To say that Tom Johnson’s 240Z had a rough start as a racecar would be a bit of an understatement. Johnson estimates that the car has caught fire seven or eight times. He had experienced brake fires, fuel fires, oil fires, motor mounts, you name it. After one fire, he rebuilt the car in three months to make it to the first NASA Western States Championships, where it caught fire again. So, he parked it to consider his options.
“It was a little embarrassing. I made a bit of a reputation for myself,” Johnson said. “You know, old Datsun motors, the intake and exhaust are on the same side so, you’ve got fuel, air and a source of ignition all intertwined, and the motor mounts were very close to the headers, and these polyurethane motor mounts kept igniting. They would just get so hot, they would auto-ignite and it would go downhill from there.”
Of course, there is a chorus of people reading this right now, chanting, “LS1! LS1!,” but that didn’t interest Johnson, who has a pilot’s license, background and a business in aviation insurance and a long history with Japanese cars. He decided to take it in a different direction, but one that makes perfect sense for an old Datsun: a VQ35HR and six-speed transmission from a 350Z.
“A ton of people have done the swap. I’m a big fan of the motor. They’re inexpensive to get, and they make great power,” he said. “I was just never an LS fan boy. I like high rpm. I grew up with Japanese cars in L.A. I’m a 7,000- to 8,000-rpm guy. That’s where I get excited. The VQ does that.”
Because the swap has become somewhat common, Johnson had a knowledge base to rely on. But he still had to do all the work himself, which is fine with him because he views it not as a chore, but as a creative outlet. He sourced a motor mount kit from McKinney Motorsports and a ready-made wiring harness. The mount kit welds in place on the unibody frame rails.
Johnson went with long-tube headers which are tricky to install, but he made it work. He had to do some creative custom work getting everything to fit, but an off-the-shelf driveshaft helped as did an aftermarket relocation bracket that puts the shifter up through the stock hole in the transmission tunnel.
“In terms of swaps, there was a fair amount of work to do, but it fits in there pretty well,” he said. The transmission is big, but the motor sits farther back. You look at it and think, ‘Oh, there’s going to be so much room in there,’ but it’s very wide and it’s tall. It sits low to the ground, and the top of the motor is tall and it’s wide on the sides, so it takes a fair amount of real estate.”
The fuel system required two fuel pumps, a lift pump in the rear and a high-pressure pump and surge pod under the hood to pressurize the injectors, but the drivetrain connects to the stock factory R200 differential. Johnson replaced the U-joint half-shafts with CV upgrades, but the factory suspension is essentially intact, save for Techno Toy Tuning lower control arms up front.
For wiring, Johnson did most of it himself with help from a few friends. The trick part is the entire engine harness is routed through the firewall via two military-spec connectors. To pull the engine, all he has to do is disconnect those two harnesses. Building on the aviation theme is the dashboard wiring, which also uses avionic and military-spec hardware.
“It isn’t all that expensive, and it’s actually pretty easy on time,” Johnson said. “You just have to learn what the connectors are and which way they go and once you get the hang of it, it makes for a much better setup.”
As much as the car is a creative channel for Johnson, he’s quick to point out that many people in his NASA family have been among the first to call or lend a hand when he’s been in a difficult spot building and rebuilding the car. Now that the risk of fire is all but gone, he’s looking forward the next step in the evolution of the car, which is adding Teves Mark 60 antilock braking system common to many ST3 cars.
Johnson also has put considerable thought and effort into the car’s aerodynamic aids. He pulled ideas for the front air dam from Miata guys, and the genesis of the rear wing stems from what he saw on winning M3’s. He routed the cold air intakes for the twin throttle bodies to large cone filters located at the outer flanks of the grille, and turned the headlamp buckets into intakes to cool the front brakes.
“I think it’s become a bit of who I am. It’s my artistic outlet. It keeps me working and healthy,” he said. “I need to spend a little more time on driver development, so maybe a little more time in TT and just trying to continue to work on my skills. I like to develop the car because it’s enjoyable.”
Owner: Tom Johnson
Year: 1973
Make: Datsun
Model: 240Z
Weight: 2,450 lbs. w/driver, no fuel
Engine: VQ35HR, 245 horsepower
Transmission: Six-speed manual
Suspension:
Front: McPherson struts, sectioned towers, Koni double-adjustable shocks, Techno Toy Tuning lower control arms
Rear: McPherson struts, with adjustable coilovers
Tires: Front: Hoosier A7 245-40-17
Rear: Hoosier A7 245-40-17
Brakes: Front: Wilwood six-piston
Rear: Wilwood four-piston
Data system: AiM Solo
Sponsors: Airpower Insurance, Techno Toy Tuning, ZTrix, Sebon Carbon, Hawk Performance, NASA.
