The 5.7 HEMI is an excellent engine but it’s known for being underpowered from the factory. It’s fair to say considering the large 5.7L V8 doesn’t even make 400 horsepower. However, the 345 HEMI offers a lot of potential with some bolt-on upgrades. Among the best mods lies a 5.7 HEMI intake manifold upgrade. In this article, we discuss 5.7L HEMI V8 intake manifold mods, power gains, benefits, costs, and more.
5.7 HEMI Intake Manifold Benefits
- 5-10whp peak gains
- 10-20whp & 15-30wtq midrange gains
- Added strength
- Improved sounds
- Better looking engine bay
Power gains can vary substantially for different intake manifolds. As such, we’ll discuss power gains in the section below and also circle back to horsepower when we discuss specific manifolds.
Anyway, the factory manifold on the 5.7 HEMI V8 is plastic. A 6.1L HEMI manifold is aluminum as with many aftermarket options. On an NA engine, the plastic manifold is plenty. However, you’ll likely want something that’s a bit stronger and flows better if you’re thinking about boost.
Additionally, intake manifold mods can improve engine sounds and lead to a cleaner-looking engine bay. That’s all subjective, though, so it might not be much of a benefit for some.
Upgraded Manifold HP Gains
Peak power gains from a 5.7 HEMI intake manifold upgrade often aren’t impressive. You may see small 5-10whp gains up top depending on engine mods, tuning, and other factors. Just because the peak gains aren’t great doesn’t mean an intake manifold is a waste of money, though. The real benefit of manifold upgrades is seen in the mid-range.
With a 6.4L HEMI manifold, some have seen gains of 10-20whp and 15-30wtq in the mid-range. That’s where a lot of actual driving happens and those are excellent power gains. You’ll absolutely feel that extra power and it makes an intake manifold well worth it.
That said, we generally think other power mods like a tune, headers, cams, etc. are a better starting point. All these mods can also offer great power and torque gains in the mid-range but also help boost top-end power. As such, an intake manifold didn’t quite make our list of the 5 best 5.7 HEMI upgrades.
Don’t let that sway you away from upgrading the intake manifold, though. It’s still an excellent mod and if you’re looking to maximize NA power then a manifold is a must. We would simply recommend starting with some other performance mods before moving on to an intake manifold.
*Above power gains are rough estimates for the 6.4L HEMI manifold swap. Some manifolds may actually lose a bit of power on the lower-end in favor of better top-end gains. We will clarify throughout when we discuss specific intake manifolds.
Best 5.7 HEMI Intake Manifold Upgrades
With some of the background topics and benefits out of the way it’s time to move on to the best 5.7 HEMI intake manifold upgrades. Please note – this isn’t an exhaustive list. There simply isn’t enough time and space to cover every single upgrade out there.
Instead, we will focus on some of the most common and best upgrades. Before choosing a specific intake manifold it’s important to understand your goals. Anyway, let’s jump right in and discuss some of the best HEMI manifold mods.
1) 392 HEMI Manifold Upgrade
Price: $769 – $1,616
Power Gains: 0-10whp peak (10-20whp in the midrange)
Buy Here: 6.4L HEMI Ram Manifold
The 6.4L HEMI uses active runners in the intake manifold. Up to 4,800rpm, the 392 manifold operates in long-runner mode to help with power and torque. It then switches to short-runner (the design of most 5.7 HEMI manifolds*) to help with top-end power.
This is a big reason the 6.4L manifold often doesn’t offer top-end gains. It’s basically acting as a stock 5.7 manifold at higher RPM where peak power occurs. However, the active runners really do help improve low-end and mid-range power.
Again, power gains of 10-20whp and 15-30+wtq have been seen in the midrange. You could even opt to port the 6.4 manifold for even better power and torque gains. The 6.4L V8 HEMI manifold is a direct bolt-on to the 5.7L engine. However, it requires some wiring and tuning to get the active runners to work on the 5.7 HEMI.
If naturally aspirated performance is the end goal then this 392 HEMI manifold is a great choice. It’s plastic just like the 5.7 HEMI intake manifold, so if you’re looking for aesthetics then it might not be the best pick. You might also consider a stronger aluminum manifold if you plan to add boost.
*The updated 5.7 Eagle in the Ram 1500 does use a manifold with active runners just like the 6.4 HEMI intake.
2) Intake Manifold Porting
Price: ~$400 w/o core charge
Power gains: 5-10whp
Buy Here: 5.7 HEMI Intake Manifold Porting
Another common and popular option is simply porting the OEM 5.7 HEMI intake manifold. The idea is simply to removing material to increase the size of the runner ports. They’re then smoothed out to ensure maximum airflow without turbulence.
It’s a pretty simple option that’s cheaper than upgrading to 6.4 HEMI or aftermarket manifolds. However, the power gains won’t be quite as impressive. You’ll likely see gains of 5-10whp on the top-end, but trade off a little bit of midrange torque.
Ultimately, this isn’t the best solution or upgrade around but it’s a cheaper route. However, if you’re looking for that little extra boost without breaking the bank then it’s a good option.
Some 5.7 HEMI owners also opt to convert to the aluminum 6.1L HEMI intake manifold. However, we’re not listing that as one of the best manifolds. Porting the stock 345 HEMI manifold, upgrading to the 392 HEMI intake, or opting for an aftermarket design are generally better options.
3) Edelbrock Intake Manifold
HP Gains: 5-15whp
Buy Here: Edelbrock HEMI Intake Upgrade
Finally, we’re moving onto a true aftermarket intake for the 5.7 HEMI. Edelbrock is a popular pick for good reason. It’s a similar design to the stock 6.1L HEMI manifold and is also made from aluminum. However, it uses a wider plenum and 14″ tapered runners. The Edelbrock manifold also relocates the injector bosses to reduce port restriction.
Long story short, the Edelbrock 5.7 HEMI intake manifold is a better option than swapping to a 6.1L manifold. At about $1,080 it’s also a similar price to swapping to the 6.1 HEMI manifold. Expect gains of about 5-15whp on the top-end. However, you’ll also trade off a little mid-range torque in favor of top-end horsepower.
4) Holley Sniper Intake Manifold
HP Gains: 5-15whp
Last but not least is the Sniper Intake Manifold from Holley Performance. As with most products on the list it’s meant to fit the Gen III 5.7L HEMI from 2009 up. It includes the high flow fuel raid kit, mounting, and o-rings.
For $675 it’s one of the cheaper intake manifolds on our list, and we think it looks awesome. This manifold should show similar gains of 5-15whp with a small loss in low-end performance.
The Holley Sniper 5.7 HEMI intake manifold really does look great, though. If your after a durable, good-looking manifold then this is a stellar option for the price. Still, the 392 HEMI manifold with active runners is likely the best option if maximum performance is the end goal.
Check out the below video to see how awesome the Holley manifold looks (with a short sound clip following the install).
Is a 5.7 HEMI Manifold Upgrade Worth It?
Yes and no. Again, this is a subjective topic. What are your goals with the car/truck? Are you willing to spend the money on an intake manifold? Do other mods make more sense for your build? There is no one answer fits all.
At the end of the day, an intake manifold can be a great mod for the 345 HEMI. We think there are better places to spend the money on the 5.7 V8. That’s simply our opinion, though. If you really dislike the design of the plastic manifold and want a stronger, better looking aluminum intake then it could be an excellent mod.
If you want to maximize performance with a NA 5.7 HEMI then you’ll likely want an intake upgrade. We would just put this mod lower on the list after things like tuning, headers, and cams. Regardless, the right intake manifold can offer some respectable power gains for the Dodge 5.7 HEMI.
What’s your experience with 345 Mopar intakes? Are you considering one?
Leave a comment and let us know!