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The air you inhale will eventually need to be exhaled, and that’s the same for your engine. Now imagine that you’re trying to exhale your deepest breath through a drinking straw – that restricts when and how much air you can inhale on the next breath, doesn’t it? Correctly matching the exhaust lets you maximize your vehicle’s power production; your Ford exhaust is no exception.
Arguably, Ford’s most ubiquitous engine, the 302’s early iterations, only produced 140 horsepower, partly because the exhaust system didn’t have the most optimized flow. Over the years, it improved, but any car lover knows that stock Ford exhaust systems leave a lot to be desired regarding sound, especially horsepower.
You can squeeze more than a few extra ponies from the 302 by replacing the exhaust. Here’s how much you can expect to increase your power when to replace it, some key specs to consider, and a few of our favorite options.
How Much Horsepower Can A Ford 302 Engine Exhaust System Add?
One significant issue in getting the most power from your stock 302 is improving airflow. From the factory, tube sizes ranged from 2 inches in diameter to 2.5 inches, although there are a few outliers. Some bends aren’t as efficient either, and crush or wrinkle bends can disrupt the flow, too. When you’re trying to pump out as much exhaust as possible, thus creating more power, reducing the restriction is the biggest hurdle to overcome.
Installing an exhaust with 2.5-inch tubes with mandrel-bent pipes for smooth flow is a great starting point, especially for models with narrow exhaust pipes. That alone can wring more horsepower from the engine, perhaps as much as 5 to 10, as the less-restricted exhaust gases can allow higher RPMs. When you factor in other components, too, such as high-flow mufflers and headers rather than cast iron exhaust manifolds, it’s not unreasonable to squeak out an extra 10 to 15 horsepower with a new Ford exhaust system alone.
But if you’re going to replace the exhaust system, you’ve probably already looked at or installed other bolt-on power adders. A new exhaust will help you make the most of a high-flow air filter, an improved air intake, a performance cam, electronic fuel injection, or any other performance parts.
Is The 5.0 And 302 The Same Exhaust System?
When shopping for Ford exhaust parts or anything else, you might be asked, “Is it a 5.0L or a 302?” At the core, both 302 and 5.0 are measures of displacement. 302 is the advertised engine size measurement in inches, whereas 5.0L is the metric designation in liters(even though it’s not 100% accurate, its actually 4.95 liters).
While the volume is essentially the same, there’s a bit of a history lesson involved, too. Generally speaking, the engine was referred to as a 302 in model years 1977 and earlier. Starting in 1978, soon after the metric system became much more prevalent, the Ford 302 became better known as a 5.0 or 5-liter.
What does that mean for the exhaust system, though? Do they use the same parts, or are they completely separate systems? The answer is… it depends. Other factors influencing choosing the right exhaust system other than engine size include the year of your vehicle, the model, whether it’s a car or truck, and even the number of doors.
Some systems will, however, fit multiple models and model years – even multiple engine sizes—for example, our JEGS 30553 Header-Back Dual 2-1/2 in. Exhaust Kit, including Mufflers, fits 1964-73 Mustangs and 1967-1973 Ford Cougar models with the 289, 302, or 351 c.i.d. Engine.
When To Replace Your Exhaust System
Obviously, after five decades of being installed in your car, any original exhaust system will be more rust than metal. So, if you’re still running a factory-installed exhaust, it’s time for it to go. Other reasons to replace your exhaust system include:
- There’s physical damage like a squashed exhaust pipe or bashed-in muffler.
- Performance bolt-on parts have been installed such as a cold air intake, computer programmer/tuner, or other components that are designed to increase horsepower and/or torque.
- You want a different exhaust note, whether a louder rumble or a deeper, throatier roar.
- Replacing exhaust manifolds and the original exhaust don’t line up.
- You’re looking to eliminate exhaust restrictions for any other reason.
302 Engine Exhaust System Specs
Ford exhaust parts might all look similar, but they have stark differences. There are four different specs to keep in mind, and JEGS offers exhaust systems to fit each one.
Single vs. Dual Exhaust
Single exhaust came standard on many classic cars, even for higher-displacement engines like the 302 V8. There are options available for a similar fitment, or you can install a dual exhaust for better flow. Modern 5.0L engines tend to have dual exhaust installed, regardless of the application.
The JEGS Cat-Back Exhaust System for the 2015 Ford Mustang GT 5.0L includes true dual exhaust from the catalytic converter back and includes high-flow mufflers. And because the bends are all mandrel bends, the airflow through it is as clean and unrestricted as can be.
Pipe Diameter
Whether you’re into sports cars or classic trucks, the more exhaust your engine can let out, the better – at least, within reason. The factory 2-inch isn’t enough when you’ve done upgrades, and a 2.5-inch is good. However, if you’re pushing even more power with forced air induction, then a 3-inch exhaust is much better. For a Ford 302, check out the Magnaflow Street Series Cat Back Exhaust System. While this setup is designed for the Mustang from 1967-70, others are available for different models. It's a fantastic option with 3-inch intermediate piping, high-flow mufflers, and stainless steel construction.
Manifold-Back vs Axle-Back
If you’re replacing a rotted-out muffler and exhaust pipe but don’t want to do the whole front-to-back system, an axle-back exhaust is enough. It’ll improve your sound and looks without getting too deep into the project. The Ford Performance Axle-Back Exhaust for the 2015-17 Mustang is a good example, and it doesn’t mess with your emissions equipment.
When performance is the goal, axle-back isn’t going to cut it, as the restriction at the engine is still there. A manifold-back system is best for these times, or even installing long-tube headers.
Race vs. Street Muffler
The factory installs mufflers that new car buyers won’t find too brash and annoying, but that’s not necessarily what you’ll want. You might wish for a raspy sound from a street muffler, or you might prefer glass-pack-style mufflers that barely dampen sound. Find a system that has the mufflers you want. This Flowmaster American Thunder Header-Back Exhaust System for the 1967-72 F-Series with a 302 is an excellent example of a muffler with an aggressive, head-turning sound using baffled mufflers in a true dual exhaust.
JEGS For The Win!
When you’re looking for performance Ford exhaust parts or a new exhaust system, JEGS has it for you. With top brands, including Flowmaster, Shafer’s, Magnaflow, and our very own JEGS products, you’ll find excellent options for any vehicle you’re working on, including almost anything you can fit a 302 V8 ( or 5.0L) into.
