How rigid is this chassis?

[TorontoNat]

Originally Posted by ILLSMOQ

Welcome back Mat, You were so focused on center of gravity and body roll, I completely missed where you actually addressed any part of my comments.

Also, I wouldn’t call your information “information”...it’s more of an opinion and you know what those are like. Everyone’s got one. You can flush what comes out of yours next time thanks

Don't worry so much, you will be able to fix the body-roll with suspension setup.

[venturaII]

Originally Posted by ILLSMOQ

Wish I would have seen that kit before ordering the Cusco strut tower brace. Any idea if it’s aluminum or steel? Looks pretty good. Those items will help for sure since the subframes are not very robust. I had to bend the rear subframe to open it up a bit to be able to slip the 8.8 diff into place...it bent pretty easily with a pry bar.

I'd be curious to know if they're steel or aluminum as well...that seems like a pretty comprehensive kit, but a fair amount of weight to add. Not an issue with you swap guys, but for those of us who are counting every ounce with stock motors, it'd be a bigger deal.

[ILLSMOQ]

Originally Posted by venturaII

I'd be curious to know if they're steel or aluminum as well...that seems like a pretty comprehensive kit, but a fair amount of weight to add. Not an issue with you swap guys, but for those of us who are counting every ounce with stock motors, it'd be a bigger deal.

https://www.agency-power.com/shop/8p...s-toyota-gt86/

These are aluminum

[Tokay444]

Originally Posted by Tcoat

Read through the swap thread and it doesn't look like you have compromised the integrity of the chassis to any great degree. Looks like it was pretty well thought out.
I would skip the idea of a cage for adding strength though. Any increase in rigidity it may give is poorly located and of little value anyway. A long piece of pipe with several bends in it and a very small contact footprint with the car is not going to gain you much.
If I was in your position I would go with one of the available brace kits. You may have to do some minor surgery to get some to work with your engine though.


https://www.frsmod.com/products/fr-s...it-for-frs-brz

A cage will most DEFINITELY increase rigidity, and likely by a fair margin.
Also strength and rigidity are not synonymous.

[Tcoat]

Originally Posted by Tokay444

A cage will most DEFINITELY increase rigidity, and likely by a fair margin.
Also strength and rigidity are not synonymous.

Any increase is marginal at best and actually counter effective at worst.

[Tokay444]

Show your work.

[Tcoat]

Originally Posted by Tokay444

Show your work.

Don't have to show anything. Unless you are mounting the cage directly to your suspension points there is little to be gained. Bolting a cage onto the floor supports of the car just allows the cage itself to flex. As strong as it may seem there is still some substantial deflection over several feet of tubing. In order to deal with that deflection you would need several cross braces high up in the cage. This adds weight and raises the COG to a point where any advantage in rigidity is negated. If the cage is too heavy it can actually cause flex at the body mounting points.
It seems counter intuitive unless you look at the big picture.

[venturaII]

Adding a cage can undo the work put into chassis design to intentionally permit and accommodate flex. Safety gained at the expense of performance.

[Tcoat]

Originally Posted by venturaII

Adding a cage can undo the work put into chassis design to intentionally permit and accommodate flex. Safety gained at the expense of performance.

Safety in a roll over situation only. Cages are used and sometimes even required for track use where there is little or no chance of a head on or high speed side impact. On the street where the bigger risk is that truck smashing into you they can turn a safe car into a death trap.
They serve a great purpose when racing and are used with all the other proper equipment but boy racers like them in street cars (that never, ever will see a track) so they can play racecar and pretend to be cool.

[Tokay444]

lol.
Ok boys.
Who anchors their cage to the floor?

[Tcoat]

Originally Posted by Tokay444

lol.
Ok boys.
Who anchors their cage to the floor?

Most of the pretenders.
I did not say directly to the floor now did I?

[venturaII]

Originally Posted by Tcoat

Safety in a roll over situation only. Cages are used and sometimes even required for track use where there is little or no chance of a head on or high speed side impact. On the street where the bigger risk is that truck smashing into you they can turn a safe car into a death trap.
They serve a great purpose when racing and are used with all the other proper equipment but boy racers like them in street cars (that never, ever will see a track) so they can play racecar and pretend to be cool.

Cages can offer considerable side impact protection as well, if their design included this requirement. More to my point though, is that randomly increasing the rigidity of one section of the chassis does not equate to better performance. Infinite rigidity does not make the car go faster, and very possibly degrades the overall ride quality.

[Tokay444]

My guess is neither of you have ever measured torsional rigidity before and after a proper cage install, and are talking out of your asses.

Originally Posted by venturaII

Cages can offer considerable side impact protection as well, if their design included this requirement. More to my point though, is that randomly increasing the rigidity of one section of the chassis does not equate to better performance. Infinite rigidity does not make the car go faster, and very possibly degrades the overall ride quality.

This is something a can agree with, but no one is looking for comfort in a caged race car...

[Tcoat]

Originally Posted by Tokay444

My guess is neither of you have ever measured torsional rigidity before and after a proper cage install, and are talking out of your asses.

You have?
A proper cage install in a well engineered, dedicated racecar is a rare thing. We are talking about slapping something into a modified street car. The effect is not going to be the same. To say that "A cage will most DEFINITELY increase rigidity, and likely by a fair margin" is not a catch all nor accurate statement by any means.