Technical - Sorta: Roll cage design
 

So another thread went a little OT with roll cage design. Let's see some of your previous/current cages for your race car(s) and design design pros and cons of what we see. :)

Also, let's use this thread to discuss FRS/BRZ specific rollcage design information. :thumbup:

And I'll start, here's the chump car cage:


http://www.itrexpo.com/users/dave/chump/IMG_0451.jpg
http://www.itrexpo.com/users/dave/chump/IMG_0452.jpg
http://www.itrexpo.com/users/dave/chump/IMG_0453.jpg
http://www.itrexpo.com/users/dave/chump/IMG_0454.jpg
http://www.itrexpo.com/users/dave/chump/IMG_0456.jpg
http://www.itrexpo.com/users/dave/chump/IMG_0457.jpg
http://www.itrexpo.com/users/dave/chump/IMG_0458.jpg
http://www.itrexpo.com/users/dave/chump/IMG_0459.jpg
http://www.itrexpo.com/users/dave/chump/IMG_0460.jpg
http://www.itrexpo.com/users/dave/chump/IMG_0461.jpg
http://www.itrexpo.com/users/dave/chump/IMG_0462.jpg
http://www.itrexpo.com/users/dave/chump/IMG_0463.jpg
http://www.itrexpo.com/users/dave/chump/IMG_0465.jpg


Cage was built to meet LeMons, ChumpCar, SCCA and NASA requirements (ie, built to the strongest requirements of each). Seat is mounted to the cage, not the car, and uses a slider system with reinforced pins to allow for adjustment. This car is used for 7-24 hour long races so adjustable was desired to allow different driver sizes, not that we ever actually adjust it...

Thoughts on the design?

FWIW, wasn't the FRS/BRZ dash designed in such a way that it didn't require cutting to install a roll cage? I recall reading that in some of the media during launch.

You definately have to cut if you want the bars forward as much as possible.. if you like Cusco death cages (or any bolt in cage) you'll have to live with the bars in front of the dash.

cage design is highly dependant on two things:

1: The race series you plan on racing with requirements
2: The inherent strength-stiffness of the body

Many cars have fairly weak bodies....Many M3's that I race with break all kinds of body parts due to the chassis flex at high G loads....Mustangs are really poor in this area too.....

I don't know how strong-weak the FRS-BRZ platform is, but I would guess its on the weaker end of the spectrum given its light weight.....

If you have a less stiff bodied platform then you build extra reinforcements into the cage to stiffen it up....and pretty much all touring car based racers have cages designed to increase stiffness......

The advantage to a stiff body is using a lighter cage to save overall weight, but of course the stronger body probably is heavier to start with....

A simple test is jacking up 1 front or rear wheel..... when the wheel you are lifting comes off the ground, how close is the opposite side wheel (if there was no droop)....really stiff cars can lift the wheels from the OTHER end....