Spool School: ZEX Diesel Nitrous Kit Improves Spool Up Times

We touched base on this ZEX Diesel Nitrous Kit a few months back and the time has finally come to make it happen. My personal truck is equipped with a 6.7-Liter Cummins engine and instead of the compound turbo kit that we had originally for the last few seasons, we went with a large single turbocharger. With that being said, it’s time for some horsepower in a bottle.

Our diesel engines are the perfect platform for the injection of nitrous. Since most of our engines run a rich fuel mixture (black smoke) nitrous helps burn that excess of diesel in the combustion chamber which inevitably churns out additional horsepower. On top of cleaning things up and making more power, it also helps with the spooling up of larger turbos.

Turbos-Less Is More?

The jump over to a single turbocharger wasn’t a hard decision. There were actually a few different pros in doing so. For instance, one turbo is simply lighter. We’re looking to be as lightweight as possible and when you remove one turbo, you’ve lost close to 100-pounds. When you account for all of the plumbing and the turbo itself, it adds up.

Secondly, at least in my opinion, it isn’t nearly as hard on your rotating assembly compared to compound turbo setups. At this level, or in this application, we’re hitting it with so much boost so fast, it will inevitably weaken those crucial internal parts.  Did the engine work fine and spool great before? Yes. I am not taking anything away from compounds, but I knew that a single made more sense for me.

So what are the so-called “repercussions” of a single turbo? For a single turbo to work, or at least a larger one, it can sometimes use a little help getting it spooled. With the help of our bolt-together torque converter from BD Diesel Performance, we made our stator stall adjustments to help with the RPM range in which the truck will start to move.

By making these adjustments, that will inevitably help start the spooling process earlier. After all, that is exactly what we’re after. Sometimes, even a converter stall adjustment can help but not quite enough. In my case, it did help greatly and is working perfectly. But, in an attempt to speed this process up even more in case of emergencies, why not ask for help from nitrous oxide?

What do I mean by emergencies? Well, in drag racing during the staging procedure sometimes you can get put on the clock. Let’s say you’re not ready when the timer starts, you let off the accelerator for some reason, or whatever it may be, you need to get that turbo lit as soon as possible. In our case, flooring the pedal will not do that. It will only make a ton of smoke in that small time frame.

With the help of our nitrous button, we can bring that turbo to life in a matter of seconds. The engine is growling, spooling the turbo up, and with the press of a button the tone changes. The turbo comes to life twice as fast. With this happening, you’re not waiting anymore and you’re not generating any extra heat in the engine and transmission.

Another cool feature of this nitrous on the truck is that if you’re just behind a truck down the track and need a little extra boost to get you around your opponent, just know you’ve got 30-200-horsepower on the other side of this button. Nitrous is really cool.

Press Here For Laughing Gas

The installation is quite simple. You need to secure the bottle in the vehicle somewhere in a safe area, plumb your nitrous bottle to the engine, and give the system controller power and ground. As you can see, I mounted the bottle close to the driver’s seat making it easy to turn the bottle on and off. Let’s assume you’re in a hurry and forget to turn the bottle on. If you do, the bottle is within reach.

As for plumbing, we ran the supplied steel-braided line up the doorline of the cab and into the engine bay area. When it comes to plumbing it into the air intake system, you will need to drill and tap a hole for your fittings to thread in. For instance, this engine actually has a factory air intake horn so we needed to make a port. Some intake systems come already outfitted with threaded ports for add-on’s like this which makes it easy to connect up.

Now that we have the connections made from bottle to engine, it was only a matter of getting power to the system. This system can actually work in multiple ways. The main way would be to let the controller do all of the work and work off of the throttle position. Since we’re using this kit as a spooler mainly, I wanted to be able to have it on a button.

With a truck like this where the cab is gutless and the options are endless for mounting anything, we decided to put the “go-baby-go” button on the backside of the shifter bracket. Our TCI Outlaw shifter has a good little area on the backside that is within reach which made it a perfect location for our nitrous ignition button.

With everything mechanically connected, all that we lacked was the wiring. Using the provided harness and more, we made our connections to our ARC Pro Mod power panel and battery. By connecting this ZEX system to the ARC panel, this forces you to arm the system overhead before the nitrous will work. This way, in case someone accidentally hits the button on the shifter, nothing will happen including emptying your tank prematurely.

Wanting to know more about this system, I reached out to the COMP Performance Group’s Director of Product Development, Matt Patrick. I asked Patrick, what do you have to say to those that are interested in injecting nitrous into their truck? “Diesel engines love nitrous. In general, the more nitrous that is sprayed, the cooler the EGTs get.  Being that excessively high EGTs are one of the primary limitations when trying to add additional fuel for more power, nitrous can really unlock tremendous power, while at the same time increasing engine safety,” said Patrick.

With diesel performance popularity on the rise, where do you see ZEX and diesel in the future? “The diesel nitrous system market has been growing tremendously for us. As the popularity of diesel horsepower modifications and tuning has grown, so has the interest in the performance benefits of nitrous injection,” Patrick said. “ZEX continues to have the best engineered, most complete, and powerful diesel nitrous systems available.”

Once you’ve armed the system, you can then press the button and hear the relay clicking.

I made a trip to the local speed shop where we got our nitrous bottle filled up. For about $6 a pound, our pretty purple bottle was topped off and ready for action. I would like to mention something about mounting options, too. Traditionally, the bottle is mounted flat with the valve on the high side. The siphon tube in which the nitrous is pulled out of the bottle from needs to be aimed toward the lowest point.

This way, when the bottle is nearing the end of its cycle and you’re nearly out of nitrous to use, the siphon tube will be able to get as much out of the bottle as possible. Now, for what I am doing, it is a little bit different. Since I am using this strictly as a spool jet, how the bottle is mounted isn’t nearly as critical as long as it is safe and secure.

Nitrous oxide inside the tank, because it’s compressed, is actually in a liquid state. Depending on how you mount the bottle, the liquid will naturally move to the lowest point. When a race car or race truck is accelerating down the track, that liquid will naturally move towards the back because of inertia. That is the difference between our scenario and the traditional way.

I will be activating the nitrous sitting still during the staging procedure therefore the liquid will be resting. The siphon tube will be able to get all of the nitrous we need. In fact, we will probably use such a little amount of nitrous using it like this that we won’t have to fill the bottle up very often.

Closing Thoughts

With everything set up and tested, I am honestly pleased with how it all unfolded. I was hesitant at first about nitrous because you always think about those who have failures because of it. As long as you’re using it within reason, you have nothing to worry about. I noticed a huge difference in spool up time and that is going to do nothing but improve my consistency on track and speed up the process of staging.

The less time you’re on the converter trying to get on top of the turbo equals less time you’re generating heat inside everything. For those of you who are in very high elevation, this is basically an absolute must too. It will help your spool up time, staying on top of the turbo down the track, and even just add a ton of extra power overall.

We’re super excited to have ZEX Nitrous on board and look forward to their help in what’s left of this drag racing season. If you’re looking to help your spool up times or want more power in general, be sure and check out the ZEX Nitrous website here. Stay tuned for more parts reviews, installs, and event coverage right here on Diesel Army.

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About the author

Artie Maupin

Artie Maupin is from Southeast Missouri and has an extreme passion for anything diesel. He loves drag racing of all kinds, as well as sled pulling competitions.
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