The Upgrades to the 6.4 HEMI Intake Manifold. We recently wrote a post on the top five greatest 6.4 HEMI engine modifications. Although intake manifolds did not make the primary list, we did explore them briefly as an honorable mention. Now it’s time to go through the 6.4 HEMI intake manifold improvements in further detail. This page examines 392 HEMI manifold improvements and porting, prices, benefits, horsepower gains, and some of the greatest upgrades.
*This article focuses on intake manifold improvements and porting for the 6.4L HEMI. Check out our 5.7 HEMI intake manifold article for more information on 5.7 HEMI manifold improvements (or switching a 6.4 manifold onto the 5.7).
6.4 HEMI Intake Manifold Stock
Before we go into porting and improvements, let’s talk about the 6.4L V8’s stock intake manifold. The little comment in the introduction is there for a reason. The 6.4 HEMI intake is popular for swapping onto 5.7L HEMI engines, and it’s a terrific upgrade.
The intake manifold on the 392 HEMI is an active runner design. The 6.4 HEMI intake operates in long-runner mode up to 4800rpm for improved torque on the low and mid-end. Above that RPM, it shifts to short-runner mode to enhance top-end horsepower.
The 6.4 HEMI manifold is a fantastic design. It’s one of the main reasons intake manifolds didn’t make our top 392 HEMI upgrades list. There are probably better upgrades to make with the money. However, for some, intake manifold improvements or porting of the stock manifold make sense. If you want to make the most power out of your N/A setup, an intake manifold is a must-have.
392 HEMI Manifold Upgrade Advantages
The following are some of the advantages of upgrading or porting your 6.4 HEMI intake manifold:
- 5-10whp (maybe more)
- Gains in torque are comparable.
- improved manifold
- Increased engine noise
- a cleaner engine compartment
Some of the advantages of 392 HEMI manifolds are dependent on whether you choose porting or an aftermarket alternative. This will be covered in further detail in the following section, as well as when we review some of the greatest 6.4L V8 manifold improvements.
In any case, horsepower gains will most likely be in the 5-10whp range. Depending on the various mods on the 6.4 HEMI, you may get a little more or less power. A ported intake manifold and an 88mm throttle body are a nice combination. Some dynos have revealed increases of 15-20whp with the combination. Torque improvements are often in the same ballpark.
The remaining advantages are mostly for individuals wishing to enhance their 6.4 HEMI intake manifold. The stock 392 manifolds are constructed of plastic, whereas modifications are often composed of metal. This modification results in a stronger manifold, a slightly louder engine note, and maybe a nicer-looking engine bay.
6.4 Porting vs. Upgrades for HEMI Intake Manifolds
As previously said, the 392 HEMI manifold’s design is excellent right out of the box. Active runners excel at maximizing performance across the entire power spectrum. We believe that remaining with the OEM manifold and merely porting it is the best option for N/A 6.4L V8 engines. Most people think that the cost of an improved manifold is simply not worth it.
So, why are aftermarket 6.4 intake manifolds even available? Depending on your build, true upgrades can be a wonderful alternative. When it comes to adding boost (especially for big boost and power projects), an aluminum manifold goes a long way. It can’t hurt to have a little more strength than the OEM plastic manifold.
There are also some fantastic-looking enhancements that provide a fantastic look and sound. Otherwise, 6.4 HEMI intake manifold improvements can provide satisfactory performance. They are, however, generally designed for high-end power. It may make sense for specific builds, but if you want street performance, the OEM manifold’s mid-range is great.
392 HEMI Intake Manifold Upgrades That Work
Now that we’ve covered the background and benefits, let’s get into the greatest 6.4 HEMI intake manifold tweaks. Please keep in mind that this is far from an exhaustive list, and there are many other excellent possibilities. We simply cannot cover every possible option in a single post. Instead, the intake manifolds listed below are some of our favorites in terms of pricing, quality, and performance.
Before upgrading your 6.4 HEMI intake manifold, make sure you understand your goals and demands. Keep in mind that some may be geared more for top-end power than a balanced powerband for street use. We’ll specify where appropriate. Anyway, let’s get started and talk about some of the best 392 HEMI manifolds.
1) Porting of the 6.4 HEMI Intake Manifold
Most 392 owners will benefit from porting the factory HEMI manifold. Again, the active runner design is excellent for maximizing output across the whole powerband. Porting the intake maintains the same active runner design while merely moving more air through the manifold.
The benefits of porting the intake manifold on a stock 6.4 HEMI are negligible. At stock output, the OEM design is quite efficient. However, as you start adding power with other upgrades such as tune, headers, cams, and so on, the greater airflow from porting becomes advantageous. Expect 5-10whp gains and maybe 15-20whp gains when combined with a throttle body upgrade.
Porting the 392 HEMI manifold costs around $300-400. Some stores or establishments may require you to send your manifold in advance. Others may have core charges that are refunded after your stock manifold is returned. A completely new manifold is another alternative, although this can add $400-500 to the cost.
In any case, the minimal cost of porting the intake manifold makes it a desirable upgrade. This is especially true if you want a high-effort NA 6.4 HEMI build.
2) Holley Sniper 392 HEMI EFI Intake
With porting completed, it’s time to install genuine aftermarket 6.4 HEMI intake manifolds. This is the manifold shown at the beginning of the post, and it is truly stunning. The hi-ram manifold is TIG welded and made of 1/8′′ truck aluminum. Those looking to go with boost will undoubtedly gain some strength from it.
The Holley manifold does come with gaskets, high-flow fuel rails, and all the necessary hardware. This EFI version includes 92mm or 102mm throttle body holes to maximize throttle body mod possibility. Finally, for less than $700, this is an excellent option.
However, this manifold is intended for high-end power. Some folks may prefer this even when driving on the street. However, most street driving takes place in the lower and mid-range, which is where the 6.4 HEMI ported intake manifold shines. Regardless, the Holley Sniper EFI manifold is a tempting option with numerous advantages.
Related : The Top 5 6.4 HEMI Upgrades
3) Edelbrock 6.4 HEMI EFI Intake Manifold
$1,079.95 (plus $223.95 for the needed fuel rail kit)
If you’re looking for an aftermarket modification, the Edelbrock Victor EFI manifold is another wonderful alternative. The intake is designed similarly to the 6.1L SRT intake manifold. However, it employs longer, higher-flowing runners, as well as relocated injector bosses and additional nitrous bosses.
According to Edelbrock, the Victor EFI prototype produced 25 horsepower more than a stock 6.4 HEMI intake manifold. We believe those figures are a little high, and most 392 HEMIs will not gain that much horsepower. Regardless, it’s a well-designed intake manifold with a lot of promise.
One major disadvantage of the Edelbrock choice is the cost. The manifold requires an additional $223.95 for a fuel rail kit. The whole cost is little over $1,300, which is difficult to take.
Nonetheless, Edelbrock is a well-known company that produces high-quality items, so you should expect to pay a premium for that. Our initial choices would be to port the 6.4 HEMI intake manifold or the Holley Sniper. If investing the extra money isn’t a big deal, the Edelbrock manifold is still a wonderful option.
Summary of 6.4L HEMI Manifold Upgrades
The 6.4 HEMI is a powerful engine that reacts well to modifications. An intake manifold is an excellent upgrade for individuals wishing to increase power on a NA setup (or who require a stronger manifold to withstand boost). It didn’t, however, make our list of the top 5 upgrades for the 392 HEMI.
Beginning with larger power mods such as cams, headers, cold air intake, and tuning is probably the best bet. That doesn’t mean an intake manifold can’t be a worthwhile enhancement. Porting the stock 6.4 HEMI intake manifold can result in 5-10whp improvements; not bad for $300-400.
Those searching for a legitimate aftermarket enhancement will have to pay a little more. However, updated manifolds can increase engine strength, sound, and appearance. The correct intake manifold can also provide significant power gains, however some may sacrifice mid-range power in favor of top-end power. Both the Holley Sniper EFI and Edelbrock EFI manifolds are solid choices for the 392 HEMI.