Jim bailey - 928 International

Mark just imagine Laguna Seca with no walls, steep slopes 100s of feet long, trees and huge boulders 10 feet off the racing line... you need a survival cell yet letting the front end crush is a good thing but you know that from when you hit the wall !

Carl Fausett

Ths SCCA mostly. Removable braces are allowed in the rear braces of a 4-point cage, and the GCR shows acceptable methods of detaching/attaching them, but you may not have a removable brace across the door, they said.

If doing a SCCA Autocross (Solo 1) event, you will not have a problem. But for Wheel-to-wheel and I think maybe Solo II events, they will pitch a fit.

Race preparations always begin with an examination of the rules first. Decide where you are going to race/drive/compete, get their rule book and read it. Saves a lot of money and headaches.

We read the Pike's Peak rules (of course) but also the PCA Club Racing rules and the SCCA Nationals rules so that the cage would be permitted no matter where I decide to go between these 3 venues.

Carl Fausett

Tubing thickness required is specified by the Rules Committee, and varys based on the weight of the vehicle.

In our case, figuring a finished weight of 2800 pounds, we could use:

1010, 1020, 1025 DOM mild steel
1.50" dia if .120 wall; 1.625" dia if .120 wall; or 1.75" dia if .095 wall

4130 Chrome Moly DOM
1.50" dia and .095 wall

This last one is the one we used.

I even found a race sanctioning body that allowed Alluminum 6061 roll cages.
The walls were pretty thiick.

John Veninger

Section 18 is the cage rules for SCCA
http://www.scca.com/_FileLibrary/File/GCR2006.pdf

Drewster67

Anyone have a bolt in cage 4 sale? My shark will never see SCCA racing just ASA and NASA - Anyone have a bolt in cage that meets ASA/NASA specs? IF so, please send me a PM

TIA

Nicole

I remember seeing this while it was fabricated at DEVEK. Hope you will never need it - and if you do, that it will protect you as designed.

Fastest928

CrMo if you want to prevent intrusion, downside is during a impact, it generally will scramble your insides. i think this is the best for track usage where there are fewer walls to hit.

1020 "bends" and thus absorbs energy, unlike CrMo which translates energy, and thus is gentler on the body.

After witnessing two crashes in which cars rolled on the high desert for almost a mile, the Corm driver had considerable internal damage, the mustang that was going over 200, went airborne for 20-30 feet, and rolled for almost .6mile, walked away with a broken leg and arm.

BC

So, really, he didn't actually WALK away. It was probably more of a Dragging along the ground.

Carl Fausett

Marc is right about the energy-absorbing effect of mild steel tubing as it deforms.

But I think your two-crash comparison is over-broad. There is a lot more that went on between those two cars and those two crashes - the angle of impact, the design of the interior, the location of tubes (like the popular knee-cap-high cross-tube I see so many of), the location and number of gussets in the cage, the difference in the cars and their factory frames... just to name a few.

We choose CrMo because its lighter. And, because its stronger, we can run a 1.5 inch tube near the driver's ribs and head instead of a 2" tube. Greater clearance before the driver gets his ribs and helmet boinked.

EspenT

This is our brand new rollcage. It's been designed to satisfy safty regulations in as many competitions as possible.
It's welded to the inside of the car a lot of places, and also weights only 45kg's

Carl Fausett

Espen - somebody really takes pride in their work! That is a beautiful cage, and the gussets are awesome.

If your welder is still availabe - stregthen those front swaybar mounts now before they crack and break.

I have a short article about that here:
http://www.928m.com/install.html

The one I am refering to is entitles "Sway Bar Mount Reinforcement"

Beautiful roll cage and paint job.

adrian928se

Here is a pic of the one in my GTS race car - fully welded.
Adrian

Fastest928

Espen
Where is the seat back horizontal bar where harnesses attach?

Awesome work!

Best

EspenT

There are 1 short bar at each side in the rear for the harnesses.

Thanks for all the posetive coments.

John Veninger

You may want to consider moving them closer to the seats. Long harness straps will cause excessive stretch.