If Formula 1 racing is the top rung of motorsports, autocross is probably at the bottom. Autocross is generally hosted in a parking lot and the track is defined by cones. The format of the "race" is a time trial, one car is sent out at a time and the fastest time wins. You receive a time penalty for each cone you hit.

Autocross is one of the most accessible forms of racing. You can show up with just about any car, and compete against people in similar cars. The course setup and generally low overall speed minimize the chance of property damage.

This event is hosted by BMW CCA, and the classifications, as a result, are amusing: all non-BMW cars are in the same class. As a result, our Miata is in the same class as this open-wheel racecar:

Nor does the Miata qualify for any points, but about 50% of the cars there weren't BMWs, because racing cars is fun as hell.

I did two sessions to understand how our bone stock car stacks up. In Autocross the most competitive mods are generally great tires and suspension. The Miata does come with a reasonably competitive suspension from the factory. The suspension design: a double wishbone suspension is generally something you find on high-end sports cars.

So that's good, but our suspension is 27 years old, and if you look closely much of the rubber boot is frayed:

There are other pretty "tired" components like our bushings that are likely holding us back as well.

The tires we're running are also possibly the worst tires for this setting. They're all-weather hard-compound tires that are pretty practical for life as a daily car. But it is very impractical for racing cars around a parking lot (a very practical activity).

But nonetheless, Autocross is a very welcoming environment so I gave it a shot.

This event is particularly lax in the way that they don't require convertibles to install a roll cage. Tech-inspection is primarily an individual responsibility which is genuinely rare in motorsports. With the setup of this event, I also got to bring a buddy who could drive the Miata without reducing any of my seat time. For the first session, I brought my Dad who very quickly discovered that racing seats are uncomfortable. And the second time I brought my best friend Travis who took a handful of these photos.

Quickly after arriving you realize that not only will you be driving your car, but you'll also be a volunteer for running the event. Volunteers run out onto the course to fix downed cones and report when cars go off track. It's not always clear where the cone goes...

Even at low speeds the process of trying to improve your time lap after lap is quite fun. It rapidly becomes an exercise in memory, if you're thinking about where to go you're probably not doing as well as you could. Hesitation at the limit of traction probably means you're going to hit a cone or go off track. A few cones were destroyed by me:

Between the first and second sessions, I installed a bunch of telemetry in the car, to better understand how I'm doing, but also give me some time between sessions to try to remember the track better:

After the event concludes race results are released: https://www.njbmwcca.org/event_info/results/autox_20231008_fin.htm. During our second, we completed 47th overall with 60 total contestants. And within our (relatively meaningless) class we were 30th out of 37th.

It's fascinating to see how all these cars stack up, and something I found particularly inspiring is that the value of our car is probably one of the lowest in the event overall, and the first session was won overall by a Miata.

It was also fascinating to see the incredible variety of cars at the event:

There were some dedicated, prepped, exotic track cars:

Some expensive cars:

Some unsuspecting stuff:

And some adorable stuff:

Overall I had a blast and I look forward to bringing more of my buddies to this eclectic weekend event, building the car, and building my skills up.

What's next for the car, is as expected: fresh tires, and fresh suspension. Before the next event, this is what we'll be taking care of.

• Address the chip in the windshield

• Make the window go up and down faster

• Change the fuel filter and oil

Windshield chip

While I was driving on the highway a rock flew up and hit my windshield. I considered having Safelight repair it. So far I've figured out how to do everything on a car myself, so I was curious if I could do this as well. I compared a few windshield repair kits I went for one from Permatex.

The process involved using the syringes and the pedestal included in the kit to inject a resin into the damaged area. This damage is probably towards the extreme edge of what this kit can handle, so I don't expect perfection. I'd just like it to be less distracting and less likely to grow into a larger problem.

Overall this went pretty well. It's not flawless and you can spot it if you know what you're looking for. But it's very easy to register it as a smudge and ignore it. On a smaller chip I think the results would be closer to perfect.

Window speed

It takes almost 20 seconds for my passenger window to roll up and down, and it takes about 15 seconds for the drivers side. And so, into the door we go to see what's going on. If everything is intact, we'll just clean and lubricate the path the window takes. If anything is broken I expect it to be the window bushings. So before I got started I grabbed a set of replacements just in case.

My dad and I pealed back the layers of the door, and on the drivers side just cleaning and lubricating was all we had to do. Doing this brought down the window travel time to 5 seconds. On the passenger side when we pulled out the window we saw that a bushing was missing.

At the bottom of the door we saw the many pieces that used to make up the old bushing. I fished them out while my dad applied the new bushing. Like the driver's side we cleaned and greased the rails. Once the door was back together the window went down in 5 seconds like the driver's side. Success!

Getting into the door was a bit of a hassle, mainly due to the vapor barrier that's adhered to the door. Unfortunately, looking at our outstanding issues, this won't be the last time we have to get in here.

Other Maintenance

I got a new Bosch fuel filter. A pretty straightforward procedure, but I'm not sure it's possible to do without getting gasoline on yourself.

When I went to change the engine oil, I found that the old oil filter was surprisingly difficult to remove on a car that's otherwise been very easy to work on. Always a bummer when you have to wait for a tool to show up to complete a job. But ultimately, with the new tool, the old oil was drained, and a round of fresh oil was poured. I used an oil filter with a nut on top just to give me another option for removal in the future.

Outstanding items

• Our windshield has a big chip in it.

• Oil change, and fuel filter replacement.

• Driver's side mirror wobbles a lot.

• To race, we need a roll bar in many classes, and a 4 point harness in some classes.

• There's a vibration at 85+mph. And there's a squeal during deceleration. I suspect the driveshaft.

• The stock suspension is very soft, I plan to install adjustable track oriented suspension and install harder polyurethane bushings in place of the 25 year old rubber bushings - the inherent softness of rubber has not been helped by age.

• The speakers sound very bad, and the head unit decides to beep a strange Sony theme song as a goodbye every time the car turns off.

• The windows move very slowly.

• The prior owner broke his key in the ignition, and as a fix decided to replace just the ignition assembly without changing the other locks in the car. So the car has 1 set of keys for the doors and a separate key for the ignition.

• The brakes fade very quickly, the pads and fluid may be at the end of their life. But it's common to just upgrade to Flyin' Miata's Big Brake Kit for a larger thermal capacity.

• Once all of these issues are sorted out, we'll embark on the journey of making more power.

Steering wheel

Presently, as I drive, the steering wheel deposits 25 year old leather crumbs into my hand. Let's try to replace it with something newer. I disconnected my battery so the airbag wouldn't deploy as I removed the old steering wheel.

Out came the old wheel, and in went an NRG quick release hub.

This hub allows the driver to detach the steering wheel prior to getting out of the car. The Miata is a small car, and once a race seat is fitted there will be limited thigh-room. Having the option to remove the wheel makes it easier to get in and out.

The final diameter of the steering wheel is much smaller which results in a sharper handling feel.

Seat

Next up is the seat: the current seat is torn in a few places. Additionally, it doesn't provide much support when cornering hard. Ultimately this car will have a 4 point harness and at that point changing the seat won't be optional.

I grabbed a pair of Sparco Sprint seats, with some Sparco mounting brackets. The Sparco Sprint seats fit in the NA Miata without having to modify the door cards or hammer in the transmission tunnel. Commonly, people will mount the seat directly to the car and give up the ability to adjust their seat. I want other people to be able to drive this car so I chose to mount the seat on the stock sliders.

I cleaned out and regreased the slider. After a mild amount of cutting and persuasion the seats were attached to the mounting brackets, and the mounting brackets were bolted to the sliders.

These seats are track oriented bucket seats. They provide strong side bostering to hold you in place when you're cornering hard. Donut media illustrated the difference between most stock seats and bucket seats in this video (jump to the end to see how bucket seats perform).

I'm not sure exactly what classes I'll be competing in long term, but thankfully these seats are FIA certified until 2028, which provides me with a large amount of flexibility.

Shifter assembly

Like the steering wheel, the shifter knob disentegrates everytime I glance at it. The knob presently rotates freely, and heat radiates from the leather boot which is torn.

I disassembled the entire shifter assembly, finding every layer to be in bad shape along the way. I also found Teflon tape under the universal shift knob.

In the shifter assembly there's nylon bushings which degrade over time, I grabbed a shifter rebuild kit and replaced all the nylon pieces.

This made the shifter feel more precise and notchy. I also replaced all the rubber boots, and added fresh heat insulation. Because of the rebuild and the transmission service we performed earlier, the shifter now feels like it did 25 years ago.

With these 3 changes the interior is starting to be a very pleasant place to be.

Outstanding items

• Our windshield has a big chip in it.

• Oil change, and fuel filter replacement.

• Driver's side mirror wobbles a lot.

• To race, we need a roll bar in many classes, and a 4 point harness in some classes.

• There's a vibration at 85+mph. And there's a squeal during deceleration. I suspect the driveshaft.

• The stock suspension is very soft, I plan to install adjustable track oriented suspension and install harder polyurethane bushings in place of the 25 year old rubber bushings - the inherent softness of rubber has not been helped by age.

• The speakers sound very bad, and the head unit decides to beep a strange Sony theme song as a goodbye every time the car turns off.

• The windows move very slowly.

• The prior owner broke his key in the ignition, and as a fix decided to replace just the ignition assembly without changing the other locks in the car. So the car has 1 set of keys for the doors and a separate key for the ignition.

• The brakes fade very quickly, the pads and fluid may be at the end of their life. But it's common to just upgrade to Flyin' Miata's Big Brake Kit for a larger thermal capacity.

• Once all of these issues are sorted out, we'll embark on the journey of making more power.

As a recap, I picked up this '97 Miata a couple of weeks ago.

Now that it's in the garage, it's time to take stock of our new toy. So the car has 113,000 miles at the moment. In the manual, the largest maintenance interval is 60k miles, which means anything that I'm not absolutely sure was done needs to be done now. So what do we know about this car so far?

I mentioned I was pleased with the vehicle history report, to summarize it said:

• The car has had about 4 prior owners

• It's been owned by people who serviced it at dealerships throughout its life. This means it's bone stock, and pretty well maintained. I'm surprised about the couple of items I don't see on this list, but we'll get into that later.

• Apart from the oil changes and various checking of parts, the carfax reports the following items have been replaced:

  • water pump

  • radiator hoses

  • camshaft position sensor

  • distributor seal

  • clutch slave cylinder

  • radiator clamps

  • thermostat, housing, and gasket

Nothing alarming there. Among other things, absent from this history report are transmission and differential fluid change. That's pretty easy on these cars, there's a fill bolt and a drain bolt. The fill bolt is at a location that constrains the maximum amount of fluid, so you drain the old fluid and pump in the new fluid until you see it overflow.

Also absent from the history is any record of spark plugs being replaced. Easy enough:

These were way past due, you shouldn't be able to tell the gap difference with the naked eye. Also replaced the plug wires while I was at it, kinda cool to see a company make the same product for over 30 years.

While I had the car jacked up, I saw that one of my fender liners was held up by thoughts and prayers:

Removing the fender liner revealed the fasteners underneath, this car was repainted at some point, possibly the shop that did it kept these down here to not lose track of where they came from. Good effort. Now only a handful are missing and are on the way from Amazon.

It took me a while to track down an annoying squeak: turns out it was coming from the hood latch.

I tried greasing it which helped for a small amount of time. There is some play in the mechanism you use to unlatch the hood but I don't immediately see how I could adjust it without adding washers. Perhaps the problem is how much the chassis flexes in general. I plan to stiffen the car a few different ways, including shock tower bracing that looks something like this.

This sort of bracing is OEM in some Miatas, but not this one. For now, I'm just going to make my hood latch not be metal by wrapping it in some electrical duct tape. It's not great, but I have bigger fish to fry.

Speaking of annoying noises, there was a rusty metal rattling coming from the exhaust, and I didn't need too much of an excuse to replace the exhaust of a vehicle. I opted for a higher-end Borla cat-back exhaust.

I struggled tremendously to get the original oxygen sensor out. I used 3/4 of the techniques in my arsenal. I started by hitting it with some penetrating fluid. Upgrading to a "cheater bar". I even tried dremelling out the old threads to create a slight relief channel. I stopped short of using MAP gas to heat the threads because I couldn't find my blow torch. Ultimately I just cut the wire on the old oxygen sensor and grabbed a fresh one from Autozone. So far the exhaust sounds great, it's a bit understated but I'll probably need to wait a couple hundred miles before I know what the real tone will be.

And that's some of the low-hanging fruit on the exterior of the car. Next up we're going to tackle this crusty old interior.

So in my exploration, I considered a number of platforms, I have a bunch of experience with Audi, but I wanted a more traditional rear-wheel drive, manual sports car. Audis are generally AWD cars, and manual variants are rarer due to a pretty good dual-clutch transmission. BMW seemed like a good iteration, I could get something newer and treat it as a normal second car for a few years and then turn it into a track car later. Or I could get something older and begin building immediately. I ended up shying away from this option for a few reasons.

• Luxury German cars start their lives as a racecar much heavier. This means you’re going to run through consumables like brakes, and tires much more quickly. And you have to make more power to be competitive.

• You’re paying a tax for the brand name at every interaction. Performance upgrades cost more when you want to go faster, and replacement parts cost more when you go too fast and break things.

• You’re more often fighting the manufacturer who wants you to bring the car into a dealership. When you’re changing rear brakes on vehicles that have electronic parking brakes you sometimes have to put the car into a service mode. On a Ford vehicle, this involves pressing and holding a couple of buttons while you start the car. On Audis, this procedure can only be done either through a dealer or by using a grassroots OBD2 bluetooth device and app which costs a micro-transaction for a variety of such services. There are also generally more luxuries in your way which the removal of may not be handled particularly gracefully by the car (racing seats and steering wheel come to mind).

After mulling this over I knew I was either choosing an American pony car (Mustang / Camaro / Corvette) or a Japanese Tuner (Miata, Z, BRZ, Supra). This was a tough choice as I’m a die-hard American, and I presently have an F-150 and surely some of that mechanical familiarity would transfer over to a Mustang. Chevy LS swaps are also pretty sick. But ultimately I opted for the foreign import for the lower cost of entry. I was particularly blown away by what I saw surrounding the Mazda Miata.

Depending on your criteria you can probably get into a Miata for as low as $4k. To most Miata grey beards this is an all-time high price, it’s not uncommon to hear about someone getting a basic Miata for $1k a couple of years ago. This leaves plenty in the build department. This also leaves plenty in the replace-the-car-if-I-destroy-it department.

And boy can you build. Anything you saw them do in a Fast and Furious movie you can do to a Miata. Almost every part is widely available and inexpensive from a restoration perspective. There are a number of companies dedicated to providing specifically the Miata with aftermarket parts like Flyin’ Miata. There’s a rich knowledge base in forums and on YouTube. Donut Media (one of the largest car YouTube channels) did a series of videos building a track Miata. There are a number of performance strategies being explored including:

• Turbocharging

• Supercharged Miatas

• Swapping engines to the reliable and more powerful Honda K-Series motor

• Swapping engines to the monstrously powerful LS V8

• Or dropping ~35% of the weight of the Miata to create the Exocet

The Miata is a “generation” based car, like the Jeep. In its lifespan since 1990 there have been 4 generations of Miata: NA (‘90-’97), NB (‘98-’05), NC (‘05-’15), ND (‘15-). They all have a very similar personality:

• Very light

• Great handling

• Not that powerful

The price gets rather high in the NC & ND range and I’m not sure it’s as compelling a purchase. The NA and NB Miatas however, are maybe the best value in the niche I’ve described so far. A great value means more room in the budget for building (and replacing the car if I go into a wall at 110mph).

There is however a key distinction between the NA and NB.

The NA Miata has pop-up headlights which make the car cute and charming.

The NB Does not.

So NA Miata it was, and NAs are a little rare in my area. But even within the NA Miata there’s a faction. During ‘90-’93 the Miata used a 1.6L engine, ‘93 onwards they used a 1.8L engine in the US (~10% more powerful). I found that this engine has a ~$1k premium. The second performance bit I was looking for was a Torsen Limited Slip Differential. A differential helps your drive wheels rotate at different speeds in turns. In traction-limited settings (off-road or while shredding tires) a normal differential will allow the power to get sucked into the wheel that loses traction, which guarantees that wheel will not regain traction. An LSD helps deliver power to both wheels regardless of traction levels. In my search, an LSD inflated the price of the car another $1k.

And so, for $8750 I picked up a British Racing Green, M-Edition Miata from ‘97 with ~113k miles. The color is rare and is also my wife’s favorite color. Doing a test drive, finding no rust, and seeing an above-average service history sealed the deal for me.

I’m excited to use this blog to share the journey this Miata will take as it is restored, modernized, and upgraded for the race track.