Brake Upgrades

Why Upgrade? Track Days.

So I decided to take the STi to the track for the first time a couple weeks ago and the result was amazing. I was talking with Matt about how hard it is to find the limits of these cars on city streets, and apparently this difficulty was founded as the limits were way past anything I was doing on the streets.

A cold morning at the track with her boxer cousins:
trackday.jpg

However I was surprised that one of the first limits I hit was the brakes. Heat was the big problem and the resulting smell and fade were worrying. Ambient temperature was just above freezing and I was only able to get 2-3 laps in before having to pit and let the brakes cool.

Granted, there were a lot of factors in play. My STi is the Limited (read “heavy”) edition and was fully loaded (fuel, donut, jack, etc.), there was a passenger, further exacerbating the weight problem, and the torque vectoring stability management was enabled. But even so, it was apparent that if I was going to continue to track the car I would need to do something about the brakes.

Big Brake Kit vs. Replacing Components

Brembo has been a huge name in brakes for as long as I can remember. When I upgraded the brakes on my Integra, I upgraded them to Brembos. And while there are a long list of advantages to a kit like the Stillen/AP Racing or Wilwood kits, for my purposes the Brembos are fine, I just need to be able to last for more than 3 laps. So I decided to replace the pads, the rotors and the brake fluid.

Pads

The STi is equipped with really nice Brembo 4-pot calipers in front and the best feature of these calipers is how easy it is to change the pads. A punch tool, hammer and a rubber clamp, and 10 minutes later you’ve got new pads. I went back and forth on whether or I wanted a street/track hybrid pad, and initially decided I wanted different pads to avoid the squeaks, maintenance pains and expense of constantly replacing race pads.

I decided on keeping the stock pads for daily use, and Pagid RSL1 (Yellow) pads which came highly recommended from the Porsche folks.

pagid_RSL_1-package

spider-RSL-1

After further research though, changing the pads isn’t the only thing required when you’re at the track — if your pads are different compounds, you need to re-bed or “bed-in” the rotors. This process is basically braking heavily, but not to a complete stop, several times to clear off leftover deposits from the previous pad. This is important as compounds of different types may not bond and as they heat up which may lead to uneven deposits on the rotors causing vibrations under braking and may also reduce the friction and stopping force.

So I decided to instead go with a different set of more street-friendly pads for both track and street. I ended up with Pagid RS29:

pagid_RS_29-package

spider-RS-29

IMG_1767

You can pick up a set of these at TopBrakes for $339 (front) and $239 (rear). Both front and rear pads are available, and though I didn’t encounter any issues with the stock rear setup I’m going to replace all four to avoid upsetting the brake balance. I’ll update this post to cover drivability and any noise annoyances I encounter after I get some miles on the pads.

Installation

Changing your pads is really straightforward, and you’ll want to do your rotors at the same time if you choose to replace those (below).

pads

Start by removing the clips holding in the retaining pins (green circles above) – simple needle nose pliers will do the trick. Then use a punch and hammer to push the retaining pins (yellow circles above) in towards the vehicle. Be especially careful not to scratch the caliper and make sure the punch doesn’t increase the size of the hole in the caliper. After you get the pin started, pressing on the flat spring you should be able to pull the pin out the other side by hand.

Once the retaining pins are removed, pop the top on the master cylinder reservoir and you can use a rubber-footed bar clamp or something similar to push the pads and pistons back toward the caliper, freeing the pads. I used one of these.

Replace the pads and shims, ensuring the arrow on the shim is pointed in the direction of rotation when the vehicle is moving forward. The rear are the same, albeit smaller. Here’s a view from the rear with the pads installed:

rear_brakes

Note on Front Pad Thickness with StopTech Rotors

If you’re going to install these pads with new rotors as described below, note that the new pads will likely be too thick to fit with the increased width of the new rotor.

I had to use a power sander and P40 sandpaper to take about 1/32″ off the new pads in order to get them to fit. Sand for a bit, rotate 90 degrees and sand again. Wear a mask or ventilator as the dust and an apron or clothes you don’t really care about as there will be brake dust everywhere during this process.

Some posts on forums suggested that you remove the shim – don’t do this. In addition to providing a distribution of force when you quickly apply the brakes, the shim helps prevent the pistons from becoming embedded in the pad backing and also prevents some brake noise.

Rotors

I also decided to swap the rotors to get more airflow. This probably wasn’t entirely necessary, but for about $350 you can get some nice slotted rotors to keep your pads clean and a really nice airflow vein pattern. An important note that I know from experience is that while drilled rotors (including drilled and slotted rotors) are significantly more likely to crack under heavy use. For street driving they’re fine and dissipate significantly more heat, but will crack and need to be replaced after 3 or 4 heavy track days.

I shopped around and all of the rotors had hit and miss reviews. The set which had consistently better reviews were the StopTech Sport rotors which I had on my inordinately heavy V6 Eclipse and they worked like a charm. I ended up buying mine from Subispeed to get my return customer discount and free shipping on something that weighs 40+ lbs is nice too.

Installation

If you’re going to replace your rotors, follow the steps above and then also remove the two 19mm bolts that hold the caliper onto the hub assembly from the back side of the hub (blue circles below).

caliper_bolts

Once you have the caliper off, set it aside ensuring that you don’t put any stress on the brake line hose. I used a foam block that was leftover from a previous project, some others have suggested zip-tying it to the spring assembly.

Next you’ll remove the old rotors and it’s likely that they’ll be pretty well bonded to the hub. In addition to the holes for the lugs, there’s also two M8 holes towards the center of the hub ring that you can run a bolt through and it will push the rotor away from the hub. If you don’t have one handy, you can borrow one of the two that holds the intercooler mount on the manifold (to the right of the blow-off valve and behind the fuel lines).

Once the rotors are off, slip the new ones making sure that the slots in the rotor are positioned to out-to-in when moving forward (as shown below). Then put the caliper back on. The 19mm bolts should be tightened to 80 lb/ft. On some STi models there was a misprint in the technical manual stating that it should be 114 lb/ft, when in fact it should be 114Nm. If you don’t have a torque wrench that beeps and you’re relying on hearing or feeling the click, be sure to pay close attention as the lock washer is loud when tightened and it’s not immediately clear when you’ve hit target torque.

Now re-insert the pads, retaining pins, flat spring and clips and you’re good to go.

IMG_1651

Fluid

So I honestly just got lazy and didn’t feel like draining and bleeding the brakes (even though the Brembo system has a really simple bleeding system). If you do want to do it yourselves (it’s a 2-person job), there’s a really good tutorial on YouTube https://www.youtube.com/watch?v=M6HH6qdW-D8

I just took mine to the local brake shop with 2 bottles of Motul RBF660 and they flushed the system for $75. If you’re really adventurous I’d say give yourself 2+ hours unless you have a lift and a vacuum bleeder.

847205-2

Conclusion

As soon as I get her back to the track and get a good amount of street miles under her belt, I’ll post a full conclusion.

IMGL7104

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