6.4 HEMI Supercharger Guide

Previously, we have looked at a ton of upgrades for the Chrysler Apache 6.4 HEMI V8; including intakes, headers, intake manifolds, and the top 5 upgrades available. These are all great ways to start your 392 HEMI build, but they will only add so much power. For those looking at really making their Dodge Challenger or Charger scream, a 6.4 HEMI supercharger is the way to go. The current production 392 HEMI makes 485 hp and 475 lb-ft, while the crate version makes 525 hp and 510 lb-ft. Adding a supercharger can easily add 100+whp to your engine without breaking a sweat.

This guide will cover supercharger upgrades for all 6.4 HEMI equipped vehicles; which includes the 2011-2022 Dodge Challenger/Charger SRT8/SRT 392/R/T Scat Pack; 2012-2014 Chrysler 300 SRT8; 2018-2022 Dodge Durango SRT; 2011-2021 Jeep Grand Cherokee SRT8/SRT; 2021-2022 Jeep Grand Wagoneer; and the 2021 Jeep Wrangler Unlimited Rubicon 392.

*The 6.4 HEMI is also known as the Apache HEMI and 392 HEMI due to its 392-cid displacement. We will use the terms 6.4 HEMI, Apache HEMI, and 392 HEMI interchangeably throughout the article.

6.4 HEMI Engine History

Chrysler built the current 392 HEMI partly as an homage to the original 392-cid HEMI which Dodge created in 1957. The original 392 HEMI was one of the first big displacement engines that drag racers utilized in the 1950s-1960s. At the time, it was not called the HEMI but the FirePower. It was popularized in the Chrysler 300C and 300D, where it produced nearly 400 hp with a 4bbl carb. Chrysler discontinued the original HEMIs in 1958 to make way for their big block B engine series.

They briefly brought back the HEMI in 1964, when they first trademarked the HEMI name, with the famous 426 HEMI. The 426 powered some of the most outrageous Plymouth and Dodges of the late-1960s to early-1970s, making 425 hp. Dodge discontinued the 426 HEMI after 1971 due to emissions restrictions, and the HEMI did not return until 2003.

Chrysler released the newest 6.4 L HEMI V8 engine in 2007 to much fanfare and delight. They released it as a crate engine and it was not available in any production vehicle, but it made a whopping 525 hp and 510 lb-ft out of the box. In 2011, Chrysler made some significant changes to the engine and put it inside the Dodge Challenger and Charger SRT8s. From 2011-2014, the production 6.4 HEMI made 470 hp and 470 lb-ft, which was increased to 485 hp and 475 lb-ft for 2015 on – where it currently stands.

392 HEMI Changes Over the Years

The 392 HEMI crate engine and the production version found cars are actually two pretty different engines. The crate version does not have VVT, but does have a different intake, intake manifold, exhaust manifold, cams, compression, and stronger forged internals. The crate version is not emissions compliant, which is why Dodge detuned it before putting it in their production vehicles.

While the crate 6.4 HEMI is rated for 525 hp and 510 lb-ft, the production version is rated lower at 485 hp and 475 lb-ft. The 2011-2022 production 6.4 HEMI is pretty much the same with only minimal updates. Some of the changes were to the intake manifold and ECU tuning for 2015. Starting in 2014, Chrysler made the block thicker and stronger on all models.

There is also a different version of the 6.4 HEMI for the Durango and Grand Cherokee SRTs, which makes slightly less power. This is mainly due to them both having more restrictive exhaust manifolds to fit their AWD drivetrain systems. They two versions also have different shaped oil pans.

6.4 HEMI SRT vs Ram Versions

Starting in 2014, Dodge also created a new version of the 6.4 HEMI to put in their Ram 2500/3500/4500/5500 Medium and Heavy Duty Trucks. They started by reinforcing the original 6.4 block by making it thicker and stronger. These new blocks are known as “Big Gas Engines,” or BGE for short. Chrysler started using the BGE blocks in all 392 HEMIs from 2014 on.

Differences between the SRT and Ram HEMIs are the intake manifold on the Ram has a top-feed throttle body, different cams, lower compression on the Ram model, and different pistons for the Ram, too. The Ram HEMIs also have more restrictive cast iron exhaust manifolds. These are mainly done to increase low end torque for towing which sacrifices top end speed.

6.4 HEMI Supercharging Basics

Now that we know a little about the 6.4 HEMI V8 engine, let’s talk about supercharging it. There is a lot to consider about 6.4 HEMI superchargers besides just picking out a blower. Even that is not quite as cut and dry as it might seem. In these next few sections, we will cover the pertinent things on any successful 6.4 HEMI supercharger build list.

392 HEMI Supporting Mods and Tuning

While 392 HEMI superchargers are certainly fun upgrades, they are not the only piece to any build puzzle. Not only do you need to consider internal upgrades to make your engine withstand the power, but you also need to think about other bolt-on mods and tuning to get the most out of your supercharger kit.

You can supercharge a completely stock engine with the stock exhaust, but your gains will be limited. Typically, you will want at least a few other supporting bolt-on mods to go along with your 6.4 HEMI supercharger. These include upgraded intakes, headers, throttle bodies, camshafts, and of course proper tuning. Previously, we looked at intakes, headers, intake manifolds, and the top 5 upgrades available, so check those out for more information.

Tuning is going to the most important supporting mod for your supercharger. Proper ECU tuning will make sure that your engine is safely running whatever boost you chose from your 6.4 HEMI supercharger. Without good tuning, your engine is very liable to explode in short order with forced induction. Tuning will also help you get all of the usable power out of your 392 HEMI supercharger upgrade.

An important note, all 2015+ 6.4 HEMI equipped vehicles will need their ECU unlocked before they can be tuned. There are several different options for this, but make sure to have that planned out before you make your purchase.

392 HEMI Block Power Limits

It’s important to recognize the power limits of the 392 HEMI before embarking on any supercharger upgrade. While these engines have to be pretty strong to withstand the already large factory power numbers, they are far from indestructible. The block itself is thought to be good until about 900-950whp, after which its days are numbered. Fueling impacts this, as using higher octane fuels – like E85 instead of pump gas – will make your build last longer.

Installing a 6.4 HEMI supercharger will also have an effect on the engine’s longevity. While a stock 6.4 HEMI can probably make it past 200,000 miles without problem, adding a supercharger effectively cuts that in-half – if not more. The massive increase in stress on the internal components greatly reduces their lifespan. There is not a magical number for how many miles a supercharger build will definitely last, but know that it’s far less than stock.

<550whp Supporting Mods

A stock 392 HEMI makes approximately 430-whp and 425-wtq on an average reading dyno. The smallest supercharger upgrade will typically net about 120whp at 6 PSI, putting you right around 550whp. For builds at these power levels or lower you typically do not need to do any sort of internal upgrades. The stock internals and block are more than capable of withstanding 550whp without issue. However, supporting mods, like an intake, headers, larger fuel pump, and tuning should still be done.

550-650whp Supporting Mods

For builds ranging between 550-650whp (~6-9 PSI) the internals need to be upgraded. At a minimum, the hypereutectic cast pistons need to be replaced with forged versions. Beefier connecting rods are also suggested at this stage. Other mods to consider, besides all applicable bolt-ons, are catch cans, larger injectors (50lb/hr+) and fuel pump, throttle body, and Dayco belt tensioner.

Depending on your transmission, that is another issue that may need to be addressed. The manual transmission is fine at this power level, but the automatic is not nearly as robust. You can buy an upgraded torque converter for both the 5 and 8 speed automatics, but those only help so much.

If you are really serious about pushing an automatic 392 HEMI past 550wtq you really need to consider swapping the transmission. One option is to upgrade the standard TorqueFlite ZF 8HP70 to the 8HP90 that is optional in the Hellcat. The Hellcat version can stand a lot more torque than the SRT automatic, up to 650wtq.

>650+whp Supporting Mods

If your 6.4 HEMI supercharger build is going to exceed 650whp, you probably need to upgrade just about everything. This means driveshaft, half shafts, differential, completely forged internals, head studs, ported intake and exhaust valves, a beefier oil pan, and upgraded intake and exhaust manifolds.

You will definitely need all supporting bolt-on mods to get to this point, and you will also need alternative fueling. Making 650whp on pump gas is pretty difficult on the 6.4 HEMI, and reliability goes out the window trying to do it on 93 octane or lower. E85 or water/methanol injection are both great options that massively increase octane, which lowers the likelihood of detonation.

The number one cause of engine failure, especially pistons, on the 392 HEMI is engine knock. Eliminating that is key to making your build last as long as possible.

How much boost can my 392 HEMI take?

Most people will argue that for 6.4 HEMI supercharger builds at 6 PSI or less nothing will need to be done. Anything from 6-9 PSI could use forged internals, and anything 10 PSI and above needs a completely built block. However, it’s important to note that just looking at PSI alone can be very deceiving. It is also important how much cubic feet/min (CFM) the supercharger blows at, too.

You can think of PSI as how much boost you’re putting into your cylinders, and the CFM is how quickly it is getting pushed in and out. The higher the CFM and PSI the more power you make, but they both have to work together. A car can have a low CFM but run high boost and still make less power than a low-boost car at a higher CFM.

So just looking at a random PSI number isn’t going to tell you how much power you will make and how safe it is. You need to consider other variables too, like CFM, the type of supercharger it is, the fuel you are using, and the quality of the tuning.

Different Kinds of 392 HEMI Superchargers

Now let’s talk about the different kinds of superchargers available for the 6.4 HEMI. There are three different options; centrifugal superchargers, roots superchargers, and twin-screw superchargers. Each of them has their advantages and disadvantages, but all are good options.

Centrifugal superchargers are basically just belt operated turbochargers. The mechanism is pretty much the same as a turbo, but a belt runs the compressor instead of exhaust gasses. Centrifugal blowers will offer the highest peak power, but at the expense of low end torque. They are also generally more complicated than other styles.

Roots superchargers are the most common type of blowers available from the factory on cars. They are by far the simplest and cheapest type of supercharger on the market. They offer lots of low end torque, but can’t match centrifugals for peak RPM power. Roots superchargers, notably, don’t actually compress any air. Rather, they push air forward very quickly – which is where the CFM we went over earlier becomes very important.

Twin-screw superchargers are the type of superchargers used on the SRT Hellcat and Demon. They are similar to roots superchargers, but they actually compress the air and are much more efficient. They are great for low end torque, like roots styles, but provide less peak RPM power than centrifugals.

Choosing which is right for you depends on your power goals and aesthetic proclivities. Do you want the most power? Go with the centrifugal. Are you after the old school muscle car look? Roots style is your best bet. Are you willing to sacrifice peak power for efficiency and low end torque? Look no further than a twin-screw.

Best 6.4 HEMI Supercharger Kits

Now that we have a good understanding of the 6.4 HEMI and what it takes to supercharge it, let’s jump into recommendations! The top 5 best 6.4 HEMI supercharger kits are:

• Magnuson
• ProCharger
• Whipple
• Kenne Bell
• Edelbrock

These five supercharger kits offer a good blend of power, performance, price, and reliability. This is not an exhaustive list of superchargers available for the 6.4 HEMI, as there are dozens and dozens available. Instead, our list only prioritizes the top options available on the market. You cannot go wrong with any of these choices, they are all top notch 392 HEMI supercharger kits.

1) Magnuson TVS2300 Supercharger Kit for 392 HEMI

Price: $6,895.00

Power Output: 550 whp/540 wtq

Type: Hybrid Roots

The first option we have for a 6.4 HEMI supercharger is going to be Magnuson Superchargers TVS2300 Challenger/Charger SRT8 6.4L V8 HEMI Supercharger Tuner Kit. The Magnuson kit is a direct bolt-on roots style supercharger for the 6.4 HEMI. It generates 6 PSI of boost at 1,900 CFM, which is good for gains of 120 whp and 120 wtq. The TVS2300 supercharger for the 6.4 HEMI is not a dramatic increase in power, but it definitely delivers where it counts.

The Magnuson kit also comes with a liquid-to-air intercooler, front mounted heat exchanger, larger injectors and fuel rails, a new intake manifold, pulley, and all necessary hardware. The TVS2300 is the same supercharger used on the Cadillac CTS-V, Mustang Shelby GT500, and Corvette ZR-1 – so you know it is capable of some serious performance with solid reliability.

This supercharger is the cheapest option on our list, but it also produces the least power. Still, the performance bump is noticeable, and the car will undoubtedly be much faster with it. The TVS2300 Magnuson kit is a great option for smaller and more budget friendly builds. Magnuson also includes tuning for their supercharger kit.

2) ProCharger 6.4 HEMI Supercharger Kit

Price: $ 7.148.00+

Power Output: 600 whp

Type: Centrifugal

Our second option for supercharging your 6.4 HEMI is the ProCharger P-1SC Supercharger Kit. ProCharger has garnered a very positive reputation as one of the leading forced induction specialists in the world. The P-1SC supercharger provides 7 PSI of boost at 1,200 CFM, which is good for gains of 160 whp and 160 wtq.

Their P-1SC supercharger kit comes in three options; their High Output Kit, Stage II Kit, and Tuner Kit.  The HO Kit is meant for stock engines with stock exhausts; the Stage II Kit is for also meant for stock engines with stock exhausts but produces more power; and their Tuner Kits provide the most powerful option for someone looking at custom mapping for other mods like headers, heads, cams, and other custom setups.

The ProCharger kit comes with the necessary fueling upgrades as well as a large air-to-air intercooler. It is a centrifugal style supercharger, so it builds power as RPMs increase, making for a smoother and more linear acceleration feel. The ProCharger is a good option for those looking at a slighter bigger power bump than the Magnuson while still retaining a mostly stock engine.

3) Whipple Gen 5 Supercharger Kit for 6.4 HEMI

Price: $ 7,800.00

Power Output: 600 whp

Type: Twin-Screw

The third option we have for 6.4 HEMI superchargers is the Whipple SRT8 6.4L Stage II Supercharger Kit W17AX 2.9L. The Whipple puts out 8 PSI at 1,600 CFM, which is good for increases of 180 whp and 180 wtq. The Whipple 6.4 HEMI supercharger kit is one of the most popular and well reviewed in the industry. It has been featured on countless builds and has an excellent reputation for performance and reliability.

The Whipple W17AX 2.9L Stage II supercharger is a twin-screw style and is therefore very efficient. The complete kit comes with everything needed for your engine, including an liquid-to-air intercooler, pulley system, high flow fuel rails and 65 lb/hr injectors, a fuel pump booster, and tuning solutions.

Incredibly, the Whipple Kit is CARB approved and 50 states emissions legal. That gives it a huge boost over the competition, and your car is still street legal even with this kit.

4) Kenne Bell Mammoth 6.4 HEMI Supercharger Kits

Price: $ 7,100.00 – $9,100.00

Power Output: 550whp – 1000+ whp

Type: Twin-Screw

No Mopar supercharger upgrade list would be complete without at least one Kenne Bell reference. Kenne Bell have established themselves as industry leaders for twin-screw superchargers over the years. Their kits go on everything from Shelby Mustangs and Camaros, to Hellcats and Demons. They are known for their performance and reliability.

Kenne Bell offers several different supercharger kits for the 6.4 HEMI. All of them are twin-screw style, and are available in 2.8L, 2.9L, 3.6L, 4.2L, 4.7L, and 4.9L options.  This makes for a very wide range of possibilities, meaning you could have a build anywhere from a modest 550 whp to a 1,100 whp monster using these superchargers.

Like others, the Kenne Bell kit comes with all necessary internal upgrades to handle the increase in power. They include fuel system upgrades, intake upgrades, and new high flow intake manifold runners. The sky is truly the limit with Kenne Bell superchargers and supporting mods, and you can crank up the boost to your heart’s desire.

5) Edelbrock 392 HEMI Supercharger Kit

Price: $ $9,658.87

Power Output: 572 whp/531 wtq

Type: Roots

Our final 6.4 HEMI supercharger kit is the Edelbrock Stage I R2650 HEMI 6.4 V8 Kit. Edelbrock have long been in the muscle car performance gain and they have a mammoth reputation for quality, performance, and reliability.

Their stage I supercharger kit for the 6.4 HEMI features a roots style Eaton Gen VI R2650 TVS rotating assembly with an integrated bypass valve. It is good for 572 whp and 531 wtq at 7 PSI at 1,600 CFM. This is all on just 91 octane fueling using Edelbrock’s provided tuning software.

The full kit includes an intercooler, mounts, pulleys, and 60 lb/hr fuel injectors. Like the Whipple Kit, the Edelbrock supercharger kit is also CARB approved and 50 states emissions legal.

6.4 HEMI Supercharger Upgrade Summary

The 6.4 HEMI V8 is already one of the more powerful production engines from the factory, but adding a supercharger can really wake it up to its full potential. Bolt-on mods are definitely good places to start when building your HEMI powered Charger or Challenger, but they don’t hold a candle to forced induction. Smiles per gallon will surely increase with a nice big blower mounted on your Mopar V8.

We went over quite a bit in this article, including 392 HEMI supercharging basics, to what your engine needs depending on your build, to some solid recommendations to look over.

Both the Magnuson and Edelbrock options are solid performers that offer only modest increases in power. They are perfect for smaller builds or those just starting their experiments with Mopar forced induction. The ProCharger and Whipple superchargers offer similar gains to each other that both eclipse the Magnuson and Edelbrocks. With a step up to these guys you’ll need to start reinforcing your internals for the extra power.

The Kenne Bell superchargers are really a league of their own and come in a ton of different options. You can customize your build much more with Kenne Bell superchargers than other kits, and they are incredibly reliable and well engineered machines.

What’s your experience with supercharging the 6.4 HEMI V8 engine? Are you considering one?

Drop a comment and let us know!