Jump to content
Monty_CZ

front brakes upgrade

Recommended Posts

If I want to upgrade from 240 mm vented front brakes to 260mm do I only need discs, callipers and pads? Hubs are the same?

Share this post


Link to post
Share on other sites

Yes, the hubs are the same. If you're not counting them as part of the calipers, you need the caliper mounting brackets as well.

Share this post


Link to post
Share on other sites

Be aware that these are solid disks not vented.

Share this post


Link to post
Share on other sites

Is the weight a big issue? If not, why don't you use Mondeo Mk3 Calipers and Focus ST170 300mm discs. Bear in mind you might also need to change master cylinder if you fit bigger calipers.

Share this post


Link to post
Share on other sites

well spotted that these are for the rear probably. Does anyonw know what kit should fit on the front? 

https://www.rallydesign.co.uk/product_info.php?products_id=3940

I do not know if the bracket would fit.

Or does standard 260mm sierra front brakes with mintex 1144 pad withstand track use?  

Share this post


Link to post
Share on other sites

thank you very much. This is exactly what I was looking for but did not found it.

If this is a sierra kit I suppose that it should work with standard master cylinder and sierra rear disc brakes, right?

Share this post


Link to post
Share on other sites

I would ask them for the piston diameters and then compare total piston area to that of a standard caliper... I have a spreadsheet for working out brake changes/ratios :)

if you look here http://www.rallydesign.co.uk/product_info.php?products_id=8317 that caliper is available is 5 bore sizes : 44.5, 41.1, 38.1, 35.1, 31.8mm

The smallest piston size of 31.8mm still gives you a noticeable difference in caliper piston area; 2290mm^2 old versus 3177mm^2 new, so you'll have increased pressure at the pad but at the sacrifice of increased pedal travel. Depends how you are with the current pedal effort/travel. By my reckoning, if you were happy with it as-is then moving to these calipers you'd want a 23.5mm master cylinder to keep the pedal effort/travel the same.

Or fiddle with pedal ratios of course :)

 

Share this post


Link to post
Share on other sites

but standard sierra caliper is floating, so you have to multiply the area by 2. At leaset it is what they say here: http://brakepower.com/help_abc_27_PAC_t.htm

According the calculation it will be probably 41,1 diameter of piston on fixed wilwood caliper (5304.12 mm^2). This should be  to be similar with sierra floating caliper with 60mm piston (5652 mm^2).

I will e-mail them what piston diameter it is.

 

 

Share this post


Link to post
Share on other sites
14 minutes ago, Monty_CZ said:

but standard sierra caliper is floating, so you have to multiply the area by 2. At leaset it is what they say here: http://brakepower.com/help_abc_27_PAC_t.htm

According the calculation it will be probably 41,1 diameter of piston on fixed wilwood caliper (5304.12 mm^2). This should be  to be similar with sierra floating caliper with 60mm piston (5652 mm^2).

I will e-mail them what piston diameter it is.

Ah yes, this is true, if you're comparing all 4 of the pistons then you should multiply the floating caliper result by 2. This is because the piston is only moving half as far to exert pressure on both sides of the caliper (it sort of has a built-in mechanical ratio of 2:1. My mistake.

Still what is your existing caliper size, 60mm seems very large? That's the Cosworth brakes, right? The 280mm discs?

Share this post


Link to post
Share on other sites

my current front brakes are from non abs sierra - so 54mm piston and floating calipers with 240 mm brake disc. Rear brakes are sierra disc brakes 253 mm with standard sierra floating calipers 43mm piston.

Brake master cylinder is from ford ka 20,6 mm. 

If I want to upgrade I can buy these wilwood callipers and they should be same as ABS sierra brakes which are 60mm piston floating caliper with 260mm brake disc. 
With this upgraded setup it should not be overbraked at the rear compared what I have now (even though I am using adjustable proportioning valve for the rear). 

My thinking was that I can buy standard sierra 260mm brakes or I can buy this wilwood brakes.

 

Edited by Monty_CZ

Share this post


Link to post
Share on other sites

Ah ok with you. Ignoring the rear brakes for now, a 41.1mm in the new will give you a slightly higher ratio of m/c to caliper, but you knew that - so expect slightly more travel but more bite for a given pedal pressure. So as long as you're not running out of travel right now, you'd be fine.

As to whether it's worth 4-pots over the standard sliding piston... this is always an emotive decision. Personally I don't see the point on cars weighing as little as ours (my car is perfectly capable of locking itself up on standard 260mm Sierra brakes!) unless you're after better fade performance, but then you can achieve that with discs and/or pad material. Saving on unsprung mass, maybe?

Most of the time I think it's just because people want the bragging rights of 4 pot calipers :) which is fair enough, if that's what people want.

  • Like 1

Share this post


Link to post
Share on other sites
On 10/22/2019 at 12:17 PM, richyb66 said:

Is the weight a big issue? If not, why don't you use Mondeo Mk3 Calipers and Focus ST170 300mm discs. Bear in mind you might also need to change master cylinder if you fit bigger calipers.

Sorry to jump in on this, my apologies....richyb66 didn't you do a piece in the mag a couple of years ago on the above.....Did you stick with a 22mm master cylinder without servo. How did this work out on your car?....Once again my apologies for breaking into your thread....

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...