Is An R32 Gtst Full Chassis?

[original]

hey guys i am having a major argument with a mate of mine that has an r32 gtst. he recently lost it around a bend and jumped the gutter and smacked the under side of the car on the gutter (he has severelly bend and damaged the thick square tubular looking metal bar which run on each side of the car (he has damaged one of them).

From what i can work out that is the chassis rail as this is what holds the front and the back of the car together. he has damaged it just after the passanger door (between the passanger door and the diff).

he is trying to tell me that it is not structural and that r32's are not full chassis and those bars under the car do nothing for support and what holds the car together is the shell and roof e.t.c????

we came accrossd another problem which i think strengthened my argument when we went to jack up the car to do an oil change. i notices that when the car was NOT jacked up the passanger door opened fine, but when it was jacked up the passanger door seemed to rub when it opened and closed giving me the impression that the car was some how bent??

can somebody please clear this issue up on what holds the skyline together and if the 2 chasis rail looking things are in actual fact chassis rails

thanks guys

[djr81]

You are both wrong. So that is the argument settled.

The chassis rail isn't a true chassis rail in the sense of a seperate chassis body arrangement (think truck, old school four wheel drives).

It is however a not insubstantial part of the structure of the car and therefore should be fixed.

The door flexing thing is actually the whole car twisting when it is jacked up. All cars do this to varying degrees. Typically the newer the design of the car the higher the torsional rigidity of the thing.

[original]

ok i understand what your saying but, those too bars that run on the under carrage of the car MUST be the main support for the rear of the car (joining the front to the rear), there is no other solid structure that runs from the front to the back. and every structure needs a solid structure holding it together or it will twist.

i have had 18 carsa and never have i jacked a car up and it has caused the door to now rub and hit the door jam except for one car and it was a daihatsu charade with the most cracked chassis you will ever see (which i new about). every time i jacked it up, the front doors overlapped the front guard thats how bad it was.

even when he came on power hard he sort of noticed the car pulled left a little bit out of the ordinary (this was the same side as the hit and the wheel allignment and sh11t like that was perfect).. the car felt like it had a twist when you come on power hard (flexing under pressure)

[djr81]

They are part of the structure but only part of it.

All structures twist. How much they twist is dependent on their torsional rigidity & ofcourse the load iimposed on them.

The torsional rigidity of cars varies. 5 door cars (ie hatchbacks) are amongst the worst in this respect because of the large openings (from the doors/match) in the MONOCOQUE structure ie the shell of the car that gives it its strength along with the two chassis rails. R32's are not particularly rigid if that is your question.

And yes even Daihatsu Charades torque steer.

[Cubes]

I jack my R32 GTST up from any point and all the doors close perfectly fine both with std and aftermarket hard suspension.

I had an old VS commodore that when I would jack up the door would NOT close no matter what. I then read the manual and it stated do not open doors when the car is jacked up lol. Freaked me out when the door was sitting ~40mm off what it should have been.

The VS had whiteline/bilstiens all round; reversing out of the drive way I could hear the front and rear windows creeking over the throb of the mildly tweaked 5litr poo. Sounded nice; didn't go all that well in comparison.

[GeeTR]

40mm - omg

The doors on my R32 are harder to shut when the front or rear is jacked up as well.

I'm not willing to agree, that Skylines have rigid bodys.. at all

Those "chassis rails" as djr said aren't really rails. Its a legacy term used in the modern automotive industry. They're ultra thin gauge and NEVER would I rest them on a chassis stand... although I cant count how many ppl i see do.

Made me a little sad when i felt the door not close properaly, but figure it'll be solved when my cage goes in.

Also, Ive seen that many if not most of the 9s BNR32's in Japan stitch weld the front strut towers, in and around the firewall as well. Supposedly 100's of 4WD 9krpm dumps can weaken that area. When my motors out, I know ill have it braced.

Edited March 27, 2008 by GeeTR

[gun32gtr]

if the motor is out of the car is it expensive to get all the stitch welding done...just curious

[GeeTR]

Not sure on exacts, but iv watched it done b4 - Its mostly labour costs. Done with a TIG to minimize localized heating.

I've seen both 'dots' every 1" along seams, as well as welding 1" 'seams', then 2" gap, 1" seams, 2" gap and so on.

I figure I'd give it a go myself, apart from making sure car is on dead level surface (to prevent chassis preload haha) and letting the work cool every now and then, I cant imagine there’s much involved.

In my case, I need to talk to my engineer about cages, to see if I can tie the strut towers properly to the A frame and firewall (re-route brake lines etc)

ne way