Getting More Ponies from Your Mustang

Maybe you finally purchased your dream car, or you've been driving it for a while and it's time for some modifications. The good news is that the current iteration of the Ford Mustang is really popular and you've got a number of aftermarket options to goose its performance a bit. Whether you're brand new to Mustangs or just ready for more performance, here are the best ways to modify your ride for minimum cash.

A black Shelby GT sits at a gas station.

1969 Shelby GT 500 | GTHO | Wikimedia Commons

Performance Intake

A factory air intake is adequate for factory horsepower levels, but for performance, it's like running a marathon while breathing through your nose when you have a cold. It's a restriction. An aftermarket intake increases intake tube diameter and reduces bends and internal turbulence, resulting in increased volume and speed of incoming air. To continue the breathing analogy, it's literally a big breath of fresh air for your engine. And in the case of cold air intakes, cold air is denser by nature and that density can help cram more oxygen into the fuel system.

Cold air intakes are common first mods since they're affordable, they are easy to install, and proven to increase power. K&N says this one, available online, is good for 13 horsepower over stock in a 1994 - 95 SN95 with 5.0L. It's easy to find intakes that are CARB (California Air Resources Board) exempt, so if your state has emissions or inspections, you'll pass. Got a newer EcoBoost or GT? You've got a lot of choices from Spectre to K&N, but selection in your local Advance will vary.

A MagnaFlow cat-back system shown in parts.

Get the sound you're after with a MagnaFlow cat-back system | Advance Auto Parts

Cat-back exhaust system

We're gonna skip the human anatomy analogy this time, so just think of an exhaust system as one of those cheapo bicycle tire pumps. With the exhaust restricted, it's like a kink in the air hose, and the pump has to work harder to flow air through the tube. A factory exhaust system on an S550 Mustang (2015+) is quite efficient, but the aftermarket has dedicated performance options that are even better. Similar to an intake, the larger diameter pipes and reduced bends enable the spent exhaust gases to easily flow out of the engine, letting it “breathe" easier, resulting in more power.

Aftermarket exhaust systems are usually stainless steel to resist corrosion, and often weigh less than factory systems. Weight reduction improves performance in every area, from acceleration and braking, to handling and fuel economy. If you're unsure which brand to get, YouTube is a great source if you want to hear sound clips of what a MagnaFlow cat-back system sounds like on a 'stang similar to yours.

Two white and blue Mustangs posed in a desert.

The 2020 Shelby GT350 Heritage Edition Package | Ford Media

High Flow Fuel Pump

Air is only one aspect of the horsepower equation. Another major ingredient is fuel. The stock fuel pump on a Fox (1979 - 1993), SN95 (1994 - 1998) and New Edge (1999 - 2004) Mustang GT is nearly maxed out with just basic first mods, so when adding air modifications like intake and exhaust, you quickly run into diminishing returns as it runs out of ability to increase fuel flow. The solution is an upgraded aftermarket fuel pump. Enthusiast forums suggest going the cheaper route and grabbing a new fuel pump from a Focus SVT or Lincoln Navigator an upgrade, but the best bet for longevity is a new aftermarket fuel pump designed for your ride. The right pump will flow well for current mods, and allow you to upgrade to bigger cams and/or forced induction later, still supporting the engine's fuel needs. Better still, an aftermarket fuel pump is going to be custom-designed and tuned for your vehicle so there's no risk of excessive fuel pressure becoming an issue.

An army green Mustang sits in front of a government building.

Steve McQueen's iconic Bullitt Mustang | Historic Vehicle Association

Performance Ignition Coil

That stock ignition system in your Fox might be holding you back. One of the key components to making power is the spark that ignites the fuel and air mix. The stock components were good for the '80s, but like tape players and beige houndstooth seats, time and tech have provided us something better. Aftermarket coils like this Accel Super Coil have highly specialized silicone/magnetic steel cores and optimized winding for lower resistance and 15-percent more voltage output. The result is quicker starting, smoother idle, and better driving performance. Round out this affordable ignition upgrade with a set of performance cap and rotor kit and spark plug wires.

The mechanics of a 4.10 ratio set.

This 4.10 ratio set can cut at least 2/10ths off your quarter mile time | Advance Auto Parts

Differential Gears

Alright, so this one doesn't add “more ponies" in terms of increased horsepower, but it will definitely make your Mustang faster for not a lot of cash. One of the best “bang for the buck" mods available, a differential gear swap does not increase horsepower, but changes how the engine hits the power band. Remember that the lower the number, the higher the gear ratio, and vice versa.

A set of 3.31s is a common Mustang gear ratio, optimized for highway on ramp acceleration and optimal MPG on the highway. The ratio is driveshaft RPM in relation to wheel/tire RPM. A 2.73 ratio means the driveshaft turns 2.7 times for every tire rotation. If you swap in 4.10 ratio, the driveshaft spins 4.1 times, meaning the engine is closer to peak power. On a 2011 Mustang GT, that increased RPM is a difference of about 150 hp in the 5.0L Coyote. This 3.73 ratio gear set is a good mix for all-around performance, without killing fuel mileage on the highway, but if you're into drag racing, get this 4.10 ratio set to cut at least 2/10ths off your quarter mile time. These higher (numerically) gears will increase acceleration at the cost of top speed. There's a lot of considerations to gear selection, such as vehicle weight, forced induction, and tire size, but in general, higher numerical gears equal better acceleration.

A red and yellow car sit in front of a house.

2021 Mach-E First Edition | Ford Media

Big Brake Kit

Adding more quickness to your ride means you need to do the responsible thing and upgrade the stopping ability. Sport brake kits include everything you need to upgrade your EcoBoost or GT without the factory Performance Package. Ford's factory Performance Package is decent, but performance kits like these shipped direct from Power Stop, include everything you need to upgrade your stopping ability. On the affordable end, kits include performance pads and drilled/slotted rotors for maximum contact and heat diffusion, as well as improved hardware. Even those changes can be enough to make an appreciable difference in braking performance. It's a great package for street driven vehicles seeing light autocross or track duty. More expensive kits include upgraded calipers for maximum clamping force in racing situations. The result is shorter stops. Do try and upgrade front and rear brakes at the same time, to keep the factory front/rear brake balance.

Any other suggestions for making a Mustang into a speeding Bullitt or King of the Road? Let us know how you made yours the Boss that can hit Mach 1, in the comments below.

Last updated February 3, 2021