drft_180sx

So, i was wondering if it was possible that with time and/or abusive driving, if there is any chassis degradation? Structurally speaking is there any weakening?

If YES...
-Would a stiffer suspension/bushings cause increased rate of degradation?
-What are possible solutions to this? Besides bandaids such as strut braces, chassis braces and roll cages?
Where does this degradation occur? @ welds? rust?

I'm trying to understand the dynamics of the chassis and how it is affected by modifying the suspension, etc. Feel free to comment, flame, educate me.

Thanks!!!

Jahan

pengarufoo

The answer to all of your questions is yes.

Uprated springs, stiffer damping, stiffer bushings, all of these things will increase the stress on the chassis which is already old.

The best thing for you to do is put in a full cage if you want to improve the rigidity of the unibody, and help it tolerate the increased abuse. If you're not ready for this extreme, bolstering the seams also helps, this is usually done by welding the seams.

TougeMonster

iTrader: (1)

more hp also will degrade the chassis. in my ae86 if you go past 200 hp welds start poppin. i plan on having my chassis digatally aligned and im going to stitch weld it while its in the frame rack, im doin this right before paint so it looks stock

Black Knight RX7 FC3S

iTrader: (7)

if you do some serious driving, I would try and weld some bars to points in the car where twisting and flexing occurs.

In a car as old as the Fcs, chassis regitity is the most important thing to remember before power.

I was going to weld a tri-point cage in the hatch connecting to the middle of the car where a C-pillar bar is already welded

Ashyukun

iTrader: (3)

Hmmm. I imagine this goes doubly for the 'verts, which with the top down will see even more flexure than the coupes, even with their 300 lbs or so of additional metal? Would something like the a rollcage (like this for example) do much good?

pengarufoo

I agree that a vert would need some help here, but the last thing a vert needs is more weight - if you were to give it a cage that gave it coupe-like (or better) rigidity I would try eliminate the vert-specific reinforcements at the same time to keep the weight down.

Regarding the rollbar, I don't think it would help very much, it doesnt attach at enough points and the points it does connect at arent really ideal for improvements. I imagine the vert is already sufficiently rigid across those points, considering thats where the channel that goes across the car behind the back seats is located, which is all boxed up and quite fortified with steel. I'm just speculating here though.

I would want a full cage in the vert, the roof area is a big open gap, there needs to be some rigid structure linking the front to the rear of the car at a maximum practical distance from the floor of the unibody... you know, like the roof on the coupe does via the A and B pillars... Adding a cage like what jeep wranglers have would probably work well, maybe with some special considerations?