Choosing and Using Fire Systems

Now that we have a little time before the rules require NASA racers nationwide to install a fire system in their cars, it seemed like a good time to do a deep dive into the finer points of choosing and using a fire system.

We wanted to learn how to select a system based on the type of car and discover some of the finer points of mounting the bottles and controls. We also were curious about the two different types of extinguishants that dominate the motorsports market today, and we wanted to get a good cross section of what’s available, from basic systems to the state of the art.

We caught up with Brandon Marshall, brand manager for Lifeline USA, the official fire suppression partner of NASA, to get a better of what we need to know before we click “buy now.”

Extinguishants

In most systems currently available on the motorsports market, the two most popular agents are aqueous film-forming foam and Novec 1230, which stores as a liquid and sprays from system nozzles as a gas.

Aqueous film-forming foam has been on the market since it was adopted by the military in the 1960s. AFFF is a water-based extinguishant that must be applied directly to a fire to be effective, but when it does, it is effective in a couple of ways.

“When it sprays out, it kind of coats the surface, and it does two things,” Marshall said. “It smothers the fire to help kind of like choke it down or knock it down, but then because it is water based, it actually dissipates heat pretty well, so it helps take some of the heat out of the area. So, it’s two-fold. It’s knocking down the heat and knocking down the actual flames itself to help prevent reignition.”

Once the fire is out, there are some downsides with AFFF, one of which is that the water-based foam can damage electronics. The material also leaves behind a residue that needs to be cleaned up. If you’ve ever used a dry chemical fire extinguisher, you know the cleanup afterward is no small task. AFFF isn’t nearly as bad, but it’s a characteristic of the material.

“I like to kind of compare it to like laundry detergent. So if you’ve ever felt the residue it leaves behind once it kind of dries up, but once it sits there and the water evaporates out of it, it has a very similar residue and consistency,” Marshall said. “Of course, trying to clean it up when you introduce water, that’s going to cause it to foam a little bit more. I’ve seen it take three or four passes with a bucket of clean water, to get most of it up, and I don’t know that you ever actually get all of it up. But it’s just going through and just wiping it up until really you don’t have any foam left.”

Developed by 3M, Novec 1230 is a clean-agent extinguishant designed as a replacement for halon, which had insidious effects on the ozone layer and also wasn’t ideal if you were the occupant of the car in which the system was triggered.

Novec 1230 makes up the lion’s share of Lifeline’s sales, for a few reasons. One, bottles for the systems are typically smaller because it takes less Novec 1230 to extinguish a fire compared with AFFF. Two, Novec 1230 is safe for the environment and for people. It poses no danger to the ozone or the driver and it doesn’t damage electronics. In fact, there are a number of videos on YouTube showing cellular phones submerged in Novec and still functioning.

“It’s actually a liquid. As far as our handling is concerned, we put it into the bottle, it’s a liquid, but when it sprays out, it turns into a gas and our nozzles are designed to atomize it when it sprays to help speed up that atomization process,” Marshall said. “So, Novec is safe for you, safe for electronics. Every year at PRI, I typically have my iPad, my phone, you know, other people’s phones get dunked in it all throughout the show. It doesn’t cause any issues. Novec is a super coolant and that’s part of how it attacks the fire.”

According to Marshall, the super-cooling abilities of Novec 1230 help it extinguish flames. It draws out the heat of the flame and creates a barrier between the flame and the oxygen source. By contrast, halon stops the fuel, the ignition and the oxygen from reacting together by chemically reacting with each of them. Novec 1230 creates a barrier that allows a fire to burn the oxygen it has, but ceases its access to more.

“So then the fire will essentially choke itself,” Marshall said. “And one of the neatest things about Novec is there’s no cleanup. I’ve accidentally set some off here in the workshop. I’ve known dozens of people that have accidentally fired them off in their cars. And that’s probably one of the biggest things they’re thankful for. It didn’t damage their electronics and then they didn’t have any cleanup. It it’ll just evaporate and there’s nothing left to do other than send your bottle in and get it serviced.”

Foam systems range from $400 to $800. Novec 1230 systems range from $549 for a manual system to $1,428 for electric-actuation systems.

System Configurations

If you are in search of a system, you need to know what the rule book says as far as requirements. In terms of size, the major differences are between something like, say, a formula car, which has a lot less area and volume that needs fire protection, and a production car, like a Mazda Miata or a BMW 3-series, the two most popular chassis in NASA racing.

In other words, the 4.0-liter AFFF or the 2.25-kilogram, and 3.0-kilogram Novec 1230 systems that work for a Spec Miata also are suitable for a Spec E46 or other larger cars.

With each type of system, AFFF and Novec 1230, there are considerations for placing nozzles, which are different depending on the system you choose.

“There’s a science behind the delivery, and it’s designed that way for a purpose,” Marshall said. “So with AFFF, we use what we call a misting nozzle, and the way it sprays, that will be very similar to like a cone pattern. You’re just getting a mist in a cone pattern.”

It’s also important that AFFF nozzles be aimed at things that could catch or ignite a fire and things that could ignite as a result of a fire, such as the driver. AFFF has to physically make contact with the fire to suppress and extinguish it. Because Novec 1230 emits as a gas, nozzles and nozzle placement are a little different.

Novec 1230 nozzles are cut with slits that create a 170-degree fan pattern, and those slits must be oriented horizontally upon installation. Because Novec 1230 in gaseous form is heavier than air, its best to mount them at the top of the space you want to protect from fire. Novec expands and fills a space and then drops, so for nozzles aimed at the engine, the top of the firewall is a pretty good location. Novec 1230 is three-dimensional suppressant.

With AFFF, aiming the nozzles at potential problem areas — fuel lines, oil lines, etc. — so the foam can cover them in the event a system is actuated is the way to go.

“You probably ideally want to cover just all four sides of the engine,” Marshall said. “I think typically the intake side is very rare that fire happens there. Whereas if, like I said, your fuel rail is, is pretty problematic, then you might cover the other three sides of the engine and then one on top. Part of that science that we figured out is we’re giving you extra nozzles. We figured out how to support those extra nozzles, but then that way we can cover more things, literally cover it in more fluid to prevent ignition, knock down a fire and then prevent reignition.”

Actuation Types

For production-based racecars, users also have a choice of actuation for AFFF or for Novec 1230 systems, and those are: manual pull cable, electric manual, automatic and even automatics with auxiliary manual controls.

As you might imagine, manual pull cables are the most economical to buy. AFFF and Novec 1230 systems come with two pull cables, one to be placed within reach of the driver and one that safety workers can access easily. Marshall said he’s seen a lot of handles for the driver located near the shifter, but he said it’s better to put it in a place where it can be accessed by the driver and a corner worker. That way, if the side of your car that has the worker-accessible handle is pinned against a tire wall, there’s another one the corner worker can reach without having to lean into a potentially burning car.

Obviously, that advice applies to manual and electric actuation systems. Marshall also suggests pulling the cables every year and lubing the inside of the casing to keep things operating smoothly.

Electric actuation systems use a 9-volt battery to power the system. Marshall explained that you don’t want the actuation tied in with the car’s electrical system because they can be shut down in an emergency. Replace the battery every six months or whenever the system is actuated.

Automatic systems offer the greatest measure of protection in the event of a collision that renders a driver unconscious. Once the temperature at the nozzle reaches a certain threshold, the system is actuated automatically.

The craziest fire in the history of the NASA Championships happened in 2012, when two cars involved in a collision became engulfed. An automatic system likely would have helped greatly.

“So with our SFI systems, you can have automatic only, or you can have auto plus mechanical,” Marshall said. “It’s just the way that the head is designed. And what we do on an SFI system is we use a thermal bulb, very similar to what a commercial building uses for the sprinkler system. Once it hits a certain temperature, the bulb pressure builds up inside it, it explodes, and there’s a piston behind it that moves and releases all the pressure.”

Regardless of the extinguishant or actuation type, most Lifeline systems take roughly 11 to 13 seconds to discharge. Lifeline also has a proprietary pickup system inside the bottle that ensures you get the full contents of the bottle regardless of how it’s mounted.

State-of-the-Art Systems

At the uppermost levels of the Lifeline product portfolio are the FIA Technical List 52/8865 systems. Using a combination of 3M Novec 1230 and an AR-AFFF blend discharged through one high-discharge nozzle in the cockpit and three in the engine bay, performance and ease of installation are ensured. FIA systems use a heat-detection cable. When the outer sheathing melts, the wires make contact and complete the circuit, and the system discharges.

These systems range from $1,700 to $3,464.

“So there’s a science to fire suppression. It’s not just putting, you know, all the nozzles, all the suppressant, etc., you can get in the car,” Marshall said. “There is what you want to deploy, what you want to deliver, etc. And at some point, you might say, you’re just wasting your money if you go too big. On the opposite end of the spectrum, you might be not doing enough.”