GSpeed Bolt-in Roll Bar

[kster1]

Originally Posted by MaximeT

What's your position guys related to using a 6 point harness, no helmet and oem airbag on the road ?

I don't care at all about it being legal. Just the safety side.

It's pretty hard to find an answer so far.

I'm no expert in this area but keep in mind that OEM belts are designed to stretch during an impact to help absorb the energy. A 6 pt harness on the other hand will remain much more rigid. This comes into play during a collision; with a 6 pt harness, I'd be concerned about a neck injury without some type of HANS device (the torso will be stopped with the stiff belts but the head continues moving forward).

[MaximeT]

Originally Posted by kster1

I'm no expert in this area but keep in mind that OEM belts are designed to stretch during an impact to help absorb the energy. A 6 pt harness on the other hand will remain much more rigid. This comes into play during a collision; with a 6 pt harness, I'd be concerned about a neck injury without some type of HANS device (the torso will be stopped with the stiff belts but the head continues moving forward).

Yes that's my concern. On the other end, HANS are supposed to help with helmet weight and head weight. (Not head weight only).

But head weight must be the most part.

But drivers survived some amazing crashes before HANS device too. (It's even better with HANS)

[MaximeT]

Ok, I just found my answer.

It's possible to use Schroth ASM 4 point harness (with 5 and 6th point added).
You can add HANS at the track.

You can drive with no helmet and a road legal and safe 6 points harness. (torso mouvement and road legal harness release included)

[GSpeed]

Sorry I missed this conversation over the weekend, but it seems like you guys have it pretty well figured out. This roll bar is designed (and recommended) to work with 6-point harnesses and no air bags, however we're also keeping in mind the likely use case and are designing it to be as safe as possible in an otherwise stock car. That means keeping the roll hoop as far as possible from the driver's head, etc.

Here's a picture of the almost stock car we're using to design this roll bar. We're using what we learned putting the cage in ours, but this car has a full interior, and we'll be keeping as much of that as possible.



Thanks for all the interest, it's very encouraging.

[GSpeed]

Main hoop is bent and placed, now we're finalizing rear brace location. The goal is to maximize space and minimize modifications to the interior. Seems like the vast majority of you would rather have the rear seats in place, even if they're not still useful. I know I would, just for aesthetic purposes.

Jake

[GSpeed]

Landing plates are done, framing up the rear support bars. The tape shows where the harness bar will run, placing it that far back keeps the harness in the 0°-20° below horizontal range harness manufacturers recommend. That angle is especially important when using a HANS device.

We'll add the diagonal bar next. Once it's framed up, we'll be adding some bolted joints (machined interlocking joints, not a sleeve or anything like that) so that it can pack flat for shipping. It's not necessary to get the assembly in or out of the car, but the additional manufacturing costs will be negated by the reduced shipping cost. Shipping these things everywhere on a pallet via freight will get real expensive compared to a large cardboard box UPS can deliver.

Jake

[Brzzee]

Originally Posted by GSpeed

Main hoop is bent and placed, now we're finalizing rear brace location. The goal is to maximize space and minimize modifications to the interior. Seems like the vast majority of you would rather have the rear seats in place, even if they're not still useful. I know I would, just for aesthetic purposes.

Jake

Street touring class requires a full interior so the SCCA rules set drive the requirement for me. Guessing other racing venues dictate full interior too.

Since I use the car on the street and carry the ocasional oversized item, I will need to keep the rear seat folded since the harness bar's location looks to block folding the seat's back to the horizontal. Perhaps the rear support tubes block the seat's movement too. Can't tell from the images. If this is the case then one must specify seat back up or down before the roll bar is installed.

Alternatively, the harness bar might be designed to be removed (i.e. Bolted where it connects to the support tubes and the tubes themselves do not also block) when not needed. If the HB is welded in place then some disassembly and partial removal of the roll bar would be needed to change the position of the seat back.

Like how closely the loop fits the b pillar and roof line. Craftsmanship on display!

[GSpeed]

Originally Posted by Brzzee

Street touring class requires a full interior so the SCCA rules set drive the requirement for me. Guessing other racing venues dictate full interior too.

Since I use the car on the street and carry the ocasional oversized item, I will need to keep the rear seat folded since the harness bar's location looks to block folding the seat's back to the horizontal. Perhaps the rear support tubes block the seat's movement too. Can't tell from the images. If this is the case then one must specify seat back up or down before the roll bar is installed.

Alternatively, the harness bar might be designed to be removed (i.e. Bolted where it connects to the support tubes and the tubes themselves do not also block) when not needed. If the HB is welded in place then some disassembly and partial removal of the roll bar would be needed to change the position of the seat back.

Like how closely the loop fits the b pillar and roof line. Craftsmanship on display!

This customer needs a full interior for Autocross classing as well.

It actually looks possible to remove the seat back with the bar in place. We'll confirm once it's done, but it looks like you'll be able to take the seat bottoms out, unbolt the bottom hinge (two bolts), then release the top latch and the seat back will slide out the bottom.

Jake

[Brzzee]

Originally Posted by GSpeed

This customer needs a full interior for Autocross classing as well.

It actually looks possible to remove the seat back with the bar in place. We'll confirm once it's done, but it looks like you'll be able to take the seat bottoms out, unbolt the bottom hinge (two bolts), then release the top latch and the seat back will slide out the bottom.

Jake

Sorry for any confusion. I'm "this customer", Tom.

Thanks for the clarification on reconfiguring the seat back.

Happy, Safe and Fast Fun Labor Day weekend.

[GSpeed]

Originally Posted by Brzzee

Sorry for any confusion. I'm "this customer", Tom.

Thanks for the clarification on reconfiguring the seat back.

Happy, Safe and Fast Fun Labor Day weekend.

Ha, of course! Sorry Tom, hard to keep screen names and real names straight sometimes! Glad you're happy with the progress, then, since it's your car.

Jake

[Brzzee]

Just confirming we're using DOM at 0.120 for the prototype roll bar.

[GSpeed]

Originally Posted by Brzzee

Just confirming we're using DOM at 0.120 for the prototype roll bar.

Tom,

I show in my notes we talked about using 1.5x0.120" or 1.75x0.095" DOM. Based off our tooling, we decided to go with the 1.75" x 0.095" DOM tubing on this prototype bar, and the production bars.

Jake

[GSpeed]

Update- yes, the rear seats can come out without removing the rollbar. Unbolt the bottom mount, undo the top latch, and they'll squeeze out the bottom.

[MaximeT]

I like it.

Do you think packaging for international shipping will be an issue ?