Written by Jason Reiss
Photography by the Author and courtesy of Holley Performance Products
The last several years of technological advancements in the drag racing world have seen incredible gains on the track from a wide variety of engine combinations. Oftentimes, these gains are attributed to one specific type of component: the electronic fuel-injection engine-management system, sold in many forms by several manufacturers. And over the last year, nitrous oxide has seen resurgence—and taken a quantum leap in capability—especially in NHRA Pro Mod, PDRA Pro Nitrous, and Radial vs. The World competition.
One tuner in particular who has had immense success using electronic fuel injection to tune several customer cars equipped with nitrous oxide is your 2019 NHRA Pro Mod Champion, none other than Stevie “Fast” Jackson, who some call the baddest drag racer in the land. Jackson’s story is an interesting one, but we won’t get into that today. Rest assured that the man knows what he’s talking about when it comes to the use of nitrous oxide on a drag racing engine.
An interesting component of his success is that Jackson doesn’t even run nitrous on his own Pro Mod or his Radial vs. The World car, but he has several tricks that have proven successful when using Holley’s Dominator engine management system.
A phone call with Stevie revealed more, but only after some begging on this author’s part. OK, a lot of begging.
“I’m trying to think of things that I can tell you about EFI and nitrous that will not help my competitors outrun me,” says Jackson.
These tips—some of which we can share with you, and others we can’t, as we did promise Stevie that we wouldn’t give away his hard-earned edge—have been record-setting under the hood of Marcus Birt’s nitrous-injected Jerry Bickel C7 Corvette, powered by one of Pat Musi’s 959ci bad-to-the-bone bullets. Jackson also has other customers whose nitrous vehicles he tunes, and the one constant is that he uses the Holley Dominator engine management system to do so, regardless of engine combination.
Something to take away from the conversation is that when you boil the use of nitrous oxide down, it becomes simple: ensure you have the right amounts of giggle gas and fuel for proper combustion, and you’re gonna be fast. Getting the details correct is the challenge, and it starts with the basics. Since Stevie tunes exclusively with the Dominator, this article will revolve around that component, but the ideas presented will likely translate to other engine management systems.
It’s important to remember to focus on the basic parameters because—more often than not—they can be cause for concern when things aren’t working correctly, or you think they aren’t working based upon the data you see. Jackson has amassed a monstrous volume of data from the customers he’s worked with over the years, and during our conversation, it was easy to tell that he has what appears to be the memory of an elephant when it comes to recalling specific runs at specific races, along with track conditions and other minutiae that most people wouldn’t notice. This uncanny ability to pin down the tiniest details is what sets him apart from the crowd and puts him into the winner’s circle at a prodigious rate. The drive for perfection extends to everything he does.
“One basic function that a lot of people miss is paying attention to your nitrous parameters—what you command the Holley to allow the nitrous to turn on and off. A mistake that a lot of people make is not setting a minimum rpm. I always set the minimum rpm that I’ll be above at idle and below on the two-step, to make sure the nitrous doesn’t accidentally arm. Even more important than that is to set a maximum rpm for the nitrous to operate at that is set below your engine’s maximum rev limiter. So that when you have a component failure—such as a driveshaft or rear gear, or you smoke the tires and don’t let out of it—the nitrous will turn off before it hits the engine rev limiter, which is what launches your manifold into the stands. These are basic items that a lot of novices don’t do,” Jackson explains.
Another function to note is the percentage of throttle when the nitrous is applied. As the Holley system activates the nitrous system internally rather than through an old-school momentary switch, it’s critical to ensure activation occurs as intended—but Jackson says that number isn’t necessarily what you might think.
“Make sure that you have your minimum TPS set at a reasonable number. A lot of people go in there and set that thing at 90-percent. I would say that three-quarters of the people whose cars I tune lift at some point during the run, whether they know it or not. They are generally coming off the throttle, so you have to make sure you have a reasonable TPS limit; that way, if they come off the throttle a quarter of the way on the shift, like most of ‘em do, that it doesn’t re-arm the time for the nitrous. I will set that at 65 or 70-percent, whereas if you have it set at 90 and the driver gets scared and comes off a little bit, or you have noise in your TPS signal, it’ll keep the nitrous lit during moments of instant acceleration, like coming off the shifts,” he says.
We were stunned to hear him say that drivers are regularly coming off the throttle—so much so that he has to account for it in the nitrous tune-up—but we’re also not going to question the integrity of the guy who just won the NHRA Pro Mod Championship in one car and the No Mercy Radial vs. The World $50K winner’s pot in another car, over seven days.
“I’ve never done it, and there are some drivers like Chad Henderson who never do; it’s subconscious, it’s not like they’re coming off the throttle half-throttle, they’re just not keeping it buried into the stop,” he explains.
He’s even used a transducer on the throttle pedal to measure the force applied, and in his racing efforts, he’s seen 600-800 pounds of pressure going down the track. It’s the measurement of the little things like this that separate the professionals from the amateurs when it comes to this level of racing.
Another area where he feels many racers could improve their programs is through the use of the Dominator’s internal datalogger function. Many racers are still using a separate datalogger acquired from a variety of companies, but he feels that as the Dominator is driving each of the engine’s functions, it’s best equipped to provide the necessary data for success.
“Most guys generally don’t download the Holley ECU—especially if they have something like a Racepak on board—unless there’s an issue. You need to make sure that you download every single run out of the Holley datalogger. It’s an invaluable tool for when there’s a problem. What’s bad is when something happens and you don’t catch it that run, then it gets worse on the next run, but you’ve already deleted the datalogger and don’t have that previous run file to compare to and see if you’re dealing with a problem that happened once or twice. Make sure that you not only download the Holley datalogger, but also study the information,” says Jackson.
Keep in mind that access to data is quite possibly the most prominent reason that today’s all-out drag cars have advanced so quickly over the last decade. As data acquisition has become more detailed and racers have learned what to do with the information that is available to them, race-day decisions are made with far more certainty and repeatability than in past years. Component selection is also driven by this data, as performance improvements can be easily quantified.
“Datalogging the run and actively overlaying the run along with the fuel and spark map—this is a very useful tool for trimming your main fuel and spark maps. It’s far easier to see a fueling or timing problem when it’s in the main fuel map versus just looking at it on the run. ‘Oh, the pan vacuum dips here, why?’ You can overlay the engine graph into the spark map and see ‘OK, that’s right where I’m getting into maximum timing,’ or ‘That’s right where my ignition timing is coming up, and it’s rattling the motor.’ It’s an invaluable tool for trimming the fueling and main spark map,” explains Jackson.
Via the CAN bus network, the Holley system can send 20 channels of Holley information to the Racepak, but the Holley system will datalog anything that a Racepak can. Jackson says you can hook up linear shock sensors, EGTs, and accelerometers to acquire information, but many racers are using the two in conjunction.
“Aside from all of the external sensors that you can add on to it, it also logs all of the internal functions. You can see each injector’s open time, each cylinder’s individual fuel and timing trims, diagnostic error collection for when there’s a problem with that stuff. There’s a massive store of data that’s in there that won’t be on your Racepak,” he says.
Jackson is a big proponent of using a dry-nitrous configuration, as controlling the fueling through the injector provides precise application.
“The injector does a better job of atomizing the fuel than nitrous and fuel going through a single nozzle, and it’s more consistent cylinder-to-cylinder. The ability to fine-tune fuel and spark makes me prefer the dry setup versus the wet setup,” says Jackson.
And when it comes to tuning the system with the giggle gas flowing, he says it’s no different than any other engine combination.
“You’re looking for anything during the run that causes the engine to accelerate rapidly, and you’re also looking for anything that causes the engine to decelerate. If I’ve got a system that’s coming on at half a second, and at half a second the engine decelerates, then I have to figure out why. On the flip side, if I have a kit that’s coming on and making the engine extremely aggressively, I have to figure out how to calm that down, so it doesn’t cause power management problems down the racetrack. With the most perfectly tuned system in the world, you won’t see your kits come on at all. You want it to be as smooth and linear as you can make it,” he says.
A testament to the system’s capabilities—and Jackson’s as a tuner—is the lack of burned pistons throughout the 2019 race season. Jackson feels that the EFI system is the most critical component of the system’s success.
“There’s a definite reason that the Holley Dominator is on the quickest nitrous-oxide-powered car in the world. Its efficiency and repeatability, and the way that it’s user-friendly from the novice level up to an advanced level, are some of the reasons that I have it on everything. It’s not an accident that I put it on Marcus Birt’s car to go out and set the world record. I believe it’s the best, and if I thought there was anything better, I’d go out and use it. They run way better on nitrous and fuel than they do on aluminum, I promise you that. I think that 3.40s are around the corner.”
Steve Jackson/Killin Time Racing