Porsche 944 Bolt-In Cage Legality

[CrookedRacer]

Hi,

 

I have a porsche 944 that I'd like to use for a NASA comp licensing school and eventual GTS-1 racing.

 

It has an autopower bolt-in cage with two glaring issues:

 

1) It lacks a second driver door bar.

2) The current shoulder harness bar does not intersect the main hoop diagonal.

 

When the car was going to be simply for DE events, I upgraded the seats and harnesses to current FIA spec. While I was at it, I realized I had to correct the shoulder harness departure angle on the very tall seats (I'm 6'-4"). To do this, I welded in a bar to the backstay bars at the optimal height.

 

Unfortunately, the new bar doesn't conform to the GCR. But I am unsure of the reasons behind the GCR. The original shoulder bar is still there, and it DOES intersect the main hoop diagonal, in compliance with the rules. I'm just not using it for the straps.

 

Anyway, I'm going to see about correcting the driver door bar situation. That's the easy one.

 

 

I'm open to ideas for what to do about the second issue. Is this a "waiverable" thing? Could I add a bar to tie it back into the diagonal? Do I have to cut off the new (and old) harness bars and start from scratch?

 

 

 

LOTS of background on how I got to where I am on this:

My Grassroots Motorsports Build Thread

 

Thanks for your input!

[Ev]

My read of the rules is it would need to intersect with the diagonal if you want to attach the shoulder straps to it. I don't think you would have to remove the current bar unless it's interfering with the replacement harness bar, but I am not a tech person, and I didn't stay at a Holiday Inn last night.

[Calif_Kid]

For the harness bar, maybe take a look at shoulder belt routing at page 12 to 13 of https://www.schrothracing.com/docs/Competition_Instructions.pdf. It looks like they're recommending the harness belts to be level going back from the seat to the harness bar, or downward to a max of 20 degrees. There are also suggestions on the length from the seat back to the harness bar. I took a quick glance at your build story, and it looks like that the belts are running roughly level from the new seat backs to the new bar, but what would be the angle if the original bar was used?

 

On my car, I'm also using some 'limiters' (shaft collars) to keep the harness belts from sliding out too far - picture is on pg 18 of the Schroth article. - Jim

[t500hps]

Is a bolt in cage legal????

 

I saw the aftermath of a bad wreck where 2 cars tumbled into the trees (weird circumstances). The car with a welded in cage looked pretty good while the other car had a bolt in and while the driver was fine......he visited the hospital first. Big difference in strength of the 2.

[Ev]

Is a bolt in cage legal????

 

I saw the aftermath of a bad wreck where 2 cars tumbled into the trees (weird circumstances). The car with a welded in cage looked pretty good while the other car had a bolt in and while the driver was fine......he visited the hospital first. Big difference in strength of the 2.

If you're referring to the wreck at the Hyperfest a couple of years ago, the impact mechanism was very different for each of those cars. No comparison.

[t500hps]

Is a bolt in cage legal????

 

I saw the aftermath of a bad wreck where 2 cars tumbled into the trees (weird circumstances). The car with a welded in cage looked pretty good while the other car had a bolt in and while the driver was fine......he visited the hospital first. Big difference in strength of the 2.

If you're referring to the wreck at the Hyperfest a couple of years ago, the impact mechanism was very different for each of those cars. No comparison.

I am. I saw them the next day.........you got up close and personal with those cars and obviously know alot more than I would.

[CrookedRacer]

Thanks for your responses!

 

If you check back on the build thread I linked to in the first post, you will see what I ended up doing with my cage to make it legal and mo betta.

 

So much fun! So much more to do!