Year after year, fresh home-brewed cars line up to have a crack at Drag Challenge. While they can’t all collect an ‘I survived’ sticker at the end, some nail it first-try, like Zac Shepherd’s LJ sedan.

First published in the April 2024 issue of Street Machine

The 28-year-old has owned the little Holden since he was 14, which checks out when you learn he grew up in a drag-racing family in the seaside town of Portland, just minutes away from South Coast Raceway. “The car was pretty well a roller [when we started], and we got it done with a hot 179 and an Aussie four-speed,” Zac says. “That did me for a while, but then I wanted to make it more fun for when I was off my Ps.”

The solution was another straight six, just not from Holden. “We went with an RB30 because it was the easiest engine to get engineered and make power with,” Zac says. “Dad and I built the car at home in the shed, racing it regularly at the local dragstrip.”

The RB30 copped a beefing-up by Simon Trigg at Trigg Engine Developments, using the standard block and crank. The rods are Spool H-beams with JE pistons, and the head is still a single-cammer, with CNC porting by Bullet Engineering. It’s now sporting a freshly upgraded 284/292 Kelford cam, which will yield Zac even more stonk next time he’s at the track.

The cold side uses a CPC inlet manifold, while the hot side has a 6boost exhaust manifold feeding a Proboost G40 turbo. The god-awful factory distributor has been deleted in favour of a PRP trigger kit, which communicates with a Haltech Elite 2000 ECU. On E85, the package has made a best of 616hp at 29psi through the Race Glides-built Trimatic, but the new camshaft should offer more power again. “We haven’t had the chance to run it down the quarter since we put [the cam] in, so it should make a decent difference,” Zac says.

He launches all that grunt through 225/50 tyres, squeezed under the factory tubs. “It has a nine-inch with a Strange centre and anti-roll bar, so it gets out quite well,” he says. “It’s down to a 1.28-second 60-foot.”

Drag Challenge 2023 was Zac’s first crack at our marathon event, and he got off to a lightning start on Day One at The Bend with a PB of 9.34@138mph. “It was a really good week; the car didn’t go wrong and we had a great time,” he says. “I’ve always wanted to do Drag Challenge for the adventure side of it, so we’ll definitely come back.”

A 5.86@116mph at Mildura’s eighth-mile, another 9.3 at Heathcote and a 9.45@136mph back at The Bend on Day Five were enough to score Zac second place in the Tuff Mounts 235 Blown class; a wicked effort for a first crack.

“I was shocked, to be honest; I would’ve been happy just being in the top 10,” he says. “We were just there to have fun and get through the week and prove we could do it, so to get a trophy as well was crazy.”

ZAC SHEPHERD
1972 HOLDEN LJ TORANA