The 5 Best Dodge 5.7 HEMI Upgrades

The Dodge 5.7 HEMI engine is a popular engine in many Dodge & Chrysler performance cars, Ram trucks, and more. Its large displacement offers solid power from the factory. However, the 345 HEMI also leaves a lot on the table. A few simple upgrades can take the 5.7 V8 to the next level. In this guide, we discuss the best 5.7 HEMI upgrades, power gains, cost, performance, and more.

345 HEMI Updates & Changes

As an 18+ year old engine the 5.7 HEMI has been through its share of updates. Many of the updates are intended to keep up with stricter emissions and maintain competitive performance and power. We wrote a detailed 5.7 HEMI engine guide, and touched on these updates in greater depth.

2009 model year saw the largest update to the engine; it’s known as the 5.7 Eagle. A lot of the changes help improve power and performance, such as variable cam timing and a better flowing cylinder head. Check out the above common problems article for some more details on the specific updates. Certain models like the Ram 1500 and Dodge Charger have some small differences and offer different power output.

The main purpose of this section is just to talk generally about performance updates. Not all engines will respond exactly the same to mods. The later 2009+ 5.7 Eagle is generally more capable. However, earlier engines have a lower starting power output and may actually gain more from certain mods like intake manifolds.

Point is – any power or performance gains we discuss are rough estimates. It’s not just about the differences in engines, either. Results can vary a lot depending on other mods, conditions, age, mileage, etc.

Dodge/Ram 5.7 HEMI Upgrades

• Tune (& fueling)
• Intake
• Headers
• Exhaust
• Cams

Less the cams these are all pretty simple bolt-on mods. They are the foundation to making more power on the 345 HEMI. Even if you’re going forced induction the above mods are still a great starting point.

Throughout this article we will take an in-depth look at these 5.7 HEMI power upgrades. We’ll cover everything from the benefits, risks, power gains, and more. Of course, there are tons of great HEMI performance parts so the above is an exhaustive list. There are simply too many options and various builds that we can’t cover it all. However, let’s talk about a few other common 5.7L V8 HEMI engine mods.

Other 5.7 V8 Performance Power Mods

The above mods are our primary focus in this article. However, we will also address a handful of 5.7L HEMI power upgrades including:

• Superchargers
• Throttle Body
• Intake Manifold
• Gearing

If you would rather consume this content via a video, check out our Best 5.7 HEMI Mods video below:

1) Tuning

Adding a tuner to your 5.7 HEMI is debatably the single best power upgrade. It’s not just about the benefits of tuning the 345 Mopar engine. A tune is also the foundation to making more power from additional mods. When you start adding air-flow and fuel it’s important to properly calibrate the computer (PCM) for all of the changes. A tune is still a great performance mod as a standalone upgrade for Dodge and Ram vehicles.

Adding a tuner comes with some of the following benefits:

• 5-15 horsepower (on an otherwise stock engine)
• Similar torque gains
• Improved response
• Better fuel economy

There may be some other benefits, but performance and power are the big ones. On a stock 5.7 HEMI you may only see gains around 5-10 horsepower. With other mods like an intake, headers, etc. the tune alone may see gains closer to 15-20 horsepower. Torque gains can be similar and you’ll likely notice better throttle and engine response. Better fuel economy is possible with the right tune.

You’ll need a tuner device to actually flash the 345 HEMI powertrain control module (PCM). Most tuners cost about $350-600 and include some basic off-the-shelf tunes. The biggest gains can be had with custom tuning the 5.7L V8 engine, but that can add another $200-300. Anyways, a tune is a solid overall mod for a fair price. It’s also required for certain mods like some intake manifolds, cams, and other upgrades.

5.7 HEMI Fueling for Tuners

It’s important to note – the biggest gains from a 5.7 HEMI tuner will be on higher grade fueling. The higher octane you have access to the better. Most only have access to 91 or 93 octane. However, if you have easy access to higher grade fuels you may be able to pick up even more power.

We’re big fans of ethanol (E85) fueling, but it’s overkill on NA engines. You can find options to convert your 5.7 HEMI to E85. This can offer extra gains of 10-20+ rear wheel horsepower. However, running full E85 is about 30-40% less fuel efficient so trips to the gas station will be frequent. That’s especially true if you’re using all of the power.

Long story short – the higher the octane (or ethanol E85) the better power gains you’ll see with a tune. 91 or 93 octane tunes likely make sense for most people unless you’re willing to deal with the hassles of E85 or race gas.

Tuner Price: ~$350-600

Tuner HP Gains: 5-15 horsepower (20-30+whp possible with race gas or E85)

2) Cold Air Intake

Next up are performance intake upgrades for the 5.7 HEMI V8 engine. You may also hear these mods referred to as cold air intakes, intake systems, etc. Performance gains with a 345 Mopar cold air intake may be underwhelming with light mods. However, as you start adding more and more power it’s important to help the engine breathe.

The right intake upgrade can also help get cooler air into the Dodge/Ram 5.7L engine. We typically don’t agree with the cold air intake designation, though. Most gains are simply from a more efficient air-box design and higher flowing cone filters. Anyway, a few benefits of a performance intake include:

• 0-7+ horsepower
• More torque possible
• Better response
• Improved engine sound

Factory intakes on the 5.7 HEMI flow pretty well for the engines intended power output. If you don’t have any mods then an intake likely won’t offer much if anything at all. However, throw a tune, headers, and other mods into the mix and an intake can offer 5-7+ horsepower. It’s not great, but an intake is fairly cheap and easy to install. We also think it looks great in the engine bay and the sounds are awesome, too.

What To Look For In An Upgraded Intake

To be frank, many intakes are going to offer similar power and performance. There still are some important factors to consider, though. Look for the following in a Dodge Ram 5.7 HEMI performance intake:

• Closed air-box design (unless going forced induction)
• Quality filter from known brand
• Easy fitment/install

An open design intake is awesome for increasing flow on engines running boost. Intake temperatures don’t matter as much when you have an intercooler. However, on a NA engine we recommend sticking with an air-box and lid. Otherwise, look for a quality 5.7 HEMI cold air intake kit with easy fitment and a good air filter. S&B and K&N are both great filter options.

Intake Upgrades Price: ~$200-400

Intake HP Gains: 2-5+ horsepower

3) Headers Upgrades

Headers can be a longer topic since there are so many options on the market. Check out our 5.7 HEMI headers guide for more info. Headers are also known as the exhaust manifolds. Catless vs high-flow cats is an important topic for exhaust manifold mods. We’ll try to cover as much as we can in this short space, but an article about 5.7 HEMI headers upgrades is coming very soon. Until then let’s jump in and discuss this awesome mod.

Without going forced induction headers are going to offer some of the best power gains on the Dodge 5.7L engine. If we were planning any two mods it would be a tune and headers without question. The whole idea of headers is to reduce back-pressure. Since the exhaust manifold bolts right to the engine it’s going to offer the biggest power gains of any part of the exhaust systems. Benefits of headers upgrade include:

• 15-30+ horsepower
• 10-20+ torque
• Louder, aggressive exhaust note

Not only are the power and torque gains impressive, but larger headers like 1 7/8″ headers can really wake up mid-range torque. Look for gains in the ballpark of 15-20 horsepower on lightly modded engines. With the other basic 5.7 HEMI upgrades you might see as much as 25-35 horsepower. A louder and more aggressive exhaust note is another benefit.

345 HEMI Catless vs High-Flow Headers

Again, the main purpose of headers is to reduce back-pressure. Fully catless headers will do the best job at that. Then there’s sizing like 1 5/8-inch headers or larger 1 7/8″ options. Larger headers are also going to offer better flow, so a 1 7/8-inch catless header is likely the best performance upgrade for the 5.7 HEMI.

However, catless headers are technically illegal in all states. It also likely you won’t pass emissions testing. That’s where high-flow cat headers come into play for the 345 Mopar engine. They still pick up incredible power gains, but not quite as impressive as catless options. Still expect gains in the 10-25+ horsepower range.

Headers Upgrade Price: $400-1,200+

Headers HP Gains: 10-30+ horsepower

4) Exhaust System

We’ll speed through this section a bit faster since it’s similar to the headers discussion. Exhausts also aren’t as beneficial as headers, so if you’re just looking for one exhaust mod then headers should be the clear choice. Anyway, an exhaust system is still among the best 5.7 HEMI upgrades.

Power gains can vary a lot depending on exact exhaust configuration. It’s a similar topic to the headers above. The end goal with an exhaust upgrade is to reduce back-pressure. A better flowing exhaust is going to offer the biggest gains. Exhaust mods on the 5.7 HEMI can offer the following power benefits:

• 3-10hp
• Similar torque
• Awesome sounds

A full exhaust system (not including the headers) can offer gains around 3-10 horsepower. 5.7 Mopar engines with a catted exhaust will likely be on the lower-end. A fully catless exhaust may offer power gains in the 7-10hp ballpark. You’ll also get some awesome engine and exhaust sounds with the right exhaust system. However, things can get LOUD very quickly if you opt for a fully catless exhaust, no mufflers, and header upgrades.

Exhaust Price: $300-1,000+

Exhaust HP Gains: 3-10 horsepower

5) Cam Upgrades

Yet another lengthy topic is 5.7 HEMI cam upgrades. We don’t have the time to cover all of the specific details in this article. However, we have an in-depth guide on 345 HEMI cam mods here. There’s a lot to discuss when it comes to things like duration, valve list, LSA, and more. All of these factors can directly effect the results of camshaft upgrades on the 345 Mopar engine.

Certain cam mods may trade-off some low-end torque in favor of massive top-end results. However, that’s not true of all camshaft upgrades. We’ve seen some pick up 50-60+ horsepower and 20+ torque without losing any low-end performance. Not everyone should expect those results, but it’s still highly impressive.

There is a downside to performance cam upgrades on the 5.7 HEMI engine, though. Basic kits can start at $500 to $800+. Add in some other stuff and cams can run up to $1,300 or more – like the Comp Cams Stage 3 HRT kit. If you can’t DIY the install then that’s another major cost. Labor for cam installs can run in the $1,000-1,500+ ballpark.

Add it all together and you could be looking at $2,000 to $3,000+ for 5.7 HEMI cam upgrades. That’s not a cheap power mod. Then again, it’s still excellent bang for you buck if you opt for the right setup. Gains of 40-50+ horsepower aren’t unheard of. It’s about as good as it can get without adding forced induction.

Camshaft Price: $500-1,300+

Cam HP Gains: 20-50+ horsepower

Other 5.7 HEMI Performance Mods

Below are some mods that didn’t quite make the primary list. We believe the above upgrades for the 5.7 HEMI offer the best bang for your buck. However, plenty of other great options and choices exist for power mods. This still isn’t an exhaustive list, but a few of the runner-ups.

1) Supercharger Kits

Superchargers for the 5.7 HEMI is a long topic, so check out the guide in the link for more info. We’re specifically referring to superchargers here, but any forced induction is a great mod. It’s the recipe for serious 500-700+whp builds. However, there’s so much to discuss.

Regardless, if you’re truly looking to make a lot of power then 5.7 HEMI supercharger upgrades are a great choice. If you really want to push the limits it gets expensive, though. Fueling, cooling, pistons, rings, and more need to be addressed. In essence, a Dodge/Ram 5.7 V8 supercharger can make serious power but it can also be seriously pricey.

2) Throttle Body Mods

Throttle bodies on the 5.7L V8 engine are 80mm. It’s actually the same size as the throttle body on the larger 6.4 HEMI’s. For this reason, we don’t believe it’s a necessary upgrade until the 450-500+ horsepower ballpark. It flows well enough even on the larger, more powerful engine.

If you do opt for a throttle body upgrade you may see some small power and performance gains on the 5.7 HEMI. We just don’t think it’s enough to justify the cost unless you’re really shooting for 450+ horsepower. Anyways, if you do upgrade stick with something modest like an 85mm throttle body.

3) Intake Manifold Upgrades

An intake manifold is another one of the most popular 5.7 HEMI power upgrades. Porting the manifold is one choice otherwise you can upgrade to a new aftermarket manifold. For the Ram 1500 some opt to upgrade to the 6.4 HEMI manifold with an upgrade kit like this. Another intake manifold mod is switching from the stock 5.7 HEMI manifold to a 6.1 HEMI manifold.

Results can vary quite a bit with manifold upgrades. You may gain 5-10 horsepower with the right manifold. However, some trade-off a little torque in favor of top-end power. We’re not totally sold on results unless you’re shooting for a powerful 400-450+ horsepower build. Hence the reason it didn’t make the main list of the bolt-on mods from above. We also have a full article on 5.7L V8 HEMI manifold upgrades if you’re interested in learning more.

4) Rear Gearing

Many Dodge, Ram, and Chrysler models with the 5.7L MOPAR engine have pretty low final drive ratios. These engines are also a bit lacking on torque for the modern days. Changing the rear axle ratio can help with torque. The trade-off is shorter gears and a higher speed at a given RPM. However, it can really help bring the 5.7 HEMI to life.

Ram 1500 trucks come with standard 3.21 rear gears. Moving up to something like a 3.92 is a solid option. Some Dodge Charger models use a rear gear set as low as 2.62. Upgrading to something like a 3.55 or 3.73 is a good change for the HEMI. This is a long topic to go all the way in-depth, but we’ll consider discussing this in an article of its own.

*We think this is a really good upgrade for the 5.7 HEMI if you want better acceleration and torque. It simply didn’t make the above list since it’s not an engine or power mod.

5.7 HEMI Engine Upgrades Summary

The 5.7 HEMI engine is a little underpowered from the factory, in our opinion. However, its large displacement means there is a lot of potential left on the table. Even simple bolt-on mods can push the 5.7L Mopar V8 to solid results. A tune is a great starting point to build the foundation to make more power.

After a tune we believe headers and camshafts are the next best upgrades. They can both be a little pricey if you go for top of the line options and don’t DIY the work. However, a tune with headers and cams can easily add 30-70+ horsepower once all is said and done. 5.7 HEMI upgrades like exhaust systems and intakes can also add a bit more power for reasonable prices.

Those looking for more should consider performance mods like throttle bodies, intake manifolds, and final drives. If that’s not enough it’s probably time to consider forced induction such as a supercharger. Go this route and you can easily build a 500-700+whp 5.7 HEMI, but you also might find yourself $20,000+ deep into the build. Regardless of what route you choose – a few upgrades can turn the 5.7 HEMI in a totally different beast.

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