If you were an avid reader of Hot4s & Performance Cars or ZOOM magazines back in the day, then there’s a good chance that COPDAT is a recognisable little Datsun to you. Known for its unique Subaru EJ flat-four engine swap, COPDAT graced the cover of both of those magazines when it was in the hands of former owner Terry Boyle.

First published in the January 2026 issue of Street Machine

“People still think it’s his car, and in fairness, he and I have stayed in touch and have a great relationship,” says current owner Emma Mullins. “Although we’ve kept the basic idea of what he’s built, there isn’t a nut or bolt on this car that hasn’t been changed.”

When the car was first built in the sex-spec era, it wore a fresh lick of Breeze BR from the BF Ford Falcon colour chart. Emma liked the core idea of the colour but had it tweaked to a darker shade in a custom mix referred to as Mirage Lake

Not long after Emma came into ownership of the Datto, a few spots of rust on the rear quarters prompted what would turn into a full-blown rebuild. “I was recommended to go to a repair shop in Toowoomba [in South-East Queensland], but what we thought was a few rust spots turned into a heap more rust and lots of bog,” says Emma. “I wasn’t comfortable with all the filler, so we replaced almost all the car – new bonnet, sills, driver’s door, rear beaver tail, rear quarters, driver’s-side floorpan – there wasn’t much of the old car used by the time we were done.”

While two years’ worth of bodywork was underway, Emma was also having a fresh 2.5-litre Subaru EJ25 built for the 1600 by Deshele Performance.

“It had the 2.0-litre in it from when it was first built, but I wanted the torquier 2.5-litre engine for street driving,” says Emma. “We kept it Subaru powered to keep the original spirit of the car, but modernised with a new engine and better parts.”

WHEELS: Some may remember the V4 Simmons rims COPDAT wore in its first iteration, but times move on, so Emma has further modernised the Datsun’s looks with new Simmons FR18s under all four corners, along with a big-boy TBS disc-brake kit

The EJ25 uses an STi nitrided crank, Deshele I-beam conrods and forged pistons. The heads are beefed up with 14mm head studs, with Deshele Stage 2 278 camshafts. For boost, a GCG-spec Garrett G35-900 shoves upwards of 30psi down the flat-four’s gullet, making the package good for 585rwhp with a splash of ethanol and control from a Haltech Elite 1500.

“I’ve noticed Subarus have a bit of a ‘stink’ about them in the car scene, a bit of a nose turn-up here and there,” says Emma. “But the most common thing I hear when I pop the bonnet is ‘that’s different!’, and no one seems to be as offended by the Subaru engine anymore.”

UNDERNEATH: There’s no massive tubs and heavy 9in diffs here; the little 1600 still uses the basic independent rear end suspension and diff set-up that really defined these things when they debuted in the late 60s. While Holden was intentionally engineering understeer into its family sedans, Datsun was pioneering the future!

Getting the EJ25 to fit was a tight enough squeeze, but then the decision was made to upgrade the gearbox to a Toyota R154 five-speed cog-swapper. “That required a custom bellhousing from Bill Hincher in the US, and the transmission tunnel had to be cut to move the engine 10mm forward to get the tailshaft angles right,” says Emma. “Fitting an EJ in a 1600 is hard work, let alone with a turbo! People ask if it’s AWD, being a Subaru engine, but that wouldn’t be as much fun.”

Once all the extensive bodywork and paint was sorted, the car came down from Toowoomba and back into Emma’s hands at home in Moruya on the southern coast of New South Wales.

ENGINE BAY: Expected an SR20 or L-series? The Subaru EJ flat-four swap is what makes COPDAT different from the rest, now sporting a stack of modern gear and nearly 600rwhp

A technology teacher by day, Emma wasn’t afraid of getting stuck in to get the car ready for its grand debut at Street Machine Summernats 37. “We missed Summernats 36 the year before, which was a bit heartbreaking for me,” she says. “I entrusted others to do the majority of the work, because the standard I want is beyond anything I could achieve with my skillset,” she says. “But I have been hands-on where I can, and it’s been a steep learning curve, one that I am really enjoying.”

The final major step before getting the Datsun to Summernats was the interior, with the car getting decked out in fresh tan leather by Ben O’Brien from Southside Stitching in Nowra.

“Benny made the interior everything I had dreamed of,” says Emma. “Originally, I was going all black with a teal stitch, but Benny said it would have no impact. I’d been seeing a lot of tartan stitch in my feed, so we decided to try that with the tan leather. It was a mission to get it done in such a short time frame, but I am eternally grateful for Benny’s work. It may be a bit sex-spec, but I love it!”

INTERIOR: Recaro buckets were retrimmed by Ben O’Brien to match the rest of the tan leather and adorned with tri-tone tartan stitching. Speakers have been moulded into the front door trims, and a modern centre console finishes it off

The mad thrash went down to the wire before scrutineering day, but the push to Australia’s biggest car festival paid off for Emma and her Datto when it took out the Top Retro-Tech award in the Street judging. “Summernats has always been a bucket-list one for me, so to win there and win with a Datsun was the most surreal feeling,” she says. “We had an issue with the timing belt skipping when we unloaded it off the trailer, so in the mayhem of diagnosing that, I got the text to say I’d made the Top 50 in Street.

“To make it through to the Top 10 and then win the Retro-Tech award, it was incredible,” she continues. “The judges also gave me a few ideas for what we could change for next time, and we’ve already done some of those. Jason Pollock has smoothed and painted the engine bay and fixed up a lot of imperfections, and SDR Motorsport has tidied up the intercooler piping for the new Plazmaman intercooler, so it’s ready to come back for the next Summernats, and I’m super excited.”

EMMA MULLINS
1970 DATSUN 1600Paint:Mirage LakeENGINEBrand:Subaru EJ25 flat-fourInduction:Process West manifoldECU:Haltech Elite 1500Turbo:GCG G35-900Heads:Standard, 14mm head studsCamshafts:Deshele Stage 2 278Conrods:Deshele I-beamPistons:Forged 2168Crank:STi nitridedOil pump:High-volumeFuel system:Injector Dynamics ID1700-XDS injectorsCooling:South Coast Radiators radiatorExhaust:3in stainlessIgnition:Subaru grey coilsTRANSMISSIONGearbox:Toyota R154 five-speed manualClutch:Direct Clutch Services twin-plateDiff:Datsun IRSSUSPENSION & BRAKESFront:MCA coil-oversRear:Standard IRS, loweredBrakes:TBS discs (f & r)Master cylinder:SkylineWHEELS & TYRESRims:Simmons FR18 (f & r)Rubber:Nitto 205/40R18 (f & r)

THANKS
Terry Boyle; the guys at Powertune; Jason Pollock at Kustom Paint; Matt at SDR Motorsport; Benny at Southside Stitching.

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