Building new chassis

[ducky45356]

I’m in the process of building a new 2.4c chassis. The sfi book show one single 1.00x.058 bar from cross bar behind rear end going to lower main chassis bar.  This is where seat pan will rest.  My question is can I put in two tubes here or is sfi book all that is allowed

[rooman]

As with anything SFI, the specs are the minimum required so additional tubing (or diameter/wall thickness) is allowed. That said, "some's good, more is better" is not necessarily a good thing if you get TOO carried away with bigger diameters and heavier wall tubing as all that adds is weight and stiffness.

Roo

[wideopen231]

Not big surprise here .Roo man is right.

.Stiffness can be good until chassis will not work with power level you are running. We had two diagonals added to chassis(misunderstanding of new rule) DNQ'd 1st race(normally top 4 car) and was NOt qualified at second race after Q3. Got pissed and cut bars,sounded like tuning fork. Q4 shut off early and qualified #2. Lesson learned. Have seen lots of alky guys running TF chassis cars and never seen them work very good.

[ducky45356]

Thank you for the info. Just trying to make sure it certs first time thru.