You can expect a 5 to 15 horsepower bump from your 5.7-liter Hemi engine by upgrading to a cold air intake system.
A cold air intake is a popular upgrade for good reasons: 1) It helps your engine breathe in a larger volume of oxygen to produce more horsepower. 2) If you’re new to the world of modifying cars, it’s one of the simplest performance upgrades you can make.
The 5.7-liter Hemi can be found under the hood of the Chrysler 300S, RAM pickup, Dodge Charger and Challenger.
But if you want to see even bigger horsepower numbers, here are some potent upgrades you might also consider. This exercise will focus on the Dodge Challenger RT since it’s currently in my crosshairs for future acquisitions.
1. Performance Cold Air Intake
The air under your hood gets very hot. So, let’s not ignore the performance difference that a simple cold air intake system can make to a muscle car like a Dodge Challenger RT.
But first, a side note: One of the reasons why I’m so gung-ho about modifying the power output of my prospective Challenger RT is because the 5.7 Hemi only makes 375 HP and 410 bl-ft of torque. Fantastic numbers in the 1990’s. Not so great in the 21st century when the latest Chevrolet Camaro SS and Ford Mustang GT makes 455 HP (455 lb-ft of torque), and 480 HP (415 lb-ft of torque), respectively.
What makes a cold air intake such a simple upgrade is that it’s a bolt on operation that only requires the turn of a few nuts and bolts. Plus, there are plenty of YouTube videos and online articles to assist you along the way.
After installation you can expect improved throttle response and better fuel economy. While adding a cold air intake is a good start, here are some more ways to rev up even more horsepower from your 5.7 Hemi.
There are literally hundreds of MOPAR parts at your disposal all designed to elevate your ride to the next level. And with so many low-cost options out there, you really don’t have to spend much unless you want to.
After a cold air intake system, likely the next easiest modification you can make to wake up that 5.7-liter Hemi is installing headers. They’re great for freeing up exhaust flow which can add up to 20 horsepower to the engine.
The reason why I’m starting here is because I’ve learned that when you’re making exhaust upgrades, it’s wise to begin at the front of the car where the engine typically is and work your way to the tail pipes. This ensures you’re getting the most out of your exhaust bolt ons. And since we started with the cold air intake – which is arguably part of the exhaust system – headers are the next logical step.
You can find all our articles about headers here.
Since we’re already under the car, why not install some mid-pipes? The whole point of mid-pipes is the same mission as performance headers: to free up the flow of exhaust.
Mid-pipes from the factory on any vehicle are going to be restrictive to meet emissions control standards. But unless the 5.7 Hemi is in a vehicle you’ll strictly be using on a track, you’ll want your car or truck to be compliant with the current emissions control regulations in your area.
I would go with high-flow mid-pipes with catalytic converters for my Challenger RT. Not only will it unlock more power and torque from the 5.7 Hemi. But it ensures that I can pass inspection since my car would also be a daily driver.
Even though installing mid-pipes promises only marginal increases in horsepower, you get the added benefit of a throatier exhaust note.
4. High Performance Muffler
We’ve already come this far and we’re still under the car. So, why not install an aftermarket muffler and exhaust? I love these things. You want to change the attitude of any vehicle? Make the upgrade to an aftermarket exhaust and you’ll never look back. This can be part of an entire catback system, or a set of mufflers you can use to replace the quieter ones from the factory.
Now don’t get me wrong, if you’re not much into the loud sound of an aftermarket exhaust. The stock units are just fine. But a high flow performance exhaust can add anywhere between 5 and 20 horsepower to the 5.7-liter Hemi engine. Along with a better V8 sound, you also get more exhaust flow with less weight.
Take a look at some of the articles we’ve written about exhaust systems here.
5. Performance Camshaft
I could do a camshaft upgrade to liven up the 5.7 Hemi motor. It’s a relatively inexpensive solution for more power compared to some of the other options coming up on the list.
But upgrading cams is by no means a simple bolt on – installation is complicated. You can find aftermarket camshaft kits for the 5.7L Hemi for less than $1000 – they can give you a boost of up to 70 HP.
Me, I prefer to hire someone with advanced mechanical skills to handle this job. A gear head I may be, but a fool I am not. There’s no shame in asking for help. You’ll have to decide if this one is worth it or not.
And now we get into the more expensive upgrades I could make to my Challenger RT’s 5.7 Hemi. You know, the kind of upgrades that might have me taking out a second mortgage.
If you’ve ever heard a big V8 engine with a supercharger. Then you know how amazing they sound – it gets you right in the gonads.
But no joke.
Installing a supercharger (the kind of serious package that offers maximum performance boost when 10ths of a second matter) is a big job that’s not for the faint of heart.
ProCharger was one of the first companies to offer superchargers for the Hemi engine. Their superchargers can add as much as 215 horsepower to your 5.7 Hemi. This is not an installation I’m bold enough to do this myself, which means it’s going to cost.
Check out some of the articles we’ve written about superchargers here.
7. New Engine
But if you really want the ultimate in unfiltered horsepower gains. Forget the cold air intake and all the other bolt-ons. If money is no object to you, why not consider a Hellcat Crate Engine?
It’s only double what it costs for a supercharger. And it’s available directly from MOPAR. This is the grand-daddy of mods for any Challenger.
It’s a plug and play engine offering 707 horsepower and 650 lb ft of torque. Not only does this Crate Hemi engine come supercharged. But the powertrain control module (PCM) is not encrypted like the factory Hellcat cars, which means you’re free to juice even more power out of it!
8. Performance Tune
Now that you’ve increased the amount of oxygen the 5.7 Hemi can breathe in to make more horsepower. It’s time to finish things up with a tune. At MotorCliff, we firmly stand behind ECU tuning after making engine performance upgrades.
A performance tune optimizes how your engine performs. You can change the factory emission and engine parameters to settings more consistent with your driving behavior – you’ll especially enjoy the difference after adding a supercharger. The results more efficiency, are better fuel economy and overall performance.
Here are some of the articles we’ve written about tuning.