of the cost by selling your existing ones

http://www.ebay.co.uk/itm/Ford-RS7-16-cosworth-whe...

You can usually pick up rough spares reasonably cheap as well still

https://www.ebay.co.uk/ulk/itm/301912225059

I've used 17s on Sierras but imho the 3-door road shells are too flexy for wheels this big and a bit of sidewall makes the handling much nicer on roads with bumps in them

Only issue with 16s might be tyre choice

Richleigh

Original Poster:

11 posts

143 months

Sunday 3rd April 2016
quotequote all
Hi SM, thanks very much for your info. I have been aware of some of the points you talk about, not all, in fact it will all help to either confirm or complete some gaps. Again thanks.