George Koustoumbardis’ exploits have been well documented here. His turbocharged ’99 Miata—a car he built when he was a mere 16 years old—sports M3-beating levels of power, serious downforce, and a friendly character at the limit. These combination of qualities qualifies this lightweight to duel cars boasting twice the power. Still, at as fast a track as WeatherTech Raceway Laguna Seca, George has to prioritize late braking, high-speed corners, and traffic management to stay in the fight.
Benefiting from BorgWarner Boost
Though not the most powerful car out there, the Miata’s turbocharger is perfectly suited for the motor and George’s intentions. Smooth delivery was a must for George, as he wanted an engine that would perform like a larger atmospheric motor. With an incredibly light titanium aluminide turbine wheel, the BorgWarner EFR 6258 delivers turbo power in unprecedented fashion. With immediate spool and wonderful transient response, this snail’s smooth delivery differs completely from some turbos’ lightswitch-like deliveries. Moreover, this snail includes an internal wastegate and integrated bypass valve, which simplify plumbing and reduce heat in the engine bay. Simply put, this turbocharger was designed with road racing in mind.
On the right tune, this modest turbo kit produces 200 lb-ft of torque at 3,000 rpm—real six-cylinder power. That amount of low-end shove means ear-to-ear grins and the sort of acceleration off the corner that allows him to hang with his acquaintance in the silver C6 ahead.
Unfortunately, a conservative tune dropped his output to just 198 horsepower at the rear wheels that day. When deployed through worn Maxxis RC1 semi-slicks, it’s still enough for stylish slides out of the slower corners (0:54), but it shows its limitations as speeds increase.
Downforce Comes at a Price
The NASCAR Car of Tomorrow rear wing is not the most efficient and changes the car’s balance considerably. “I noticed the car would just ‘hit a wall’ around ninety miles an hour, but it did make a lot of downforce. Actually, it made so much downforce that it would make the car push in faster corners!”
Prior to adding that massive wing and a 3″ splitter in front, the Miata’s behavior at higher speeds could be described as playful; a little oversteer that wouldn’t kill you. With the aero elements in place, the balance verges into strong understeer through faster corners. Note the amount of steering lock he uses through Turn 4 (1:08)—the front tires are obviously losing some grip there.
Where the aero pays off best in is the heavier braking zones. After both cars are given way by a courteous set of slower drivers down the front straight, George is able to close the massive gap by Turn 2, but is then quickly left behind on the long straight between Turns 4 and 5. Unfazed, George gathers all his courage and brakes fantastically late to stay in contention.
Strategy Over Slipstreaming
Nipping at the bumper of the Corvette once again, he has to wait as the same process repeats itself and the Chevy streaks away up the hill. Wisely, George bides his time and a plans for a move starting at Turn 8. If he manages a clean run down the hill, the red Miata ahead and might be used as a pick. Of course, George needs to be in the right spot to make an opportunistic move when the chance presents itself.
By braking a hair earlier into the Corkscrew, he ensures an untrammeled run down the hill. There, his horsepower disadvantage won’t handicap him much. George’s plan to strike around Turn 10 goes awry when the Miata ahead brakes much earlier than predicted and disrupts his momentum. Still, George has his fantastic Wilwood brakes to rely on for a second stab at it.
Closing the gap again in Turn 2, he gets a much stronger exit before taking the conventional line into Turn 3. The Corvette’s driver defends along the inside, but dithers, brakes too early, and concedes the corner. Finally, George gets around the Corvette and shows just how capable the little Miata is in a battle with punchier cars, and just how fast it can navigate faster corners (3:00) when there’s nothing impeding its path.