Chris Kurumolla’s VL Commodore is one bad-arse machine. Powered by a single-cam RB30 six-cylinder, it has run 6.64@209mph over the quarter-mile, and there’s more to come! Yet while its accomplishments on a 275 radial are extraordinary, the car retains real street composure despite its polycarbonate windows, parachutes and race wheels.

First published in the July 2024 issue of Street Machine

Chris, who owns Melbourne workshop CK Automotive, is clearly a capable racer and mechanic, and his VL has been built to an impeccable standard. From the very beginning of the project, he had seven-second quarters in mind. “We started with a dead-stock VL with the intention of running a seven-second pass,” he explains. “We were focused on single-cam RB30 performance only, but we really wanted to keep the car as street as possible – something my mum could drive.”

Chris’s first move was to send the car to Nextgen Metal Fabrication with a big to-do list, including mini-tubs and a full chrome-moly rollcage that extends through the floor and ties into extensive bar and support work under the car. The rear ’cage area was fabricated with tabs to mount the fuel system accessories, while a sheet-metal Pro9 diff housing was fitted with a Strange Pro HD centre sporting 3.5:1 gearing, a Race Products floater kit and 35-spline axles. Afco rear shocks were fitted initially, but these were later swapped out for Menscer items.

The car’s first RB mill was a billet-block, cast-headed combination by Bullet Race Engineering, fitted with a Nitto 3.2 stroker kit. Assisted by a single Pro Mod 88mm turbo mounted on a 6boost exhaust manifold and with a Precision wastegate, that engine pushed the car into the 7.80s on E85.

However, not long after Chris had the car up and running, one of his customers was impatient for a new motor combo, so Chris sold him his engine and moved on to another single-cam deal.

A new motor meant new goals, and although a single-cam VL had already run into the sixes, the 200mph barrier was still up for grabs, so for Chris, the race was on.

The new mill has the same capacity as the previous one but is based around a new-generation Bullet RBx block featuring bigger main bearings. A Callies crank and BME alloy rods and pistons have been fitted for a static compression ratio of 10:1. Instead of a cast head, Chris got to trial Bullet’s first billet head. It’s matched to a three-piece, CNC-machined billet inlet manifold built to accept 12 Siemens 2400cc injectors (two per cylinder), which are fed by a cam-driven Kinsler fuel pump and matching regulator from the front 15-litre header tank. A boot-mounted Bosch 044 pump draws the go-juice from a 20-litre fuel cell and sends it up front.

The billet head called for a new port design, so Queensland’s 6boost came up with a V-banded exhaust manifold, while the turbo was upgraded from an 88/91 to a Precision Next Gen 98mm piece.

As the new combo was to run on methanol, the smart coils were replaced by an M&W CDI ignition unit, and an Emtron ECU controls the whole show.

With the engine being turned to 10,000rpm, the oiling system was upgraded from a wet sump to a four-stage dry sump with a Barnes pump, Peterson oil tank and ASR oil pan.

With Chris having run 7.80@171mph and a 1.28-second 60-foot with the previous combo, expectations were high that the new engine would send the VL into the sixes at 200mph. That goal was achieved in March this year when the car ran 6.92@200mph, breaking the single-cam RB30 record, followed several weeks later with a 6.79@206mph. And just as we were going to print, the VL hit a new PB with an incredible 6.64@209mph pass at Sydney Dragway! Buoyed by that result, Chris and his team are now looking to beat the twin-cam record – currently 6.58 seconds – with his single-cam combo!

Despite running a full-alloy six-cylinder, the all-steel car was no lightweight, tipping the scales at 3400lb (1540kg) with driver when it ran the 6.79. The boys then swapped out the doors for carbonfibre items and downsized some of the fit-out accessories, shaving almost 400lb (180kg), which no doubt helped the VL hit that 6.64-second PB.

Chris has Michael Kalaitzakis from QuickBitz handling the tuning and race strategy, and he’s throwing everything at the car to hit that 6.58. “We leave on 40psi at 6000rpm, and within one second, we have 75psi in it,” Chris says. “We are using a small shot of nitrous to get it out of the hole, but we are going to start spraying it as it goes down the track to drop our intake temps and hopefully pick up a bit more power.”

The bigger turbo, nitrous and more power has already lowered the car’s 60-foot to a mind-blowing 1.09 seconds! Incredibly, the car still runs an air-to-air intercooler; Chris points out that a straight pipe from the turbo to the intake would do nothing to help intake temps.

On the dyno, the car makes 1600rwhp, and based on mph and weight, the engine is showing around 1900hp at the flywheel. “Unfortunately, we are near the end of making power,” Chris says. “I’ve stepped aside for a lighter driver to save weight, and we have nothing left in the 60-foot, so hopefully spraying nitrous and a lighter car will get us into the 6.50s.”

After some issues with the parachutes, Chris had PSIDUP Fabrications remount both ’chutes and add a weight bar (currently at 20lb) to the front of the car to stop it wheelstanding. Keeping the nose down will stop the transmission from bleeding converter pressure from the external dump valves, and by running the car with the dump valves fully closed, the team can pick up time and speed in the front half of the track.

Given the VL’s performance so far, Chris is more than happy sticking with a single-cam mill. “The twin-cam combinations do traditionally make more power, but they don’t have the reliability,” he says. “We can do back-to-back six-second passes with no issue; the twin-cams only seem capable of four or five runs and they seem to tear them up.”

Chris credits Bullet Race Engineering, Protrans, GJ Drivelines and Dominator for their role in the car’s success to date, and gives special mention to Jonny Tig Industries for the intercooler and the car’s new pilot, Menza, for the great wheel work. Other key players include Danny at DesignWire in Adelaide, who rewired the car with mil-spec wiring, and Sherif Tawaf for the phenomenal suspension set-up.

Finally, Chris gives a big shout-out to CK’s head mechanic, George Darmos, who does everything in the car except the motor. “He knows more about the car than I do,” he laughs.

Let’s hope these boys keep hitting it as hard as they have been. One thing is for sure: this is one of the baddest six-pot Commodores ever built in Australia.