To share some of the FC related information for the car we're building into a dedicated, stripped, track car.

We bolted the rear of the car to the concrete and measured the torsional stiffness to get a baseline reading.
The baseline reading was 3031 nm with the car completely gutted.

We then fabricated a rollbar and harness bar and welded it into the car and re-measured
The updated measurement was 4480nm, an increase of almost 50% rigidity.

We measured using various weights up to 360lbs total. It was a fun experiment, and gives us an idea of how much, or little, chassis flex we'll be working with once we get the car fully assembled.

 

 

Non sunroof car, unsure on mileage. There was minor damage to passenger front. You can see the new support pieces in black in the first picture.

I had the same thought about how much more a cage would provide, but we have no intentions of adding one at this time.

 

This truly is an interesting thread, but I'm going to close it since it's a repost.

FC Chassis Torsional Stiffness (With Numbers)

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