Showdown at Sonoma: Battle Between the Fastest Stateside A90 Supras

They’d known each other from the forums and hours on the phone, but they hadn’t met in person. For the last few years, both Jackie Ding and Will Kwok have developing some of the fastest A90 Supras in the country, and only recently were about to partake in some friendly competition.

Jackie’s PhD Racing Supra, now famous online thanks to his growing YouTube channel, caught the attention of Will in 2019. “Will quickly became a huge supporter of PhD Racing Lab and is now our biggest customer. He’s always a great guy to talk to, so he was one of the first people I told I was coming out to the West Coast. Naturally, we started talking about a little battle when I was there,” Jackie told us.

It was Gary Wong, Will’s hired hotshoe, who supplied Jackie with Speed SF’s schedule. Jackie picked the dates that interested him, and the two decided to have themselves a duel. If Jackie couldn’t finish more than a half second ahead of Gary at Gary’s home track, he’d have to buy dinner.

Footwork

Since Will got most of his pointers from Jackie, perhaps first real time attack driver to develop the A90 Supra in the U.S., the parts used on the two cars aren’t that different. Both share most of the SPL catalog available for the A90, including the SPL front lower control arms, SPL adjustable front caster rods, SPL rear toe links and eccentric lockouts, SPL bumpsteer correction kit, SPL rear traction links, SPL rear upper lateral links, and SPL front swaybar endlinks. There are a few notable differences, though; Jackie’s car sports the Reinharte two-ways coilovers while Will’s is on MCS three-ways.

Powerplants

Supras have a certain reputation to live up to, and both these cars do that with over 1,200 combined horsepower. Jackie’s B58 is improved with VP MS109 direct injection and a Garrett GTX3076R Gen 2 as part of the AMS Alpha 6 turbo kit. The total output: somewhere in the 650-horsepower range.

Will has explored a little more of his motor’s potential. His sports the Pure800 turbo, flex fuel, and port injection,—enough for 700 horsepower at the real wheels, depending on power map. The power outputs are similar, but Jackie has to leave a little on the table as his gearbox hasn’t been built, unlike Will’s.

Though slightly heavier, Will’s car is a little faster on the straights due to a stronger gearbox and another fifty horsepower.

For both Sonoma and Laguna, both cars sported the same tires: 275/40/18 CSR. However, the grip levels provided varied due to weight and aerodynamics. Jackie’s car-driver combination is somewhere around 150-200 pounds lighter than Gary and the purple car, and the configuration of wings and splitters are different enough to provide very different characters. While Will’s car has the Spage V1 front splitter, Jackie’s has the V2. Both running the Spage SP012 68” swan neck GT wing, but Jackie’s wing is mounted slightly lower for a less understeery setup.

Similar setups, similar parts—that would be the case since Will has relied on Jackie for tuning advice. However, their design ethos differ somewhat. Jackie’s car is much more suited to the high-speed stuff, while the purple car is more compliant, more squishy, and better suited to the slower tracks on the West Coast.

Subtle Differences OVER one Lap

For the first half of Sonoma, Gary held the edge. The bumps in Turn 1 were tough, but when it came to hard braking and high-speed direction changes, as in Turns 7 and the 8/8A esses, Jackie and his slightly pointer car pushed ahead. Turn 10 obviously favored the aero grip of the red car, but it wouldn’t be fair to say it was as simple as turning the wheel and matting it. As we can see in the footage below at 8:53, a little braking too late and adding a little too much throttle after the speed change prior to Turn 10 caused a moment which might’ve given Jackie a little heart palpitation. Without a doubt, Sonoma is a driver’s track that Jackie had to learn in a hurry.

“Their car handled the bumps better, so in sector 1 at Sonoma, Gary definitely had an edge on us. Our car, being more stiffly sprung and heavy on compression, is a really high-speed focused aero car. While we lost a little in Sector 1, we gained that back in Sector 3’s high-speed esses,” Jackie elaborated.

“I was surprised with the braking performances. We were both running the same CSG pads, but I think I had more confidence in my brakes, even though I’ve only got a Stoptech Trophys on the front axle. Will’s car has APs 9660s front and rear. I think the big reason for that was our more advanced front splitter; having that extra downforce gives us extra front grip under braking,” he added.

At the end of the day, the main difference was in downforce. Both cars produce comparable grunt and share the same footprint, but subtle changes in aero balance and perhaps a slightly svelter shape gave Jackie a slight edge around Sonoma, though it’s only fair to mention he’s been developing this car longer and driving it a lot more. Still, nobody felt shortchanged at the end of that glorious day. Sonoma’s not the easiest of tracks, and it definitely doesn’t suffer fools, and to put that much power to the road through moderately sized tires and not crash is an accomplishment in itself. Dinner looks cheap after the cost of a smashed carbon clamshell.