We Take Sneaky to Level 5000 with a 130-HP Self-Contained Airbox Nitrous System!

Having a magazine project vehicle is good (if slow-paced) fun, we’re not going to lie. After a while though, you get tired of bolting on other people’s parts, and start to look to make your own waves. In a round about way, this is how our wireless nitrous system came to be. Nitrous is probably one of the single easiest ways to add power to a diesel engine, and can add a good 50-80 hp even on stock trucks. On trucks that have the fuel turned up it can add even more, and on full tilt race vehicles it can add up to 1,000 hp! We weren’t looking for extreme though, we were looking for something different.

Nitrous Express 1 lb. nitrous bottle, 10 lb. nitrous bottle
Pictured here is a small 1lb motorcycle bottle next to a “normal” 10lb bottle. Sure there’s less capacity, but the small size got us thinking.

Hiding nitrous has been another fun way to mess with your opponents on either the dyno or the dragstrip. In tractor pulling it’s a no-no, but elsewhere it seems to be all in good fun. One of our old rides had a bottle mounted under the bed, and the nitrous lines snaked around under the intake tube. Since diesel engines operate on such a wide air/fuel ratio range, oftentimes you can just inject nitrous straight into the airbox without hurting anything. The nitrous mist is simply sucked in by the compressor, and the power numbers climb up!

Dodge Airbox, Nitrous bottle
Step one in our nitrous theory was complete! The bottle fit in the bottom of a stock, unmodified Dodge airbox. It was secured at the rear with a clamp we acquired from our local fastener supply store.

A few weeks ago while we were looking for new air filters, we noticed how big a stock Dodge airbox is compared to gas intakes. A buddy of ours races motorcycles that use 1 and 2-pound nitrous bottles and we joked that one would probably fit in there. Then that got us thinking…what if one would actually fit in there? A test fit of the bottle proved that yes, it would, providing hiding place number one for our secret nitrous setup.

Nitrous Solenoid with extension
We couldn’t just mount the solenoid on the bottle because it hit, so we had to buy this extension from a local speed shop.

The rest of the pieces came together in an even weirder way. We were bringing and old R/C car we’d had since the ‘90s back to life with a new radio and speed controller, when we noticed we were charging the small Lipo batteries to 12.4 volts. The wheels started turning. That’s roughly the same voltage as a low car battery, could there be enough juice to fire a nitrous solenoid? A quick search revealed the speed control we were using was rated to 60 amps; nitrous solenoids were only about 6 to 25 amps. The battery is rated in MAH (milliamp-hours) which doesn’t exactly translate into amps, but what did we have to lose? After cannibalizing our R/C car that we just built, we now had a makeshift wireless nitrous controller. Even if things are well-hidden, you can almost always find a nitrous system by tracing wires. But what if there were no wires?

R/C car remote for Wireless Nitrous
Yes, we really did use an R/C car remote. After looking at a variety of options, we figured the remote and speed control would trigger just about any solenoid we threw at it. Plus, it was only $84. As a comical aside, it gave us enough range that we wouldn’t even need to be the ones that triggered it. A friend in the stands or crowd could perform the task if somebody was looking.

After we squeezed everything in the stock Dodge airbox for a trial fit, we closed the lid and it shut! We now had a completely self-contained nitrous system in a stock Dodge airbox. All that was left to do was the test. We took a breath, hit the button, and…nothing. Crap. We must have not had enough juice for the solenoid. Next came the more-difficult-than-it-looked step of wiring in a car relay into the system, which would drop the overall amp load and for sure fire the solenoid. We hit the switch, and, nothing. After some irritation, we finally took our solenoid over and just jammed the wires into the car battery. Nothing. Our brand-new solenoid was bad!

11.1V Lipo battery
We’re not sure if an “old school” 7.2V or 8.4V R/C car battery would work, but we figured a 11.1V Lipo battery might. It was $40 from our local hobby store.
Battery Charger Screen
Part of the puzzle involved the battery’s actual rating. While it says 11.1V on the side, it actually charged up to 12.4V, which we figured was more than enough to trigger the solenoid.

After snagging a solenoid from a buddy’s nitrous Camaro (from a different manufacturer) we hooked it up and bam, it triggered instantly. We took the relay out of the system and it still triggered. With our little motorcycle bottle all the way full, it sent a solid stream of spray out of the airbox for about two feet and five seconds until all our nitrous ran out. Obviously this type of tiny bottle wouldn’t be practical for full quarter mile passes, but for the eighth-mile or dyno runs, we could definitely see it. But how would it work in real life?

Solenoid wiring
We originally had our solenoid all nicely shrink wrapped and soldered to the R/C connector. Unfortunately, a solenoid failure (while we were trying to test) meant a bit of a last minute hack of a wiring job.

Testing

Now, keep in mind that this is us installing products, not a shop, so there were the usual growing pains of trying something new. Solenoids, wiring issues, the bottle mount pulling through the airbox, and other fun stuff. The actual test however, was pretty exciting. It just worked! After an initial 375rwhp pull (it’s always good to re-dyno a baseline under same-day conditions) we hit the spray through our R/C controller and could definitely feel it hit. A look at the dyno graph revealed a whopping 506rwhp, or a 131rwhp gain! Peak power was also at 2,400 rpm, which meant a whopping 1,107 lb-ft of torque. If we upped the ante to a 2 1/2-pound bottle (which we’re pretty sure would fit) we’d basically have enough nitrous for one pass, and about a second off our elapsed time. As it is, we’ve lost plenty of races by a fender or two, so even our 1 pound bottle would be some pretty good insurance. It was icing on the cake that we built the entire system for under $400.

Dodge Airbox with Wireless Nitrous System
Everything fit in the factory airbox with room to spare. We even twisted the solenoid around and found that the stock air filter would still fit over the assembly, but for our trial purposes we decided to run it with no filter.

Final Thoughts

Originally we were going to title the article “World’s First Wireless Nitrous System!” After some digging though, we found a system described exactly like we were building all the way back in 2001. Like everything else, it appears that it’s been (secretly) done before, but we have to admit it was still a good time, and still an exciting idea. The fact that the setup actually makes a significant difference and can be swapped from truck to truck in about 2 minutes is a riot, as is a stock-appearing 12-valve engine that makes more than 500hp at the wheels. We’re going to go “legit” for our airflow upgrades next with a larger turbocharger, but we gotta give the wireless nitrous setup two thumbs up for taking us on a pretty fun ride.

Wireless Nitrous System
We put a small spacer at the front of the air box and attached a 90 degree fitting so that the nitrous would spray directly down the intake tube towards the turbocharger.
Dodge Airbox with Wireless Nitrous System inside truck
The airbox was more or less secured using the factory mounts, minus the one we were using to secure our bottle. We even reused the old dusty stock intake tube.
Dodge Airbox with hidden wireless Nitrous System
We’re not sure how your 500rwhp engine looks, but with Power Driven Diesel’s Hot Rod lift pump, Scheid Diesel’s 5×18 injectors, and our hidden nitrous system, there’s virtually nothing to indicate the engine is anything other than a 160hp stocker. Keep in mind the 506rwhp reading was even through the factory exhaust!
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