Once I had the FastLapSim5 racing simulation program from COMP Cams installed on my laptop, I have spent hours and hours changing small parameters on my race car in the ultimate search for speed. Why not? It doesn’t cost me anything to make these digital changes and run the simulation over and over again until I find the fastest lap. The physics model inside the program is incredibly precise. I have verified its accuracy comparing my simulated lap times with my Honda Challenge race car against actual lap times around the same track.
We detailed how to modify and build a race car in the FastLapSim5 software in a previous article here at TURNology: FastLapSim5 Cuts Lap Times Without Turning a Wrench. However, there is a limit to the number of tracks that come with the program. The good news is that you can add one yourself. In this current article, we are going to detail how to create a racetrack in the program to test with your car.
One of the only limitations in the program is the lack of certain racetracks within the software. As a racer from California, I was disappointed that tracks like WeatherTech Raceway Laguna Seca weren’t represented. Selfishly, I wanted to use the program to help tune my car for my next trip to that track, but unfortunately, the simulation program didn’t have it represented.
The good news is the program has a Track Editor component within the software where anyone can build their own custom track. If I want to run my car around a simulated Laguna Seca, then I have to be the one to create Laguna Seca in the software. FastLapSim5 has the horsepower to make it happen.
Playing with the FastLapSim5 program, I found the Track Editor wasn’t a difficult tool to use. It allows a user to create any track they would like (for instance, the track closest to your house where you run and test the most). I could see autocrossers using this to represent a Solo2 course, which is constantly changing.
I can also visualize oval track racers using the program to help determine gear ratios for a track they haven’t been to yet or want some insight on how to set up a car before arriving in the paddock. As I was playing with the software, I decided the track I wanted to build was WeatherTech Raceway Laguna Seca. The corkscrew is just too iconic to pass it up.
In order to build a track, obviously, I needed information about it. What is the shape? What is the length? How banked are the corners? It is crucial that information going into the FastLapSim5 software be as precise as possible.
According to Kevin Martin, from COMP Cams, millions of physics calculations go into every simulation. The track itself is as important as the vehicle, in order for the simulation to provide good useful information. The term “garbage in, garbage out” applies here, so I needed to ensure my digital track of Laguna Seca is as accurate as possible.
Using this very detailed track map of WeatherTech Raceway Laguna Seca, I set out to build the racecourse in FastLapSim5. What I didn’t find inside the Track Editor was the ability to enter Cartesian coordinates, track segment lengths, or the radius of a curve.
The program is set to build a track digitally with “point-and-click,” versus entering data like “straight 642 feet, left 942-foot radius.” Even though I had a detailed track map of Laguna Seca with the radius measurements of each curve, I’m not able to enter that data. Now what? It was time for Plan B.
Since the program wanted me to click along a grid the shape of a racetrack, I decided I would trace Laguna Seca. I printed a hard copy of WeatherTech Raceway. Using skill sets I learned in kindergarten, I used scissors to cut the shape of the track, then sourced some transparent tape to stick it to my computer screen. It may sound a bit unconventional, but sometimes it is the simplest solutions that work the best.
In the Track Editor menu of FastLapSim5, there is a “Build/Add To Track” tool — the icon looks like a hammer. This tool allows for clicking along the grid to create a track. After clicking at least three points, the tool always self closes to the original first point to create a course. You can click as many points as you would like. The more you click, the more accurate the shape of the track will be.
I tried to painstakingly click along the cutout paper track as accurately as possible to make my digital Laguna Seca as precise as I could. The process wasn’t difficult since it was as simple as point-and-click. As I clicked along on the screen, the track shape began to come together.
I started with my first point near the Start/Finish and clicked along the course in counterclockwise fashion as that is the direction WeatherTech Raceway Laguna Seca is run. If the track is designed this way in the Track Editor, then the simulation in the program will run it in that direction as well.
When I was done tracing the track, I had a digital shape that looked just like Laguna Seca, but it still needed some detail work. If there was a corner that looked too blocky, I was able to use the “Build/Add To Track” tool to add points to the curve to round things out.
I used the “Set Start/Finish Position” tool to set the starting line for Laguna Seca at the correct location. Setting the correct Start/Finish point helps with accurate lap times around the track in the simulations. Now that I had the shape of Laguna Seca it was time to scale it to accurately represent the 2.238-mile racecourse.
In the top corner of my screen using the Track Editor, the length of the track I traced around the paper cutout was listed at 2.47 miles. I know from my track map and from the WeatherTech Laguna Seca website, the actual length of the track is 2.238 miles.
I needed to do some simple math to determine the ratio needed to scale my digital track so its length was exactly 2.238 miles. I took the actual track mileage (2.238 miles) and divided it by the current digital track mileage (2.47 miles), which equaled 0.9060728745. Next, it was time to use that number to scale the digital track.
Using the Track Editor, I scaled the digital track to represent the actual track with the same size and distance. I was also able to click on each of the different 57 data control points and enter the track width at each point. Laguna Seca is between 30- to 50-feet wide depending on where you are on course. There is also the ability to round out the corners at each data control point using the Curvature Scale tool.
Not only can I widen or narrow the track width, but I can also add banking to each corner using the Track Editor. I went through the entire course and banked each corner based on the data I had from my track map. This banking will assist in more accurate simulations as banked corners can be taken with higher speed, especially Turns 5, 6, and 10 at Laguna Seca.
The whole process to create Laguna Seca in FastLapSim5 using the trace method probably took me about an hour of data entry time. I tinkered with each corner, adjusting the radii of the curves to make them as smooth as the actual track, versus my clumsy pointing and clicking as I traced the paper cutout of a track. When I was finished, I had Laguna Seca in my track menu for the software and can use it over and over again.
I already created a very accurate representation of my current NASA Honda Challenge race car in FastLapSim5. Using a 1997 Acura Integra which was already in the program, I modified the car by entering dyno information, weight distribution, gear ratios, spring and shock data, wing angles, and other parameters from my real race car. Using this data to run my car around a simulated Mid-Ohio course, I was able to test different settings and simulated a new track record for Honda Challenge 4 around the track.
The good news is the simulation around my created version of Laguna Seca worked. The current NASA Honda Challenge 4 track record around the track is 1:49.850. Making some adjustments to my track width and my rear wing angle, I was able to simulate a lap of 1:48.962. That ‘breaks’ the current track record by 0.888 seconds.
The fact that the simulated times around the track are within a second of actual data from WeatherTech Raceway Laguna Seca is incredible. The accuracy is a testament to the physics calculations in FastLapSim5 and the detail work in building the car and the track itself. The process of creating the racetrack wasn’t difficult. I now know I can create any track I want, to test any car I want using the FastLapSim5 software. In the end, all it takes is a little tape and some scissors.