Roll cage modification

[wondersparrow]

Hello everyone,

 

Well, things are going well in reviving my track beast. There is one problem, I hate where the seat is. I would like to move the seat back about 3", but the bar that the belts are attached to is in the way. I will cut it out some time this week, I would just like to know what the experienced HybridZ crowd would suggest.

 

The two options I have been toying with are...

1- replace the current straight bar with a curved one that allows the seat to move further back.

2- add in a bar to the rear hoops (that go back into the hatch) that goes the entire width of the car.

 

Option 2 is attractive because it would allow for passenger side belts to be installed. As I am new to racing, it might be handy to have a passenger seat for instructors, etc.

 

The problem with option 2 is to get the bar to sit low enough (so that the belts are near 90 deg to my shoulders) it needs to be so far back that the belts would be super long. I dont know if there are concerns if the belts have an angle much more than 90 deg and the rules are kinda vague.

 

I am pretty sure that using the strut tower bar is not an option.

 

Let me know what you guys think.

 

 

 

More images available at http://www.pictures.meech.ca/v/sparkys_240Z/

 

let me know if a different viewing angle would help.

[Lukaniuk]

I've seen some pictures where the harnesses are attached to the strut tower bar. I have no idea if its against regs, or even strong enough. I just know that I've seen it a few times.

[johnc]

Here are the best race harness mounting instructions available:

 

http://www.schrothracing.com/docs/Competition_Instructions.pdf

 

In general you want the shoulder harnesses no longer then 18" from mounting point to shoulder and level with or no more then 20 degrees below the top of the shoulders.

[wondersparrow]

Thanks John, thats a fantastic read.

 

Here is what I have come up with. On both sides of the car, run a piece of tube down from the rear stays to the main hoop (somewhat parallel to the side of the car). and then between those two tubes, run a tube the width of the car. That should allow the belt angle to not be too steep or far away.

 

If anyone thinks that is a terrible idea or has a better one, let me know.

[slyhog22056]

Why not try this remove the bar completely running from side to side and replace it with a bar running from top hoop outside corner and cross it to end up at the rear floorpan just in front of the taillight assembly, run a different bar across the top of the rear shock towers BOLTED on, not welded, hook your harness to the strut bar. mine is done like that and i can move my seat all the way back to within 3" of the rise behind the seat. welding in of strut bars isnt allowed in every kind of regulated racing i have been in, autocross, scca, and most every drag racing event i have entered. it doesnt have to encircle the strut, bolt 3" x 5" x 1/4" plates just outside where the struts are (where the old shoulder harness was) and use a weld 90 to rise up about 2" and run the bar across to the other side, kinda like an upside down "U" I used 1 1/2" schedule 40 erw pipe for my entire rollcage, which measures 1 7/8" OD which is good for cars up to 3000 lbs by most rules.

[wondersparrow]

Well that strut bar is welded in, and it has been raced before. I would have to check, but I am pretty sure that there is some specific rule about using a strut bar for the harness.