Bringing the professionals’ tricks to the clubman racer | Articles

Spec Miata

Spec Piñata, Smash Miata, Spinning Monkeys: Call it what you will, Spec Miata is the road racing success story of the decade. The first prototype hit the track late in 1998, and today Spec Miata features packed fields of closely prepared Miatas battling lap after lap for the win. Credit cheap donor cars, nimble chassis designs, judicious modifications, and just enough power to be fun. A bonus is that the guys in Mazda’s glass tower also care about the class.

The Spec Miata rules for car preparation are well thought out, starting with a suspension package that’s readily available from Mazdaspeed Motorsport Development, the company’s competition arm. Bilstein shocks, Eibach springs and Mazdaspeed anti-roll bars are all called out by specific part numbers. 

From there, participants must run 15×7-inch wheels that weigh at least 13 pounds apiece—a rule designed to eliminate the need to tie up five grand in a dozen 10-pound wheels. Tires, which are usually a budget-killer, must be 205/50R15, usually an inexpensive size.

Most SCCA and NASA groups specify either a Toyo, Hankook or Hoosier, but both of the year-end finales call for Toyos as the spec tire. Surprisingly, tires are one of the simplest parts of the equation, since racers have found that shaved—but not fresh—Toyos are the way to go; well-worn examples were on all the top cars at the season-ending championships. 

You’ll notice that we mentioned both SCCA and NASA in the preceding paragraph. That’s right, Spec Miata is a popular national-level class with both sanctioning bodies. The rule sets for the two groups are essentially identical, making Spec Miata a stellar class for racers in just about every area of the country. (In fact, several independent regional groups have also adopted the class.)

The rest of the Spec Miata rules are simple and easy to understand: open exhausts are okay; 1.6-liter cars can run a high-flow air intake; a limited-slip differential can be added; and the 1.8-liter Miatas must receive a restrictor plate. Minimum weights are used to equalize the different cars, meaning that a 1.6-liter car has to haul around less weight than a later 1.8-powered racer. Of course, the latest approved safety gear must be run, meaning full cages, race seats and harnesses.

The goal is a class that allows a team to adjust and tune the car to make it faster without creating a giant money pit. A typical enthusiast can build a race car for about $10,000, including the cost of a good running Miata. While that won’t guarantee a pole position, neither will buying a fully prepped car from a race shop at three times that amount. 

To the Front!

Say you’re five or six seconds a lap behind the leader. Do you really think that cheating is going on? Can you say that without sounding like a bowl of sour grapes? 

Let’s assume that the leader is not breaking the rules, and instead is just better at this whole racing thing than you are. What is causing the difference in lap times? Is it in the car? Does the driver out front know a special secret for Spec Miata power? Could it be a magical alignment setting? A pact with the devil?

We trucked out to MotorSport Ranch in Cresson, Texas, to find out just where the pros get their power and speed. We picked one of the fastest Spec Miatas in the country, as well as one of the fastest Miata drivers, to serve as our benchmark. 

Two mid-pack racers were also asked to bring their cars to the party. We chose two regular Midwest competitors who have had good, solid efforts, but have yet to break into the ranks of the truly fast Spec Miata frontrunners.

Traqmate data acquisition allowed us to keep tabs on our drivers and gather lap time data. The drivers were asked to switch back and forth between their own cars and our pro mule. After baselines were gathered, we took the cars to Team MER’s shop, located on the grounds of MotorSport Ranch, to see if we could even up the gaps between the fast and the fast-nots. 

Let’s meet our players.

Pro: Jason Saini

• occupation: race car driver
• age: 30
• height: 6 ft. 3″
• weight: 200 lbs.
• exercise regimen: treadmill daily, mountain biking
• race day nutrition: nutritional smoothies, keeps hydrated
• races per year: 8-10

Jason Saini started autocrossing in 1991 in a Ford Escort. He later graduated to a Volkswagen Corrado and then a Honda S2000. He won a pair of SCCA national Solo titles with the Honda, nabbing jackets in both 2003 and 2004. 

Jason started road racing in 2004 by jumping feet first into the Pro Spec Miata class. He ran there for two years before switching to the MX-5 Cup in 2006, finishing second in that inaugural year’s championship series. In 2007, he won the MX-5 Cup championship, entitling him to a full season of SCCA Speed World Challenge racing thanks to Mazda’s ladder system for up-and-coming racers. For 2008 Jason has a seat in the Tri-Point prepared Mazdaspeed/StopTech/Racing Hart Mazda6; he started off the season with a ninth-place finish at Sebring. It’s not surprising that Jason feels this is a big dream come true.

1994 Miata

• owner: SafeRacer 
• engine: 1.8 liter
• number: 30

The SafeRacer Spec Miata that participated in our test is one of several cars that the team of Charlie James and Mike Asselta fields to promote their safety supply business. They attend an average of 12 race weekends per year, including the SCCA Runoffs. To say that the SafeRacer car is a great example of a fast Spec Miata is no stretch—there are plenty of consistent top finishes dotting its logbook. At last year’s Runoffs, Andrew Caddell put No. 30 on the pole and wound up second.

This 1994 Miata began its new life as a race car by being stripped to a bare shell. The team then removed all of the undercoating and sound deadening to reduce weight and make the whole car easier to work on. A custom roll cage was welded to the unibody; the front legs extend through the dashboard, maximizing interior room and safety. The whole car was then repainted a basic refrigerator white, making oil leaks easy to spot. The Miata was painstakingly rebuilt to the letter of the rules. 

Clubman: Chris Edens

• occupation: wholesale wheel dealer
• age: 23
• height: 5 ft. 7″
• weight: 140 lbs.
• exercise regimen: Nothing specific beyond some running, but says he “tends to slack off in off-season.”
• race day nutrition: “I don’t eat much on race days, but I do drink a lot of Monster energy drink.”
• races per year: 5

Chris’s racing career began when he was just 11 years old with Briggs racing karts. He later jumped to faster shifter karts in both dirt and asphalt racing series. 

Chris started SCCA road racing with a Formula Ford, but was disappointed with small fields. He and his dad then converted his Miata to a race car to take advantage of Spec Miata’s healthy level of entries. Edens and his dad are on a tight budget, attending just five races a year. 

1993 Miata

• owner: Chris Edens
• engine: 1.6 liter
• number: 26

The Edens’s 1993 Miata was built in their home garage in Sherwood, Ark. Looking at it, however, you wouldn’t be able to discern its humble origins. It’s one of the cleaner and better-finished Spec Miatas we’ve seen on track. 

Part of the credit for the clean aesthetics goes to the custom paint, which cost the crew just $13—the price of two dozen doughnuts for some friends at their local Pulaski Technical College autobody shop. 

For safety gear, the Edens installed a Miatacage.com kit, which made for a clean and simple build. A Momo seat and steering wheel interface with the driver, while a set of G-Force Racing Gear belts keep Chris in place. 

Clubman: Mike Babin

• occupation: FedEx pilot
• age: 55
• height: 5 ft. 9″
• weight: 215 lbs.
• exercise regimen: “I work out a little, but clearly not enough.”
• race day nutrition: “Not much appetite, but I do drink a lot of water.”
• races per year: 4

In his past career as a Navy pilot, Mike learned how to deal with that heady concoction of fear and adrenaline. It came as no surprise to his friends when he chose road racing during his off hours to satisfy his addiction to speed.

Mike has been road racing for five years, four of which have been in this Spec Miata. He admits that he’s a consistent mid-packer who attends just a few races a year, when his pilot’s schedule allows. He does have the advantage of listing Cresson, Texas, as his home address, which is also home to our MotorSport Ranch test track. 

1994 Miata

• owner: Mike Babin
• engine: 1.8 liter
• number: 87

The car was built by Dave Stewart in Memphis, Tenn., several years ago; Mike purchased the car in 2004. The Miata was reasonably straight and clean, so there wasn’t much preparation needed to make it into a presentable race car. 

The interior was stripped for the installation of the Stewart-built roll cage. Unlike the other cars, the forward legs of Mike’s roll cage don’t go through the dashboard. This is an easier and less expensive way to build a cage, but it sacrifices some egress. 

After the required Mazdaspeed Spec Miata suspension was installed, along with all of the necessary safety gear, the car was raced for several seasons without incident. Some engine trouble in 2006 led to a full long-block rebuild by Jim Drago.

Setting Baselines

Now that we’ve introduced our players, it’s time to hit the track. We sent our drivers out onto MotorSport Ranch’s rolling asphalt to set some baseline laps. All three of our drivers have dozens of race weekends under their belts at this track. 

After the initial warm-up we called everyone back to the paddock to reset tire pressures. They were then sent back out on track for some timed laps. Everyone was evenly spaced to avoid any bunch-ups. 

All three of our drivers were consistent during this outing, posting no real outliers—they were all turning stable lap times with little variation. This told us that each of them was comfortable and wasn’t trying to pull out a flier that would skew our data later.

Jason quickly ripped off a 1:25.179 lap, a pass that was within a few tenths of the Spec Miata track record. Clearly our pro was on his game. Mike Babin was about 4.5 seconds back, turning a 1:29.793. Chris Edens was also well off the leader’s pace, turning a 1:31.443 in the same session. 

A four- to six-second deficit per lap is a huge chunk of time on such a small track. After a 20-minute race, for example, the back markers would be in danger of being lapped by the faster traffic. We had our work cut out for us. 

Key Swapping

Our drivers then swapped keys and went back out to see how much of their lap time differences could be attributed to the car, and how much was the loose nut behind the steering wheel. Jason evaluated both Mike’s and Chris’s cars, while Mike and Chris each drove the pro car to see what they were missing. 

Jason turned a 1:26.132 in Mike’s Miata, beating its owner by about 3.6 seconds. Despite that fast time, Jason said that Mike’s car was very sloppy and slow to react. “The car leaned over slowly as the suspension took its set, then it had a tendency to lose grip once the roll was done,” Jason explained. On the plus side, at least the power was there, though he added, “It was not quite as crisp and willing to rev as the pro car.”

Chris’s car was clearly in need of horsepower, with Jason struggling to keep up at 1:29.593—only about 1.85 seconds faster than its owner. “It was grossly down on power,” Jason noted. “As a result, the handling was a bit hard to determine since it was so slow—I couldn’t carry much entry speed, since straight-away speeds were so low.” 

Jason said that Chris’s car felt tighter than Mike’s, but not as much as the pro car. “It was slower to react, mostly due to the extra ride height,” Jason explained. “The car felt well balanced, if not a bit pushy on corner exit.” 

Next we put Mike in the SafeRacer ride. Despite some problems with ergonomics—Mike’s long torso and short legs required some extra lumbar padding—he turned a 1:29.045, about seven-tenths ahead of the time he posted in his own car.

Mike noticed that the pro car’s clutch had a somewhat shorter throw than his own. The pedal travel was the same, but there was a shorter distance between the fully engaged and fully disengaged positions. He noticed this most when leaving the paddock, but it wasn’t such a problem out on track. Given some more practice in the car, Mike felt that this difference might be exploited into quicker shifts.

As far as handling went, Mike loved the pro car’s sense of lightness and nimbleness in the turns. “The pro car would turn in quicker and [seemed] lighter throughout the turn,” he said. “It would take a set quicker, but then steering had to be played through the turn. My car understeered a bit at turn-in, but once set, felt more solid. On corner exit, balance was about the same, both tending to understeer slightly under power from apex to track-out.”

Both cars accelerated about the same, Mike said, but he added that the pro car would occasionally get asymmetric wheelspin if he touched a curb at apex or track-out. “Once or twice I thought there might be an LSD problem,” he added.

Jason also felt the weakness in that car’s factory differential. “The SafeRacer Miata would spin the inside tire up under load, which actually helped keep it from understeering as much coming off the corners,” he explained, showing how a pro driver can turn a perceived weakness into a strength. 

Next we put Chris in the pro car for a few laps. He clicked off a 1:28.815—just a tick quicker than our other clubman driver. Predictably, Chris enjoyed the power of the SafeRacer Miata. “The power was impressive, especially compared to my poor, underpowered 1.6.” 

Chris felt that handling was very similar to his own car’s, echoing Jason’s statements: “Handling-wise, the pro car didn’t seem to handle that much different—it had slightly more rear grip, maybe.” Chris noted that the pro car seemed a lot lower in the front than his car, “which made it bounce over some of the bumps.”  

With our baselines squared away, it was time to head in and see how we could improve the lap times. We had plans to improve both our cars and drivers. After all, it takes the two elements together to make a winning combination.

Pro Power

Our first stop was the MER dyno to see how our three cars compared in terms of horsepower and torque. MER’s Dynojet chassis dynamometer was operated during our test by Springfield Dyno’s Sam Henry, an expert in wringing power out of a Spec Miata. He’s a fellow Spec Miata competitor himself.

The SafeRacer car churned out 121 horsepower to the rear wheels.

The SafeRacer Miata has a Sunbelt-prepared engine that is rebuilt annually just prior to Runoffs. (While the Spec Miata rules require a stock engine, gains can be made by working within the factory tolerances.) During the regular season, the engine is given leak-down and compression tests after every race weekend. The engine is put back on the dyno every three weekends to make sure it’s still putting out the proper amount of power. 

Mike Babin’s 1.8-liter Miata went from 117 horsepower to 119 horsepower with a few tweaks.

And what is the proper amount of power for a topflight 1.8-liter Spec Miata? The pro Miata churned out 121 horsepower on MER’s rollers. These numbers are a couple of points lower than Sam usually sees for this car on his own Dynojet dyno, however, illustrating how actual chassis dynamometers can vary. 

The Edens’s 1.6-liter was well down on power, but we did manage to gain 12 horsepower in a few pulls with some key part swaps.

Sam and the rest of the team also know some tricks that make consistent power in a Spec Miata. Joe Gibbs 20-weight engine oil is used to minimize the parasitic drag, and it’s only filled to the bottom end of the dipstick range so the crank doesn’t cause any foaming issues. The lower-weight oil causes the engine to use about one quart per race weekend, but so far there haven’t been any signs of extra bearing wear. 

Pro Knows Suspension

Once we had addressed the cars’ straight-line speed potential, it was time to pull them out of the dyno side of the Team MER shop and head over to the scales for some handling and chassis tweaks. 

The first Miata to roll across the scales was the SafeRacer Pro car. With Jason sitting in the driver’s seat and just vapors in the gas tank, it weighed in at the bare minimum, hitting the required weight: 2350 pounds on the nose. The crossweights were also pretty close at 49.5 percent, and this “de-wedge” actually helps the car around MotorSport Ranch’s predominantly left-hand turns. Clearly, nothing was left on the table. 

Next we put Chris Edens’s 1.6-liter car on the scales. It was surprisingly heavy—not good, since this should be the lightest car of the bunch. Plus, Chris was our lightest driver. The car had 100 pounds of ballast bolted to the right-hand floor pan; fuel load was estimated at about five gallons. 

The Edens car was considerably over its 2300-pound minimum weight. There were a few factors at work here: For one, the minimum weight for 1.6-liter Spec Miatas was lowered by 25 pounds, to 2300 for the 2008 season. This is why drivers need to stay on top of the rules.

Their weight problems were compounded by the fact that the team had installed a heavier Torsen differential a few months ago. Chris has also gained about 20 pounds. “This is mostly since he got married last year,” his dad smirked. The Edens family was aware of all these factors, but hadn’t adjusted the amount of ballast the car carried. 

We removed 50 pounds of ballast and reset the corner weights. (While we possibly could have removed a few more pounds, the fact that there was still some fuel in the tank meant we couldn’t bring it down any closer to the minimum.)

Before we rolled Mike Babin’s 1994 Miata onto the scales, SafeRacer’s expert wrenches Derek Gresham and Chris James installed the upper spring perches—also known as top hats—from a 1999 model. These updated parts recently became legal and allow for more suspension travel, allowing Mike’s car to be lowered from just about 5 inches of ride height at the pinch welds to just under 4.5 inches—all without hitting the bumpstops. This lower height should get rid of that sloppy feeling Jason noticed during our first sessions. 

Mike’s car had around five gallons of gas in the tank and no ballast. It came in at well over the 2350-pound minimum. While gas could account for around 35 to 40 pounds of the excess, it’d still be about 25 pounds high.

We suspect that much of this excess weight could be removed if the car was taken down to a bare shell and stripped of its undercoating. We didn’t drink enough caffeine to undertake that task, so we left it for Mike to handle. 

Pro Knows Driving

With our cars’ suspensions squared away, we heard the school bell chiming—it was a time for a lesson in racecraft. Our pro driver Jason Saini and Traqmate’s Glenn Stephens showed our drivers the results of the first session’s worth of data gathering. 

Fig. 1: Mike Babin knocked off 2.5 seconds; you can see by the Velocity vs. Distance graph in the middle of the screen shot that much of this improvement was found through increased trailbraking. 

One thing that both drivers needed to work on, according to Jason, was keeping their cornering speeds higher by braking later and ultimately slowing the car less as it turns in. This, coupled with some trailbraking, would keep the horsepower-challenged Miatas going faster around the circuit. 

Fig. 2: Chris saw improvements in both power and driving through the course of the weekend, so his cornering and straight line speeds were both improved. 

Check out the Traqmate’s velocity versus distance graphs (Fig. 3) for a visual: The Pro’s velocity doesn’t have the downward spike at corner entry found on the other drivers’ graphs. Of course, entering a turn at a much higher speed requires some nerves, as there’s that “oh no!” moment when the driver realizes that he’s just skating at the edge of adhesion for a second. It’s quickly replaced by the “oh cool!” moment when he realizes that the car hasn’t left the track in a blaze of glory. Seat time and course familiarity allow a driver to do this consistently. 

Fig. 3: At the end of our testing, our drivers hadn’t quite caught up to our pro, but they were certainly much closer. Jason still had the edge in cornering speed thanks to his skill and experience.

Jason felt that Chris had a solid foundation of skills to build upon, “but he also listened well and applied what we talked about on the Traqmate screens.” Jason also said that it’s obvious Chris and his family work hard at this, and it shows in his attitude about driving. “Frankly put, he listens and applies what he hears. That’s hard.” 

For Mike, Jason recommended new shift points that would better keep the car in the powerband when leaving the corners. Mike also needed to work on breaking away from traditional generic racing lines and instead focus on ones specific for this particular track. For example, there were cases where Mike could give up some corners to gain in others. He was also breaking too late in some places in an effort to maximize a preceding straight, which killed that corner’s exit speed. “This was definitely outside his comfort box,” Jason noted, “and it was great to see him stretch himself in that way.”

Back on Track

With our freshly tuned cars and tweaked drivers, we went back on track for our final sessions. There was a lot of nervous excitement floating around after our long days of testing. Temperatures were a few degrees cooler, which could have helped our Miatas make more power, but there was also a stiff Texas breeze rolling across the track and creating a headwind on the longest straight. 

These two factors should have canceled each other out to keep our pro at about the same pace. Jason, however, went a smidge faster in the pro car to reset the baseline at 1:24.632. 

Chris used his car’s newfound power and lighter weight to drop to a 1:28.011, some three and a half seconds faster than his earlier baseline. He was understandably happy with the faster time, but he still that like a lack of power was holding him back. “I guess it’s time to build an engine,” he quipped. 

Mike had a little trouble adjusting to his car’s lowered ride height, but after a few laps he turned a 1:27.293, some 2.5 seconds faster than before. He said it felt as if the car would now turn in slightly more quickly, and there was less understeer, both while turning in and tracking out. “The main impression I had was one of greater confidence in the car at turn-in, which translated into a willingness to brake less and carry more speed through the turn,” he explained.

Mike immediately realized where he made the gains. “Of the time I picked up, I attribute about one-third to the changes in the car, and two-thirds to Traqmate data acquisition and driver coaching, with having Jason in my car for comparison being a key part of that.”

We then swapped our pro driver into the subjects’ cars to see just how much the equipment had improved. Jason turned a 1:27.500 in Chris’s Miata; he noted that there was a continued lack of power, “but much better than before.” Unfortunately, the power we had managed to add made the understeer Jason noted before even worse. Now that the car had more power, the push needed to be corrected. Still, Jason had some good words for the car: “It was very consistent and the easiest to drive.”

Jason actually bested his own Spec Miata lap record in Mike’s car after the facelift, setting a 1:24.475. Of course, since we weren’t part of an official race weekend, that won’t count as the record. Still, it’s nice to see a clubman-level Spec Miata run down a pro-built car.

After the changes, Jason noted that Mike’s car was much quicker to react to input, but it also got more squirrelly as a result: “It would very quickly lose grip in mid-corner, especially if you were off the throttle,” he said. “It didn’t lend itself well to trail braking.” While Jason was able to turn a good time, maintaining that speed through an entire race would be a challenge. “It would have been hard to do those times consistently,” he explained, “where [in] the Pro car, I could do fast laps all day long.”

Pro Knows Everything

The next time you hear racers whining that they got beat, realize that the most obvious answer is not that the victor was cheating; winners get everything right. 

The top teams and builders will know all of the rules and updates as soon as they appear in print or on the Web. Our experiences with our clubman competitors revealed that slower teams don’t always pay as much attention. We improved their times by adjusting ballast on one car due to a changed minimum, and installing newly legal parts on the other. 

The pro tests everything in a quest for more power. A typical race engine should see a significant percentage of its use on the dyno, with its owners taking the time to test ignition settings, oil, filters, exhausts and intakes to get every last bit of oomph in this rules- and horsepower-limited class. Nothing should be left on the table. 

Sometimes those details aren’t so obvious. Who would think that different stock ECUs would yield more power? Or that running the oil on the low side would be the hot ticket? We certainly didn’t know about these Spec Miata tips before this session, but we do now. It pays to talk to the front-runners and investigate this sort of specialized knowledge.

A strong race team will also nail down details like fuel levels. Ideally, a car will just about run out of gas as it’s being rolled across the scales during post-race impound. Both of our club guys were running much more gas than necessary and burning it off over many sessions—whereas our pro was adding gas in dribs and drabs before the car went back out on track each time. 

Then there’s the driving end of things. Our pro knew the track like the back of his hand. That experience goes beyond the basic line, to the point where he knows just how far the car can be pushed into a corner and beyond. 

Let’s not forget to mention that Jason is a talented, professional driver with years of experience—there’s a reason that he gets paid to do this. That’s something that can’t be bought or cheated; you just have to pony up the time and commitment and hope you’ve got what it takes to make it on track.