We just released an article listing the top 5 ways to improve the performance of your 6.4 HEMI engine. Intake manifolds were almost on the must-have list, but they fell just short. Here we will delve more into the topic of 6.4 HEMI intake manifold improvements. This article explores the best improvements for the 392 HEMI manifold, including porting, prices, benefits, and horsepower gains.
This article focuses on the 6.4L HEMI and how to improve performance by porting the intake manifold. Check out our 5.7 HEMI intake manifold article if you’re in the market for information on 5.7 HEMI intake manifold modifications (or 6.4 manifold shifting onto the 5.7).
6.4 HEMI Stock Intake Manifold
It’s crucial to talk about the stock intake manifold for the 6.4L V8 before getting into porting and enhancements. That remark at the beginning serves an important purpose. The 6.4 HEMI intake is a popular choice among those looking to improve the performance of their 5.7L HEMI engines.
The intake manifold for the 392 HEMI is an active runner style. The 6.4 L HEMI’s long-runner intake is active up to 4800 rpm, maximizing low- and mid-range torque. At higher revs, it changes to short-runner to improve peak power.
The 6.4 HEMI manifold is, in a word, fantastic. This is a major factor in why we didn’t rank intake manifolds higher among the best modifications for the 392 HEMI. Most certainly, there are more worthwhile enhancements you might get with that kind of money. However, for some people, it makes sense to upgrade the intake manifold or have the factory manifold ported. An intake manifold is a must-have for any high-output, naturally aspirated engine design.
392 HEMI Manifold Upgrade Benefits
Benefits of a 6.4 HEMI intake manifold upgrade or porting include:
- 5-10whp (more possible)
- Similar torque gains
- Stronger manifold
- Louder engine note
- Cleaner engine bay
Whether you choose to have your 392 HEMI manifolds ported or purchase a true aftermarket part determines some of the benefits you’ll experience. In the following section, along with a discussion of the top manifold upgrades for 6.4L V8 engines, we’ll go into greater detail on this topic.
Anyway, the boost in horsepower will most likely be around 5-10 hp at most. Depending on the other modifications you’ve made to the 6.4 HEMI, you could gain or lose some power. It’s worth noting that a ported intake manifold and 88mm throttle body make an excellent pair. Depending on the dyno, the combination has been demonstrated to yield improvements of up to 15–20 horsepower. The increases in torque are often within the same range.
For individuals who already have an updated 6.4 HEMI intake manifold, the remaining benefits will be minimal. Aluminum is commonly used in improvements compared to the plastic used in stock 392 manifolds. As a result of this modification, the manifold should be more robust, the engine sound should be louder, and the engine compartment might look a little better.
6.4 HEMI Intake Manifold Porting vs Upgrades
The factory design of the 392 HEMI manifold is fantastic, as we’ve already established. Runners who consistently push themselves to their limits consistently excel at using the entire range of their available strength to their greatest advantage. We think the OEM manifold should be kept and ported for N/A 6.4L V8 engines. The majority believes that upgrading the manifold is not worth the cost.
Why then do we have aftermarket 6.4 intake manifolds if the factory ones are so good? Depending on your setup, true upgrades can be a fantastic choice. An metal manifold is a great investment for anyone adding boost (particularly for the big boost & power builds). Having a manifold with a little more heft than the OEM plastic one is never a bad thing.
As an added bonus, you can get some really cool-looking add-ons that improve both the visuals and the audio. However, the intake manifold on a 6.4 HEMI can be upgraded to provide acceptable performance. Nonetheless, their primary focus is on producing maximum output at the highest possible levels. Though this may make sense for some builds, the OEM manifold’s midrange is where you want to be for optimal street performance.
Best 392 HEMI Intake Manifold Upgrades
Now that we have covered some context and the advantages, we can go into the top 6.4 HEMI intake manifold upgrades. This is by no means an all-inclusive list, and there are many other excellent choices. There are too many possibilities to list them all here. Instead, we recommend looking into some of the intake manifolds listed below.
Before investing in an intake manifold upgrade for your 6.4 HEMI, make sure you have a clear idea of what you hope to achieve and what features are necessities. Keep in mind that the powerband of some may be unbalanced and unsuitable for everyday street use because they were built for peak performance. Whenever possible, we’ll add further detail. Whatever the case may be, let’s get right down to business and talk about some excellent 392 HEMI manifolds.
1) 6.4 HEMI Intake Manifold Porting
For the vast majority of 392 drivers, a ported version of the factory HEMI manifold is the best option. To reiterate, the active runner layout is fantastic for increasing output all the way across the powerband. To increase airflow through the manifold, porting the intake does not alter the active runner architecture.
Gains from porting the intake manifold on a stock 6.4 HEMI are negligible. The original equipment manufacturer layout is adequate for standard output. The added airflow from porting is useful, however, until you start adding power from other mods like tuning, headers, cams, etc. With a throttle body upgrade, you should expect improvements of 5-10 horsepower, and possibly 15-20 hp.
Porting a 392 HEMI manifold can set you back around $300-$400. Some retailers may require that you pre-ship your manifold. When you return your original stock manifold and receive your core deposit refund, certain companies may use this as a marketing gimmick. A new manifold is an alternative, however it will increase the price by around $500.
Porting the intake manifold is a cheap but effective performance boost. This is especially the case if you want a 6.4 HEMI engine with the most possible power from a naturally aspirated setup.
2) 392 HEMI Holley Sniper EFI Intake
Now that we’ve completed the porting process, we can install genuine aftermarket 6.4 HEMI intake manifolds. At the top of the post is an image of a manifold that seems like it could kill someone. The 1/8″ truck aluminum used in the hi-ram manifold is entirely TIG welded. Anyone seeking an extra strength boost can count on this.
The Holley manifold comes complete with gaskets, high-flow fuel rails, and the necessary hardware. This EFI model comes with either a 92mm or 102mm throttle body opening, allowing you to make the most of your throttle body upgrades. At less than $700, this is a fantastic option.
But this manifold was built for maximum output. That’s a preference that some people have even when driving on public streets. However, the 6.4 HEMI ported intake manifold really shines in the low to mid range, where the vast majority of street driving takes place. Despite this, the Holley Sniper EFI manifold is a tempting option with many advantages.
3) 6.4 HEMI Edelbrock EFI Intake Manifold
If you’re in the market for an aftermarket improvement, consider the Edelbrock Victor EFI manifold. The intake was styled after the 6.1L SRT intake manifold. However, it features repositioned injector bosses and more nitrous-ready bosses in addition to longer, higher-flowing runners.
Edelbrock claims that their Victor EFI prototype added 25 horsepower compared to a standard 6.4 HEMI intake manifold. We think those figures are very high, and most 392 HEMIs won’t see a power increase of that magnitude. Whatever the case may be, it’s a well-designed intake manifold with promising potential.
The pricing of Edelbrock is a major drawback. To install the manifold, you will need to purchase a fuel rail kit, which will set you back an additional $223.95. This is a bitter pill to chew, as the total price is now slightly over $1,300.
Still, Edelbrock is a well-known company that produces high-quality goods, so it’s reasonable to assume that you’re paying more. We recommend either porting the intake manifold for the 6.4 HEMI engine or installing a Holley Sniper. If you can afford to spare the cash, an Edelbrock manifold is still a fantastic choice.
6.4L HEMI Manifold Upgrade Summary
The 6.4 HEMI is a rugged motor that benefits greatly from enhancements. If you’re using a naturally aspirated engine and want more power, an intake manifold is a wonderful upgrade (or for those needing a stronger manifold to tolerate boost). Unfortunately, it wasn’t quite good enough to be one of the top 5 392 HEMI improvements we considered.
Adding major power upgrades like cams, headers, a cold air intake, and tuning first is probably the best bet. But that doesn’t rule out the intake manifold as a useful addition. Gains of 5-10+ hp can be seen after porting the factory 6.4 HEMI intake manifold, which is not bad for around $300-$400.
Those who want a genuine aftermarket upgrade will have to shell out extra money. However, manifold upgrades can boost the engine’s power and efficiency while also enhancing the vehicle’s aesthetics. In addition, the correct intake manifold can provide substantial power gains, however some may require giving up some mid-range performance in exchange for increased top-end velocity. Both the Holley Sniper EFI and the Edelbrock EFI manifold are top-notch choices for the 392 HEMI.
