My FK8 gets much needed upgrades (PT 2)

This week I will be showing you how to install Giro Disc rotors on the front of an FK8 and what performance benefits you can expect from them. In case you missed part one of this series you can click the link below to read “Part one” which was about installing a baffled oil pan and Spoon Sports Rigid Collars on my FK8.

My FK8 gets much needed upgrades (PT 1)

See more

On to the Giro Disc install…This are my last-ditch effort to solve the overheating caliper/brake issue and stop the further browning of my BROWNBO’S. So far, every track day I have done, I have had some sort of “brakes getting too hot” issue. Whether it is just the brakes themselves getting too hot and discoloring the caliper, the pedal growing longer due to overheating pad and rotor, or a bad case of brake fade going into Sunset or Sunrise corners at Buttonwillow. TALK ABOUT ABS INTRUSION

I know there are people that are tracking their FK8’s without this issue but my question to them is, what are their lap times? I bet they aren’t driving quick enough to experience brake fade. I’m running 2:00 flat at Buttonwillow CW13 with 265/35 RS-4’s (aka the last real street tire), stock ECU (no tune), stock exhaust, full interior (floor mats and all).

I will accept some blame and say that my driving style might need to be tweaked to better fit the FK8 platform. This is something that I have identified and am working on every time I’m on track. The FK8 platform can’t be driven like the golden era Honda’s of the 90’s and early 2000’s. The FK8 is nearly 1000 pounds heavier than a B series hatchback (EG/EK), has MacPherson front suspension, and some crazy dual axis suspension to help combat torque steer.

Anyway, Giro Disc’s have been proven time and time again by many fast guys to hold up even under the harshest of conditions. Giro Disc’s have also been proven, again by multiple people, to last for more than 25+ track days before needing to replace the rotor rings.

• Giro Disc’s have a proprietary metal that they use that increase rotor ring life.
• Improved cooling due to vane design
• Are lighter than OEM rotors (even the OEM two-piece rotors. as seen below)

These rotors are the exact same diameter and thickness of the OEM and will bolt directly on without any modifications.

Starting off, below you will see my current setup. OEM two-piece rotors, Hawk DTC 70 pads and Paragon Titanium shims.

It’s tough to see, but below I have tried to capture all the micro cracks and overall rotor condition. This is after a total of six track days, and two different pad compounds. My first choice was Raybestos ST-43 pads that I had in for five of those six track days. The ST-43 pad actually worked fairly well for me, but towards the end of the session you could tell the pad was out of its optimal operating temp range. This was apparent because I was having to push harder on the pedal to get the car to brake the same as it was at the beginning of the session. I still have about 1/3 pad life left on the ST-43’s but I wanted to try something with a little more heat capabilities.

So… On my sixth track day I opted to try the Hawk DTC 70 pad. I only had one track day on these pads and wasn’t convinced they were right for me, but to be fair the track day was kind of a shit one altogether. There was such dense fog that we didn’t even get on track until 1:00pm (we were supposed to start at 8am), it was literally freezing cold and wet all morning long, so once the fog and cleared and we were allowed on track, it was still damp.

I had also read online that the dust created by the DTC 70’s would stain my car, and my wheels. Since my car is new, I didn’t want to risk ruining the paint less than a year into ownership. This was really the main reason I decided to try out the Carbotech Xp12’s up front.

Jumping right into the install process. Start off by removing the pads: On this car this is very easy, just simply hammer out the two pins that hold the pads in and they will slide on out. Most likely you will have to wiggle the pads back and forth to get the pistons to compress back into the caliper. This will not only allow the old pads to slide out easier, but you will also need the added clearance to put the new pads in.

Now, just unbolt the X2 17mm bolts holding the caliper to the knuckle, remove the Philips head rotor screw, and to help get a little more brake line slack/clearance I also remove the 10mm bolt holding the small aluminum block where the hard line meets the soft line.

The rotor should easily pop off (as seen below). There is no need to disconnect any brake lines.

Below you can see the up-close differences in the cooling vanes.

Below you can see what the OEM 20/21 FK8 two-piece rotor weighs. My scale measures in Kilograms, 10.03 KG is the equivalent to 22.11 lbs.

Giro Disc is 9.53 kg, which is equivalent to 21.01 lbs. That is a weight savings of 1 lb. per side! which is huge because it is rotational weight too.

Like mentioned above I went with Carbotech XP12’s for the front. It’s worth noting that in the rear I have always and still do run Project MU club racer pads and the same ones have been on the car throughout all six of my track days. The key to rear pad life on these cars is to ensure you have it in +R mode with a long hold of the VSA button. By long hold I mean longer than 5 seconds. When you press the VSA button it will beep once after 2 seconds but continue to hold and listen for the second beep, that will signify everything has been turned off.

It is debatable if doing the pedal dance is better too fully disable every aid. I don’t want to argue. I never pedal dance, no one else I have talked to (that is fast) does the pedal dance. We all do the long hold and that’s all you need. Plus, when you do the “pedal dance” it takes the car out of +R mode and defaults to “sport”. There is no way to change back to +R until you turn the car off and then back on, effectively taking it out of the maintenance mode (Pedal Dance).

Recently (March 17th, 2022) I was at Buttonwillow on a very low car count day with tons of seat time. I decided to try and do the pedal dance to see if it would in fact help improve my time… Sadly it did not improve my times and slowed me down a half second on a 5-lap average VS doing the long hold of the VSA button.

With the VSA “off” (long hold, two beeps) you are still able to get the car to oversteer and there is nothing the interferes with the possibility of you getting a fast lap.

When installing the new rotors be sure to clean them thoroughly with brake cleaner to get off all the oil that is on the rotor. New rotors will come coated in oil to help prevent rust while in storage or shipping. If you do not clean it all off, it will cause your pads to not bed in properly and you will not be able to get the most from your new setup.

Slide the new rotor on… Take note! The Giro Disc’s are directional and if you install them incorrectly the cooling vanes will not work as efficiently. Once the rotor is back on, reinstall the Phillips head screw that holds the caliper flat against the knuckle.

Now you can reinstall the caliper and bolt back down the small aluminum block where the brake lines meet (the one you removed to get more slack in the brake line).

Slide the new pads in. Remember, you might need to push the pistons in to gain more clearance depending on how worn down your old pads are. Be careful because when you push the pistons back in on one side of the caliper, the pistons on the other side of the caliper will get pushed out. DO NOT LET THEM POP ALL THE WAY OUT. There are special tools that can compress both sides at the same time, but they really aren’t necessary.

After my first track weekend with the car (when the calipers turned from bright red to BROWNBO’s) I thought maybe I would try titanium shims to help mitigate some heat being transferred to the caliper. I purchased some Paragon Ti shims and hoped for the best.

After my next track weekend, a month later, I wasn’t able to determine whether or not the shims helped. During one of those days, I took the pads out to inspect and when I went to reinstall the pads, as I hammered the pins back through the caliper, I accidently pierced the Paragon Ti shim because they are so thin.

I only mention this because, this time around I opted to get the Giro Disc Ti shims (since I was already ordering the Giro Disc’s). Upon arrival It was immediately noticeable how much thicker the Giro Disc shims are compared to the Paragon ones.

Hammer the pins back in and you’re all done.

The finished product. I’ll have to say, there is just something about how the Giro Disc’s look that is very menacing.

It is safe to say that after upgrading to the Giro Disc, Carbotech xp12 and TI shims, I no longer have any braking issues. This was just recently tested on Thursday March 17th during a “SoCal Drivers Club” event at Buttonwillow raceway on March 17th, 2022, where I managed to finally Sub2 (1:59.82 to be exact).

This time around the cars brake system never missed a beat and I have regained every bit of confidence in the brakes again. I even noticed that the ABS no longer comes on during hard braking like it was doing previously. I can only assume this is because there is less heat, and the brake system is able to do what it needs to do without me having to overly press the pedal and potentially cause ABS to kick in.

When the brakes are operating within their optimal heat range there is usually very good pedal modulation, and you can get the brakes to slow the car down quicker without the need for exercise pedal force.

Modulation: Brake modulation is the ability to control the amount of clamping force precisely and accurately on a disc with a given amount of pedal input. In other words, it means you can scrub off as much or as little speed as you want without tire lockup.

When the brakes start to get too hot and the pads start to get out of their operating range, there is a lot of brake efficiency lost which requires you to press harder on the brake pedal. Well, with more pedal pressure comes more friction, and more friction will create more heat. All this combined will cause your brakes to overheat to the point where they no longer work. Therefore, it is important that you have an adequate brake system set up on your car. Otherwise, you’ll only just overheat your brakes until the point of not being able to slow the car down in enough time or having to brake too early. Braking too early is not going to get you a fast lap time.

Hopefully this writeup helps guide you in your brake upgrade selection on your FK8. If you are reading this and don’t own an FK8, then hopefully you learned something about brakes.

Again, there are many variables to what I have mentioned above. Yes, there are fast guys with the FK8 platform doing 56/57’s at Buttonwillow. But those guys all have tunes and much extra power. And power, as we all know, can really help shave seconds off lap times.

Remember, I am only reporting to you my personal experiences and what has worked best for me, someone who has gone sub 2 with no tune, stock exhaust, stock airbox, full interior, just swift lowering springs, RV6 rear sway bar, some Cusco braces, on a 265/35 18-inch RT660 tire.

So, if you want a combination that works very well, I highly suggest getting the setup that I’m currently using for my brakes. I never had one single issue the whole day and air temps even got into to high 70’s, don’t just think the brakes were working well because maybe it was cold out.

I hope you don’t interrupt the aforementioned lap times for me bragging. I’m only mentioning it so you can get an understanding of my driving level. Because everyone’s experience and skill levels all vary, so what works well for someone that is a beginner or slow on track, will definitely not work well for quick people. It’s always easy to talk about the “way” things are supposed to work or what “works” well based on word of mouth. But speaking from experience is much more factual and if you’re very experienced then it makes your statements all the more valid.

Thank you for following along on my little FK8 series that I’m doing now. I hope you are learning, and I hope you are getting motivated to work on your own car. This car is very capable out of the box and with only a few tweaks it can be made into quite the track weapon. If you have any questions or comments about this post or any others, please feel free to reach out to me: Email, Billy@Functiontheory.com, Instagram @Functiontheory, or simply comment below. I’d love to hear what you have to say, what you might think, or what you have questions on.