1 week from now we’ll be in the middle of a race. The weather outlook is sunny with highs around 88F. Not everyone likes wearing a coolshirt, but I certainly would be if I was driving. Let’s take a look around the interior.

I changed the Lithium battery in the front to a lead-acid in the rear. The battery box is a kitty litter container strapped to the floor. I got approval for this from JP, the tech chief. It’s just there in case of an acid splash. The battery is actually held down by a hefty aluminum bar.

Inside the cockpit, the biggest change is the addition of RATTY. The shifter has a button in the top. The base screws into the stock shifter threads. Yes, I tapped both the button and shifter. The metal in the base wasn’t as thick as I would have liked, so there’s a nut internally that screws in from the top. I didn’t have a very tidy solution for the wiring coming out of the shifter knob, so there’s some tape around it.

You can see the DIY cold box in the background. This is simply a marine bilge pump sitting in a standard cooler. The tubing and wiring come out of the top. It takes about 5 minutes to make one of these since the only thing you need to do is put a couple holes in the top.

The brains of RATTY (Arduino) are in a black box fixed to the base of the passenger seat with a hose clamp. There are 2 wires coming out of this, one for the shifter button (black), and one for USB power (white).

RATTY talks to my old iPhone 6S Plus via WiFi. Depending on how you press the button, it sends canned messages to a Discord channel. It takes 3-5 seconds for a button click to show up in the channel.

• 1 click – Yes
• 2 clicks – No
• Many clicks – Bad shit has happened
• Hold – I need to talk

The idea is that the pit and spotters can send status messages to the driver such as “Yellow in T2” or ask questions such as “is everything okay?”. The driver then responds mostly with yes/no answers.

In the picture above, you can see several devices in view.

Just to the left of the red stripe on the steering wheel is a RumbleStrip lap timer. Despite much fancier stuff on the market, this is still my favorite delta timer.

The stock gauge cluster is above the RumbleStrip. We don’t use it for anything other than the warning lights. The speedo doesn’t have a needle, and it isn’t missed since the RumbleStrip displays current speed.

To the left of the RumbleStrip is the tach. The car didn’t come with one, and honestly doesn’t need one. There’s no reason not to run it right to the rev limiter. It’s pretty conservative.

The rectangular screen to the left of the tach is an UltraGuage. This is an OBDII reader that displays up to 8 different things at a time. We use it to track engine temperature, stint time, and fuel usage. It works very well and is not expensive.

The car is also outfitted with a radio. I have spare NASA and IMSA headsets as well as adapters. I haven’t had great experiences with radios, but having redundancy is always a good idea. The radio mounts to the rectangular aluminum bar to the lower left of the UltraGauge.

The iPhone mounts on the far left. It gets fed power from a USB port on the passenger side of the car. Speaking of power, there are 2 12V outlets as well as 4 USB ports (half in front and half in back). The USBs power the iPhone, RATTY, and 2 cameras. The 12V outlets are not used, but exist in case we need to power something else (in the past this has been a Raspberry Pi and a monitor). The UltraGauge is fed power through OBDII and the RumbleStrip and tach are powered directly from 12V.

I just got back from a Golden Gate Lotus Club track day where I brought both my Yaris and Z3.

Z3 on East

I’ve owned my Z3 for about 2 years, but due to a variety of issues, I’ve only driven it on track a handful of times, and never on Thunderhill East. So I was pretty eager to see what it would do. Today, we were running the Bypass configuration, and my best lap was a 2:15.7. I was using the bargain 205/55/16 Maxxis VR1 (old stock from 4-5 years ago) that are still on sale direct from Maxxis for just $60 per tire.

Racebox Mini

I just received a Racebox Mini that I purchased when it was in its Kickstarter phase. The hardware and software are very simple. Shown below is a screen grab of a lap comparison. I think the Racebox Mini is very well designed with a self-contained battery and a magnetic base. It was really easy to take from car to car. It’s surprisingly inexpensive. I highly recommend it.

Yaris

The testing plan for the Yaris was two-fold: make sure it is running well, try a couple tire configurations.

The Yaris felt great on track. The steering is even better with the hard-mounted front suspension. It’s 100% ready to race.

The mix of 225/45/15 RS4 front and 205/55/16 VR1 rear works very well. There’s just a tiny bit of lift oversteer. I’d like more, but I think the various guest drivers in the upcoming race will find it reassuringly neutral. Mounting the VR1s on all 4 corners wasn’t as good. It’s a change of 1″ higher ride height in the front and a corresponding change in angle. It felt like I was driving a bus. Also, the tires rubbed under hard braking or cornering. So I’m just going to use the VR1s on the rear.

I can’t believe there are only 2 weeks until the next race. What am I doing to prepare? Not much. The car is pretty much ready to go.

I have a track day coming up on Monday with the the Golden Gate Lotus Club, which is my favorite track day host. What makes GGLC the best for me? It’s a mixture of laid-back atmosphere, low cost, and cool cars. Honestly, there aren’t many Lotus cars at a Lotus Club event, but the cars people bring tend to be unusual.

I signed up with the Z3 because I’ve never driven the Z3 on the East track. On the other hand, the Yaris hasn’t had a test drive since the last race. Not much has changed, just a little suspension tweak on the front and relocating the battery to the rear. While I really want to drive the Z3, as team manager, I think it’s my responsibility to do a bit of testing with the Yaris. I haven’t driven it with the 205/55/16 tires yet, so doing some mix-n-match tires will give me some experimenting to do.

Ideally, if I’m doing experiments, I’d have my AiM Solo DL so that I could compare performance with previous days. However, that unit is sort of on permanent loan with my brother. However, I did just receive a RaceBox Mini. That’s something that needs testing too. Oh, and I should probably do a live test of the Discord-based in-car communication system.

OK, so I guess I do have a few things to do before the race. Check back for a report next week.

4 weeks until the next race. It’s a 24 Hours of Lemons event at Thunderhill. Every race has something different planned, and this is no exception. The big change is…

I’m not driving

For only the second time in my “career” I’m going as dedicated crew. The last time I did this was with a trio of mad hombres, (no, not the Three Amigos) who played pit crew for XX Racing, an all female racing team driving our Miata. It was really fun focusing on taking care of the drivers and the car rather than thinking about the race, so I’m looking forward to it again.

I’m not sure how much racing I’m going to be doing in the future. I don’t really need to race anymore. I like driving on track, of course, but the part of me that needs to shame faster cars is feeling sated.

Modifications and Fixes

So what’s new with the car? We’re going to race under the Toyota Kazoo Racing name again. I aim to put some rally-inspired thematic decorations here and there, like a roof vent and mud flaps.

At the end of the last race, the battery broke. It’s one of those insanely expensive Lithium batteries that weighs 5 pounds. The plastic literally broke, exposing circuit boards. I’m not buying another one of those, so we’re going back to the original lead-acid battery, but this time it will be located in the back.  I removed the tow hitch, meaning the overall weight will go down a little and the front-rear balance will be a little better. I doubt it will be noticeable, but in theory it’s better.

At the end of the race, the front right top hat pulled through the hole. Not sure how that happened. I’ve replaced rubber with some solid metal mounts I had purchased but never installed. They’re supposed to sharpen the steering.

As I mentioned previously, we’ll be using radios for the crew, but communication to/from the driver will be via Discord. I can’t wait to see how that works out.

Drivers

Let’s meet our drivers.

• “Crazy” Mike Kimball – Mike has been in Lemons a long time. He races Beetles, Minis (the original ones), Volvos, and whatever else you put in front of him. He’s sort of the chief mechanic these days. His better half, Amanda, serves a lot of great food at Lemons events.
• Danny Hart – A few years ago I contributed a “come race with us” item for a charity auction.  Danny was the high bidder and he joined us for a Lucky Dog race at Laguna Seca. The next race was a full 24 hour race at Buttonwillow. If you can race in the dark, on a track you’ve never been to, not crash, and help the team to a 3rd overall place, you have spot on my team.
• Daniel Melters – Daniel used to be a graduate student in my lab. He was one of the original team members and returns from time to time to generate more great memories. He holds the current record for longest stint in the Yaris at 2:43. Pretty amazing considering the car holds 10.5 gallons.
• David DeFlyer – David has raced with us several times, but has been out of racing for a few years. David is equally at home behind the wheel or under the car. He’s weirdly faster on shitty tires than good ones. No, that doesn’t make any sense, but the rest of him does.
• Tiernan Armstrong-Ingram – While Tiernan is the newest member, he’s been to enough events that he’s become a regular. He lives a few streets over, so he frequently helps out on the car. He’s one of the lead writers for Donut Media, but don’t hold that against him! A guy’s gotta eat.

I don’t like fast cars, nannies, supercars, ricers, donkers, drag racing, or people doing burnouts in the middle of the night. I don’t follow Formula 1, NASCAR, Indycar, or any other racing series. I would be hard-pressed to identify a car from its silhouette or engine sound. And yet, I am a car enthusiast. I love the interaction of car and driver at the limit. I think that still makes me an enthusiast, just not the common kind. Let me tell you a bit more about my unusual tendencies.

Z3

I consider my 1996 BMW Z3 to be the ultimate track-daily. In some world where I’m much wealthier than I am today, I would drive an electric car to the track where my purpose-built racecar would be waiting for me in a garage. My reality is that my track car doubles as my commuter. That means compromises. On the street, it’s a bit too stiff and a bit too loud to hear my audio books. I have to draft trucks to cut the wind noise down. There’s only room for 1 passenger and a few grocery bags. But when the weather is just right, commuting with the top down is the next best thing to riding a motorcycle (I gave that up long ago). And on track, with the top open and 4 wheels howling, it’s pretty fucking perfect.

One of the things I like about my Z3 is that it doesn’t have intrusive nannies. It didn’t come with stability control, so there isn’t even a button to turn off. It does have ABS and power steering, and I’m okay with that. But I’d also be okay without it.

I think most people would look at the 1.9 Z3 specs and think it doesn’t have enough motor. The weight (2670) and power (138 crank) aren’t very different from a commuter like a Toyota Corolla or Honda Fit. On the street, I have no need for power, because I drive for economy. On the track, I don’t really want to go much faster than I do now. It’s more dangerous, takes more fuel, wears more tires, generates more heat etc. There are economy enthusiasts too! I’m sort of half-way between those crazy hypermilers and those crazy track addicts.

Shifting and Coasting

My Z3 is over 25 years old. In order to extend the life of my transmission as long as possible, I reduce the number of times I shift by skipping gears. If I am at a complete stop, I will usually shift into 1st gear. As I speed up, I’ll switch to 3rd and then 5th. Sometimes I’ll take off in 2nd (especially if I’m doing a rolling stop or pointed downhill) and then switch to 4th and eventually 5th. I try not to shift from 2nd to 3rd or 3rd to 4th. Those gear changes are reserved for the track. What about heel-toe downshifting? Also reserved for the track.

I do a lot of coasting on the street. I’ve driven from my doorstep in Davis to downtown SF without using the brakes. I drive all cars like this, not just the Z3.

Tires

I don’t buy sticky tires. The stickier the tire, the more wear you put on everything: pads, rotors, suspension, bushings, subframes, etc. Z3s are great handling cars and don’t need sticky tires. They should be slid around corners. It’s a lot easier to explore the right side of the slip angle curve in less sticky tires. Let’s review the merits of harder tires.

• Less wear on the car
• More fun
• Better for training
• Cost less
• Last longer
• Slower/safer

Fuck R-comps. They are a scam.

Spirited Drives

I have never taken my Z3 for a “spirited drive” and probably never will. Driving 5/10ths on public roads cannot compete with track driving or even sim racing. What about driving over 5/10ths on public roads? I don’t see the point in endangering the public when sim racing and track driving are more fun.

Exterior & Interior

My car’s clearcoat is pealing like crazy. 25 years of sun will do that. I’m okay with wrinkles on people too. I don’t wash my wheels very often. I don’t care how the wheels look. I don’t like getting my hands really dirty when I swap them though, so sometimes I do break out a bucket of water. I screw/glue RAM mounts into my dash. I’m not saving my car for the next driver.

Also

My favorite racing channel on YouTube is 3D Bot Maker.

In the last post, I mentioned offhand that DiRT Rally completely changed my perspective on driving. When I started sim racing, my style was very tidy: meaning I didn’t slide very much. There were several good reasons for that:

• I was driving in iRacing, and if you lose control, you pick up penalty points
• My steering wheel was a Logitech G25, which has a weak motor, which makes it difficult to sense and catch slides
• All of the tracks were asphalt, and the optimal slip angle wasn’t very large

There were also these less good reasons:

• I didn’t know how to drive with a lot of yaw
• I was proud of my CPI stat (corners per incident)

Taken together, I actively avoided driving with a lot of yaw.

Enter DiRT Rally

Steam suggested DiRT Rally when it was in Early Access. I didn’t know anything about rally racing in the real or virtual world. I bought it on a whim. When I started it up, there were no directions at all. I found myself at a starting line somewhere in Greece with the road ahead of me disappearing as it dropped to the right. Seconds later I was driving off a cliff. I don’t know how many attempts it took for me to finish the first stage. You might think that repeated crashing and re-starting would turn a person off to a game, but no, I was enthralled. The roads were unsafe. The cars were old and squishy. The grip was terrible. There was no help at all.

While I tried to drive tidy, there wasn’t much point. When a course is covered with gravel or ice, you have no choice but to slide around. I was forced out of my comfort zone and weirdly loving it. It was also fun listening to my co-driver’s directions, though I must admit I drove each stage enough times that I had them mostly memorized.

The Drill

These off-season training exercises are based in Assetto Corsa, so that’s where we’re headed. I don’t think Assetto Corsa has the best model of loose surfaces, but it’s also not bad. It doesn’t have to be authentic to be a great training exercise anyway.

The key to high performance driving is driving with the right amount of slip. While it’s true that driving on dry asphalt doesn’t require much yaw, bad shit happens on a race track! If you suddenly find yourself in deep shit, you don’t want to hope your way out of it. You want to rely on your training. So how do we train for slippery conditions? By driving in slippery conditions of course.

• Track: Karelia Cross (follow link to download)
• Car: NA Miata
• Tires: Default (Street 90s)
• Weather: Default

Karelia Cross is a fantasy dirt track that was originally made for rFactor. It’s also available in rFactor 2, but I can’t really recommend it on that platform. The reason we are driving a small circuit and not a long rally stage is because I want you to experience the same corners over and over. This will let you set up and evaluate experiments in your head.

These are the goals:

• Drive hard
• Experiment with something
• Drive harder
• Recover as best you can

You will probably crash a bunch at first. Good, you’re supposed to do that. The goal of this drill isn’t to drive around as tidy as possible and not get into trouble. You can’t recover from disaster if you don’t experience disaster. So go drive the ragged edge. Vary your driving style. Drive way off line. Figure out what does and doesn’t work. Eventually you will learn how to recover from near disaster.

The ultimate rewards of this drill are:

• Better disaster recovery skills
• More confidence in your driving skill
• Faster lap times on every surface

It will be frustrating. But once you come out the other side, you too may come to the opinion that the only thing better than driving the limit is a brief trespass and safe return from well beyond.

Although the goal of this drill isn’t lap times, try to get down to 1:05 or so.

iRacing Variation

If you don’t have Assetto Corsa, try driving the MX5 on rallycross courses. It’s basically the same thing.

FWD Variation

FWD and RWD have slightly different behaviors, so if you want to increase your car control vocabulary (you do), then definitely do the drill in FWD too.

THE END

This is the end of the offseason training posts.

Braking! It’s literally my favorite topic when it comes to driving.

Braking Poorly

Let’s set the stage for this drill by talking about some specific braking problems exhibited by typical novice and intermediate drivers.

• Coasting before applying brakes
• Ramping up pressure
• Braking too hard
• Snapping off the brake pedal

Novices

Novices tend to coast into the braking zone. That is, as they approach the braking marker (if they have one), they lift partially or fully off the throttle and coast. And coast. After a few seconds, they finally apply the brake pedal. They generally aren’t even aware they are doing this, and may even deny it outright. That’s why we record data.

Ramping up brake pressure is a related problem. There is no need to progressively apply the brake pedal. You can hit it hard. Whether you apply the brakes soft->hard or just go hard doesn’t really change your lap time that much. So why am I saying it’s a serious problem? Because it’s backwards of what you want to do. You’re supposed to go hard->soft, not soft->hard. So why do they do it backwards? Fear. Eventually novices will get over this fear, but until they do, they will probably justify their actions as “smooth is fast”.

Taken together, the novice approaches driving as such:

• unconsciously coast into braking zone
• apply brakes smoothly
• apply more brakes because it wasn’t quite enough
• put put around the corner

Intermediates

The hallmark of the intermediate driver is aggressive inputs. Braking too hard creates all kinds of problems later. If you enter into a corner well below the optimal corner speed, you will be invited to stomp the throttle. Depending on how much you add, this will result in understeer or oversteer. Intermediate drivers often think their car has too much understeer when the problem is that they’re creating the understeer.

Snapping off the brake pedal causes an imbalance in your suspension. Your vehicle will rock back and forth. If you’re braking in a straight line, there is no great crime to having your car rock a little. But if you are cornering, the sudden change in grip causes 2 problems: (1) your overall grip is lower so you go slower (2) reducing grip in the rear suddenly may cause you to spin (this is exacerbated in RWD vehicles). And so intermediate drivers brake in a straight line.

Taken together, the classic intermediate driver approaches their craft as such:

• hit the brake pedal hard enough to engage ABS
• over-slow by 10-15 mph
• snap off the brake pedal
• turn into the corner
• add a bunch of throttle mid-corner
• complain of understeer or oversteer

Setup

Well, it’s time for a drill to help us break these bad habits. It doesn’t matter if you have these bad habits or not. Your knowledge of the drills will help someone else who does.

• No ABS. It’s really important not to use ABS (or any other nannies). We’re trying to train our muscle memory, and ABS will let us stomp on the brake pedal without bad consequences.
• No shifting. Focus all of your attention solely on the brake pedal.
• Track. Whatever.
• Car. Whatever.

Brake to the Apex

In this drill, your focus is on 2 actions:

1. hit the brake hard
2. gradually release brake pressure all the way to the apex

Imagine braking on a 0-10 point scale, with 10 being full lock-up and 0 being brakes off. When you hit the brakes, try to get to 9 on the initial hit. It’s okay if you hit 10 briefly, just back it off until you hit 9. But please don’t make the initial hit 5 or 20.

Ideally, in this drill, your brake pressure over time will look like 9, 8, 7, 6, 5, 4, 3, 2, 1, 0. But when you first try it, you will probably do something more like 9, 9, 9, 4, 4, 4, 4, 4, 0. Training your foot to release gradually will take some time. It’s not going to have a deft touch right away. Like every skill, it takes dedicated practice to improve.

You may end up going way too slowly through the corner. That’s okay. Pick a slightly later braking marker next time. The point of this drill isn’t lap times, so don’t worry about that. The point is to get your muscles used to hard-on-soft-off.

As you learn to carry more speed, you may find the car start to rotate as you mix cornering and braking. You may even spin. Good, keep that feeling in mind. We’ll need it later. However, for this drill, you should slow down a little so that you don’t spin. This isn’t the rotation drill, it’s the brake-to-the-apex drill. You may need to mix in a little steering to control the car. That too will come in handy later.

This is a short follow-up post to the last one. I’ve named my project RATTY. Trying to mount 5 buttons within easy reach of the driver turned out to be a difficult problem to solve. So instead, I decided I could get away with a single button if I used a combination of clicking styles. I put the button on the gear shifter. I think the steering wheel would be a good place too.

I’m planning on using this as follows:

• Single-click: “Yes”
• Double-click: “No”
• Multi-click: “Bad stuff has happened”
• Long-click: “Pit request”

Here I am interacting with RATTY from the comfort of my desk. This is the output as it looks on my iPhone 6S Plus. I set the font slightly larger as the default is pretty small.

Here’s a link to the ratty GitHub repository where you can get the code if you want to build one yourself. I’m using an Arduino Uno WiFi R2, but I think you could use an Arduino Nano 33 IOT, which is about half the price ($22.55 with tax and shipping). I have one on order to build a second unit. A HotSpot will cost around $100, but you could use a phone instead.

The next step is to mount everything in the car.

One of the things I’ve been really frustrated with is radio communication. Even when the radios are behaving well, you often have to ask “can you repeat that?” My experience with radios is that most of the time they aren’t working well. So far, they have been more trouble than they are worth. So I’ve decided to build an alternative. Before I discuss those details, let’s review what kinds of communications happen during a race.

Pit to Driver

What does the pit need to say to the driver? Some are ordinary questions about the state of the car.

• Is everything okay?
• Is the water temperature good?

The pit might also have some status messages or warnings

• Green, green, green
• Yellow flag in Turn 5
• Emergency vehicles on track
• Red flag, stop the car in a safe place

Driver to Pit

How many things does the driver need to communicate to the pit?

• Yes in answer to a question
• No in answer to a question
• I’m pitting now, something bad has happened
• I’m pitting soon because I’m running low on fuel
• Oops, can you check for penalties? (maybe)

This is a really small list. Instead of radios, how about something else? Like 5 buttons.

Prototype

I’ve built a prototype messaging system for racing communications. It’s built using an Arduino, Discord, a HotSpot, and some buttons. The driver pushes buttons. That’s it. The pit and spotters communicate to the driver via Discord. The messages persist on the screens so nobody has to say “can you repeat that”.

Next

I have to build a robust box for the buttons. I may include an LCD for status messages. It needs a good name. Maybe it should send messages to a #team channel with driver or car data. It has an inertial measurement unit, so it’s capable of making friction circles and such. There’s a lot of stuff I could do, but some of my favorite things (e.g. RumbleStrip timer) do only one thing, and maybe all this does is text communication. I’d love to hear your thoughts about it. And if you can come up with a snappy name, that would be amazing.