Michael Mihld’s Stunning Spec E30

Balancing a busy work schedule and a full racing schedule is not for the meek. Michael Mihld is the founder of Cadent Technologies, Inc., an Electronics Design and Manufacturing company specializing in the Medical and Aerospace industries, though his dedication to racing could classify him as someone with, effectively, two full-time jobs. With a full plate at work, the foremost challenge of racing has been the practical concerns involved and how to fit them into his busy schedule.

The ease of transportation, relative low cost, and simplicity of karting were what first helped him enter motorsports. After a decade of winning San Diego Karting Association (SDKA), International Kart Federation (IKF), and SuperKarts (SKUSA) Mission titles in 80cc and 125cc shifter karts, he started considering another vehicle, and learned just how much more challenging running a full-sized car was — in terms of the practical concerns, as well as the driving technique needed to excel.

As simple and intense as karting was for Mihld, he was always planning for a full-sized racing car.

Whereas a weekend of karting only really called for a small truck, a few tools, and a gas jug, a car entails quite a bit more; a trailer, more expensive parts, more time wrenching, and at least two gas jugs. With these practical concerns, and only so much time and energy to dedicate to racing, he had to find a car that wasn’t too demanding, finicky, or expensive.

Avoiding Spreading Himself Thin in Spec Racing

Among the usual introductory club racers, he didn’t have a difficult time choosing. He was never a huge Porsche 944 fan, he had a tough time squeezing into the cramped confines of a Spec Miata, and always had an affinity for BMW. Plus, as he’d already owned every generation of M3 to date, the answer to his track toy question was obvious: Spec E30.

Mihld taking a set at Auto Club Speedway.

Similar to Spec Miata, the Spec E30 offers its users unrivaled thrills for the money. However, it is slightly taller and heavier than the Miata, and its 2.5-liter M20 provides enough torque to spin the rear wheels, which changes the driving experience significantly. Though these cars run sticky, 205-section Toyo RR tires, the Spec E30 is still a momentum machine which does not lay long stripes easily, however, the torque does contribute to the car’s colorful character.

Like Spec Miata, class rules for the series mandate strict build guidelines to ensure all competitors cars are at parity, and it’s the competitor’s skills that make the difference. Even the stock differentials are tested for locking strength, which cannot exceed 65 pounds. That said, Mihld’s BMW and its immaculate presentation say something about the focus which Mihld’s put into the build, and hints at the way he’s sought out a few vehicular advantages while remaining within the rules.

Though the rules limit suspension upgrades quite stringently, Mihld’s done everything in his power to gain an advantage while remaining legal. New front A-arms, new front hubs, rebuilt front and rear calipers from Turner, stainless braided brake lines front and rear, new rear hub bearings, and rebuilt rear half-shafts show the lengths he’s willing to go with stock components. After all, it’s a 30-year-old car, and there’s plenty of sense behind replacing components that have seen better days.

On track, the E30 looks right at home doing a slalom through the esses at Sonoma Raceway in California.

Even within the strict rule book, there is some room for upgrades. Vorshlag camber plates, Spec E30 sway bars front and rear, Jongbloed silver wheels, Turner long wheel studs with bullet ends, UHMW motor mounts, motor mount reinforcements, an IE shock tower cross brace, and a skid plate add to the car’s resilience. For appearance, he went ahead and powder coated all the suspension components, such as the trailing arms, uprights, and cross members.

The mandated suspension package consists of Bilstein shocks, H&R springs, and Suspension Techniques front and rear sway bar kit.  

Fortunately, the rules allow for some tweaking of the suspension to get the most out of the boxy Bavarian. Camber and toe adjustments help sharpen the car’s benign handling traits, and while the front sway bar must remain fixed, the rear bar can be adjusted for just a little more rotation on turn-in. Essentially, the suspension setup is kept intentionally simple to place an emphasis on driver involvement, not chassis tweaking.

A glimpse at the cost-effective rear suspension.

“I’m a little strange; I like to build the car from the ground up, unlike a lot of guys running Spec E30,” he adds. First, he and a friend tore the car down completely to the tub, then tore out the wiring, brake lines, and suspension. They welded in an immaculate rollcage, after which, they trial-fitted all the new parts. Without any hesitation, the two perfectionists then removed all the parts and prepped the car for paint. Once doused in a brilliant shade of yellow, all parts and goodies were re-installed on the car. Talk about commitment to details.

The interior is just as attractive as the exterior, and just as focused. Schroth harnesses link twin head-containment style OMP seats to a complicated and reassuring roll cage. The utility and ergonomic improvements gained from certain add-ons make the E30 a modern racer; a UUC Evo3 shifter aids in shift times and accuracy, and the suede Momo wheel — no longer cantered away like a bus wheel — features a PTT button to chat with his pit crew.

Simple and functional interior with all controls within reach and custom tailored to fit the drivers preference.

While ergonomic improvements don’t necessarily contribute to the outright performance, they help strengthen Mihld’s driving. The center switch panel uses industrial-grade toggle switches and indicators, which are all set within arm’s reach. Information is relayed through the dash-mounted gauge pod sporting an oil pressure gauge, oil temperature gauge, and a water temperature gauge, as well as the AIM EVO dash and data logger — all of which are mounted very closely to the driver.

“I spent a great deal of time setting up the interior of the car to suit me; putting all controls within reach while belted in,” he notes.  “I have seen guys build immaculate cars and then have a hard time toggling switches or activating the fire system!”

The balanced engine was rebuilt with stock components, except in the few areas where go-fast upgrades are allowed. Included in that short list are ARP main studs and head studs, Ireland HD rocker arms, and the Spec E30-specific exhaust system. A valve job and flow-tested injectors help rustle up a few additional horsepower. Again, the obsession with details is what give this restricted racer a small but considerable edge, and when most of the field’s power outputs hover around the 150-horsepower range, a few extra ponies can translate into an additional five miles per hour at the end of the straightaway.

Mihld’s M20 motor is completely rebuilt to free up every one of the limited legal ponies available.

The motor sends power down through a rebuilt gearbox with stock ratios. The drivetrain is stiffened and stabilized by UHMW Crossmember bushings, transmission mounts, and center support bushing for the diff. The stock 325is differential is rebuilt, and fitted with a Z3 cover with extra fins for more consistent differential performance over the course of the race.

This meticulous preparation helped in several ways. Aside from being one of the prettiest cars on the grid, it’s also one of the lightest — weighing some 30 pounds less than the 2,700-pound minimum weight limit with Mihld’s 195 pounds on board! Though he’s required to add ballast to meet the minimum, it also allows him to add some extra pieces without a cost in weight, and tweak the weight distribution to his liking.

Taking a Set

This new car forced Mihld to change his driving style considerably. As the basic H&R springs and Bilstein Shocks aren’t the stiffest items around, the Spec E30 spends a lot of its time leaned over on its outside tires. This roll and sway — the typical characteristics of a softer, production-based racer — required Mihld slow his inputs so the car could transfer its weight completely before asking much of the tires.

Mihld smoothly transferring the weight to maximize the grip available.

As weight transfer takes longer with a heavier, softer car, the responses aren’t quite as crisp as those of, say, a kart. This meant that Mihld’s first trips to the track in his E30 were frustrating; he asked too much of the tires before they were able to give him much. By softening his inputs and practicing some patience, Mihld could direct the weight over the intended tires with more control, and generate much stronger cornering, braking, and accelerating forces.

“In the kart, things happen much quicker and in some instances you are tossing or flicking the kart into a corner. In the Spec E30, you just can’t do that. You have to be slower with your hands. I used a driving coach to help me make the transition and give me feedback, he helped me make the transition much quicker than I would be able to on my own,” he says.

Once he’d learned to allow some time for the weight to transfer, also known as “taking a set,” he was then able to plant the front tires before braking heavily, the outside tires before cornering at the limit, and the rears before accelerating fully. After few enlightening track days to understand the car’s requirements, Mihld was able to move from the back of the pack to the front.

If one Spec E30 is good, then two are even better! A second E30 was built as a backup and demonstrator to take friends and customers out for track days.

In this yellow car, Mihld has taken the 2014 and 2017 SoCal NASA Spec E30 Championship titles, and it’s not only taught him about the challenge of managing a production-based racer, but it’s acted as a springboard into faster machines. Currently, Mihld is focusing his racing efforts in Trans-Am TA2, in which he runs a stunning Chevy Camaro. However, he still drives his E30 regularly, and has even built a second Spec E30 for a backup — this one doused in slime green — built to the exact standards of his yellow car. It seems you can’t keep some people down.

About the author

Tommy Parry

Tommy Parry has been racing and writing about racing cars for the past seven years. As an automotive enthusiast from a young age, he worked jobs revolving around cars throughout high school, and tried his hand on the race track on his 20th birthday. After winning his first outdoor kart race, Tommy began working as an apprentice mechanic to amateur racers in the Bay Area to sharpen his mechanical understanding. He has worked as a track day instructor and automotive writer since 2012, and continues to race karts, formula cars, sedans, and rally cars in the San Francisco region.
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