Rollcage rear leg position

[ducman]

I'm getting an 8 point cage put in next week but I'm unsure of the best position for the rear legs.
I have seen them go to the shock turret, the boot above the spring mounting point, top of the wheel arch and even base of the wheel arch.

Is there a consensus on the best position?

Any advice appreciated

[xxlbimmer]

I've built a few E30 cages. I find the shock tower (turret) would be the best, as many are using a 650 to 800 lb spring in the rear and having that reinforced would be best in my opinion. Just my 2 cents!

[Emre]

Check your rulebook. Without a doubt, tying the cage to the shock towers will give you a stiffer chassis. All else being equal, you'd certainly prefer to do so. However, many race classes specifically disallow extending the cage past the front and rear bulkheads.

Think of it this way: some race classes allow you to build a cage for safety purposes only; others allow you to design a cage that also increases performance. Make sure you know your class rules before proceeding!

[matt]

The rear shock towers are OK, not great. The rear spring perches are better (the front of the trunk floor behind the bulkhead).

[djjerme]

The cage in my Pro-3 car is tied to the bottom of the rear shock towers, but the plate they are tied to extend around the tower, to reenforce the whole rear sprung area. Hard to explain, but really stiffened the whole back half of the car.

[NigelStu]

Assuming you are still running springs in stock-location, directly above the upper spring perch. On the floor, just as Matt said.

Spring perch is where the majority of the forces are going from the suspension. And its a more robust area of the car for the cage to attach in case of a roll-over or other significant impact.