Roll Cage/Chassis Stiffening Discussion Thread

[o1roadkingrider]

Let's discuss roll cages/roll bars/tension sets/chassis bracing, but in an organized fashion.

1. List make and model of your car.

2. Tell us what type of cage, or bracing you have, or what you plan to have in your vehicle. (For example: Do Luck tension set, or 6 point cage with nascar bars, welded in, mild steel, blah, blah, blah.... )

3. Tell us why you are choosing, or have chosen to install a particular type of cage/roll bar/brace. (For example: to meet tech for a specific class, chassis stiffening, safety, protection, etc.)

4. Describe any departure from the "standard", and why, and if it still passes tech inspections.

5. If you can, provide pictures of your cage/roll bar/bracing, or the cage/roll bar/bracing you plan to install.

Hopefully, this thread can be used to educate those searching for real world information on roll cages, roll bars, and chassis bracing to help them make educated choices in their own build.

[djsilver]

1. 1990 240sx coupe (my autocross car)
2. Autopower 1.75" 4-point roll bar.
3. Installed it to be legal for SCCA track-trials
4. Standard bolt-in installation
5. No pictures right now but nothin special.

[o1roadkingrider]

Hey, thanks djsilver.

Do you DD your autocross car?

[o1roadkingrider]

Hmmm... this doesn't seem to be going over well. I'm all for someone deleting this thread if you can.

[Tower240sx]

just quit posting and give it a day or 2, people on here all have lives, it aint zilvia,,, patience grasshopper patience

[Sleepy_Steve]

I have plans... Will try to remember to post later.


So now that I'm remembering to post my plans for a cage:

Std weld in, custom, 6 point + the 2 allowed points to the firewall for foot protection.
X bars on the doors that bow out into the door frames.
Rear X brace in the horizontal plane tied into the door bars like Matt93SE.
Normal reinforcements at major joints, probably of slightly smaller diameter than the main tubes of the cage.
It would be for NASA PT specs, so I think I'm somewhat limited in my 6+2 mounting points for the cage.



LOLS brainstorming model cage of ****. (1/10th or 1/12th scale) Yes the welding skills will be better when its full size.

[Colorado S14]

No cage yet for me will be going custom for that though, I have not been satisfied with the fitment and gaps with most any off-the-shelf option.

I have front and rear strut bars and a Nismo Power Brace on right now, the front components I can definitely tell the difference, the rear not at much.

[T-Rex]

[McCoy]

This discussion has come up a few times and most all of us with cages have piped up in one, if not all of them. Might as well link them here as it takes a while to track them all down through a search.

http://nissanroadracing.com/showthread.php?t=2562&highlight=roll+cage

http://nissanroadracing.com/showthread.php?t=1675&highlight=roll+cage

http://nissanroadracing.com/showthread.php?t=1328&highlight=roll+cage

http://nissanroadracing.com/showthread.php?t=707&highlight=roll+cage

Nothing special about mine, basic 4-pt cage (.095, 1.75" DOM tubing) tied into the rear strut towers... built by a local guy. Car is driven to HPDE/open lapping days and parked the rest of the time.



Built to SCCA/NASA just in case I ever decide to do something with the car besides what I already listed. SFI rollbar padding, 6-pt harnesses, and a pair of Sparco Evo L seats.

[o1roadkingrider]

Thanks for the links, McCoy. Good reading.

Here is my contribution: (open for criticism)

YEAR/MAKE/MODEL: 1996 240sx SE

CAGE: (planned)
6 point, modified. Welded in, but with removable diagonal and horizontal bracing in the main hoop behind the front seats, to allow usage of the rear seat. Main hoop to be just aft of the b pillar to allow comfortable front seat position.

USE/REASON:
Primarily daily driver, two kids to transport in mornings which is why I need to retain use of the back seat.

Intention is to improve chassis stiffness, provide protection in a roll over, and be able to add weld in bracing later for track use.

[Air]

just my .02, but you do not want to put a cage in a car that is going to be used to transportation... I would never have a cage in my daily (excepting a miata or similar)

you are adding more headache then the benefits will help you.

[Sleepy_Steve]

Updated my initial post w/ plans for a cage.

[o1roadkingrider]

just my .02, but you do not want to put a cage in a car that is going to be used to transportation... I would never have a cage in my daily (excepting a miata or similar)

you are adding more headache then the benefits will help you.

If a cage is not a good idea for a street driven car, how would I achieve similar chassis stiffening results otherwise?

I plan on adding front fender braces, front and rear strut tower braces, a C-Pillar bar, and Nismo Power Brace, but from all that I have read, a roll bar/cage is the best stiffening add on there is.

[Matt93SE]

IMO, a cage simply isn't suitable for your application.
For a DD, a cage is a bad idea. For a DD that hauls children, it's an even worse idea.

All it takes is one small fender-bender to do serious damage to those little noggins bouncing around in the back seat. Even with padding on the roll bar, one impact (even in a 10mph accident) with someone's head is enough to cause a concussion. There was a pro rally driver killed a few years ago in a 5mph impact. they were driving through the pits with no belts and no helmet. bumped another car and that was it. lights out.

Also, the rear down supports in my car go right through the back seat area. there's no way possible you can fit people in the back seat and still have a cage. You do not want to make those bars removable for strength reasons either.

Plus, by the time you make a bolt-in cage, you're really losing the chassis stiffening you were trying to accomplish by the cage. in order to remove those bars, there's got to be enough play in them to remove them, which means there's a fraction of an inch gap at every joint. that's all the car flexes really. so in the end, you're just adding weight.

Now.. to answer your question...

There's a ton of pics of my cage on my website: not going to bother posting them cause I'm on a REALLY slow connection (makes 56k look lightning fast. I get like 650bytes/sec... )
Anyway..

http://blehmco.com/pics/240SX/roll_cage/

Car is a '96 base model, still has KA. race-only. Built for SCCA Club racing, Super Touring-Under 3.0L class

6 pt cage, SCCA-spec. Custom-built by local race shop.

1.50" x .120" DOM. (don't waste your time with Chro-mo tubing.. especially not on a half-ass cage. full out race cars only.)

NASCAR door bars. very easy to get in and out, but I had to gut the doors to do it.
No window tracks- windows just pull out of the top of the door and rest in the top 6" of remaining window track.

Additional x-bracing right where the rear seat is. Makes doing anything in the back a nightmare, but adds torsional stiffness to the rear of the chassis and helps distribute impact loads around the driver.

[josh18_2k]

ive wondered about the taco gussetting between cage+pillars. see it all the time on FD cars, but not really in anyone's DE/track cars. are they unnecessary? seems like they would add a bit of rigidity. not worth the weight up high maybe?