Chassis strengthening

[e240]

Have you confirmed the racing activities you want to do? and checked the regs for the cages they allow?

IPRA does not allow cages to protrude from the cabin and link the towers.

just a thought.

Just an update on this front, I've got a cage design sorted in Chromoly and there is a possibility the car could be going in next week to start the work. Otherwise, it will be a couple of weeks before they can fit me in. Look forward to seeing the difference a tower to tower bird cage makes :-)

[Slaz]

Yeah whilst its a better option strenght wise, as e240 says, might wanna check race class reg's if thats what u intend on doing?

[STiR]

Fair point, the car is actually a daily driven street car. I will only ever use it for club sprint events, john bowe high performance driver training days etc. where there is no necessity for a roll cage. The cage is for my own safety, and for superior chassis rigidity. It's part of my take on Porsche's RS concept... drive to the track, on the track, and back home again...then to uni the next day!

[rpm boy]

Fair point, the car is actually a daily driven street car. I will only ever use it for club sprint events, john bowe high performance driver training days etc. where there is no necessity for a roll cage. The cage is for my own safety, and for superior chassis rigidity. It's part of my take on Porsche's RS concept... drive to the track, on the track, and back home again...then to uni the next day!

Big money for a everyday + track car... whats the chassis welding costing you alone???

[SPEEDCORE]

I've never understood why in 3J (don't know about other CAMS sanctioned catagories) that they can't go through the firewall and onto the shock towers with a good plate/box design.

Cage on the street I am always a fence sitter when it comes to this... on one hand (depending who builds and signs off the cage) you have the chance to have a track car that does not have the hassle and expense of tow car and trailer.

On the other.... you have the safety issue of driving with steel pipe very close to your noggin. Some gusseting I have seen comes awefully close to where your head would be. As for the whole "but you cover it with foam"..... have someone swing one of those foam covered baseball bats at your head.

Sure it might stop you splitting your head open.... but the impact is still there IMO.

[bennjamin]

just a thought....id hate to be inside a car with a full or semi roll cage , in a normal everyday road accident. Rather be in a car that crumples and absorbs the impact rather than be violently thrown around and perhaps into more trouble

[beeza]

True true true benny.

[Benson]

Fair point, the car is actually a daily driven street car. I will only ever use it for club sprint events, john bowe high performance driver training days etc. where there is no necessity for a roll cage. The cage is for my own safety, and for superior chassis rigidity. It's part of my take on Porsche's RS concept... drive to the track, on the track, and back home again...then to uni the next day!

For this instance, get any cage.. Cusco or custom bolt-in. Dont get welded in case you want to remove the cage.

Nice concept

[STiR]

Number of points mentioned, most valid. The cage is being built with safety in mind, this also relates to occupant safety on the road. The b-pillar roll-over hoop will be placed rearward of the b-pillar but will be tagged, as an example. The cage is being done by Fabraications, and they will ensure all members are as far away from occupants as possible. No bars near the head for sure...

As for safety in the case of an impact, there are a number of things to remember. The crumple zones front and rear of the car will not be affected. The cage is designed to stop the zone in which the occupants are from crumpling, which is of course desired. Forward and rearward of the strut towers the car will be unaffected. Hopefully the side-intrusion safety will be significantly improved.

Still, as safety is very important, I have a fixed bucket seat and will be using a harness. As you will see in race cars, the key is to limit the movement of the occupants in the event of an impact. The passenger seat is an EVO RECARO which has much more lateral support than the factory seat ever did...

With regards to having a bolt-in cage, there are a number of disadvantages. None of them offer the same protection, and none of them offer any rear advantage in chassis rigidity. With the weld-in, you have both, and they are cheaper to fabricate too.

Also in terms of weight, I was told the cage would weigh around 40kg in cold-drawn mild steel, and around 20-25kg in Chromoly (my preference). I believe much of this weight can be offset by gutting the doors (removal of heavy steel bars and drilling to remove excess material). Also investigating carbon doors, if i can get some at a good price. I think I might be able to completely offset the weight of the cage using carbon doors!

I think you guys will like the car when it's complete

[STiR]

Here's a pic showing a very similar cage design:


And a picture of what the door will look like (will have a pretty aluminum sheet over it, plus manual window winder and door handle and lock will be retained (not very heavy at all).

[e240]

Thats pretty Hard core. I compete in the NSW Supersprint Championships and like you, the reason for having a cage in for safety. I've at this point opted for a 1/2 cage per recommended designs in the CAMS manual but as I have more or less decided this car may be converted to a full on track car in the future, I'm not concerned about restoring the car back to original.

Its also made out of mild steel so as to avoid future homologation problems.




Note: From your picture, see his uncovered battery and fuel surge tank? Thats actually not CAMS approved in any form of racing in AU.

[STiR]

Good looking cage there. Yep, aware that the surge tank set up should be covered. I don't have anything like that though. I will be having my battery relocated to the same position (behind the passenger seat), however it will be in a nicely fabricated battery box. This is to allow for A-pillar member to be extended through the firewall to the front left shock tower.