V8 FIERO project

1988 Pontiac Fiero with a 4.6L Cadillac Northstar V8 swap


  • 1988 Pontiac Fiero that has the engine, transmission and electronics from a 1996 Cadillac Seville swapped over. Everything is made to look stock like it came from the factory.
  • The original 2.5L 4 cylinder in the Fiero came with 92 horsepower. The 4.6L V8 now installed has 300 horsepower. It also includes the 4T80E 4-speed automatic transmission.
  • All aluminum V8 doesn't weigh significantly more than the cast iron 4-cylinder it came with. Total weight is 2600 lbs.
  • Front hubs drilled to 5x115 pattern to match rear. Rear axles are from the Cadillac. Brakes are upgraded parts from a C4 Corvette.
  • The Fiero is a mid-engine car with the engine seated behind the driver. The drivetrain layout is transverse and able to fit many FWD GM engines and transaxles.

32-Valve v8

DOHC V8 power

The 32-valve 4.6L V8 Northstar engine generates 300 HP @ 6000 RPM and 295 lb/ft torque at 4400 RPM. Fuel cutoff at 7000 RPM. This the L37 high-output version. PCM is a factory modded tune with VATS disabled. All modules from the donor car are installed. Custom Magnaflow high-flow exhaust installed. Best 0-60mph time on pump gas is 5.2 seconds. Pounds-per-horsepower ratio is 8.66, which is similar to a 2017 Chevy Camaro SS, which has a ratio of 8.61.


With no aftermarket tuning options based in the US, we will be looking at a PCM solution based on open source, or looking at different engine swaps with better aftermarket tuning support. The LS4 5.3 V8 is a potential swap candidate, as it is already used in FWD GM vehicles and the LS platform has many tuning options.