Solid rear brace?

[E-volve]

I'm sorry, but i'll have to say that NoHachi is right, this is such a crap.
It wont work like this... the brace in the pictures above won't do anything.

Al the forces on the car are going right up and the only forces out of sideways are going trough the lateral rod. Offcourse the body wil twist a bit, but the only way to fight that is to weld the whole chassis and weld in a cage that has also some fixed points on the B-pillar and the roof between the A-pillars.

In the front on the struttowers it will work a bit. But it's hard to feel the difference.


If it should work, you would see it on every racecar. It's not like you will discover 'the wheel' again, as we would say here in holland

[assassin10000]

You guys aren't quite getting it. It DOES work and help in an unmodified chassis.

I completely agree that stitch welding and cages do a whole lot more.

These are for guys who do not have the time/money/skills/etc to go all out. Or simply don't want a cage in their daily driver but still want a stiffer chassis.

Anyways, those upwards forces will cause twist which transfers laterally across the car (similar to how a swaybar does as well, it transfers upward force laterally to make the cars suspension to work differently). So it does work. Your thinking a little too much 2-dimensional (I think). Otherwise they would never bother to create crazy ass triangulated cages to create a super stiff chassis/platform for any form of racing.

Andrew

[NoHachi]

Hiya Andrew,

The pics you showed might actually work..stiffening what is basically a ladder chassis can pay dividends if the original connecting points became a bit weak.
Mind you, that has nothing to do with the shock mounts.
The double triangle structure you pictured looks ads a bit of stiffness to the rear ladder structure, but you really want to be careful about where you attach them. I can't really tell from looking at your pictures, but I've seen some mega bars attach to sheet metal that is just a couple mm's thick.

[robokill]

euhm ok lets get back to spitfire.... Spit if you don't use the car for track its not necassary. Most bar mods are between your head to have you think you have a better car feeling.

But decide I think you should look at racecars as those are designed by drivers that know what they want. Strole around the project section.

[Spitfire]

Sorry Robo, forgot to reply last time
The thing is that the car will actually see a lot of track days, hillclimbs (and downhills ), autocross and so on.... as many as possible. I know the chassis will twist and I want to prevent it as much as I can, the problem is that Im not actually pretty much sure how exactly to do so.
But help from everyone here is simply amazing, thanks to all of you guys!

[assassin10000]

NoHachi Wrote:Hiya Andrew,

The pics you showed might actually work..stiffening what is basically a ladder chassis can pay dividends if the original connecting points became a bit weak.
Mind you, that has nothing to do with the shock mounts.
The double triangle structure you pictured looks ads a bit of stiffness to the rear ladder structure, but you really want to be careful about where you attach them. I can't really tell from looking at your pictures, but I've seen some mega bars attach to sheet metal that is just a couple mm's thick.

Yeah, you've got it exactly right. The fact the the bar attatches near the shocks IS NOT to strengthen the shock mounting points.

That placement was chosen to strengthen the chassis itself as you have said. The reason that they attatch there; is the shock tower areas have a lot more 'material' spot welded to strengthen that area which ties directly down/into the rear subframe rails. Which is almost inline with the upper spring seats which do see a bit of force applied to them.

Make sense?

NOTE: only the 2 front bolts (one of which isn't pictured in the installation picture) go into this much thicker area, the third one (furthest back on the font mounting point) goes into a 'relatively' thinner area. But even that is still thicker/more reinforced than the other sheetmetal on the car from what I can remember.

Andrew

[E-volve]

Still the 45 degrees bars are not good like this.

If you want to make it real stiff, you don't want any bending in de thin pipes you are using. Simply said, the bending stiffnes is almost 0 of this tubes you are using.

You should have made a cross (left front-right rear and mirrored), so you will use the pipes pure as normal force beam. Then you will get the most strength out of you're frame, then its really braced.
Like in the rear of most rollcages, for example

Not to piss you off or something, at least the welds are looking nice

[assassin10000]

E-volve Wrote:Still the 45 degrees bars are not good like this.

If you want to make it real stiff, you don't want any bending in de thin pipes you are using. Simply said, the bending stiffnes is almost 0 of this tubes you are using.

You should have made a cross (left front-right rear and mirrored), so you will use the pipes pure as normal force beam. Then you will get the most strength out of you're frame, then its really braced.
Like in the rear of most rollcages, for example

Not to piss you off or something, at least the welds are looking nice

No worries I like discussion. We could have made a full trapezoid shape (the arms aren't at 90 degrees from the main bar) and put a true cross bar/pattern in. I don't disagree that we can make an even stronger design, but this bar is built with some compromises for keeping the spare tire well functional. While still improving on the other design.

Andrew