
Even though Dale Earnhardt Jr. was wearing the best safety equipment money could buy when he crashed this American Le Mans Series Corvette in 2004, he still suffered second-degree burns on his neck. Note the charring on his firesuit. The two-layer suit did its job. Courtesy of AP
Did you know that you get roughly twice as much fire protection from an SFI-5 rated suit versus an SFI-1 rated suit?
Did you also know that there's about a $200 spread between a single-layer and double-layer suit?
How many square inches of skin graft can you buy for $200?
Think about that for a minute.
Credit for that last question goes to Bob Mantell of Safe-Quip. Here's his point: By spending a little extra money on a quality suit, you can save a ton of money in medical bills if, God forbid, you experience a flash fire.
While nobody ever wants to talk about it, ours is a dangerous sport. Fires can and do happen. You would think that having the best in safety equipment would be a no-brainer for anybody who straps into a race car. But all too often we hear the argument that safety equipment doesn't make you go faster. While this is true, it is also pretty hard to go fast when you're lying in a hospital bed with second-degree burns.
Sure, you could drop $1,200 or more on a custom-made designer suit. But don't think for a minute that you have to take out a second mortgage to afford a quality two-layer firesuit. In fact, there are numerous options available that offer excellent protection at an affordable price.
Before we go through the checklist for selecting a firesuit, we need to go to school.

This double-layer SFI 3.2A/5 suit from Impact costs roughly $450, a great deal for superior protection. Photo by Impact Racing
History Lesson
The first fire-retardant racing suit was manufactured by the Indianapolis company J.B. Hinchman over 80 years ago. onceptually, the suit has changed little over those eight decades. The idea is still to provide protection from fire. However, today's suits bear little resemblance to their early counterparts. High-tech materials, proprietary stitching patterns, and fashionable designs not only set you apart in the winner's circle, but also save your life on the track.
There are essentially three types of suits: single-layer, double-layer, and triple-layer. In addition, you have one, two, and even three-piece suits. Drivers need to wear one-piece suits, and crewmen can choose from any of the three multipieces depending upon their race-day duty.
What Do All Those Ratings Mean?
The quality of any fire-retardant material can be determined by looking closely at two measuring factors: Limiting Oxygen Index (LOI) and Thermal Protective Performance (TPP). LOI is the most commonly used measure for flame retardancy and refers to the amount of oxygen needed in the atmosphere to support combustion. If a fiber or fabric has an LOI of 25, that means that oxygen needs to be present in at least 25 percent of the air for the fabric to burn. Consequently, a higher rating equals more fire protection. Many fiber manufacturers achieve high LOI ratings by chemically treating their fabrics with a flame-retardant finish. The downside is those chemicals can be washed and worn off over time without proper care. You won't often see LOI in race suit literature, but it is an important factor in good fire protection.

Second degree burn-need we say more? Photo by Dr. Rick Malta
On the other hand, TPP refers to the garment's ability to provide thermal protection when exposed to both direct flame and radiant heat while taking into account the length of time before a person is subject to second-degree burns. While that's a mouthful, TPP is the second most important number you need to know when firesuit shopping. The TPP rating is derived from a mathematical calculation performed with the results of a sophisticated test procedure that utilizes two different heat sources, sensors, and the fabric to be tested. The TPP rating is divided in half to determine the number of seconds until the human tissue reaches a second-degree burn. For example, if a particular fabric has a TPP rating of 35, it takes 17.5 seconds until a second-degree burn occurs in a flashover situation.
The only way to increase a TPP rating is through adding multiple layers. However, as you increase layers, suits get bulkier, and bulk does not equal comfort. Your goal in selecting a firesuit should be the balance of comfort with maximum protection.
Mom always told you to wear clean undies-now we know why. A great way to increase the TPP without jumping up to a three-layer drag racing suit is to wear fire-retardant (FR) underwear beneath your suit. If your budget doesn't allow for FR underwear, even a cotton sweatshirt adds some protection.
Some suit manufacturers promote the TPP rating of their suits alongside the SFI rating. Check out the chart below to determine which rating fits your particular needs.
Here's a great question to ask yourself after looking at that chart: How fast can the safety crew at your local track get you out of a burning car? If they can do it in 3 seconds, go ahead and buy that $99 single-layer special and drop me a note telling me your home track because I want to race there.

This NASCAR Busch East crewman favors G-Force's SFI 3.2A/5 suit because it is "really cool even on hot days." Photo by Robert Fisher
The SFI Foundation
Now that you know a little about what goes into a firesuit rating, meet the SFI Foundation. Originally started by SEMA, SFI is now an independent non-profit organization that issues and administers standards for a wide variety of specialty/performance automotive and racing equipment. All ratings are established by a technical committee and then adopted by different sanctions or organizations. Participation in SFI standards by manufacturers is strictly voluntary. So it may be possible to find a firesuit out there that doesn't carry an SFI rating, but I wouldn't buy it and neither should you.
All the manufacturers mentioned in this story carry SFI ratings. A typical rating looks like this: SFI 3.2A/5, where "3.2A" is the foundation's standard for firesuits and "5" is the rating. The higher the rating, the better the protection. In this example, "5" is the most important number you will see, especially if the manufacturer does not release TPP numbers.
Most sanctioning bodies, such as ASA and IMCA, as well as racetracks, such as Indiana Speedrome, require you to have a firesuit with a minimum SFI rating in order to compete. However, that does not mean that you should buy only their minimum. In fact, world-renowned safety guru Bill Simpson says quite the opposite. "We don't even make a single-layer suit," says Simpson. The man who brought Nomex to auto racing in 1967 believes that two-layer SFI 3.2A/5-rated suits should be the norm.
"If they [sanctioning bodies] would make a mandatory rule for the SFI-5, then it seems to me that they could go to their insurance underwriter and say 'we've reduced the incidents of fire injuries here by probably 90 percent,' and they could probably get some kind of discount on their insurance."
Simpson brings up an excellent point. While directed at the sanctions, what he says can also apply to you, the racer. Check with your personal insurance carrier to see if there are any discounts available for wearing top-rated safety equipment.