It has come to the attention of NTPA Technical Services that certain variations in construction of the SFI 47.3 rollcage do not meet standards set forth by SFI or do not meet NTPA roll cage mounting guidelines. The SFI 47.3 standard for vehicles that compete at 2,000 lbs., namely Modified Mini division, has been in place since 1998 and the specifications for construction and mounting of the rollcage have never changed.
Therefore, the WPI Board of Directors has determined the following corrective action is necessary.
- All 47.3 rollcages must have a diagonal bar installed between the front and rear vertical tube on each side of the rollcage as specified. This tube may currently be installed in the horizontal position and will need to be removed and a new tube fitted diagonally in the correct location according to the SFI specifications.
- NTPA rollcage mounting standards for both tube type or channel type chassis require a 1/4-inch x 3-inch steel web plate be properly welded at base of rollcage on each side between front and rear vertical tubes as well as across the rear of the rollcage. The flat, 1/4-inch x 3-inch steel plate needs to be installed between each vertical tube all the way around the rollcage, connecting all vertical tubes together.
Any SFI 47.3 rollcage that is in violation of the issues described will have until June 01, 2023 to complete the repairs in order to compete during the 2023 season. Once the roll cage has been updated to meet the requirements described, the rollcage will be re-certified by a NTPA Rollcage Inspector at no charge to owner and a new 5-year certification sticker will be installed.
NTPA Technical Services recommends that competitors contact their chassis / rollcage manufacturer for more details regarding any corrective action necessary. A copy of any SFI standard can be obtained by contacting SFI directly at 858-451-8868 or follow the following link to order, https://sfifoundation.com/tractor-pulling/
A copy of NTPA Rollcage Mounting Standards can be obtained by contacting NTPA Technical Services.
Marvin Epperson
NTPA Director of Technical Services
317-852-0630
marvin@ntpapull.com
You can reach out to your chassis builder if needed: Here are three which have agreed to help in expediting this process for you and have the SFI 47.3 Spec in their possession.
TRB Machine | Zeeland, MI
todd@trbmachine.com
616-875-7673
GMS Manufacturing & Machine | Hamilton, OH
gmshiperformance@gmail.com
513-756-9900
Modern Machine & Tool | Van Buren, IN
modernmachineandtool@yahoo.com
765-934-3110
Examples of acceptable ways to fix the diagonal brace.
Examples of acceptable ways to fix the webbing.
Webbing must retain 65% material of the 1/4-inch X 3-inch flat bar when scalloping for weight; which means retaining 1-inch material at any edge.
