[Golfguy11800]

As pointless as this thread might sound, I wish I had it when doing my rear brakes on my Focus ST and Fiesta ST...

How to replace the rear pads on a Fiesta ST and Focus ST and compress the rear piston. (Shameless SEO-ing). Was surprised that it took me nearly 15-20min of Googling to find the answer to my problem.

I come from Porsches and have only serviced those brakes for the past 7 years, they are 4 piston monoblock calipers F/R. So when I came upon the rear caliper of my Focus ST and Fiesta ST I was scratching my head on how to compress that little piston!

You will need this tool here:

Put it in your 3/8" drive ratchet

(There are 6 configurations on the cube to accommodate for different sized holes on the rear caliper piston. Just play with the cube and see which one fits best.)

Push HARD and tighten down on the caliper piston at the same time. If you don't push hard enough, then the piston will not retract.

For the fronts, I picked up this nice tool for $8! Wish I had this a longggg time ago

Put one brake pad against the piston and then mount the tool in the caliper and then just hand tighten. Couldn't be easier. No more Hercules sized channel lock pliers (can't believe I ever used those.)

I did a full brake install after cooking them in just 2,500-3,000 miles. The fronts were toast and the rears were about fine. It was a nice pad while it lasted, but it definitely didn't last long enough for my satisfaction. I ended up with Carbotech RP2 front and rear. Cryo Stoptech rotors in the front and Centric high carbon rotors in the rear. I didn't go for the Cryo's in the rear since the high carbon's were so cheap ($30/ea) and they will grab the pad better than if they were also cryo treated. The pads from CarboTech are an endurance race pad, had to be custom made and took about a month from order to door step.

Here are some photos of my stock front Fiesta ST pads after 2,500 miles... I don't really push the car that hard tbh. Always have DSC or traction fully off with the console button. Only time I leave it on is commuting in traffic.

Rear of the above pad had some heat on it lol

Here are some measurements compared to the new CarboTech RP2's vs the old pads...

Rear Old:

Rear new (RP2):

Front Old of the most meaty pad I had left:

Front New (RP2):

Fronts installed:

No other photos for the pads.

Putting on stainless lines this week and flushing out the stock fluid for Castrol SRF.

Also took a stab at routing some brake ducts :whistling:

Do not do it this way!

Problems:

1. 3" ducts were too big and would scrape ground.
2. The location of the inlets would work if you don't drive the car on the street and only track race. Unfortunately my car likes getting airbourne every now and then on my private rally roads so I ripped these things off within 20 minutes. Would have loved if they worked since install was a breeze and I was able to retain factory fog lights.

I'll go the light mounting route if I think I need it. Problem with running endurance pads on the street is that you want to get them up to operating temperatures and I think the brake ducts would make them run too cool.

So far the RP2's are technically not as responsive/ user friendly as the stock pads (this was expected). But I haven't had the chance to really ring these things out yet and beat on them for 40 minutes of mountain roads.

Will report back once I get everything installed and do some testing.

Oh yeah... ran into this spaceship on some back roads while testing out the brake ducts for the first time.

Hope some stuff here helps!

 

[Chuckable]

Thanks for the DIY and tips, and for the pics of your brake ducting set-up. If/when you try a new set-up let us know. These "ducts" may work, though they will no doubt be less effective:

These are not OEM parts, but shouldn't be too difficult to fabricate something similar.

 

[Mr UFO]

Might want to take off the dust shields around the rotor to allow the heat to escape.

 

[CrookedRacer]

Awesome stuff! I was thinking about mounting those exact scoops in a very similar way... Your installation certainly confirms that the $15 scoops will fit in the front skirt. They look great!

I got the same cube tool when I had to do the rears. And I've always just used a bigaz pair of channel-locks for compressing the fronts. But I like that other tool. Just watch your fluid levels - you might have to siphon some off if to prevent overflow during compression (if you've topped it off at any point).

I was hoping to just do a flap like the one in the picture above posted by Chuckable. Mikelly made a neat home-made install on his Focus ST that I was hoping to duplicate on my Fiesta in some fashion:

http://www.focusst.org/forum/focus-...brake-duct-brake-pad-brake-fluid-success.html

But the Fiesta doesn't have a whole lot of structure to mount the leading edge to, and the lower arm is actually swept forward, which makes using that member a little more difficult.

So I think I'll be trying a design with all the same materials as you. My plan was to use those same duct scoops but mount them a few inches further out from the center of the car, and flip them so the nozzles are offset towards the sides of the car, instead of towards the center. I suspect that would pick up more rammed air, aerodynamically speaking.

From there, I think I'll bring the duct straight back and then turn them out, attaching them to the leading edge of the lower arm, directing at the hubs from the front side, (which isn't as optimal, but any air is better than no air). This will result in a shorter duct run, and I don't think the ducts will need to hang any lower than the front skirt.

I don't plan to get airborne at any point while driving this car. If I ever do, my ducts will probably be the least of my worries.

 

[Golfguy11800]

Awesome stuff! I was thinking about mounting those exact scoops in a very similar way... Your installation certainly confirms that the $15 scoops will fit in the front skirt. They look great!

I got the same cube tool when I had to do the rears. And I've always just used a bigaz pair of channel-locks for compressing the fronts. But I like that other tool. Just watch your fluid levels - you might have to siphon some off if to prevent overflow during compression (if you've topped it off at any point).

I was hoping to just do a flap like the one in the picture above posted by Chuckable. Mikelly made a neat home-made install on his Focus ST that I was hoping to duplicate on my Fiesta in some fashion:

http://www.focusst.org/forum/focus-...brake-duct-brake-pad-brake-fluid-success.html

But the Fiesta doesn't have a whole lot of structure to mount the leading edge to, and the lower arm is actually swept forward, which makes using that member a little more difficult.

So I think I'll be trying a design with all the same materials as you. My plan was to use those same duct scoops but mount them a few inches further out from the center of the car, and flip them so the nozzles are offset towards the sides of the car, instead of towards the center. I suspect that would pick up more rammed air, aerodynamically speaking.

From there, I think I'll bring the duct straight back and then turn them out, attaching them to the leading edge of the lower arm, directing at the hubs from the front side, (which isn't as optimal, but any air is better than no air). This will result in a shorter duct run, and I don't think the ducts will need to hang any lower than the front skirt.

I don't plan to get airborne at any point while driving this car. If I ever do, my ducts will probably be the least of my worries.

Aerodynamically, you want the inlets of your brake ducts to be as close to the highest pressure zone on the front of the car, which is the center, that's the only reason why I put my intakes where they are. If you look at any prototype racecar, hell, even the new Z06, you'll see that the intakes are at the center for the brake ducts.

However there is something to be said of form vs. function. I wish that the front calipers were on the other side of the rotor, would have made install A LOT easier.

Be sure to go with a 2" hose, or else you'll have steering issues. I lost about 15% of my steering with the 3" ducts because when attempting full lock, the hose would bind on the spindle.

I really need to post my Google Doc of all the brake research I did for our Fiesta so that the brakes don't overheat. About 9 pages of hardware, suppliers, and knowledge.

Once I order 2" hose I'm going to go for the fog light install and fabricate my own mounting brackets out of aluminum or stainless steel sheeting. Might upload the template for others to use if successful. Only problem with fog light intakes is that it will get tight behind bumper with the on board components like the washer fluid reservoir. Everything can be modded but I would like to keep the car stock-ish LOL. Won't need the dogs anyways with my rally lights. Can't even tell when the fogs are on or off!

I think that going for some aero duct brackets like the Porsche GT3 ones and modding those will be the ticket for ease of install.

We'll see!

 

[CrookedRacer]

Great points you make, and here is a neat paper which illustrates your point...

http://www.wilwood.com/PDF/DataSheets/ds254.pdf

You're right... the further out you put it, the likelier it would be that the velocity of the air past the opening is enough such that it creates low pressure, sucking it out instead. (No way that would happen with your design).

However, I still think moving it out a few inches (still in the front-facing area, before the skirt it starts to be curve back) wouldn't make a lot of difference on our car given its shape.

Whether I move them further out or not, I still think I would flip the outlets to encourage that air to sweep into the hole, like the ramp of a NACA duct. That's just my gut, not an assertion that it's the correct way to go.

 

[Golfguy11800]

Great points you make, and here is a neat paper which illustrates your point...

http://www.wilwood.com/PDF/DataSheets/ds254.pdf

You're right... the further out you put it, the likelier it would be that the velocity of the air past the opening is enough such that it creates low pressure, sucking it out instead. (No way that would happen with your design).

However, I still think moving it out a few inches (still in the front-facing area, before the skirt it starts to be curve back) wouldn't make a lot of difference on our car given its shape.

Whether I move them further out or not, I still think I would flip the outlets to encourage that air to sweep into the hole, like the ramp of a NACA duct. That's just my gut, not an assertion that it's the correct way to go.

Nice little article. I couldn't even imagine, unless on a 21" wheel and 458 Speciale rotors, fitting three 3" tubes stacked going to cool the brakes and having enough room for full steering lock.

Cool design though. The opening inlets from small to large diameter to small should create a vaccuume effect, albeit some turbulance. Although I have not reached the aero engineering part of my engineering school yet

 

[Golfguy11800]

After 17,000 miles of "road" use (never tracked) these pads did last a very long time compared to the stock ones. However they finally failed at the front left with the outer brake pad cracking in half.

I'll post a picture soon.

Next pad will be a Hawk DTC60. $100 cheaper and I'm going to add some bumper ducting...