Wilwood brakes

[Dialcaliper]

So would you say that the front Wilwood big brake kit and the rear ST170 280mm set up will provide the best brake balance?
The problem is that I’ve bought the Wilwood rear brakes now and will lose a bit of money if I return them. I would keep them, but if the standard rear hubs are inferior or weaker than the ST rear hubs then I don’t really want to be changing them over.

It’s honestly hard too say - the Wilwood front kit actually has too much piston area compared to the OEM calipers (4.04 in^2 compared to stock 3.54 in^2), which moves brake bias way forward especially with the larger front rotors. You’re increasing front by almost 30%, So you need to do *something* in the rear or you’ll be underutilizing the rear brakes.

For reference, the stock bias with 278/253 rotors and 54/34mm pistons is 73% F, 27% rear. With the wilwoods up front only, that makes 78% front, 22% rear, which likely leaves a bit of rear grip on the table.

It’s not as big a problem with modern ABS regulated proportioning but with that much front bias, you’ll have grabby brakes that feel good and handle heat well, but if you go to the track actually have lower peak/threshold braking before the ABS kicks in (basicallly means longer stopping distance). The reason is that front tires only have so much grip, and if there’s still any weight on the rear axle, there’s extra braking grip that’s just not being used.

The rear wilwood kit uses the same as OEM piston diameter on a 300mm rotor, so while you probably won’t have any issues, (and it will probably make up for the front piston diameter)

Looking at the diagrams, the issue I’m seeing is that the Wilwood kit is designed not just for the drum hubs, but also for the drum rear torsion beam.

The difference in the service manual is that the disc hubs bolt on from the inside (threaded holes on the hub), and the drum type actually bolt in from the outside (threads on the torsion beam flange. The Wilwood bracket bolts onto the exterior of the hub, where there’s no bolt head on the disc version.

That said, I think you *can* make it work from what I see in the Wilwood diagram. What you’ll have to do is get some drum hubs, and get long enough bolts to put a bolt, washer and nut through the flanges to hold the hub and Wilwood bracket in place. Hopefully the longer bolts can actually fit behind the hub, or you’ll have to get creative.

Keep in mind this gets into custom DIY/race car parts modification kind of territory, so if you’re going to do it, make sure you are comfortable and know what you’re doing as you’ll be mounting not just the brake caliper, but also the hub (that holds the wheel on) in a way that is different from the both the Ford factory and Wilwood kit design.

The OEM bolting method uses torque-to-yield 10.9 bolts, so at a minimum you’ll need too locate appropriate class 12.9 bolts, nuts *and* washers, or better yet, ARP bolts, nuts and washers. Also you’ll have to determine the correct torque value to use, as you cannot blindly use the factory torque-to-yield method on class 12+ hardware.

If it sounds a little sketchy and out of your comfort zone, I would not do it. I’m trying to strike a balance in advice here between “go custom!” and “realize you’re trusting your life to this DIY solution”. Don’t just take my instructions blindly.

The “safer” option would be the SVT/ST180 brackets and rotor, which will would be fine.

 

[Rhys1983]

Thank

It’s honestly hard too say - the Wilwood front kit actually has too much piston area compared to the OEM calipers (4.04 in^2 compared to stock 3.54 in^2), which moves brake bias way forward especially with the larger front rotors. You’re increasing front by almost 30%, So you need to do *something* in the rear or you’ll be underutilizing the rear brakes.

For reference, the stock bias with 278/253 rotors and 54/34mm pistons is 73% F, 27% rear. With the wilwoods up front only, that makes 78% front, 22% rear, which likely leaves a bit of rear grip on the table.

It’s not as big a problem with modern ABS regulated proportioning but with that much front bias, you’ll have grabby brakes that feel good and handle heat well, but if you go to the track actually have lower peak/threshold braking before the ABS kicks in (basicallly means longer stopping distance). The reason is that front tires only have so much grip, and if there’s still any weight on the rear axle, there’s extra braking grip that’s just not being used.

The rear wilwood kit uses the same as OEM piston diameter on a 300mm rotor, so while you probably won’t have any issues, (and it will probably make up for the front piston diameter)

Looking at the diagrams, the issue I’m seeing is that the Wilwood kit is designed not just for the drum hubs, but also for the drum rear torsion beam.

The difference in the service manual is that the disc hubs bolt on from the inside (threaded holes on the hub), and the drum type actually bolt in from the outside (threads on the torsion beam flange. The Wilwood bracket bolts onto the exterior of the hub, where there’s no bolt head on the disc version.

That said, I think you *can* make it work from what I see in the Wilwood diagram. What you’ll have to do is get some drum hubs, and get long enough bolts to put a bolt, washer and nut through the flanges to hold the hub and Wilwood bracket in place. Hopefully the longer bolts can actually fit behind the hub, or you’ll have to get creative.

Keep in mind this gets into custom DIY/race car parts modification kind of territory, so if you’re going to do it, make sure you are comfortable and know what you’re doing as you’ll be mounting not just the brake caliper, but also the hub (that holds the wheel on) in a way that is different from the both the Ford factory and Wilwood kit design.

The OEM bolting method uses torque-to-yield 10.9 bolts, so at a minimum you’ll need too locate appropriate class 12.9 bolts, nuts *and* washers, or better yet, ARP bolts, nuts and washers. Also you’ll have to determine the correct torque value to use, as you cannot blindly use the factory torque-to-yield method on class 12+ hardware.

If it sounds a little sketchy and out of your comfort zone, I would not do it. I’m trying to strike a balance in advice here between “go custom!” and “realize you’re trusting your life to this DIY solution”. Don’t just take my instructions blindly.

The “safer” option would be the SVT/ST180 brackets and rotor, which will would be fine.

Thanks for such a detailed reply. I’m not keen at all on fitting new hubs and a rear beam. It was my fault for not looking into it enough to realise that our cars needed this modification.
I think that the best option going forward for me is to keep the front Wilwood brake kit and then fit the Focus ST170 rear brakes with 280mm discs and fit a good quality fast road/light track brake pads and some braided lines.
This should in theory provide a better balance front to rear without having to mess about with modifications to make the rear Wilwood brake kit fit.
I’ll lose some money sending the Wilwood rear kit back, but the st170 rear brake kit isn’t too expensive as I’ll only need the discs, pads, carrier and braided hoses.

 

[Dialcaliper]

Thank

Thanks for such a detailed reply. I’m not keen at all on fitting new hubs and a rear beam. It was my fault for not looking into it enough to realise that our cars needed this modification.
I think that the best option going forward for me is to keep the front Wilwood brake kit and then fit the Focus ST170 rear brakes with 280mm discs and fit a good quality fast road/light track brake pads and some braided lines.
This should in theory provide a better balance front to rear without having to mess about with modifications to make the rear Wilwood brake kit fit.
I’ll lose some money sending the Wilwood rear kit back, but the st170 rear brake kit isn’t too expensive as I’ll only need the discs, pads, carrier and braided hoses.

Just to clarify the “through bolt” solution I was talking about would be the way to make the drum hubs fit on the ST rear beam. Other than the bolting direction, it seems like the hub/bearing piece is otherwise the same.

That said, the ST170 bracket is a far less involved option involving no “creative” solutions to a safety critical part of the car

 

[M-Sport fan]

The main applications you might actually need something like the wilwood rear upgrade for are either driving around with factory traction control on all the time, or in something like an R4 rally car with a line lock that regularly abuses the rear brakes.

Even the Rally 3 cars (AWD 'kit' added, sequential gearboxes, but factory power levels and bodywork) still use solid rear rotors, but with fixed Alcon calipers.

 

[M-Sport fan]

Thank

Thanks for such a detailed reply. I’m not keen at all on fitting new hubs and a rear beam. It was my fault for not looking into it enough to realise that our cars needed this modification.
I think that the best option going forward for me is to keep the front Wilwood brake kit and then fit the Focus ST170 rear brakes with 280mm discs and fit a good quality fast road/light track brake pads and some braided lines.
This should in theory provide a better balance front to rear without having to mess about with modifications to make the rear Wilwood brake kit fit.
I’ll lose some money sending the Wilwood rear kit back, but the st170 rear brake kit isn’t too expensive as I’ll only need the discs, pads, carrier and braided hoses.

It is also probably much easier to find those brackets/rotors/calipers for conversion over there than it is becoming for us over here lately.

 

[Rhys1983]

It is also probably much easier to find those brackets/rotors/calipers for conversion over there than it is becoming for us over here lately.

Yes, most of the fiesta online shops sell them and they’re quite cheap. The main cost depends on what disc you go for.
I think this is the route I’m going to go down as it’s a lot less hassle!

 

[LilPartyBox]

I’ve spoken to Ron and he’s confirmed that I’ll need the rear hubs from the standard fiesta for the rear brake kit to fit.

It's a shame that he forgot to mention that when you reached out to him pre-purchase. But he was ready to sell you the additional cable... Maybe he would be so kind as to waive any restocking fees since he could have mentioned the rear hub requirement when you first reached out to him.

 

[Dpro]

It's a shame that he forgot to mention that when you reached out to him pre-purchase. But he was ready to sell you the additional cable... Maybe he would be so kind as to waive any restocking fees since he could have mentioned the rear hub requirement when you first reached out to him.

ya would not hold my breath on that Rons a nice guy but restocking fees are business.
On another note per discussion with a friend about the bias issue it was suggested running a lot more agressive pad in the rear compensate for the bias issue that was raised which is actually something that has been being done for years in the Honda community when putting larger fronts on . Apparently it seems to correct that peak threshold breaking before the abs kicks in. Honestly though unless you romp on your brakes super hard I do not see the ABS kicking in as an issue. I will be testing my Willwoods out in the canyons sometime this week but as for right now applying my brakes actually just stops my car rather quickly with the Wilwoods😂 So I think just running EBC blues in the rear with my USR rotors will be fine😂 I am running Yellowstuff currently