Hiding Horsepower

Mike Thermos reveals where he hid the juice!

Words and Photos: Jeff Smith

Nitrous — it’s all you really have to say. It is a power-adder that by nature is stealthy. Blowers and turbos either stick through the hood or announce their presence with whistles and distinctive air surges. But nitrous — it just lends itself to be like the underdog’s secret weapon. A small bottle stashed somewhere followed up with a couple of hidden solenoids, and you have everything you need to make chemical horsepower.

Sure, nitrous was first used by the Germans in WWII; everybody knows the story. But, the fun stories you haven’t heard are about what you never saw. Like any good conspiracy, whether documented or imagined, the stories have their champions. The problem is these are all third or fourth-hand stories. Perhaps just urban legend passed down like tribal lore from generation to generation. Origins are soon lost and with it, their veracity.

But like any good Hollywood movie script, there’s a likable old character who knows a few of the stories firsthand. He knows the players. He often even designed the schemes, or at least was an unwitting parts supplier. Our wizened veteran is no less than Mike Thermos, co-partner with Dale Vaznaian in the creation of Nitrous Oxide Systems (NOS) in the early ’80s. The partners didn’t invent nitrous. They weren’t even the first to build a kit for sale to the public. But, like the cagey CamFather Ed Iskenderian, they figured out a way to market the stuff like nobody else.

Thermos and Vaznaian sold NOS to Holley long enough ago that the non-compete clause has long since passed its limit. You can probably guess what Thermos did. Yep, he started up a small company called Nitrous Supply in his old stomping grounds of Huntington Beach, California. Thermos is a big, likeable guy who reminds you of your fun-loving uncle who could be found leading his nephews in questionable adventures.

He took time with us to pull out a few old stories about some of the best nitrous cheats he can recall from the past crazy days of racing. These are just some fun stories about things that Thermos has seen during his near four decades of working with nitrous oxide. But he’s not a cheater. “I don’t want people to think that all we do is think about ways to cheat.”

Top Fuel Fun

If all’s fair in horsepower contests on the street; on the racetrack, there are tech inspectors and rules that prohibit its use. Even in the supposedly unlimited class of Top Fuel, did you know nitrous is banned? Tech inspectors hate nitrous because it’s hard to find. This makes nitrous the easy excuse anytime somebody goes fast.

There’s a story that Don Prudhomme used nitrous in his Top Fuel car at the 1982 U.S. Nationals (when it was still legal) to run two-tenths quicker than the existing record. His crew chief Bob Brandt plumbed a nitrous bottle directly into the engine’s fuel pump. Thermos was there, looked at the design, and said, “Bob, that won’t work!”

Brandt made some excuses, but did nothing to change the layout. All of Prudhomme’s competitors assumed he ran quick because of the nitrous. NHRA eventually banned nitrous in Top Fuel by the end of the season. But the wily Brandt was actually using the nitrous tank and plumbing as a smokescreen. It was a crafty misdirect away from the more efficient vane fuel pump that was the real reason for his much quicker car. What follows are some of his recollections of other sneaky tricks he’s run across. All these tweaks just add to the mystique and lore that has become nitrous oxide. Thermos pressed us to avoid using names and places for the sake of anonymity, and that’s fine for this story. We are only interested in learning about some of the highly innovative ways racers have used to take advantage of the fast gas.

To steal a line from Bruce Springsteen, a creative cheat with nitrous is a little like looking directly into the sun — ’cause “Momma, that’s where the fun is.” We’ll leave the rest to the rules makers, harried tech inspectors, and managers of the “Automotive Karma Bank.”

Battery Boost

We’ll start with one of the best ones. Thermos had his crew build this rig just for this story because it’s so cool. He started by buying a brand new Group 27 battery case complete with the lead terminals in the top. After removing the internal cell partitions, they fitted a Nitrous Supply 2.5-pound bottle and a small solenoid into the case, with braces to keep the bottle positioned properly.

Next, they fit the solenoid with a relay and a pair of 9-volt batteries that wired in series (+ to – and – to +) to double the voltage to 18, sufficient power to open the relay. Next, they mounted a common remote control receiver inside the box that would trigger the relay. This way, the system was completely separate from the driver, so there would be no telltale switches inside the car.

The black discharge hose is plumbed through the negative terminal in the lid and wound through the cable where it is shown here exit-ing the cable end. All that’s left is to drill intersecting holes in the mounting bolt and then allow the bolt to exit into the intake manifold.

The black discharge hose is plumbed through the negative terminal in the lid and wound through the cable where it is shown here exit-ing the cable end. All that’s left is to drill intersecting holes in the mounting bolt and then allow the bolt to exit into the intake manifold.

Next, they drilled an access hole up through the bottom of the battery’s ground terminal and routed the small black plastic output line from the nitrous solenoid, up through the terminal, and out through the middle of the ground cable. They removed just enough copper wire from the cable so most of the cables were still intact, yet the hose would fit through.

Thermos says the next trick would be to drill a hole into the mounting bolt that you would “ground” at the intake manifold. Inside this lug, you would drill an access hole that could then feed nitrous into the engine.

To trigger this system, the Nitrous Supply crew just used a simple radio transmitter, like for an RC car or airplane, but Thermos says you could use a garage door opener or even a car key fob — anything with sufficient transmitter range to reach the receiver.

The down side to this system is the driver really has to trust his crew chief, because the driver will not have control over when or how long the nitrous is applied. Of course, with a nitrous-only (no additional fuel), you should be smart enough to know that too much nitrous without sufficient matching fuel is only asking for engine trouble. With a 2 ½-pound bottle, this would be good for several 60-foot shots that would drastically improve the elapsed times, but not necessarily bump the trap speed.

Obviously, this fake battery would be located in the engine compartment, while the real battery would be in the trunk. But, if you’re crafty, you could outfit this fake battery with a live battery cable because the ground on the case would still work. That would also supply power for the solenoid, so you wouldn’t need the twin 9-volt batteries. Our Chicago street runner pal Nick Scavo used this exact fake battery idea as a way to trick the local drag strip tech inspectors when he wanted to avoid adding a battery cutoff switch at the back of the car. This subterfuge was intended to make the car appear stock.

Nitrous on the Ovals

Mike Thermos at his desk in the middle of another tale from his days selling nitrous oxide.

Mike Thermos at his desk in the middle of another tale from his days selling nitrous oxide.

There’s a story that made the rounds back in 1998 during Pole Day for the Indianapolis 500. An AJ Foyt team car driven by Billy Boat qualified with a four-lap average of 223 mph, running in the heat near the very end of qualifying in a backup car. Boat had earlier crashed his primary car in practice. The lap was a solid 2 mph faster than Greg Ray, the No. 2 qualifier. Another Foyt car driven by Kenny Brack was on the outside of Row 1 with a four-lap average of 220.9 mph.

Apparently, there were some hard feelings in the pits after Pole Day that Boat’s backup car just could run that fast in the heat of the day. Protests were filed, but nothing came of this. The contention was Foyt’s car was using nitrous, but no evidence was ever discovered. Thermos says Indy 500 tech people called and asked if there was any way to test the engine for nitrous residue — which of course there is not — and that’s what Thermos told them.

With nothing more than a 0.030-inch hole drilled through the middle of a simple aluminum rivet, you could have a discharge hole for nitrous into the air inlet of an Indy car.

With nothing more than a 0.030-inch hole drilled through the middle of a simple aluminum rivet, you could have a discharge hole for nitrous into the air inlet of an Indy car.

But, if you were going to try to get away with this, how would you do it? Thermos heard that hiding the gas inside a frame rail or other area would not be difficult, and then a line could be plumbed inside the bodywork to lead up to the air inlet scoop for the engine.

Back then, the cars still used aluminum bodywork, and Thermos says it would not be difficult to plumb the line to an individual rivet with a carefully drilled 0.030-inch hole in its center. All methanol engines — especially during qualifying — run rich for a touch more power, so it would be easy to trigger the nitrous as the car entered each of the track’s over half-mile-long straightaways. Of course, this is purely supposition since nothing was ever proven. Boat finished 23rd on race day.

Rental Car Madness

If you haven’t heard the suggestion to never buy a used rental car, this next vignette should certainly reinforce that statement. Thermos and Vaznaian really didn’t have any trouble hiring young guys to work for them. Among his crew were some sharp people who soon came up with an idea they called the Rental Car Kit.

It consisted of a small solenoid plumbed with a long hose connected to a sharp nitrous probe. This probe would protrude into the rubber air inlet bellows just upstream of the MAF (mass airflow sensor) and throttle body on the engine.

One of the perpetrators in this scheme was then-employee Trey McFarland. He and his fellow co-conspirators would fly to their destination, rent a car, and plumb the entire system in a matter of minutes. They used two alligator clips to the battery for power and a simple momentary switch to trigger the system. Since they couldn’t fly with a full bottle of nitrous, they would borrow one from one of their customers at the track, strap it into the back seat, and go looking for victims on the street.

“The transition to MPFI by the OEs and the introduction of the NOS Dry EFI kit opened a whole new world for us to abuse with nitrous,” McFarland said. “We returned a few cars with noisy transmissions, misfiring due to cooked plugs, and most with a lot less rubber.”

Thermos remembers the guys reporting that one car ended up with a melted piston but the rental company never caught on to the chicanery. “The melted piston must have been after my time,” McFarland said. He also said that often their rental car performance would help sell kits on Monday morning, so it was all in the name of added sales. Even if the rental car company paid the price!

Line of the Times

“There used to be a guy running a really nice, black ’57 Chevy at OCIR (Orange County International Raceway — in the ’70s and ’80s, this was a big-time track). He used one of those thin plastic lines like you use for an oil pressure gauge and slipped it into his PCV valve. Then he found a small nitrous bottle that would fit inside the waist band of his fire suit. The bottle solenoid was powered by a pair of 9-volt batteries. He would route the line through the firewall ahead of time and then hook it up to the bottle as he was strapping in the car.

“This was just nitrous — no fuel. He would hit it right off the starting line. He ran the engine a little rich, and it was enough to give him a decent shot on the starting line. We were impressed with his system, and we eventually signed him up as one of the cars we sponsored. I think it was like a 9-second car, which was fast back then.”

This idea eventually found its way into the NOS lineup as the Sneeky Pete system, using a 10-ounce bottle powered by two 9-volt batteries.

Nitrous Ice

Among the most obscure ideas Thermos has run across, he received a call one day from a NASCAR team with a question. They wanted to know if it would be possible to freeze nitrous inside an ice cube. The idea was that they would “trap” the nitrous gas in an ice cube and place the cubes inside the engine’s air cleaner right before qualifying. As the engine warmed up, the ice would melt and the nitrous would be released.

The problem with this idea, Thermos said, is that nitrous is only a liquid within a very narrow range of temperature between -127 degrees F and -130 degrees F. It would be very difficult to maintain these temperatures to freeze nitrous into an ice cube and then keep it cold enough to allow it to boil and escape as a gas at the appropriate time. A better idea might be to just freeze the air filter itself, using it to chill the incoming air. There’s no doubt that’s also been attempted. If nothing else, it does show how far the NASCAR guys are willing to go to create an ever-so-slight advantage.

Source: Nitrous Supply, nitroussupply.com

About the author

Jeff Smith

Jeff Smith, a 35-year veteran of automotive journalism, comes to Power Automedia after serving as the senior technical editor at Car Craft magazine. An Iowa native, Smith served a variety of roles at Car Craft before moving to the senior editor role at Hot Rod and Chevy High Performance, and ultimately returning to Car Craft. An accomplished engine builder and technical expert, he will focus on the tech-heavy content that is the foundation of EngineLabs.
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