(This article first appeared in the March 2008 issue of SportsCar magazine)

By Philip Royle

It had been decided from day one: Project Miata would eventually turn into an Improved Touring A Club Racing car. It wasn’t until the roll cage prep work began, however, that reality hit us. This was going to be a race car. There would be no going back. And with that, we unceremoniously ripped out the carpet, tossed the stock seats aside, chucked the factory seatbelts and wrenched out the dashboard.

Up to this point, the Miata had gone through a variety of iterations. First the 1996 Miata autocrossed in Stock class trim, then in STS2, it had a brief stint in SM2, it went back to STS2 and finally the car wound up in CSP, where it will remain forever unless the Solo Events Board deems to the class ITA Miatas elsewhere.

There was a wrench in the works, however. At the time, it was early October and we wanted to make a Regional race on the Nov. 17-18 weekend – the last race of the season in our region. Work had to be done, and it had to be done fast.

Pay a shop to do this part

The point of this project has been to build a competent autocross car – not a nationally competitive one – that would be easily converted into an SCCA Club Racing car and could still autocross. Consequently, almost everything we’d installed along the way would transfer directly to Club Racing and would make the final conversion relatively simple and as inexpensive as possible.

The first step was to install a roll cage. There are a couple ways to go with this. The first is to have a custom roll cage installed. There are many advantages to custom cages, as the cage will be built around the driver, meaning there will be no question as to head clearance and harness angle. The downside is this usually takes longer than installing a pre-manufactured roll cage and the cost is often more.

The alternative is to have a welder install a pre-manufactured roll cage. Going this route can help cut costs because in theory the labor time is reduced. This method, if done correctly, can also guarantee the roll cage is completely SCCA legal as the pre-manufactured roll cages generally have already been used by Club Racers and have passed tech many times.

For Project Miata, we ordered a MiataCage.com roll cage. The roll cage is an eight-point cage that has been used in Spec Miatas nationwide, including many championship-winning Miatas – there is no doubt this cage is legal. The kit consists of 24 pieces of 1.5-inch by 0.095-inch DOM tubing and, according to MiataCage.com it weighs roughly 100 pounds installed. The kit comes with landing plates, gussets and an installation guide. The cage is also designed with NASCAR bars on both the driver and passenger side and allows for the passenger seat to be reinstalled if so desired. The kit retails for $950 and we received our kit shortly after the order was placed.

To install the MiataCage.com roll cage, we called Beta Motorsports in La Habra, Calif. Beta Motorsports owner John Coffey has been an active SCCA member for years and has competed in everything from fendered cars to Spec Racer Fords. He has also helped build many competitive Club Racing and Solo cars. We also tossed a couple other chores at Coffey, like installing the kill switch, the Cobra Imola 2 race seat we’d ordered from Sube Sports and installing the Momo Rally Model 78 steering wheel with the I/O port quick release in such a fashion that we could go back to the factory steering wheel should we so choose.

With the roll cage half installed, we returned to Beta Motorsports to test various seating positions. After measuring, marking and climbing in and out of the car a multitude of times, we decided on a seating position that would offer the best visibility while keeping the seat low. Coffey also installed the Ultra Shield six-point harness we’d ordered from OK Miata, positioned the Safe-Quip window net and attached the MiataCage.com hard top mounts.

Soon thereafter, we returned to the shop, picked up the Miata and started the mad dash of throwing parts at the car to make it pass tech.

The mad dash

We had a few weeks left to make the car SCCA Club Racing legal. We didn’t need a fast car, we simply needed something that would enable us to complete a Regional race.

The first step was to paint the roll cage. For that, we purchased Rust-Oleum black enamel, emery cloth, a can of paint thinner and a roll of masking paper. We found the quickest method of getting through the painting process was to mask the car in large sections, scuff the roll cage with the emery cloth, clean the cage with paint thinner, wait for everything to dry and then squirt as much paint as possible in every which direction. When you’re done you will have undoubtedly missed a few spots, but if your luck is like ours, the bare spots are nothing some roll cage padding can’t cover.

Speaking of which, we used a liberal amount of BSCI roll cage padding to protect ourselves from the roll cage. It’s important not to skimp on roll cage padding. While the GCR doesn’t necessitate its use, it’s highly recommended to utilize padding that meets or exceeds SFI 45.1 or FIA 8857-2001 for curved padding. If you use a different type of material, the padding may drip during a fire, possibly leading to injury. Also, in the event of an accident, softer padding may not completely stop your helmet before it impacts the cage; BSCI’s padding has great energy absorbing properties. The padding we installed is SFI 45.1 approved and cost about $20 for a 36-inch stick. It’s easy to cut through the padding with a small saw, and the adhesive backing holds the padding in place around the cage. For security, we also used cable ties around the padding.

The last items we installed were items we’d neglected to order beforehand. Luckily, before Project MX-5 went back to Mazda in mid-2007, we’d stripped out some goodies we knew would come in helpful on other projects. In the days before our Club race, we popped the hood and plumbed in the 7s Only Racing fuel test port, attached the Sparco fire extinguisher and dressed up the interior with an SV Technologies video camera mount and helmet hook.

We also realized we’d forgotten a safety item we weren’t willing to race without: a center window net. For that we placed a panicked call to MiataCage.com, at which point the company immediately shipped us a Safety Solutions net. The center window net is another item not required by the GCR, but it is highly recommended. Installed correctly, the center net not only helps direct the head in the event of a side impact, but it also helps reinforce the headrest and shoulder portion of the race seat. We installed it per the instructions so the bottom two straps cradle the race seat and the top strap connects to the main hoop. We attached the front strap through one of the car’s dash vents and onto the MiataCage.com roll cage dash bar.

As everyone knows, stickers make a car fast. When the car was an STS2 Solo car we’d ordered a set of Solo Performance Specialties magnetic numbers, and we plan to continue to use those when we autocross. For the track, however, vinyl was the way to go. For that, we contacted iZoom Graphics for the company’s LeMans Style Race Car Number Set. The set includes two white door meatballs with numbers, a hood meatball with number and two class stickers, all for $52. We also ordered a variety of other stickers, including car numbers for the rear bumper – something that is not required but the GCR recommends.

Installation of the stickers was very straightforward, although at first the task seemed daunting. All the stickers came on graphed backing paper, making trimming and lining up items very easy. The set also came with complete instructions as well as an application tool. With a steady hand, we attached the 19-inch door meatballs and the accompanying black outline with no issues. The key with sticker application is to take your time. It took us roughly two hours to apply all the stickers, including the necessary SCCA Club Racing stickers, and the result is rather attractive.

Finishing the car, we installed a set of Kumho V710 205/50-15 tires on the Motegi Traklite 1.0 wheels. We chose Kumho V710s for a variety of reasons. Club Racers and autocrossers alike have had massive success on this tire, and in fact, our Associate Editor Jason Isley has won three Solo National Championships driving on the V710. The tire has proven that it is a good choice if the plan is to autocross and Club Race on the same setup – which we plan to do. ITA rules allow for any size tire that can fit on the 15×7 wheel, so eventually we’ll test the 205/50-15 against a 225/45-15 to find the advantages and disadvantages of each configuration.

The final item we’d forgot to order was brake pads. As a base setup (and to save time and money), we purchased a set of Hawk Blue 9012 front brake pads and retained the stock rear pads. In the Nov. 2007 issue of SportsCar, we’d interviewed a number of drivers regarding tuning with brake pads and we noted that lighter cars can make-do with stock rear pads. Good front pads, however, are a necessity. This brake setup is one we’re going to tweak in a later project installment to find the best balance for our applications.

We had also forgotten to defeat the car’s steering wheel locking mechanism. A trip to the Internet revealed the problem could be solved by drilling a hole with a 5/32-inch drill bit in the small rectangular area of the forward facing portion of the lock mechanism. Centered from side to side, measure 9/32-inch from the top and with the key in the accessories position, drill until you’re through the metal casing. Install a 3/4-inch sheet metal screw in the hole and the steering lock mechanism is defeated. If you ever need the steering to lock, simply remove the screw.

To the track

With one day to go, the car was ready to make its first Club race, but then we realized the car had a stock intake, exhaust and ECU. While we couldn’t do anything about the exhaust or ECU, we did manage to cobble together an intake using spare parts from our Project Sentra. Did this increase the car’s power any? If it did we couldn’t feel it, but it didn’t hurt and it dressed up the motor.

The race we attended was the last Club race of 2007 for Cal Club Region in the Southern Pacific Division. The race was at Buttonwillow Raceway Park in Buttonwillow, Calif. While not a famous track, it is one of our local favorites. The first mistake we made, however, was not adjusting the suspension from its STS2 Solo settings. On street tires on the Solo course, we’d discovered our Miata would dramatically oversteer; consequently, we had disconnected the rear Racing Beat sway bar. At Buttonwillow, this setup meant we had to drive deep into every corner using heavy trail braking, ultimately heating the front tires and resulting in lost grip on turn-in. We plan to reconnect the rear bar for the next race. In fact, we did reconnect the rear bar and autocross the car with the Kumho V710s and the car was mostly neutral, but it was far more drivable with the rear roll bar connected on the V710s then with the rear bar connected on the Hankook Ventus R-S2 street tires we were using in STS2.

We’d also never weighed the car before going to Buttonwillow. After the race, we pulled the car on the scales and discovered the Miata was 97 pounds underweight. That will obviously be fixed before the next race, too.

There’s a lot we plan to do before the next Club race and autocross. While adding power is on the agenda, first up is to get a good baseline suspension setup performed by people who know what they’re doing. Up to this point we’d simply installed the Koni 8041 RACE shocks and Eibach springs, set the ride height to 5.25 inches, set camber at -2.0 degrees and the toe to zero. The car has performed admirably, but we know there’s a lot of untapped speed. From there we’ll fish for more power, and who knows, we may even work on our driving.

SOURCES:
Beta Motorsports, http://www.betamotorsports.com

BSCI, http://www.rollbarpadding.com

Hawk Performance, http://www.hawkperformance.com
I/O Port Racing Supplies, http://www.ioportracing.com
iZoom Graphics, http://www.izoomgraphics.co
m
Kumho Tires, http://www.kumhousa.com
MiataCage.com, http://www.miatacage.com
Momo Italy, http://www.momousa.com

OK Miata, http://www.okmiata.com

Safe-Quip, http://www.racequip.com

Sparco USA, http://www.sparcousa.com
Sube Sports, http://www.subesports.com
SV Technologies, http://www.svtek.com