Ford Focus ST Forum banner

Project Frankenbrake - Larger rear brakes on a budget!

202607 Views 519 Replies 108 Participants Last post by  STallion18
***EDIT***

You can now use the RS rear rotor for the Frankenbrake. The RS rotor has the proper wheel stud hole diameter
compared to the Volvo's larger wheel stud diameter.



I was asked to make this more of a how to.

So you upgraded your 320mm front rotors to the 332mm, but what about the rear? What if you could upgrade your rotors from a 271mm to 302mm for just for as little as $220 and retain the factory caliper? Well you can and this is how.

Rotors for a 2008-10 Volvo V70 share the same bolt pattern (108x5) and dimensions as the ST and are available in plain to slotted from EBC and StopTech. Mazda uses the 114x5 bolt pattern

ST
Disc brake Vehicle brake Auto part Automotive brake part Steel


V70
Disc brake Auto part Vehicle brake Product Clutch part


Source some pre 2008.5 Mazda 5 rear caliper brackets. I used the part number in the photo. dealer want $108ea, parts.com wants $75, if you can find them used you could probably get the set $25.



Auto part


Tools needed.

Tire Automotive tire Vehicle Auto part Wheel


I'm assuming you already know how to lift your car and remove the wheel. Give the brake assembly a good dousing with brake cleaner. Leave your parking brake down and remove the parking brake cable from the caliper. Remove the caliper spring. Remove the caps covering the guide pins. You need a 7mm L Allen key to remove the guide pins. Pull the caliper off setting it to the side. Support it don't let it hang on the brake line. Remove the pads

Use a 13mm wrench to remove the bolts securing the bracket to the knuckle. These bolts are going to be tight. If you don't have a cheater, link two wrenches together.

Tool Metalworking hand tool Adjustable spanner Metal Cutting tool


Pull the rotor off the hub. If it's stuck lightly tap with the mallet.

Clean and wipe everything down. Use a caliper reset tool with the M adapter to reset the piston into the caliper.

Wipe down and install the V70 rotor. Thread on a lug nut on to hold the rotor in place.

Install the Mazda bracket reusing the bolts. Install the pads onto the bracket. Replace them if the near the ending their life. Use brake grease on the contact points.

Install the caliper over the pads and reinstall the guide pins. Reattach the caliper spring, and parking brake cable.

Put the wheel back on.

Congrats, now go do the other side!

Don't forget to pump your brakes before you take off and bed the pads.
Auto part Disc brake Vehicle brake Rotor Wheel


Alloy wheel Tire Rim Wheel Automotive tire


Their may be other years or model vehicles the use the same parts but the ones listed are what I used.

Size comparison

Auto part Rotor Vehicle brake Rim Disc brake

Attachments

See less See more
10
  • Like
Reactions: 5
1 - 20 of 520 Posts
It's similar to what the Speed 3 guys do for a inexpensive upgrade. Moving the caliper farther out will provide more torque and help balance out the brake bias, at least that's the plan. Mazdas have a different bolt pattern than Ford but Volvo has the same bolt pattern. So I'll be using a Volvo rotor and a Mazda bracket.

I got some schooling from Todd on braking and help from Alex for part selection.

Researching has shown me the the ST has a somewhat unique rotor size. similar sized cars have a 280mm and the heavier cars have a 302.
  • Like
Reactions: 2
Success!

Auto part Disc brake Vehicle brake Rotor Wheel


Alloy wheel Tire Rim Wheel Automotive tire


2010 Volvo V70 302mm rotor vs the ST 271mm. The Speed 3 gets a 280mm and uses the same caliper.

Auto part Rotor Vehicle brake Rim Disc brake


2008 Mazdza 5 bracket. Parts.com for $75, Mazda wants $108.



Brake tool for resetting the rear piston

Text Label Font Technology Electronic device


Thanks Alex for suggesting the proper bracket.
See less See more
5
  • Like
Reactions: 5
That's all one needs? The volvo rotor and the caliper bracket??

If so, I'm all over this. Thank you for sharing!!
  • Like
Reactions: 1
That's all one needs? The volvo rotor and the caliper bracket??

If so, I'm all over this. Thank you for sharing!!

Yup, that's it.
  • Like
Reactions: 1
I bought budget rotors because I wasn't 100% this was going to work. Slotted rotors should be available.

Disc brake Auto part Vehicle brake Product Wheel


Door handle Auto part Automotive exterior Hardware accessory


Disc brake Auto part Vehicle brake Wheel Brake


Might as well get some SS lines from TCE to finish it off while you're there.
See less See more
3
So, Kevin, I assume your track time has lead you to want to change the break bias? When is your next track day so you can report back on the results?
  • Like
Reactions: 1
So, Kevin, I assume your track time has lead you to want to change the break bias? When is your next track day so you can report back on the results?
March 21. My braking points will probably have a significant change.

This what I did to the front a few weeks ago.

Auto part Disc brake Vehicle brake Brake Rotor


This was to help equal it out. Speaking with @[email protected] the ecu might learn to adjust the bias. I don't want to put words in his mouth so maybe he could comment on that further.
See less See more
  • Like
Reactions: 2
Awesome - had a feeling this would work out! Glad it did Kevin!

The car has EBFD and I am not sure how much of it is learned but it definitely uses it as part of stability control and ABS.
  • Like
Reactions: 2
Awesome - had a feeling this would work out! Glad it did Kevin!
Thanks again for your help.
  • Like
Reactions: 1
word
  • Like
Reactions: 1
Just verifying, this still retains use the factory handbrake?
Awesome - had a feeling this would work out! Glad it did Kevin!

The car has EBFD and I am not sure how much of it is learned but it definitely uses it as part of stability control and ABS.
So if the car does relearn this what does that mean for this upgrade?
Just verifying, this still retains use the factory handbrake?
Yes
  • Like
Reactions: 1
So if the car does relearn this what does that mean for this upgrade?
You get more torque while still using the same caliper and pad. the larger mass of the rotor will dissipate heat better.
  • Like
Reactions: 1
Do you have any pictures of the Brackets side by side to compare the stock and the upgrade? I like the idea of keeping the factory look in the rear just larger rotors.
very cool, nice write-up
  • Like
Reactions: 1
Do you have any pictures of the Brackets side by side to compare the stock and the upgrade? I like the idea of keeping the factory look in the rear just larger rotors.
I forgot to take some but this a pic of a Mazda 5 bracket next to a Speed 3, they all look the similar

Auto part Automotive exhaust


The Speed 3 it taller than the ST
See less See more
  • Like
Reactions: 1
1 - 20 of 520 Posts
Top