Paul Butler may have got his 1976 TX Gemini from the original, 76-year-old owner, but make no mistake – this Gemmi is not Nana’s asthmatic runabout anymore.

First published in the June 2024 issue of Street Machine

Using turbo SR20 power, this little beige rocket has nabbed just about every piece of no-prep drag-racing silverware the northern east coast has to offer. Wins at Rockynats, Roll Racing Queensland, Torque Time No-Prep Eighth-Mile and the Oz Aid Kooralbyn Shootout are just a few of the honours Paul and the Gemini have gathered over the years. Not bad for a car that was originally intended to be used for parts.

“It started as a basic 420hp deal, and it’s evolved over the past 10 years or so to what it is now,” Paul says. “In the beginning, I didn’t know anything about four-pots – I’m a V8 guy. I swapped a race suit for the first SR20 just to get it going, and that’s where it started.”

It has since evolved into a bloody potent package, now boasting over 50psi of boost to make 1000hp at the hubs. Stroked to 2.2 litres, Paul’s SR20 was built by Peter Phillips Performance Engines. The extra displacement comes from a Nitto rotating assembly, and the block is sleeved. The head is actually a front-wheel-drive SR20DE item from a Pulsar, using a custom set of cams. “I found that head on Gumtree during the first build; it was all set up, but I had no idea there were different heads!” Paul laughs.

Hanging off either side of it is a modified Otaku Garage inlet manifold, the hot side using 6boost pipes to feed the G35 1050 turbo. A Haltech Nexus R5 controls the show, while fuel is pump E85. However, this mill’s secret sauce is the two-stage nitrous system. That gives the SR its four-figure punch, tuned to perfection by Paul’s good mate Justin Simpson at Horsepower Solutions. “He’s the wizard with the nitrous; that’s what gives us such a good edge,” he says.

Oh, and if you’re wondering how Paul combats the famous SR20 rocker problems, it’s fairly simple. “We keep the rpm low at 8600, and a properly set up head is key, which takes a lot of time,” he says. “It’s still standard Nissan rocker gear.”

As for the rest of the car, that was put together by Paul’s own two hands. He’s built a number of high-end cars in his time, most notably Billy Shelton’s SICKEST VL Calais, cover star of our August 2021 issue. That car has cracked the sevens comfortably, so it’s no surprise that the Gemini shows the same potential.

“I’m always looking to improve it and stay ahead, because that’s how you run at the pointy end,” Paul says. “I had to tub the rear end three times, first to fit the 235s, then the 275s, and now the 325s. It’s all part of going faster.”

Until recently, the transmission was a Ford C4 with an SDE 6850rpm converter, sending the power back to a BorgWarner diff with full-floating axles and 4.11:1 gearing. However, since we shot the Gemini at Rockynats 4 over the Easter long weekend, Paul has already swung the axe to keep the car on its toes. “It’s now got a Garrett G40, a 6boost Pro Mod forward-facing exhaust manifold, and we’ve upgraded to a 2000hp Powerglide,” he says.

The car is yet to run a representative time over the quarter on a prepped track, but Paul is looking to change that soon. “Once Willowbank opens, we’ll head there with some 235 radials and see what it can do, and we’ll have a crack at a Kenda round as well.”

PAUL BUTLER
1976 HOLDEN TX GEMINI

THANKS
Justin Simpson at Horsepower Solutions; Billy Shelton at SICKO Motorsport; Anycrete Concretors; Peter Faulkner at Air-Con & Auto Electrix Mechanical; Peter at Peter Phillips Performance Engines; Jeremy Hassell at Weldwerx; Todd Protheroe; Andy at Fireball Kustom Fabrication; Bob Jane T-Marts Redcliffe; Ben Vlekken at Elite Automatics.