1978 Mustang with a Nissan Turbo Inline-Four

Jason Bowman purchased a 1978 Ford Mustang II Mach 1 in 1992 when he was 18 years old. Over the years it has seen a full restoration and several engines. However it’s the last engine choice that really separates this Mustang from the herd.

The Mustang ran several Ford 302 ci V8 engines with the last having a .060 overbore. The engine had a hard time staying cool even with an aluminum radiator and electric fans. The three-speed automatic transmission didn’t help either, especially on the highway.

When Jason started considering another engine, he knew he wanted fuel injection and if possible drop some weight in the front. He also wanted taller gears only a five or six-speed manual could only deliver. Jason thought back to a 2.0 L SR20DET inline-four he installed in another vehicle and how well it performed. He realized the Nissan engine and accompanying transmission would solve his issues.

Originally Jason wanted a SR20DET and six-speed manual from a Nissan S15 but the Importer recommended using a Nissan S14A because it comes with a T28 ball bearing turbocharger and stronger five-speed manual.

Installing the inline-four into the Mustang engine bay required custom mounts that connected to the factory mount points. Even though it probably will never be turned back to a V8, Jason felt good knowing it still could. He also switched to a Subaru Justy alternator and Spriso Motorsports mount because the factory Nissan alternator and mount was too large.

Jason upgraded the engine with a Nissan 300ZX mass air flow sensor, FiveO 550 cc injectors, and ECU tune by RS-Enthalpy. Jason estimates the engine produces 275+ horsepower and 245 lb-ft of torque. To keep the front looking stock Jason opted for an air-to-water intercooler inside the engine bay.

The five-speed manual transmission was installed thanks to a modified Mustang II crossmember and GM transmission mount. Since the Mustang originally came with an automatic transmission Jason needed to build a clutch system. He built it using a Nissan 240SX master/slave cylinder and custom linkage.

The transmission connects to the factory Ford 8″ rear end via a custom driveshaft.

Jason upgraded the front brakes with KVR 11″ slotted rotors and Hawk HPS pads. The wheels are five-lug thanks to an Allstar Performance brake kit that uses Ford Granada rotors, custom brackets and GM metric calipers.

Inside the cabin Jason made a custom dash from aluminum, fiberboard, and fiberglass. The dash holds a rail Tech Vapor all-in-one dashboard flanked by AEM wideband and boost controller gauges. Below that is a series of toggle switches to control functions like lights and wipers.

Jason’s Mustang has given him many years of enjoyment and thanks to his tremendous work it will continue to do so.