roll bar design
05-07-09, 12:13 PM
#1
skookum
Thread Starter
iTrader: (3)
Join Date: Jul 2007
Location: Fishersville, VA
Posts: 335
Likes: 0
Received 0 Likes
on
0 Posts
roll bar design
Alright so quick background. Just happened to make good friends with a old drag racer who still happens to have all his tools and still does all his own work on custom nhra drag bikes. He builds frames from scratch for cars and for motorcycles and has a mandrel bender and welder obviously, and he has offered his assitance in any fab projects I may start. well reading in a fd race setup thread someone brought up how our fc's have weak chasis that can be fixed by installing a rollcage.
So my s5 is not a dedicated race car and more than likely never will be. I auto-x and used to do the drifting thing and may one day get back into it when funds open back up (which is just about very fc owners excuse), and its really isnt a DD but more of a weekend warrior with hopes of doing pdx events and time attacks. So i want this cage/bar to be a bolt in affair with fairly minimal cutting of interior incase i decide to go elsewhere with the car.
SO the real question is are the standard autopower mounting points for their rollbars (4 point street not full cage) optimal. Are there any improvements anyone would make upon this. and really is there benefits to be had with just the roll bar in the rear or would i really need to extend it to the front?
Really its obvious i new to the idea of this and i am looking for pointers in design,contact points, harness bar design for proper mounting, and camera mount ideas. So throw anything out there for me to chew on
So my s5 is not a dedicated race car and more than likely never will be. I auto-x and used to do the drifting thing and may one day get back into it when funds open back up (which is just about very fc owners excuse), and its really isnt a DD but more of a weekend warrior with hopes of doing pdx events and time attacks. So i want this cage/bar to be a bolt in affair with fairly minimal cutting of interior incase i decide to go elsewhere with the car.
SO the real question is are the standard autopower mounting points for their rollbars (4 point street not full cage) optimal. Are there any improvements anyone would make upon this. and really is there benefits to be had with just the roll bar in the rear or would i really need to extend it to the front?
Really its obvious i new to the idea of this and i am looking for pointers in design,contact points, harness bar design for proper mounting, and camera mount ideas. So throw anything out there for me to chew on
05-07-09, 01:10 PM
#2
Dig through the sticky thread called 'Show me your cages' in the race section. You'll get tons of ideas.
IIRC the Autopower stuff goes to the floor, not the best but it is easy. One trick I used to do on Porsches for guys that wanted bolt in stuff is to pick plate location and weld nuts to the underside of the plate. Put holes in the chassis to fit the nuts into so the plate is flush and weld the plate in. Use another plate bolted on top of that one for your cage foot. You now have the removable cage mounted to a welded in plate.
IIRC the Autopower stuff goes to the floor, not the best but it is easy. One trick I used to do on Porsches for guys that wanted bolt in stuff is to pick plate location and weld nuts to the underside of the plate. Put holes in the chassis to fit the nuts into so the plate is flush and weld the plate in. Use another plate bolted on top of that one for your cage foot. You now have the removable cage mounted to a welded in plate.
05-07-09, 07:33 PM
#3
skookum
Thread Starter
iTrader: (3)
Join Date: Jul 2007
Location: Fishersville, VA
Posts: 335
Likes: 0
Received 0 Likes
on
0 Posts
I was looking through that sticky and it did give me some good ideas of how to route certain things.But thats for that idea. It sounds like a pretty good plan to compromise between welded and bolt in.
Still the question remains of will a rollbar as simple as i am talking about provide enough chasis bracing? I have also considered this matched with foam filling the chasis but i do worry about moisture building inside the frame.
continue to interject ideas and thoughts
Still the question remains of will a rollbar as simple as i am talking about provide enough chasis bracing? I have also considered this matched with foam filling the chasis but i do worry about moisture building inside the frame.
continue to interject ideas and thoughts
05-07-09, 08:51 PM
#4
They are stiff for their vintage. Computer design has moved chassis designs lightyears forward.
A simple roll bar will do very little for chassis stiffness. The problems are all the big holes in the chassis, like door and window openings. When you consider where a roll bar will attach and where the loads get put into the chassis a roll bar is almost just a safety addition.
The foam in the rockers will do more for you than a roll bar for affecting the feel of the car.
A simple roll bar will do very little for chassis stiffness. The problems are all the big holes in the chassis, like door and window openings. When you consider where a roll bar will attach and where the loads get put into the chassis a roll bar is almost just a safety addition.
The foam in the rockers will do more for you than a roll bar for affecting the feel of the car.
05-07-09, 09:57 PM
#5
For a DD with limited time and funds I'd invest in suspension and tires before thinking about cages and filling the frame with foam. Coil overs, light weight rims...do you have experience with soft tires?
Why do you think the chassis is weak? Can you feel it twist? Are your support channels under the floor pans crushed? Do you have suspension tower support bars?
Why do you think the chassis is weak? Can you feel it twist? Are your support channels under the floor pans crushed? Do you have suspension tower support bars?
