Justin’s RX-7: Domestic Dalliance

After league night at the local indoor karting track started to feel a little repetitive, Justin Merritt began considering his options. He’d always wanted to jump into track driving, and with the foundation laid by lots of wheel-to-wheel kart battles, he felt ready to step into full-sized sports cars. With his Scion FR-S, he moved rapidly out of autocross and into HPDE at Sonoma and Thunderhill, the two closest tracks to his home in Reno.

After making the usual list of track mods, he felt he started to see the short-term potential of the car. Truth be told, he’d gotten tired of his friends in fast Mustangs 5.0s leaving him on any straighter sections of the track, and so decided to make a shift into a sportier platform.

Weighing only 2,750 pounds wet, this V8-powered RX-7’s acceleration put him ahead of his Foxbody-driving friends.

The car had to be sensible, though. Justin hadn’t splurged for a truck and trailer yet and so he wanted to be able to make the trek over the Sierras in some comfort – at least the comfort of knowing his car wouldn’t likely leave him stranded. He’d had a thing for old RX-7s. The FC, in particular, and its doorstop shape left him feeling a little smitten.

Though he was in no position to start and finish a complete V8-swap, the thought of that had stimulated his imagination. Unfortunately, most of the typical examples of V8-swapped FCs have lived hard, unloved lives, and he knew better than to get involved with a thirty-five-year old Mazda with cut corners.

He had the good fortune of finding a half-completed ’89 that had an LS1 conversion underway. Along with the 5.7-liter in place, the previous owner had fitted a Tremec T56, a few cooling modifications, and a questionable exhaust setup.

The car’s wiring needed work, though. Whatever – the cost and the promise of a lightweight, rear-drive sports car with a fairly modern Chevrolet LS motor was worth sorting out a rat’s nest.

JTR headers, the custom y-pipe and 3” exit, a Summit CAI, and a tune from Gabe at Real Performance in Reno, Nevada, net 320 whp and 330 lb-ft of torque.

The ECM received no signals regarding coolant temperature or oil pressure, and the connector to a coil harness, well, one of its pins had backed out and caused a misfire. All fairly simple fixes. The ECM, as he found out, wasn’t even bolted down.

Once the electrical gremlins were sorted, Justin had to address some of the shoddy exhaust work. Some tubes were round, some were square, and they leaked everywhere. He left these to his fabricator friend, who added a set of JTR longtube headers, a custom y-pipe, and an HKS 3” single exit.

When all those issues were resolved, Justin had the confidence to start using it as an occasional daily. However, it was on stock suspension, so it nearly wheelied every time he stood on it.

When the time was right, he threw a set of BC DS coilovers (8k/6k) as well as the entire Parts Shop Max catalog at it. The adjustable rear toe links, adjustable toe and camber rods, new wheel bearings, a set of special bushings to do away with Mazda’s active toe, trailing arm bushings, and the typical swaybar bushings and front control arm bushings made a night and day difference.

To cap the first round of modifications off, he opted to install the larger four-piston Turbo II brakes along with Hawk HP+ pads and Stoptech rotors. The item tying these simple but effective braking mods together was the Chase Bays booster delete kit, which improved feel as well as offered the ability to change the brake balance with its proportioning valve.

“I didn’t know why there was a rattling noise coming from the passenger’s footwell until I noticed the new carpet and decided to look underneath it. There it was: the ECM, unbolted and bouncing around like a soda can.”

That helped set the nose, as did a reasonably wide track up front 255-section Kumho V730s at the end of the front axle, and 265-sections Falken RT660s at the rear.

The aluminum V8 isn’t the heaviest motor around, and though somewhat longer than the rotary it replaces, it doesn’t seriously disrupt the RX-7s famous balance and responsive front end.

That footprint proved more than adequate on the autocross, where he found he didn’t have much difficulty putting that power down. Not too shabby considering the car still runs an open differential.

Where it struggled slightly was in cooling. “I thought the big Spal fans and Griffin radiator would be fine on their own, but it overheated on hot days. I looked a little closer and saw that the radiator needed some ducting.”

With a little homebrewed ductwork and a few blockoff plates, he could redirect the air into the cooler and keep the LS happy in any temperatures. During his first outing at Thunderhill West, he was able string enough laps together to get a sense of the line, and went quickly enough to lap the clockwise configuration in 1:32.

It’s been an exciting eighteen months with the car, but it’s now looking for a new home. The reason? Justin’s looking for a new home of his own. A down payment must take precedence over a track toy, so anyone in the market for a nicely sorted, lightweight, visceral track RX-7 with the perfect amount of power ought to take a look at its listing.

Thomas' Corvette: In Good Company

Finishing out his senior year of high school, Thomas DiGioacchino listened to a friend’s suggestion and scrounged the money together for his first track day. Crap tires, decent weather, and a near-stock Mustang GT were all he needed to find that thing that’s been steering his life for the last five years.

Thomas decided to pursue the mechanical side of things and enrolled in Ranken Technical College’s High Performance Technology course with a focus on Chevrolet LS engine design.

That emphasis allowed Thomas to build a motor for a car he hadn’t yet bought. It began with an iron-block LQ motor and LS1 heads, and as the LQ block only displaced 5.3 liters, he bored and honed it out to 5.7 liters to fit the LS1 head. With forged pistons and rods, oil pan baffles, and the other pieces that made it a 500-horsepower workhorse, he unknowingly set the tone for the rest of this build.

The car itself came next. During his final year at Ranken, he found himself a base 2002 Corvette within his price range and tucked it away in his side yard until graduation, when he loaded up his truck with his furniture, his motor, and began his drive from Missouri to his hometown.

Back in San Mateo, he reached out to his then-limited network for car parts and, with some luck, gainful employment as well. As he’d relied on Elite Performance to direct him towards a few bolt-ons for his Mustang, they were the natural resource to consult. One day, while speaking to Elite’s Melody Cannizzaro about getting his Corvette aligned, she provided up with a job opportunity. He didn’t have to think twice.

Working with Elite gave him access to one longtime customer who happened to be offloading some go-fast bits from their recent Corvette build. Thomas was able to grab a set of Titan 7 T-S5 wheels for peanuts, and then came big brakes, bushings, and a bucket seat. Soon, the plans for keeping the Corvette tame and civilized went out the window.

Wisely, he went for safety equipment next, and decided that this car would only help him become a truly quick driver if it was reliable first and fast second. “I knew that seat time would be the priority if I was going to run with guys like Gary Yeung,” he said.

That said, it would be silly not to make use of the big motor sitting in his parent’s backyard. Soon, it found a new home in the Corvette’s engine bay, and Thomas took the half-built C5 to its first track day, where it ran without a hiccup. It ran well the second day, too, as well as the third. Clearly, he’d paid attention in class.

Aside from the minor repairs any twenty-year-old car needs, it was the epitome of dependable. His focus was on learning to drive the car better, but, to his credit, a C5 on stock suspension does leave a lot to be desired. It would lean excessively, and under trail braking, it had a habit of snap-oversteering.

After several months of saving, Thomas bought a used set of JRZ two-ways. While he was at it, he pulled and refreshed the entire drivetrain, then upgraded the springs and clutch packs in the OE LSD. Those modifications made the Corvette much more progressive at the limit, regardless of whatever cheap tires he happened to be running.

When he found the time to fine-tune the suspension, he increased the rake to increase rotation at corner entry. A square 295-35/18 setup was the cost-conscious tire option, and he stretched every set until the cords showed. Still, the car was mostly neutral with a hint of understeer in the faster stuff thanks in part to his APR GTC-300 wing.

As his confidence grew, he started to recognize that driving around on worn rubber was no longer the training tool it had been, so he sprung for a set of AR-1s and turned his first sub-two-minute lap at Buttonwillow 13CW. “I had to fight it the whole way around, but I got 1:58. A sloppy 1:58, but still,” he said.

Good tires helped, as did having a hare to chase. With Gary Wong driving his S2000 off into the distance, Thomas was able to see where he could push harder than he believed was possible. It’s a huge help having an experienced driver luring your outside your comfort zone.

Logging that first milestone lap gave him the confidence to try the Speed SF Challenge the next weekend at Thunderhill’s five-mile configuration. He did his homework and studied several record laps, focusing on curb usage. With Gary Yeung giving him some basic feedback the day of, Thomas saw his lap times fall by as much as four seconds. In the end, he was able to clinch third place in S2 — just half a second behind Kevin Schweigert in his BMW M2.

That success turned Thomas into a sponge. His subsequent lapping days have been spent studying data and having the experienced drivers like Joe McGuigan critiquing his onboard videos. “Joe’s been a huge help; giving me pointers on which gears to use so I can put the power down more easily.” The result of this traction-conscious approach to driving is evident in the footage below:

He’s also benefited from picking a short list of prime parts. In fact, he’s never bent his Titan 7 wheels or broken any suspension parts, despite hammering curbs and dropping wheels regularly. Maybe it has something to do with emphasizing robustness with this build—a tip he picked up from his mentor, Gary Yeung.

‘I’ve learned a decade’s worth of motorsports knowledge in the last two years. Everyone’s been so supportive, and I owe my progress to all of them. They’ve pushed me to improve as a driver and a builder—especially Gary. Watching him work inspired me to raise my game, and I think it shows. My Corvette’s overbuilt, so I can push it all day. Like Mango, my Corvette is a workhorse that’s made it possible to attend almost every Speed SF event in the last two years. All I do now is change the fluids and try to find out where I can go faster.”

Parts

• JRZ motorsport coilover conversion

• Titan 7 T-S5 wheels 18x10.5”

• Trackspec hood vents

• Dewitts radiator

• Spal fans

• Improved Racing oil cooler

• Improved Racing oil pan baffles

• Prothane polyurethane bushings

• APR GTC-300 wing

• APR splitter