The Porsche Killing LS3 Powered NC Miata

Dave's NC Miata

I’d be lying if I said I wasn’t a bit anxious when I went to see Dave and his monstrous LS3-powered MX-5 on that chilly October morning. A bit of a legend in the Canadian Miata community, Dave and his team at “Dave’s Garage” have been fixing, modifying and building Miatas significantly longer than I’ve possessed a driver’s license. These guys live and breathe Miata, and their obsession with the quick-turning, feather-weight sports car has lead them to push the limits of how far this little car can be taken.

The 170 bhp that came in Dave’s 2007 NC Miata is more than ideal for a weekend autocross or cruising twisting country roads, but his heart lives at the racetrack. The traditional approach for bumping up horsepower has always been forced induction. Though as efficient as modern turbo-charged setups can be, the Miata’s little four-cylinder has its limits. If your goal is to produce 400+hp, you’ll be looking at a built motor, a beefier clutch, upgraded differential, a larger radiator, oil-cooler, the list goes on. Not only are such builds expensive, but high-strung turbo monsters also have a tendency to spontaneously combust if not built to absolute perfection.

Dave chose a different approach and ditched the entire stock drivetrain in favor of a shoehorning a 6.2l LS3 Chevy V8 under the hood. The result is a weight increase of just 200 lbs spread across the entire car, 400 whp, 400 wtq and OEM Chevy reliability. This leaves us with a car that’s more than capable from pulling away from modified Corvettes and GTRs, though this special MX-5 was built for so much more than highway pulls and car shows.

Dave’s Miata sees action all around Ontario and Quebec racing in CSCS (Canadian Sport Compact Series), and it’s loaded with everything needed to survive constant abuse on the racetrack. Ohlins’ coilovers and other suspension goodies keep everything planted, while fat 255/40-17 RE71Rs on beautiful TE37 wheels reduce unsprung weight and allow it to put 400 whp to the floor. Brakes have been upgraded with Hawk HP+ pads and a Mazdaspeed Motorsports cooling kit directs cool air towards the rotors to combat brake fade. A Hard Dog roll bar along with Sparco seats, not one but two fire extinguishers, and a custom gauge cluster completes the whole package.

While the car was built to embarrass Porsches around a circuit, this is ultimately a street car that’s driven to and from the track. That’s the beauty of this build; it turns at 1500 rpm on the highway so it achieves a better-than-stock 29 mpg. It’s fairly quiet with the exception of that lovely v8 soundtrack and can be driven for hours on end without any qualms. It’s even fairly easy to drive, though without ABS or any sort of traction or stability control, it quickly becomes a handful in inexperienced hands.

Surprisingly, the entire build was fairly straight forward and required no custom work, aside from the gauge cluster and steering wheel. Mounts and drivetrain components were purchased from US V8 Miata specialists V8 Roadsters, and the entire project was put together in roughly three weeks. Dave reckons that getting a V8 Miata budget-build running can be done for around $20,000; add in the cost of a used NC or older Miata, and the mechanically inclined can build one for well under $30,000.

As a package, the car is perfect. It sits at the right height, on the right wheels and makes all the right sounds. It is comfortable on the highway, while dominating at the racetrack. On that note, it appears the recipe for the perfect car is two-part’s Miata and one-part ‘MURICA.  

2007 MX5 - Mod Sheet

Drivetrain

  • LS3 6.2l Crate Engine
  • LS3 430hp PCM Controller
  • LS7 Clutch & Flywheel
  • AAM Camaro Differential 3.45
  • T56 slave cylinder
  • Tranzilla Upgraded T56 Transmission
  • V8 Roadsters Mounting Kit
  • V8 Roadsters Driveline Kit 
  • V8 Roadsters Cold Air Intake Box
  • V8 Roadsters Race Radiator & Fans
  • Borla Custom Exhaust
  • Borla Headers 1-3/4"
  • Aluminum Driveshaft
  • Baffled Oil Pan

Suspension & Brakes

  • Ohlins DFV Coilovers w/600/400 springs
  • V8Roadsters Sway Bar Front
  • Whiteline Sway Bar Rear
  • Racing Beat Sway Bar End Links
  • Mazdaspeed Motorsports Brake Cooling Kit
  • Hawk HP Plus Brake Pads
  • Volk Racing TE37SL 17x9 Wheels
  • Bridgestone Potenza RE71R Tires 255/40-17
  • Hard Dog M3 Hard Core Roll Bar
  • IL Motorsport Under car Braces

Exterior

  • OEM Club Blacked Out Headlights
  • 2013 OEM Mazda Bumper
  • OEM Club Front Spoiler
  • Trunk Spoiler
  • Mazda OEM Hardtop

Interior

  • Custom Speedhut Gauges
  • Guardian Design Custom Steering Wheel
  • Mazda Brushed Vent Rings
  • Moddiction 1lb Shift Knob
  • Sparco Grid Sea

Gallery

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