ExclusiveTech Articles

Safety Tech – Fire Suppression Systems: An Introduction

Not everything is as it seems; this is a phrase we are all too familiar with and accustomed to in racing. A flashback to PRI 2022, the World of Outlaws announced 2023 would bring a new rule with the requirement of fire suppression systems on board in sprint cars.
It is important to note that the end goal for the implementation of the onboard suppression systems is to allot drivers extra time to get out of their car. Without a doubt, it is extremely easy to confuse the purpose behind a fire extinguisher and a fire suppression system. Where extinguishers will do simply that, extinguish a fire; a fire suppression system is meant to suppress the fire and slow down or prevent reignition of the fire. It is key to know that the end goal of implementing this new safety rule is to buy drivers time to get out of their cars.
The WoO has recommended four manufacturers where drivers may purchase suppression systems that meet the SFI 17.3 standards and have successfully passed testing. On the surface, these four manufacturers don’t seem that much different aside from pricing, but after doing some deep digging and reaching out to each manufacturer, not everything is as it seems on the surface!
Shortly after the list of approved manufacturers was released by the World of Outlaws, we reached out to each of them with the same detailed list of questions and the expansive list of differences between the four systems was staggering. What stood out even more was that of the four manufacturers, SPA Tech, Safecraft, Lifeline-Fire, and Safety Systems, the transparency in their processes varied from clear as day to opaque and in one case silent.
Let’s talk some basics about the suppression systems before comparing any of the systems. With SFI 17.3, if any suppression system fails any of the parts of the approval testing, the system then has to pass that test twice in a row. Two auto tests are also performed. The systems consist typically of one nozzle, aimed primarily at the fuel pump by the feet of the driver. Each system has a thermal activated light that will trigger the system at specific temperatures to disperse either a gas or foam agent. The color of the light on the system will indicate the temperature at which the system is triggered. Once systems have been discharged, they must either be sent back to the manufacturer, or authorized service center of the manufacturer, to be charged. The turnaround time will vary, 1-3 days seems to be an average expectation. SFI requires each system to be serviced every two years, and requires the bottle portion to also be inspected every six years. (Per Lifeline Fire, routine service on their system runs about $200 and to recharge the system it runs about $400. While other manufacturers did not share the costs, this does give an estimation of what to expect as additional costs.)
Only one of the SFI approved systems uses a foam agent – SPA Tech. When I was speaking with Dan from SPA Tech (who had participated in the R&D of their system) he advised they felt the foam agent was the best choice for a system like this because of the high re-ignition potential in a sprint car. With this decision, this does make their system a bit heavier and their bottle is a bit larger in diameter. While foam will not fil the air like a gas agent would, and has to be pointed directly at the fire point, it is important to note that the SPA Tech system has an additional nozzle pointed at the torso of the driver for additional coverage. Since the AFI testing does tend to lean in favor of gas agents, it is also much more difficult to design a system with a foam agent that will meet the standards for SFI 17.3.
This means that the other three systems utilize a gas agent – either 3M Novec 1230 or Dupont FE36. There is a percentage of gas required in the air, if too low the effectiveness of the gas goes away and re-ignition could occur. Gas is more of a three-dimensional agent which enables it to fill the cockpit of the car on discharge, and a supporting reason as to why Lifeline Fire chose to use a gas agent. The nozzle in the system is designed to spray in a 360-degree pattern, therefore the gas systems require only one nozzle.
While each system has a manual pull to discharge, there is also a thermal bulb that once the temperature rises to a certain degree will activate and discharge the system. It’s important to know that if the bulb is broken, it will also cause the system to discharge, both Lifeline Fire and SPA Tech have assured that the bulbs are fairly robust and while sprint car accidents can be quite violent the bulbs should withstand the force of an accident. While that seems to be the only common trait when it comes to the thermal bulb as not all activate at the same temperature. For instance, a yellow bulb is 175F, a red bulb is 150F, green is 200F, and blue is 289F. SPA Tech and Safecraft use a yellow bulb in their system, Lifeline Fire uses the red. This is an important detail as methanol fires tend to burn much cooler than a normal fire.
Installation per the SFI 17.3 rule has the systems bottle mounted underneath the seat and from explanation sounds to be relatively simple across the board with few concerns for incorrect installation. That being said, in looking at where the bulbs are mounted and the bottles connections are in the installation process does vary. While the three manufacturers I spoke with assure me that there is little room for accidental discharge outside of pulling the manual discharge chord, the bottle head too far forward in the cockpit of a sprint car puts your feet in a dangerous place risking the bottle’s safety. Location of the thermal bulb also varies and can be in a very close proximity of the headers for some. SPA Tech is the only system we found with the bulb mounted higher in the cockpit and the head of the bottle further toward the rear of the seat. Without checking the gauge of your bottle, if a system is accidentally triggered to discharge, unless the driver is there to witness it, there would be nothing glaringly obvious a gas system has gone off.
Let’s face it, safety equipment as a whole most often gets selected based on funds available versus the funds it costs. All of the manufacturers have clearly passed the testing required by the SFI and will all aide in gaining driver’s crucial seconds in getting out of the car and to safety officials. (If they can get out on their own free will and the fire doesn’t reignite that is.) When looking at components and location for installation, it all looks the same across the board. But truly nothing is as it seems, they are very different and each team will have to make the selection they are most comfortable installing.