NASCAR Moves Harness Mounts from Roll Cage to Seat

[Mystic_Cobra]

I just saw a video talking about the Austin Dillon wreck at Daytona last July where he was caught by the catch fence. They said NASCAR's change to move harness mounts from roll cage to seat likely prevented serious injury.

 

Is there any discussion regarding a similar change in the NASA CCR?

[Mystic_Cobra]

Dillon's wreck in case you missed it:

 

Article on the change:

http://www.nascar.com/en_us/news-med...ytona-500.html

 

quote:

Harnesses will no longer be mounted to points on the car body (chassis) and will no longer pass through an opening in the seat between a driver’s legs.

 

Patalak said the harness change was “an incremental step in safety improvement.”

 

“We’re not addressing a particular problem or issue but it brings just overall improvements and optimization of the seatbelts and seats for the driver,” he said. “When we look at issues like that, that’s just part of the continued march forward on making things safer.

 

“There are other situations that require immediate attention. We just have to evaluate each of those different situations as they come up and present themselves.

 

“We can put the bolts that hold the seat belts in the seat … exactly where they need to be for optimal performance of the restraint system.”

 

Because car builds may differ slightly, not all belts had been attached in exactly the same spot. “So you have to move an inch here or an inch there,” he said. “By bringing all of that inside the seat, we no longer have to work around those parts and pieces. We’re down to the level now that we’re trying to tune the restraint system literally fractions of an inch for small gains.”

 

That also eliminates the concern of hardware from the harness becoming stuck or cut by sharp edges. And it allows safety workers to remove the seat and driver as a single unit should it become necessary following a crash.

 

“If the seat belts attach to the chassis we can’t move the seat and driver (simultaneously) because we’re rigidly fixed to the vehicle,” Patalak said. “If we bring all of the seat belts inside the seat, then we can move those things as a unit if we ever were to find that necessary.”

[kbrew8991]

It may be a tougher thing to properly do using a production street car tub and all that to achieve a similar level of protection.

[takjak2]

It may be a tougher thing to properly do using a production street car tub and all that to achieve a similar level of protection.

 

It sounds like the whole point is to make the driver safety as contained as possible, so it should be easier.

 

Sounds expensive.

[mcmmotorsports]

For the record, their seats are around $15k.

[Ev]

For the record, their seats are around $15k.

Odd, I am finding SFI 39.1 seats for around 2K...

[mcmmotorsports]

For the record, their seats are around $15k.

Odd, I am finding SFI 39.1 seats for around 2K...

True, but the seats used by the top teams, for the most part, are supplied by Hendrick Motorsports and are custom built Carbon Fiber units that are a bit more than $2k.

I am sure the seat Austin was using was similar to that.

[Ev]

For the record, their seats are around $15k.

Odd, I am finding SFI 39.1 seats for around 2K...

True, but the seats used by the top teams, for the most part, are supplied by Hendrick Motorsports and are custom built Carbon Fiber units that are a bit more than $2k.

I am sure the seat Austin was using was similar to that.

Any idea who makes them? They are required to be Sfi certified so their must be some info somewhere.

[mcmmotorsports]

Any idea who makes them? They are required to be Sfi certified so their must be some info somewhere.

 

The Hendrick seats are made by Hendrick. I know the aluminum ones, ButlerBuilt is the major supplier of SFI 39.1 seats. I believe the Kirkey SFI 39.1 seats are only allowed in the lower NASCAR top tier series: Mexico, K&N and Camping World Truck series

[kbrew8991]

For the record, their seats are around $15k.

and they're attached to something more solid than the floorpan of a half-rusty 1988 Honda Civic.

[DavidNJ]

This will show you many SFI 39.1 seats: http://circletrackwarehouse.com/?page_id=317

 

The belts are mounted to the seat to both shorten their length and therefore their elongation and to ensure they move with the seat and don't hurt the driver.

 

SFI has belt mounting instructions: http://www.sfifoundation.com/wp-content/pdfs/guidelines-bulletins/Seatbelt%20Installation%20Guide%2006-05-12.pdf

 

Schroth has a great presentation on them: http://www.trackhq.com/forums/attachments/f195/3562d1305232920-questions-proper-harness-bolt-points-imis-guide-seatbelt-installation.pdf

 

Note that the current standard is a 7-pt or 9-pt harness. The crotch belt mounts under the driver to the seat; its purpose to prevent submarining under the belts. The 7th is the old single crotch belt now called a negative-g belt; its job is to hold the belts when the car flips.

 

The 9-pt has double shoulder harnesses. Current HANS compatible shoulder harnesses are dogbones, 2" over most of their length and 3" at the bottom. The 9-pt has 3" shoulder harnesses and a separate 2" belt that goes over them. The HANS device (now called a Frontal Head Restraint, FHR) goes over the 3" belt and under the 2" belt.

 

Note that any containment seat needs to have the upper back of the seat connected to the roll cage. As a result, there isn't that much difference with having the shoulder harness on the roll bar as long as it is reasonably close (say 4") to the seat.

 

The new crotch belt standard is under the drive and to the seat. The lap belts and negative-g belt are the bigger issue as they need to be on the same cage/frame member as the seat.