The numbers are pretty good.

Approximately three months ago, we saw an almost stock 1989 Ford Mustang on the dyno generating respectable 228.69 horsepower (170.53 kilowatts) at about 4,800 rpm and 292.52 pound-feet (396.6 Newton-meters) of torque at 3,500 rpm. Not a bad figure for a car that has roughly 173,000 miles (approximately 278,500 kilometers) on the odometer.

Today’s guest on the dyno is a slightly newer 1990 Mustang with several performance modifications. These include a new intake system, valve springs, injectors, throttle body, and a massive supercharger. The upgrades are complemented by a custom exhaust system and a custom engine map.

Not everything comes from the aftermarket scene though. The driveshaft and the gearbox are all standard parts which means the dyno run is going to be completed in fourth gear that has a 1:1 gear ratio. 93-octane fuel in the tank and 17-inch wheels are also part of the equation. 

So, the numbers. One word - WOW! The 4.9-liter engine is seriously capable when equipped with the right components and this dyno run comes to prove it. A peak output of 429.85 horsepower (320.53 kilowatts) at 5,630 rpm and 407.6 pound-feet (552.63 Newton-meters) at 5,090 rpm. These numbers sound pretty good for a 30-years-old car and are quite good even for a performance car in 2020.

It turns out you can have a lot of fun in a small street car if you have the correct setup of parts and calibrations, even without a modern turbocharged engine. One thing we’d definitely change is the four-speed automatic transmission which we’d replace with a five-speed manual. Other than that, this is an awesome fox body Mustang.