Custom Sierra 4×4 Uprights Part 2

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Outlaw Calliper
A while back, I’d bought some super light weight billet Outlaw aluminium callipers (Wilwood copies). At the time I didn’t have the front discs to check them against so they were just put under the bench. When the Granada 278mm front discs arrived, I soon saw that these callipers were designed for much smaller discs (I’m guessing 210 – 230mm).

Haynes Roadster Big Brakes

I do not intend to use use Sierra front uprights and have already spent several hours on the lathe making new uprights. Making custom uprights gives me complete freedom to use any callipers I like. I could use this opportunity to add some huge brakes. This is not a DIY Sierra brake upgrade, more of a complete re-think. I therefore looked for some cheap 4 pot callipers.

A set of W220 Mercedes callipers came up for less than £25 (inc. delivery). Many people use 4 pot E38 7 series BMW callipers, but these seem to fetch a real premium (more than new Wilwoods). These worked out less than £7 each (before I rebuild them). W220 Callipers

They were very tatty, but under the rough paint job, they were in surprisingly good condition and probably rebuilt. The Mercedes / Brembo callipers are designed for 300 to 330mm discs (24-30mm thick).

Granada 278mm Discs

I have offered them up to the Granada discs and the pads cover the whole breaking surface millimetre perfect, however it is clear from the curvature of the pad, they are designed for bigger discs (roughly 300mm). Despite being quite large, being 50% aluminium are roughly the same weight as the Granada single pot sliding items.

There would be no way you could make an adaptor plate up and use these with Sierra Uprights but for what I was doing they seem surprisingly good. Granada Discs with Mercedes W220 pad Granada Disc with Mercedes W220 pad

I am tempted to use them with my Granada discs. I briefly started to strip the paint. – more to keep my hands clean than to make them look good. Granada Disc with Mercedes W220 caliper

A while back, I acquired some knackered Porsche 330mm 32mm thick discs from a 4×4 Cayenne. Trust me, when I say they are blooming heavy. I threw them straight out. Way too heavy for anything other than a heavy weight 4×4. I reckon one disc weighed roughly the same a whole set of Ford Sierra Cosworth items. The 312mm x 24mm discs on my Seat Cupra are substantially lighter.

I didn’t want to go as big as the Cayenne or top of the range Mercedes items.

Mondeo 300mm Discs

Problem…  Mercedes use the same 5×112 bolt pattern as my Granada 4×4 front hubs but the central hole is much bigger. 67mm (Mercedes) vs 63.5mm (Granada) My plans might change, but currently I am going to use Mondeo ST220 / Jaguar X type items (£17 each – new) and machine them with a second set of bolt fixings. The Mondeo items are 300mm x 24mm thick and have a 63.5 central hole. They aren’t going to be super-light but they should be considerably lighter than the Porsche items.

If I was building a 600Kg racer, then this upgrade would be somewhat ridiculous. I’m not….
My project will get a fully enclosed body and detailed interior. Roughly 20% heavier than a standard Locost / Haynes Roadster.

There’s lots going on in my head at the moment and I change my mind every ten minutes on how I am going to construct the front uprights.

I have swapped the rack from a front mounted MK2 Escort item to rear mounted Citroen BX item and as a result I’m having quite a few Ackermann angle issues. Throw in new discs and new callipers and designs change almost on a minutely basis. This is the latest version (by the time you read, it will have changed again).

Custom Sierra 4×4 Uprights CAD

Custom Sierra 4x4 Uprights - Steel

It’s hard to tell from the CAD but the steering arm is detachable. The mounts are the same spacing as the Mercedes W220 Callipers. This means that I could make 2 identical Custom Sierra 4×4 Uprights and by attaching different steering arms swap them from one side of the car to the other.

The CAD model shows the uprights without boxing. I will bend some 3mm steel plate to fill the gaps. The central portion will end up extremely similar to Sierra items. Steel Custom Sierra 4x4 Uprights

The front 2 lugs are for the calliper and the rear for the steering arm.

Having the steering arm detachable also enables me to add spacers (green) should I need to increase or decrease the Ackermann angle. Steel Custom Sierra 4x4 Uprights

The new upright design also cures the problem I was having with clearance on bottom ball joints nut. I’ll now have a perfectly tapered reamed hole for my Austin Princess ball joints.

Making Custom Sierra 4×4 Uprights

I had some EN3B steel from a ‘job lot’, it seemed to machine and weld nicely so I have used it to make some new bearing housings. The dimensions were taken from standard Sierra Cosworth 4×4 uprights. The wall thickness seems a little thin but is in fact exactly the same as what Ford designed. EN3B Hub

The walls are 6mm thick, which seems a little thin but by the time I add the remaining metalwork, they should be as strong as the Ford cast items. If I were to start again I’d go for around 12mm walls. The bearing surface is currently under sized and just quickly smoothed with wet ‘n’ dry. I did this purely to see the finish I could get rather than getting clearances spot on. It will all need doing properly once welding is completed.

Making Custom Sierra 4×4 Uprights isn’t going to be quick, so I started to make a jig. I only want to do it once.

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