Suspension Setup and Cages?????, at what point do you NEED a cage, or not Options

[Mueller]

I've been reading all the suspension improvments that Trekkor has been doing, the car is getting stiffer/stronger parts on it, but how much more effective would all these parts be if a cage was installed?

has anyone done back to back testing without and then with a cage with no other changes???

[SirAndy]

(IMG:style_emoticons/default/chowtime.gif) mhmmmm, cages ....

[Mueller]

need a "smilie" with handcuffs, hahahahaha

[J P Stein]

I dunno. At what point do you wanna have the front & back ends move semi-in-concert? Just a cage won't accomplish this. Ya gotta add some extra tubes.....mine is in the "semi" catagory cause I need more tubes, but it's a heap (maybe even a shitload)better than stock. (IMG:style_emoticons/default/biggrin.gif)

[Trekkor]

I am thinking cage and chassis stiffening. (IMG:style_emoticons/default/idea.gif)

I love welding. Are there cage kits that will pass current certification/inspections for th DYI guy?

[campbellcj]

The point when you "NEED" a cage, is when your car is upside-down, 4' off the ground, at 100mph! (IMG:style_emoticons/default/blink.gif)

The added rigidity is a fabulous side-effect, but I'm not sure I would install a cage with that in mind as the primary objective. (IMG:style_emoticons/default/confused24.gif)

[neo914-6]

Here's a related question: Is it safe driving w/o a helmet on the street when you have a cage installed? I suppose a harness should keep your head well away from the bars...

[campbellcj]

The ideal situation is to NOT drive any caged or gutted (of its soft interior) car on the street.

However if a cage is properly designed, I think the tubes are well enough away from critical body parts that the odds of injury are far reduced. This assumes that you have a good restraint system and seat, too, which the stock parts probably do not fulfill.

Basically I (and a lot of other folks) believe that if you have a cage, you should go all the way with harnesses, seats, steering column/wheel mods, fire safety, and a head & neck restraint... The cost of all this safety eqpt. adds up fast but is an essential investment in my view.

[SirAndy]

Is it safe driving w/o a helmet on the street when you have a cage installed? I suppose a harness should keep your head well away from the bars...

my usual response ...

if you hit something hard enough to really bang your head on the cage, it doesn't really matter because you would have banged your head on the windshield frame or targa bar or somewhere else if you hadn't installed that cage ...

btw. you're supposed to have padding anywhere where you can possibly hit the cage with your head ...

Andy

[RocknRollFrenzy]

the SCCA rules don't allow extra bars added to a cage for the pupose of stiffening the chasis. I know that NASA follows the SCCA cage building guidlines as well. If you're planning on racing, buy a rulebook before you build anything. There are companies that make pre-bent, pre-cut cages that you can weld in yourself that are race legal. Cost will be anywhere from $600 to $1000 depending on where you get it and whether or not you want things like nascar style door bars. If you're seriouly considering a cage, check out goto:Racing. We build custom cages from scratch at pretty darn good prices. We just finished an awesome cage in a Honda Del Sol this last weekend which has the same extra rules that apply to 914's tacked onto it.

*edit* Hmm. It would appear that our site's forum, and gallery are having some problems. If you are at all interested, or just have some questions, and things aren't working just gimme an email.......oh...and sorry 'bout the shameless plug.

[J P Stein]

No shit?
Here's a legal FP SCCA AXer

[RocknRollFrenzy]

yep....but if you were to try to run it in an IT class, or say, one of NASA's enduro classes, you'd be classed as 'unlimited' because of your cage.....if you've still got your stock engine, that's bad......course, if the car's fast enough, thats where you want to be anyway.

[Brad Roberts]

Mike,

All the cages you have seen (including yours) are all 1 bar away from SCCA ITA legal. They do not provide any rear or front suspension point stiffening. Yes. Some of the "spring" in the cars is being absorbed by chassis flex (this is why the rear shock towers rip away from the body when you start introducing 300# and higher springs into a stock tub with NO bars leading to the shock towers.)

PCA says:

We cannot have bars passing through the rear windows in our production classes.

SCCA says:

If you dont have any bars going back from the main hoop you have to run one going forward (Petty Bar.) You have seen only 3-4 out of the 15-16 T has done with Petty bars because those people needed it for SCCA (Julius/Hole/....)

B

[Scott Carlberg]

I love welding. Are there cage kits that will pass current certification/inspections for th DYI guy?

Great question, not because I know how to weld... cause I don't.

But I would like to know the answer to that.

[lmcchesney]

I believe this or the other 914 board had a recent post on roll cages.
When do you get a roll cage. Well, for me, it was following driving the 914 bact from New England and realizing that the Buick's tires were at the height of my head! I went with a weilded in Stable energy cage with side impact bars. I also went with the 3" five point harness. I pad the roll bar adjacent to my head, but I'm not fooling myself, the padding does not replace a helmet in protective value. Most data reveals more leathal injuries occur with ejection. The roll cage and harness when used correctly, restrain movement. Additionally, with this roll cage, I can still attach my targa top. I believe the SCCA rules describes roll cages which tie into your suspension system as criteria for advanced class.
L. McC

[machina]

we run rear bars as our 7th & 8th mtg points and a petty bar. Vintage rules prevented us from going all the way to the top of the shock towers but we still gained alot of rigidity at the rear with them.

I don't believe the petty bar which we have as well adds any support to the rear (aft of firewall) section. They do complement each other however.

Regarding driving a caged car on the street. Our little cars seem to get even smaller when you start putting all those welded tubes in them. You will have tubing inches from your head compared to the stock interior.

I don't think anyone could say with certainty that you are safer on the street with or without a cage.

dr

[groot]

In my GCR, the number of tubes are not limited, only the number of attachment points to the body, and that's only in IT (8 attachment points). In production, you can mount to the body as many times as you like and use as many tubes as you like. You can get creative and add a lot of stiffness to the body/chassis with these "restrictions."

So, I don't understand this statement: "the SCCA rules don't allow extra bars added to a cage for the pupose of stiffening the chasis."

I just wish I could use the engine as a stressed member to connect the trailing arm points across the car.

Just trying to clear up the discussion.


Brad, thanks for the tip on the shock towers. I didn't realize this and will move my main hoop supports accordingly. I already put the plates in the rear above the inboard trailing arm mount, but I'll have to put some more in and run a tube to the shock tower.... progressing slowly......

[Randal]

The point when you "NEED" a cage, is when your car is upside-down, 4' off the ground, at 100mph!  

Well said.

I put a full cage in just to be safe, but couldn't believe the handling difference when I first took it out. It was simply a different dimension (literally) as the car wasn't twisting all over the place.

My guess is that a full cage will get you 1 to 1 1/2 seconds on a 50 second AutoX course.

[RocknRollFrenzy]

So, I don't understand this statement: "the SCCA rules don't allow extra bars added to a cage for the pupose of stiffening the chasis."

its in the rulebook for IT cages, though i'm really not too sure why. don't have my rulebook with me, so i don't have the exact wording of it, but its there. if you run a production class you don't have to worry about that part.

actually, one of the cool things about the 914 (and the previously mentioned del sol from my earlier post) is that because you don't have to have rear stantions, you're required to attach the main hoop to the seatbelt mounting points, which is against the rules for other cars. and you don't have to remove that attachment if you add the rear stantions. the two together actually add a lot of stiffness to the chasis.

[groot]

From GCR, ITCS, page 23, Section 10.a.1.A.5. "Any number of tubes may attach to the plate or each other which shall be considered one point."

Page 24, Section 10.a.5, "...Any number of additional reiforcing bars are permitted within the structure of the cage, provided they meet the minimum tubing size...."

Page 24, Section 10.a.4, "Main hoop braces may be mounted at the rear shock mounts/towers or the suspension pickup points...."

You may be thinking of the section that prevents one from penetrating the firewall... page 24, Section 10.a.4, "...No braces may pass through the front firewall." which could lead one to that conclusion.



I decided to turn my 914 into a race car once I realized what the Detroit roads were doing to the body/chassis. The potholes were flexing the body so much, I figure the only way to save the car was to through a cage in it and go racing.