guys with modified suspensions, do you run strut bars too

[Axxe]

Hinged vs. Solid: Do you ever see hinged roll cages? End of story.

[Lurker27]

Hinged vs. Solid: Do you ever see hinged roll cages? End of story.

This shows a deep and profound understanding of the forces involved in automotive chassis.

Wait, no, it doesn't.

[markseven]

I have the Sparco, btw.

[Farbin Kaiber]

Hinged vs. Solid: Do you ever see hinged roll cages? End of story.

Yes, I have. Hinged door bars. Boo-yah...

end of story.

[Axxe]

Yes, I have. Hinged door bars. Boo-yah...

end of story.

Post pics of this. Was it a ghetto cage?


BTW, think of the strut towers and lower sub frame as a U shape. Now, if you tie both together with a hinged bar, your limiting factor will be the (lack of) friction in the pivot, since the opposite pivot exerts a huge moment of inertia about it. Is it a huge amount of pivoting? No, but it's enough to make the already marginally effective strut bar, more ineffective. If you want pretty pictures, I'm not making them.

[nando]

Post pics of this. Was it a ghetto cage?


BTW, think of the strut towers and lower sub frame as a U shape. Now, if you tie both together with a hinged bar, your limiting factor will be the (lack of) friction in the pivot, since the opposite pivot exerts a huge moment of inertia about it. Is it a huge amount of pivoting? No, but it's enough to make the already marginally effective strut bar, more ineffective. If you want pretty pictures, I'm not making them.

did you even read the link I posted?

[Farbin Kaiber]

Post pics of this. Was it a ghetto cage?

No, it was not a ghetto cage, some mid range (read : not fuh raze) cages in some cars have a swing out door bar that allows ease of entry, rather common in some street performance style drag cars like the Camaro. Locking pin pulls out and the side bar swingsoutward.

[Axxe]

did you even read the link I posted?

Yes. I've read it before, and am familiar with the physics involved during cornering. Here's how I see it (effectiveness split into tension and compression):

Under tension: Not much difference, if any. Hell, a chain/rope/line/whatever could be placed there, so long as it's modulus of elasticity was enough to offer resistance to the applied force (say 333 lbs). But a solid bar offers additional resistance to geometry change simply because it is a rigid system.

Under compression: Ever try to push on rope? Doesn't work too well. A hinged bar doesn't have the friction in the joints required to make it a rigid system.

You can argue that under cornering, tension is the main force, and you'd be right. But, is max cornering the only goal of a strut bar? Lets assume that hinged and solid bars do the same work under tension, for arguments sake. Now that the cornering is equalled out, the hinged bar offers less strength in the compression department. Why pay more for a less effective bar? Hinged bars are usually pretty, bling bling type deals, which is fine for people who just want it for show, and for new cars with much more rigid unibodies and no abuse (yet). An e30 can use all the help it can get.

My main point is that strut bars don't have a huge effect, but solid ones are more effective than hinged ones.

No, it was not a ghetto cage, some mid range (read : not fuh raze) cages in some cars have a swing out door bar that allows ease of entry, rather common in some street performance style drag cars like the Camaro. Locking pin pulls out and the side bar swingsoutward.

Wow, I would never bother with that. Your life is hanging on some hardware. You'd never see that on even a cheap road racing cage.

[nando]

Under compression: Ever try to push on rope? Doesn't work too well. A hinged bar doesn't have the friction in the joints required to make it a rigid system.

You can argue that under cornering, tension is the main force, and you'd be right. But, is max cornering the only goal of a strut bar? Lets assume that hinged and solid bars do the same work under tension, for arguments sake. Now that the cornering is equalled out, the hinged bar offers less strength in the compression department. Why pay more for a less effective bar? Hinged bars are usually pretty, bling bling type deals, which is fine for people who just want it for show, and for new cars with much more rigid unibodies and no abuse (yet). An e30 can use all the help it can get.

huh? you're arguing that the hinges have the same strength under tension, but not compression? that makes no sense at all. Think about that again and come back to me..

as for why? some of us have no other choice. But it doesn't matter, because a hinged bar is just as effective. Some people don't "feel" that way, but feelings hardly matter in the case of physics.

[Axxe]

huh? you're arguing that the hinges have the same strength under tension, but not compression? that makes no sense at all. Think about that again and come back to me..

as for why? some of us have no other choice. But it doesn't matter, because a hinged bar is just as effective. Some people don't "feel" that way, but feelings hardly matter in the case of physics.

How about you post some proof of this? Take a door, a simple door, and pull on it away from the hinge (IE, along the surface of the door). It will give you resistance in the same angle that you are pulling, right? If you push on the door, what happens? You have to use force to keep the door from swinging.

[Farbin Kaiber]

Wow, I would never bother with that. Your life is hanging on some hardware. You'd never see that on even a cheap road racing cage.

Well, SFI, and most venue tech inspectors haven't had an issue with it and it is cert. I guess you have all this info down and must be a cage god as you are arguing with the rest of this thread. Sorry, I MUST be wrong then.


Don't you know better than to argue with a mod?

[nando]

How about you post some proof of this? Take a door, a simple door, and pull on it away from the hinge (IE, along the surface of the door). It will give you resistance in the same angle that you are pulling, right? If you push on the door, what happens? You have to use force to keep the door from swinging.

The strut brace isn't a door. it's connected on both sides unless you're running with one side disconnected. the "force" needed is supplied by the other end of the strut brace, if you want to argue that way.

[BlueIX]

I picked up a ebay one for the rear and noticed a slight difference. I thinks its because my car had been rear ended before I purchased it so the body might have suffered some weakening. Anyway, I always like the way they look so the $60 it cost me was worth it.

:up:

[Axxe]

The strut brace isn't a door. it's connected on both sides unless you're running with one side disconnected. the "force" needed is supplied by the other end of the strut brace, if you want to argue that way.

Still haven't shown proof that they are the same.


And Carbon boy, who cares who it is that I'm arguing with? Argument is argument, a mod isn't automatically correct because he's a mod.

[e30love]

A x-brace on the e30. Where you get that?