SoundGuyDave
This Space For Rent
- Joined
- Apr 9, 2007
- Posts
- 1,978
- Reaction score
- 28
Since this came up more than a couple times in the last few weeks, I thought I would post this up here:
From the NASA CCR, concerning HPDE technical requirements:
11.3 (section 2):
The driver and any passenger must utilize modern style stock seatbelts in very good condition, or a DOT approved restraint system, while operating a vehicle on the track. Lap belts used without any shoulder restraints are not permitted. Restraint system requirements are listed in Section #11.4.8. The only four-point belt systems that are allowed for use in HPDE / TT are 1) those that carry an “FIA B-xxx.T/98 certification, or 2) those that carry a label from the belt manufacturer stating that the belts meet Federal Motor Vehicle Safety Standard (FMVSS) 209 AND that the belts were designated for the specific vehicle (e.g. “For use only in BMW E36 models”). Such label must be easily visible to the NASA inspector. Note- four-point belt sets that have a DOT-only certification are not allowed.
---AND---
11.4.8 Seatbelts and Harnesses
The seatbelts should be in good condition. No damage may be present on the seatbelts and they must be the factory configuration. Any harness or any restraint system, other than factory stock, shall conform to CCR section #15.5*, in all respects except for the expiration regulations. Harnesses that are expired for racing may be used providing that they are in at least very good condition. The use of a lap belt without any shoulder restraint is not permitted. Passenger seatbelts must meet the same minimum requirements per the CCR as the driver seatbelts if being used by a passenger. Note-passenger equipment need not match the installed equipment on the driver’s side. See Section 11.3 for more about four point harnesses. Stock / OEM belts should not be worn with hard shell, fixed back racing seats. Those seats should have a racing harness.
* 15.5 from the Competition section: "The material of all straps should be in new or perfect condition. The buckles should be metal quick release. There should be a single point of release for all belts."
What does this boil down to?
1) Stock seats and belts are perfectly fine
2) If you replace the seat with a fixed-back racing seat, you should run harnesses. Note that "Should" and "May" are NOT the same as "Must" and "Will." That said, it really is a good idea!
3) 4-points are HEAVILY regulated! If it doesn't carry an FIA T/98 cert, or have a vehicle-specific FMVSS tag, they are NOT allowed.
My take on things (NOT official NASA policy):
4-points are (apparently) quite popular at Autocross events, however there is a very big difference between the potential for injury! The "worst case scenario" if you completely lose it at 50mph in a parking lot is nowhere NEAR what could happen at 130MPH on a road course. The potential for injury is MUCH greater (though this is still a vanishingly rare situation!), and as such, the safety game has to be stepped up.
In general, 4-points fail to adequately protect the wearer in high-speed (and thus high-load) crashes. The lap portion of a harness is designed to ride across the illiac crest of the pelvis, directing all the crash forces onto solid bone. In a 5-, 6-, or 7-point belt set, the "anti-submarine" portion of the harness is there to actively pull DOWN on that lap set, locking it in place across your pelvis. In a crash, as the belts stretch (and they do, as a function of their length), your torso WILL move forward, pulling UP on the lap belts. With a 4-point, there is nothing there at all to keep the buckle (and thus the lap belts themselves) from being pulled up off the pelvis and into the soft tissues of your abdomen. You know, liver, spleen, intestines, etc. These soft tissues are absolutely incapable of sustaining potentially massive crush forces without injury, in the way that the pelvis CAN. This tendency for a 4-point to "ride up" is further exacerbated by the amount of tension that you want in the shoulder portion of the harness.
The bottom line, at least for me, is to treat your safety package as a system. Stock seat, stock belts, airbags and a helmet? All good, nice and safe. Race seat, 6-point harness, no airbags and a helmet? All good, nice and safe, but even better if you have a HANS (or DefNder, or another SFI 38.1 compliant head-and-neck restraint). Some cobbled-together mix of the above? Not necessarily that safe.
NASA has these rules in place to foster safety. Period. For you folks that are contemplating doing the HPDE thing, I would just suggest keeping it stock. If you've gotten to the point where you're fast enough to need harnesses and seats to keep you in place, then you're also going fast enough to need to do it right from a safety standpoint!
"Let's be safe out there!"
From the NASA CCR, concerning HPDE technical requirements:
11.3 (section 2):
The driver and any passenger must utilize modern style stock seatbelts in very good condition, or a DOT approved restraint system, while operating a vehicle on the track. Lap belts used without any shoulder restraints are not permitted. Restraint system requirements are listed in Section #11.4.8. The only four-point belt systems that are allowed for use in HPDE / TT are 1) those that carry an “FIA B-xxx.T/98 certification, or 2) those that carry a label from the belt manufacturer stating that the belts meet Federal Motor Vehicle Safety Standard (FMVSS) 209 AND that the belts were designated for the specific vehicle (e.g. “For use only in BMW E36 models”). Such label must be easily visible to the NASA inspector. Note- four-point belt sets that have a DOT-only certification are not allowed.
---AND---
11.4.8 Seatbelts and Harnesses
The seatbelts should be in good condition. No damage may be present on the seatbelts and they must be the factory configuration. Any harness or any restraint system, other than factory stock, shall conform to CCR section #15.5*, in all respects except for the expiration regulations. Harnesses that are expired for racing may be used providing that they are in at least very good condition. The use of a lap belt without any shoulder restraint is not permitted. Passenger seatbelts must meet the same minimum requirements per the CCR as the driver seatbelts if being used by a passenger. Note-passenger equipment need not match the installed equipment on the driver’s side. See Section 11.3 for more about four point harnesses. Stock / OEM belts should not be worn with hard shell, fixed back racing seats. Those seats should have a racing harness.
* 15.5 from the Competition section: "The material of all straps should be in new or perfect condition. The buckles should be metal quick release. There should be a single point of release for all belts."
What does this boil down to?
1) Stock seats and belts are perfectly fine
2) If you replace the seat with a fixed-back racing seat, you should run harnesses. Note that "Should" and "May" are NOT the same as "Must" and "Will." That said, it really is a good idea!
3) 4-points are HEAVILY regulated! If it doesn't carry an FIA T/98 cert, or have a vehicle-specific FMVSS tag, they are NOT allowed.
My take on things (NOT official NASA policy):
4-points are (apparently) quite popular at Autocross events, however there is a very big difference between the potential for injury! The "worst case scenario" if you completely lose it at 50mph in a parking lot is nowhere NEAR what could happen at 130MPH on a road course. The potential for injury is MUCH greater (though this is still a vanishingly rare situation!), and as such, the safety game has to be stepped up.
In general, 4-points fail to adequately protect the wearer in high-speed (and thus high-load) crashes. The lap portion of a harness is designed to ride across the illiac crest of the pelvis, directing all the crash forces onto solid bone. In a 5-, 6-, or 7-point belt set, the "anti-submarine" portion of the harness is there to actively pull DOWN on that lap set, locking it in place across your pelvis. In a crash, as the belts stretch (and they do, as a function of their length), your torso WILL move forward, pulling UP on the lap belts. With a 4-point, there is nothing there at all to keep the buckle (and thus the lap belts themselves) from being pulled up off the pelvis and into the soft tissues of your abdomen. You know, liver, spleen, intestines, etc. These soft tissues are absolutely incapable of sustaining potentially massive crush forces without injury, in the way that the pelvis CAN. This tendency for a 4-point to "ride up" is further exacerbated by the amount of tension that you want in the shoulder portion of the harness.
The bottom line, at least for me, is to treat your safety package as a system. Stock seat, stock belts, airbags and a helmet? All good, nice and safe. Race seat, 6-point harness, no airbags and a helmet? All good, nice and safe, but even better if you have a HANS (or DefNder, or another SFI 38.1 compliant head-and-neck restraint). Some cobbled-together mix of the above? Not necessarily that safe.
NASA has these rules in place to foster safety. Period. For you folks that are contemplating doing the HPDE thing, I would just suggest keeping it stock. If you've gotten to the point where you're fast enough to need harnesses and seats to keep you in place, then you're also going fast enough to need to do it right from a safety standpoint!
"Let's be safe out there!"
Last edited:
