A C6 ZR1 isn’t an ideal beginner’s car, and NASA Mid-Atlantic driver Clayton Eley would admit as much. “I was probably getting in over my head with that, but I remember coming home after my first track day beaming. I had to tell my wife, ‘This is it!’ I couldn’t believe this is legal,’” he exclaimed.
That led to a GT2-spec E36, and later a set of his and hers Spec E30s to cut their teeth with. The vibrant Southeast Spec E30 scene, the reasonable costs of that class, and their proximity to Virginia International Raceway made it possible to pursue their new passion with a special sort of commitment.
For the abundance of fun and high-caliber of driver education Spec E30 offered, Eley couldn’t deny he missed some of the ZR1’s craziness. Not many cars can manage 160 mph at the end of VIR’s front straight, and the way it handled was equally inspiring. The prospect of an accident in a cageless car at those speeds, along with the Corvette’s appetite for consumables, made him wonder if he could enjoy a powerful V8 in a safer, lighter, grippier package.
“I loved doing it in the moment, but it seemed a little excessive on later reflection. I mean — I’ve got a family,” he recalled.
He didn’t find big-bore performance in a sportier package immediately, so he settled on a Radical SR8, a small-displacement V8-powered sports racer weighing 1,500 pounds. For what it lacked in torque, it made up in grip. After a little time spent adjusting to the downforce, Eley was soon lapping VIR in the high 1:40s.
Fast and slightly insane, the Radical had satisfied his need for the extreme. The sports racer had that immediacy and supercar-rivaling acceleration that made him as giddy as he felt that first day on track.
However, it wasn’t perfect. The maintenance costs were obscene. “I had to send the engine back to England to be rebuilt after 40 hours,” he began, “and that definitely hurt.”
Eley wanted something well-supported with similar cornering speeds and engine performance, but without the exotic repair costs. This was early 2019, and something slightly used and totally perfect for Eley’s needs was about to drop in price. Ligier would unveil the latest iteration of its popular LMP3 car at that year’s 24 Hours of Le Mans, the JS P320.
That meant the P320’s predecessor, the P315 started going for $60,000 to 80,000 less than the newer car. Structurally, the two are remarkably similar, but the pace at which prototype racing proceeds nowadays had rendered the old car obsolete. But for someone not interested in running a professional effort, a used prototype is a reasonable proposition for club racing and Time Trial.
Eley found one of the earlier cars for sale, complete with a spare package. Eley made a low offer on the package — a price closer to what a parts package alone would cost, and the former owner bit, surprisingly.
A P3 car with reasonably high production numbers, the JS P315 was already well sorted by the time Eley picked his up. The VK50 engine, a Nissan truck power plant mated to a dry sump in this configuration, was plenty powerful at 420 horsepower and as reliable as any motor he had ever run. Though the Radical’s 2.6-liter V8 produced the same peak figure, the 5.0-liter VK had real torque — something he’d been missing since he parked the ZR1.
With the exception of an issue with the factory tripod and axles — a problem compounded by the pandemic’s effect on the supply chain, the car was rock-solid. This was rectified later with a Pankl tripod/axle setup, which was not cheap, but proved its resilience over the subsequent issue-free years of regular track days and Time Trial. Though getting into one of these cars can be quite expensive, their overbuilt nature promises years of smooth sailing and relative kindness to its consumables.
At the 2021 HyperFEST Presented by Grassroots Motorsports, Eley figured out some of the thermal limitations of the Ligier and went on to set a 1:47.727 late in the day, winning the Ultimate Track Car Challenge and bringing home $1,000. As Eley said in the GRM article covering the event, “Even with optimizing some of the parts choices for Time Trial, it needs a little heat to work optimally, so my best lap is usually later in a session, which is also tricky because that’s when traffic starts to become a factor. So there’s definitely some strategy to the approach to every session when it comes to getting the best single lap.”
Over the following year, he made one upgrade pulled from the JS P320: the dual-element rear wing. This produces comparable downforce with reduced drag. Beyond that, the only running costs were tires, fuel, and the occasional set of brake pads and rotors.
Eley had gotten comfortable in a relatively short span with the P3 car, and his record lap at VIR set last October is proof of the rate at which he could adapt to the demands of a top-tier prototype. Currently, that NASA Mid-Atlantic TTU record of 1:45.644 still stands.
Bigger, Better, and Uncorked
There’s no reason not to strive for more when the opportunity arises, and if a step toward more speed coincided with his long-term financial considerations, why not try something new? That approach pushed Eley to consider a relatively new engine swap as his VK neared the 10,000 km-mark, he had to begin considering the costs of an engine rebuild.
While reasonably priced, the VK50, unfortunately, had been out of production for some time. Even its successor, the Nissan VK56, as used in the P320, had been out of production since 2022, though some of the motorsport components were still supplied by Nismo and Oreca. His fraught experience with the aforementioned axles had him wondering if he’d have to deal with a similar parts shortage when it came to rebuilding the engine.
This prompted Eley to consider an option he’d been made aware of through Eric Suits, Lead Motorsport & Product Development Engineer at Katech. Katech’s LS swap kit not only promised more power, but widely available parts, and rebuild costs roughly 25 percent cheaper.
“We came up with the idea for a swap package recently as more of these cars are being phased out of professional motorsport and are looking for a new home. Considering how overbuilt they are, they can handle an increase in power without negatively affecting their running costs, which makes them ideal for the club racer,” Suits described.
Katech already had ordered a set of custom bellhousings from Xtrac to connect the Ligier’s standard gearbox to a Chevrolet LS. This 1152B transmission is rated to 550 Newton-meters of torque (roughly 405 pound-feet), which the VK did not quite produce.
The Katech engine package Eley chose — the punchiest of the three available — comes with a hotter cam and forged internals. It also requires a stouter transmission, since the 600 horsepower and 750 nm (550 lb.-ft.) it produces would exceed the 1152B’s capacity. Xtrac rates the stronger 1152D variant to 750 nm at a full service life of road racing. Like the engine and the car it powers, the transmission is meant to last.
This 1152D variant also comes with a wider-spaced set of gears, which should help service intervals remain reasonable. “As long as it’s not spun too high, the LS should run about 40 hours before we would recommend a rebuild,” Suits said.
Beyond the fortified transmission, the swap requires custom headers, oil lines, and trunnion supports, because the LS is a semi-stressed member of the chassis that connects to the tub at the rear bulkhead. A Daly structural pan and four-stage pump make up part of the Katech-designed dry-sump system. The OEM coolers can be retained, too.
The crack team at JRIII Racing in Mooresville, N.C., looked over the car post-purchase and helped Eley get acquainted with track support. When COVID hit, however, the team no longer could assist him at the track and he was forced to become a one-man operation, which worked out just fine. The prototype might lead some people to think it requires a small team to run, but the P3 was designed to be as easy for the smallest outfits to field. In fact, Eley now does it himself.
After swapping the motor, nothing about the startup procedure had really changed. “Our operating manual is only a few pages long, and most of it details the operating parameters,” Suits added. Eley unloads the car, lifts it on its air jacks, removes the rear wheels and attaches a set of special run-up hubs to locate the rear brakes during the transmission warmup procedure. First, he cranks for oil pressure, then once that’s verified, he fires the engine and lets it idle until the transmission reaches 50 degrees Celsius, when he begins running through the gears at slightly elevated revs until the temperature reaches 95 degrees Celsius.
Recently, Eley added another to his team. Mike Skeen’s take on the P315 may surprise the onlooker impressed by its exotic shape. “It sounds crazy, but driving the car is a little like driving a really fast Miata — it just has way more grip than power.”
The powerband has been sculpted to make it as tractable as possible. Because a special camshaft was chosen to limit torque, the shove plateaus fairly quickly while power builds toward its 7,400-rpm redline.
Though applying the power in slower corners may take a little more care not to spin the wheels, the grip is more than sufficient for the power available. In fact, the only reason Skeen decided to disable the traction control was due to unnecessary intervention. “I ran without it because it would intervene over curbs.”
Nearly twice the displacement helps in less obvious ways. Aside from the added shove, the ability to dispense with concerns over drag helped the duo get to speed that much faster. The rear wing angle could be leaned forward like a barn door and the aerodynamic wall, once a considerable factor at 150 or so, is nowhere near as noticeable. “The VK would run out of steam in fourth and fifth gear,” Skeen mentioned. “Katech filled the void (in the powerband).
It’s really beautiful,” Eley added.
The LS3-powered Ligier netted a remarkable 170 miles per hour into Turn 1, the top of the Esses and the back straight at VIR, making it the fastest accelerating car Skeen’s driven there.
Most of the older cars are not equipped with ABS, but considering the additional speeds the new car would be reaching with another 60 percent of the original output, JRIII went ahead and installed Bosch Mk60 ABS, which they monitor via MoTeC.
“The brakes grab so hard, I rarely take it to threshold, so the ABS doesn’t intervene in the high-speed braking zones. At VIR at turns 3 into 4, I’ll feel a little judder through the pedal, but not much,” Eley elaborates.
All these aids, though not necessary, contribute to the sense of security he feels inside the car — something the ZR1 never quite gave him. “You realize there’s a carbon cell with a roll cage inside,” he said.
That peace of mind is useful when trying to match Skeen’s data traces. After one bold lap trying to match his mentor’s pace, Eley dropped his wheels in the dirt outside VIR’s Turn 10, spun 180 degrees, and hit the wall hard. Thankfully, the chassis took the impact well and Eley walked away a little shaken, but otherwise fine.
Being able to get within a few seconds of Skeen’s times is a remarkable accomplishment, no doubt accelerated by Eley’s natural ability, but also bolstered by a supportive and challenging platform to build upon.
The Ligier and the Katech engine were engineered to aid drivers who hadn’t been karting since their 10th birthday. In other words, it is a package that will make the gentleman racer feel at-home quite quickly.
The Ligier has served Eley well, providing more safety and performance than a production car, and more reliability than other, more exotic prototypes. Without a doubt, that rare combination of qualities has helped him advance from novice to nipping-at-a-pro’s-heels in a short time span.
The thinking behind this swap package is now being put to use again as the LS motors are being phased out and parts aren’t as available as they once were. Katech now offers Gen-5 LT swaps, albeit without direct injection, for those looking to give their aging prototype a new lease on life.
