Bigger Calipers, help needed

[JayDawg]

Hopefully there is someone who knows what they are talking about when it comes to brakes and can help me out with fitting bigger calipers- or tell me I'm been stupid.
The old man has a 3rd gen Focus RS (as most middle aged men who suddenly think they're street racers seem to) and has had a load of work done including bigger brakes.

As a result, there's now a pretty pair of Brembo twin pot calipers sitting here that I can have for free if I wanted.
In my head, surely Brembo don't make different calipers for every single vehicle that they are fitted to so my question is: Other than the usual thing like wheel clearances, can I just get some form of adaptors and the right sized disks that fit, or would they not really be suitable and/or it take too much to try and get them to fit that it wouldn't be worth bothering.

Apologies if this is a really naive question but I've never messed about with brakes much so thought I might aswell find out.

 

[Random Dan]

You would be surprised how many variations of brembos there are.

To the great question of 'Will it fit?'
Anything can be made to fit but if there isnt an off the shelf solution it is going to need an amount of R&D.

Julian did make a post some time ago about modding the FD front hubs to suit evo 6-9 calipers to fit.
The mods are fairly straight forward but they do need a fairly aggressive style/fit of wheel to clear.

 

[jdmr_neil]

Sure you can make some adaptors to fit them up, it will depend on where they sit in relation to the disc.

Oem mazda are twinpots anyway

 

[Nite_Shayde]

The question is how much bigger the pistons in those calipers are compared to the OEM Mazda ones. 4 pot, 6 pot, etc don't really mean much by themselves.

There are two types of OEM caliper - one (Type R/RB) uses pistons which are all 36.1mm in diameter, and the other (Type RS) uses two 33.9mm and 38.1mm pistons in a staggered configuration. The overall piston area is more or less identical for both though.

Almost any caliper can be adapted for use on any hub/car, but of course it has to be a worthwhile upgrade to warrant the hassle. Know though that it is easier and often cheaper to adapt radial mount calipers as opposed to axial mount calipers, since the bracket can be adjusted with relative ease during the development stage. In some cases, axial may not work at all as it might be impossible to find a position that the lug holes and caliper holes can work together. After a very quick google, it looks like the Focus RS calipers are axial mount. Axial mount calipers are also supposedly more prone to flex. Most BBKs and high end calipers are radial mount, but I think it only really matters if you are doing hard driving on a track.

If the pistons are indeed bigger, then it may be worthwhile. A company like Reyland or BG Developments could fabricate the adapters and bells you would need to get them to fit, but as above, they may not work at all.

 

[Gavzzorz]

i believe Evo 8 front calipers have the same bolt pattern but need different disks

 

[JayDawg]

Thanks guys, my thinking behind it was that they were bigger pistons but to be honest I think it’s going to be too involved to make it worthwhile if it does work.
I don’t want to end up with ‘bodged’ brakes and by the time I’ve paid for people to do it all the fabrication etc for me, I don’t think it wouldn’t be worth while.

 

[Calum122]

Surprised no one has mentioned this, but in some cases it's not enough to merely swap out the brakes, you need the appropriate sized master cylinder to displace the right amount of fluid to the brakes.

 

[Nite_Shayde]

In most cases the 929 master cylinder upgrade will do the trick.