Give Your 6.2L Supercharged HEMI® Engine Some Gas!

Nitrous Oxide is a product that has been used for decades in the racing industry. It’s simple, effective and relatively cheap for the amount of power you get for your money.

The simple rundown of “nitrous” is injecting nitrous Oxide into your motor, which increases horsepower. There is more than one way to skin a cat, of course, so there are lots of kits, brands, products and systems out there for adding nitrous to your car. Systems range from very simple and basic without many components, to crazy complex. For our V8 HEMI® motors, most nitrous kits require injecting nitrous and additional fuel into your motor. This is done via a bottle of the good stuff mounted in the vehicle, generally the trunk, and a switch or controller that opens and closes solenoids that feed the nitrous and fuel to your motor.

Recently, Nitrous Express, a very well-known and established company that produces nitrous kits for a large variety of autos, came out with a really slick and new approach for adding nitrous to the 6.2L supercharged HEMI motor. We are talking SRT® Hellcats, SRT Demons, Trackhawks and SRT Redeyes here. Most systems utilize a plate system that injects the fuel and nitrous at the throttle body. Some of the more complex systems use extension plumbing to inject the nitrous at each port on the intake manifold. Some kits have everything hidden, making it hard to tell at quick glance that the car has been outfitted with any sort of nitrous setup.

When I saw this new product from Nitrous Express, I had to give a round of applause to them for stepping outside of the box in putting together a product tailored so specifically to our platform. Enter the Nitrous Express Billet Supercharger Lid!

If you read my article about installing a supercharger pulley on your SRT Hellcat, you would have seen how the factory supercharger comes apart. The top most part of the supercharger, called the supercharger lid, comes off with just a handful of bolts after removing the wiper cowl from the car.

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The supercharger lid is the same size/shape/dimension on all the 6.2L supercharged motors. What Nitrous Express did was machine a completely custom lid for the supercharger that integrates nitrous all in one package/piece. And boy is it a beauty.

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The company claims that now the product will produce more power both on and off nitrous than any other kit that leaves the factory supercharger lid in place. So I just had to test this out. Because, you know, who likes to leave stuff alone? What really stands out about this kit is where the nitrous and fuel is fed into the motor. Instead of being sprayed at the throttle body in front of the supercharger, it feed the fuels directly over the supercharger rotors, which I totally love.

I already had nitrous installed on my Dodge Challenger SRT Demon using a plate kit like I mentioned above. So it was the perfect opportunity to compare, back to back, how well this new system works.

Install of a lid is super simple. The rest of the kit can be a little more complex depending on exactly what options you chose to run with your nitrous kit. You can keep it simple and basic, or stack on a ton of accessories and safety features. If you are using a more complex progressive controller that allows you to program how your nitrous works (compared to just on and off Fast n Furious style), or adding bottle heaters, purge kits or bottle openers, wiring can get a little extensive. However, installing this beautiful chunk of aluminum is a breeze.

The first thing you need to do is remove the wiper cowl from the car, which I went over in detail in the “Pulley” How-To

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Next, you need to remove the Torx bolts holding the lid on to the supercharger, vac hose retainer and remove the MAP sensor on the lid.

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After removing all those, you are now able to remove the lid from the supercharger. It might be stuck on there pretty good; be careful not to tear the lid gasket when removing the lid.

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Make sure you don’t lose the 3 small O-rings in the center of the supercharger. Your lid is now removed and there are a few parts we need to transfer over to the new lid.

Remove the factory bypass valve via the four Torx bolts and gasket and mount it to the new billet lid.

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Now we need to remove the blue rubber gaskets off the factory lid and attach them to the new lid in the machined slots. In addition, attach the MAP sensor that we removed from the factory lid and mount it on the new lid.

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We are now ready to install the lid back on to the car. Just go in reverse! Make sure the O-rings in the center are in place, check that the blue gaskets and the lid gasket are all where they need to be, set the lid down, and hand thread in the Torx bolts to make sure all thread in easily and the lid alignment is good.

Follow the factory instructions below to properly bolt down the new lid.

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With the lid now on, your install from here may be different depending on which electronics and accessories you chose. The driver-side rear of the lid is where the nitrous and fuel lines connect into the supercharger. These hoses are run from the nitrous and fuel solenoids. I chose to mount mine under the cowl so that they are not visible with the car assembled, and running the hoses out from underneath the brace. You are free to mount yours wherever you wish, but I prefer to have as short of line as possible between the solenoid and where the nitrous and fuel is injected.

The kit as it comes is meant to utilize a fitting that goes into the main fuel line disconnect between the fuel line and fuel rails.

On 2018 and newer cars, the driver side fuel rail has a port on it. I prefer to pull my fuel from this port with a custom hose instead of using the supplied adapter at the fuel line disconnect.

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Wire in your solenoids, switches, controller and accessories as indicated in their respective instructions. I’m using a Maximizer 5 progressive controller, which is programmable to function based on a variety of sensor inputs from the car, such as RPM, throttle position, MAP sensor readings and more. 

Install your nitrous bottle in the trunk and fill that bad boy up with the good stuff we all love (nitrous). Run your main supply line up to the solenoid in the engine bay.

Throw your cowl back on and button up the install and you are ready to go. Pick your jet sizes appropriately to your setup (how much fuel and nitrous will be sprayed into the motor) and have your tuner supply you with a new tune to function with the new found glory of nitrous.

So does it work? Well, we all know that yes, nitrous does add power effectively. But did this specific product back up the claims of adding more power than using another style kit on the factory supercharger lid? Check it out:

Before pulling the stock supercharger lid off, we strapped the car down on the dyno and made some “before” runs to get some numbers. We made a pass with the stock lid and no nitrous, and the stock lid with my original nitrous setup.

Stock lid with no nitrous: 872 hp/818 tq.

Stock lid with nitrous: 1,055 hp/998 tq.

Those numbers are our baseline. We swapped the system over to the new billet lid, everything else exactly the same, so all variables were the same before and after the new billet lid. We even used the same dyno, tune, jets and as close to the same atmospheric conditions as we could get!

After installing the Nitrous Express lid, our results were:

New lid with no nitrous: 900 hp/874 tq.

New lid with nitrous: 1,063 hp/1,048 tq.

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Wow, that is instant results! That is a 28-horsepower increase without nitrous just by changing the supercharger lid. With nitrous, the horsepower gain wasn’t as significant, but it picked up 50 lb-ft of torque! With so many aftermarket companies out there and so many products to pick from, I have to say that this one really delivered. If you are considering nitrous as a power adder, I can’t help but fill you guys in on the results from this specific kit. I won’t debate if nitrous is a good power-adder or not. Either you are a fan, or you are not. I’m a fan, as are tens of thousands of others. But I can tell you that this kit is very well thought out, produced and clean. I think it’s a really great out-of-the-box approach for a product specific to our HEMI engine-powered cars. And who can argue that something like that is a bad thing?

1 Comment

good article, the lid alone sounds interesting