In relation to your cage, it sounds as though you could add quite a few additional mounting points that would tie the cage into the chassis further - along with quite easily adding extra tubing that would link the front box into it.
Sounds as though you have the rear stays and floor hoops already (making 6 points), there was a cross brace that ran from left to right across the main hoop (meant to go across just above the tunnel) and you can tab off it and tie into the bulkhead body mounts that are on the top of the chassis at the start of the “V”(or put something a little more substantial for them to tie into there).
There is a petty bar that runs from the top of the main hoop (on your passenger side of the tunnel) and bolts into the inner seatbelt mount on the chassis at floor level (diagonally projecting down and forwards).
Assuming you have the roof bars that run over the doors and down the A pillars to the floor bars? If so, do you have the dash brace that runs across the car (steering column can mount to this to give you an idea of its height) - this can be tied into the body mounts on top of the tunnel in front of the gear stick.
You can also use the dash brace and forward legs of the bars that run over the doors to tie into the outer ends of the front box on the chassis (works Esprit cages did this) - added benefit is you gain an anti intrusion to the footwell should a front wheel be hit hard etc AND you can reduce flex where the front box joins the backbone….
Hope this helps with what you already have - pretty sure I’ve covered all of the mounts I have on my Banks cage… you could also put a cross between the two rear stays over the top of the engine (also done on the Works Esprit’s)
Hi JR,
my roll cage pretty much loks like the attached photo of a banks cage built up on a yard. The 2nd photo shows my actual main hoop installed inside the car.
I will try and run the exisiting roll cage as long as the FIA allows it, maybe with some minor modifications/additions. Your suggestions are right. There is a lot of room for improvement on my current roll cage situation. When the safety regulations will change, I'll go to a company, which builds customized roll cages with FIA certification. I will show them the best ideas of the Banks and Jensen cages and then I hope, that they will calculate and construct the best possible solution for safety and stiffness.
I hope, that the necessity to replace the roll cage will come in several years time and not too soon. This will be a quite costly thing. And if possible, I'd like to replace my original (and quite abused) chassis with a space frame from Spyder Cars or Banks. That's my dream, but it will take some years to reach it.
Before that, I'd like to do some actual racing and not only modifying the car. Since I re-started this racing project, it's been two years now. During that period, I just drove 2,5 hours and about 210 km on track. If this year works out as planned, I could add another 9 or 10 hours and 1000 - 1200 km of pure track driving between April and October 2022. That would be great.
Hey Mecky,
You certainly have done a lot race prep to your car. I think the real question is do you really need all that frame protruding past your last transmission cross member. You already have a cross member from the shock mounts and a lower cross member on the transaxle. I would say cut it all off back there like they did with Lotus 47 and save some weight. Spoken from the cheap seats on the side lines.
Cheers,
Ross
Hi Ross,
my car is in its present form somewhat around 50 kg shy of the minimum weight in my class. I had to bolt the difference as ballast (lead and steel plates) into the passenger foot area to the floor of the car. That's why 3 kg additional weight is no big deal for me. I can just take a little bit of the ballast out.
But what I noticed and what made me think about my above shown mod is the following: When I lift the car with a jack underneath the gearbox mounting cross member, the ends of the Y-section of the chassis spread by about 3 - 5 mm in comparison to when the car is stationary on its wheels. I guess, that the flex could be even higher under cornering load.
I hope that the additional cross member doesn't remove the sweet-tempered and predictable characteristics of the car's oversteer.
