In attempting to keep with my catch phrase "The best things come out of Iowa," I have begun building my Miata without any regard for SCCA classing. If you don't already believe the best things come out of Iowa, then just take a look at Ron VerMulm's E mod Camaro
Starting from the beginning.
It's December 2014, I had a big fat insurance check from somebody totaling my daily driver a month earlier. I find myself contemplating the purchase of a Miata almost two times a day. At that point, I did what any general car enthusiast does and I hit the forums for information and the local craigslist to see what I could dig up. After some research, I had decided that I wanted something with the Torsen and a 1.8, preferably on the NB platform.
After a couple weeks I found this "gem" on craigslist. It was a price I could easily afford, and it checked the box on every single one of my requirements.
Throughout the summer, I campaigned the car locally in E Street with a set of BFG Rivals and some Carbotech brake pads (1521 front and ax6 rear). I was always on the pointy end of the class, even with old and worn out suspension. I even won a local series quite handily (though, the classing is a bit...easy to cheat... more on that later). Things were great, I was getting used to driving the car, but I just kept on wanting more.
At the end of the season, I decided it was time to step up a class or five... into D Prepared. At the time, I saw this as the set of rules that would best allow me to achieve my goal of a modest power - super lightweight car. So, I put the car up on jack stands and started tearing it down, getting rid of everything that isn't necessary for race car things.
A few hours into the tear down process, I had some not so pleasant findings...
After finding all this rust (on both sides of the car), I decided it was a good idea to check the strength of said rails. This is the result.
As you can imagine, I was completely devastated. I spent weeks trying to come up with a plan to fix the rust. Should I try to cut it out and weld some new metal in? Oh wait, I have zero welding skills. Maybe I can afford to have somebody else fix it. But then on second thought, that's probably going cost more than the car is worth.
After discussing some possibilities with a friend that lives in Arkansas, I had come to the conclusion that it was most economical to just start over with a new (to me) chassis. Fortunately for me, he had a friend who had just tested the strength of a concrete barrier with the driver side fender of his NA6 and was looking to offload it for a very low price. After pouring over the literally dozens of pictures he took of nearly every square inch of the car, I decided to pull the trigger on it. We met half way in Warsaw, MO (which is kind of funny since he is German born). After viewing what is quite easily the cleanest Miata I have ever seen in my lifetime (aside from the light body damage), I handed my cash over, and it was time to start the 5 hour trek back to Iowa.
Here it is the day after I brought it home (with my TRM C1s on it).
At this point, I had done enough reading to know that I had just procured the lightest Miata and already owned the Miata that has a powertrain that would support my modest goals. It was like a match made in Miata heaven, but one thing was missing. Racecar parts. In order to remedy this, I called Emilio at 949 up and discussed my short and long term build goals. A couple weeks later, I placed my order, and all this showed up at my doorstep. Ignore the second swaybar, that belongs to a friend that added his order on top of mine to save on shipping.
So far, a pretty standard "I'm building an autocross car" thread.
This next part requires a little bit of background information about myself. I work as a technology specialist in a middle school. Part of my required duties is teaching 7th and 8th grade level engineering/technology classes. We spent a month working with Autodesk's Fusion 360 3D modeling software. In order for me to effectively teach that software, I first had to learn how to use it myself. What better way to do that than to design race car parts? I started with something fairly simple: a front splitter. After that was done, I decided to tackle rear wing design.
This opened up a whole can of worms for me. What air foil should I use? How wide should this thing be? How long should my cord length be? And lastly, the question that would determine the answers to the previous questions... Do I care about breaking any rules about aero? If you can see where this is going, the answer to that last question is positively a "NO".
After arriving at this conclusion, I started doing research. Most specifically on how to make lots of down force at relatively low speeds. After several failed ideas, and some brainstorming with an engineering buddy of mine, a light bulb came on. That lightbulb was Formula SAE. They know how to make downforce at low speeds.
After reading some dissertations written by some graduate students, I finally settled on an airfoil profile that I wanted to try for iteration #1. After choosing the profile, I did some math. Theoretically, with the cord lengths I chose, the wing should make ~70 pounds of downforce at 27 miles an hour. ~280 pounds at 54 MPH. ~1,120 pounds at 108 MPH. All at maximum angle of attack before it starts to stall.
The second best part about it is that it looks completely ridiculous when attached to the car.
After getting everything the way I wanted it, I sent the profile to a CNC foam cutting company. A few weeks later, I had some foam cores that will soon be fiberglassed.
Yes, it's massive... and it looks smaller than at that angle...than it does at this angle:
Next on the to do list was to install all my parts from 949 and the torsen out of my 99.
All suspension parts installed! Let's not forget to put the giant MAZDA stickers on the sides.
Next on the agenda was to get wheels and tires. Now, before I divulge any more, I'm going to note that I know this is not the optimal setup for the tire/wheel size.
I ordered a set of Konig Dial-In 15x9s (which will become my street wheel after this year) and Hoosier R25Bs in 23x9.5R15. This is another point where I decided that I was going to run what I want and not care about what class I'm going to get thrown into.
Here, have some more pics: