Sigma-powered Chevy S10

Manny Spiteri’s journey towards automotive fandom starts as humbly as most of ours did - he wasn’t swooned by the supercars racing around on the television screen, nor was he particularly enamored by the European exotics that adorned his buddy’s walls. He just thought his dad’s car was kind of cool, and that car was a Mitsubishi Sigma.

“I bought a really nice black Sigma and wanted to build a tough street engine for it. I got in contact with Paul Testa from MR2600 Racing and he helped me build the whole car. On its debut at Sydney Jamboree twelve years ago the car went straight into the 9s and won the Street 289 class with Paul behind the wheel!” he exclaims. 

Of the litany of feats that make this achievement super impressive is the fact that it was a genuine street car - nothing too crazy, just a decent auto box, a T51R turbo and a Ford 9in diff. “The engine was making a lot of torque though and it started to twist up the car. The black car was way too nice for that, so we dialed the power back and cruised it on the street,” Manny continues.

However, Manny and Paul’s 4G54 development program continued, which included campaigning Paul’s famous orange 7sec Galant, all the while developing a one-of-a-kind billet 4G54 cylinder head.

“They’re weak between the valves and tend to crack, and when Paul told me he was developing a billet head I quickly did the math on how much money I’d spent welding up damaged cast heads and having them machined over and over. Paul designed it and had a local mob machine it. They did an amazing job in terms of adding enough material to make it much stronger than a cast head, whilst still allowing it to fit our existing parts like the intake and exhaust manifold,” explains Manny.

Straight out of the CNC, the heads are delivered to APM for final machining and assembly and then amazingly, slapped on to a standard, grout-filled cast iron block with a standard crank in it! “It’s really hard to compare this little engine to anything else out there, as we’re a four cylinder with only one cam’ and 8 valves. I guess it’s kind of like an RB30 but even then, they’ve got two extra cylinders and more displacement. Whatever the case, Paul’s Galant has run a best of 7.30sec and we didn’t build this engine or the truck to go any slower,” he says decisively. 

Everything you see in the engine bay (and for that matter, the rest of the car) is Paul’s handiwork, which is made more impressive when you realise that he builds race cars in his spare time out of his garage at home! Paul’s two decades of experience with these engines has led to the development of parts like the billet intake manifold (machined by fellow Illawarra business, CPC Manufacturing), the dry sump, the exhaust manifold and a long list of other one-off parts that contribute to the team’s outrageous success with the unloved 4G54 platform.

The engine bay is dominated by the giant GTX55 94mm turbocharger, with a shot from the blue bottle to help the little four-pot get the turbo making some steam. Between the water-to-air intercooler, and on a steady diet of methanol, the 4G54 is kept plenty cold enough. It’s been converted to a dry sump set up, and has been wired back to front by Paul’s brother Joe (Wired By Joe), who’s also the man dissecting the data and tweaking the tune in the Holley ECU at the track.

The chassis itself is just as interesting. Originally built in the States, the car arrived in Australia via New Zealand, where Manny purchased it from Sam at KTEK Industries. “I think Sam originally wanted to put a Barra in it!” laughs Manny. “I liked it because people who build utes into 4-cylinder tube cars. We got it back to Paul’s and he went through and redid a lot of the chassis, rear end and tin work to suit what we wanted out of the car.”

With the distinctive wrap applied by Alex from JetPac Dezign, the Mitsubishi-badged Chevy S10 is a huge departure from the small tyre street cars that the boys are used to playing with, but they’re extremely familiar with racing the Sigma engine thanks to Paul’s Galant and its success at events around the country. 

“Craig from SCF aligned the car and gave us somewhere to start, but much like we’ve always done, we’re forging our own path with this car and gradually creeping up on its full potential. I know I’ve got a lot to learn as a driver, but as a team we’re learning a lot about the dynamics of the tube chassis and big tyre,” he states.

And while they learn, the boys are smiling from ear to ear as the little Mitsubishi four-banger is about as reliable as you can make a big-tyre drag car! “We’re basically bringing it back to the pits, making our adjustments and going back out again. At the end of every meeting we’ll do the fluids and adjust the rockers but we’re not leaning on it hard enough to break anything - I think this is the one car I can honestly say I haven’t wasted money on!” beams Manny.

To date, Manny is continuing with licensing passes in the car. They’re understandably hesitant to put a number on the car’s potential, but confidently admit that they’d like to see its first full pass in the 7sec zone.