Approved race suits for Speedway use are SFI 3.2A and then they have a number after this on the suit label. This number signifies the rating of the material in the garment. For example an SFI suit with a label SFI 3.2A/1 would usually signify a single layer suit but may also be a two layer but with a lower rating fire retardant material. Each of these rating signifies a TTP rating as below.
The TPP rating is the product of exposure heat flux and exposure time. The TPP results can be converted to the time before a second degree burn occurs. The higher the garment rating, the more time before a second degree burn. Below are the SFI ratings with the corresponding TPP values and times to a second degree burn:
As you can see the time before second degree burns can occur is very short however this is significantly increased with a higher rating race suit.
While it is compulsory to have approved underwear for the SFI 3.2A/1 suits, it is highly recommended that approved flame retardant underwear is worn under all race suits.
Share this Post