Cheap Chassis Bracing Bits You Can Buy And Bolt In

[sonicz]

Yes

http://www.r33gt-r.com/2013/07/trunk-bar-another-noticeable.html

About fitting the ECR33, just look in your boot to see if there's any predrill holes, according to the blog, there is predrilled holes on r33 gtr series3

I don't think I have those hole predrilled though but will check tomorrow. Mine is a series 1 GTS-t let alone series 3 GTR lol. If they are not pre-drilled I wonder how hard it would be to drill them in and prevent rust?

Certian models of the s15...hmm? I guess I'll post in the WTB section and look around on ebay and maybe some wreckers.

[sonicz]

It really does sound like you need new bushes mate, if the car takes a while to settle from a corner or a bump? Creaking? This would be due to worn out bushes and shocks.

If you can't afford all of them at once, just get upper and lower control arm bushes first, swaybar bushes are cheap. And then buy some solid strut tower bars front and rear and some sway bars front and rear and new shocks front and rear.

You are most definitely right about that too. If I brake hard enough in a straight line it will actually change the alignment of my front. The steering wheel will be pointing slightly differently and the feeling of "load" on the steering wheel will be shifted.

My suspension doesn't hold alignment from the 3-4 alligments I've done either. I think 1-2mm off. There is also a vagueness to the steering. I did replace the outer tie end rods but that didn't do much. What it did do is carry the slight wobbles to the steering wheel more while driving, until about 6 months passed and I guess the new tie end rods wore out again.

I also suspect I have a bearing issue which may be wearing out components I put in faster, like the tie end rods. I took it to my mechanic to replace them ( bearings) but he wobbled the wheel around with his hands and said its fine don't waste your money so I sort of gave up (still have the bearings and some control arm bushes but places like pedders want a fortune to fit them).

Point yes probably most of the steering and suspension is a mess. But that doesn't change the fact the body also wobbles excessively after the suspension has transferred its force. Someone else in the family also has a low km R33 and thats so much tighter.

I feel like even if I change all my bushes, the body will still slop. So I though id start with some minor bracing I can get my hands, even though i know the bushes have to be done at some point too.

You guys say bracing wont do much, but I figure solid pieces of steel bolted to crucial parts of the chassis that normally flex and deform, will do something rather than nothing. It has to. I cant imagine a under-body or fender brace, or trunk brace is going to stretch or flex much , but I I can imagine that a long ass 4-5 metre long chassis un-braced will.

Edited February 27, 2014 by sonicz

[GTSBoy]

You guys say bracing wont do much, but I figure solid pieces of steel bolted to crucial parts of the chassis that normally flex and deform, will do something rather than nothing. It has to. I cant imagine a under-body or fender brace, or trunk brace is going to stretch or flex much , but I I can imagine that a long ass 4-5 metre long chassis un-braced will.

Here is your error. They WON'T do what you want them to do. They WILL NOT stop the motion in the direction you need them to stop.

The fender brace will help a bit. Almost anything that goes flat across the underside of the car can only do precious f**king little. If you do not box something in in 3 dimensions, then you are adding almost no resistance to twist. And twist is what YOU want to get rid of. And all those braces are pretty much only 2D.

/engineering.

[ichi-go]

I don't think I have those hole predrilled though but will check tomorrow. Mine is a series 1 GTS-t let alone series 3 GTR lol. If they are not pre-drilled I wonder how hard it would be to drill them in and prevent rust?

Certian models of the s15...hmm? I guess I'll post in the WTB section and look around on ebay and maybe some wreckers.

Judging by your post, it sounds like bracing is not your problem so i would go with what others have suggested and try something else

Tie rod ends wouldn't wear down that quickly if you have just recently replaced it, check wheel bearing or LCA bushes

As for the brace, they are standard on ALL s15s

[FBRacing]

Here is your error. They WON'T do what you want them to do. They WILL NOT stop the motion in the direction you need them to stop.

The fender brace will help a bit. Almost anything that goes flat across the underside of the car can only do precious f**king little. If you do not box something in in 3 dimensions, then you are adding almost no resistance to twist. And twist is what YOU want to get rid of. And all those braces are pretty much only 2D.

/engineering.

200% agreed. That's why I suggest a full cage. It will make that uni-body chassis have nearly .0001% flex. I understand cages are a pain in the ass for a daily but what the guy is wanting is literally the only way to achieve it. You can't achieve a stiff anti-flex chassis with braces. You might get a couple done but it will allow other areas to flex that can't handle it. I've crack front and rear glass before twisting frames up. But first thing I'd do if I had his car is take it to a body shop to get the doors realigned. Then work on stiffing.

[Trex]

Like this?

[hardsteppa]

they are standard on ALL s15s

spec-R I believe, not S?

That back-of-boot brace for the r33 gtr got a "noticeable difference" from the driver. I'm inclined to make something myself though which I don't think will cost that much and will be a bit more solid, ie, exhaust shop to bend a section of tube to run across back between mounting points, then welded to probably 3mm steel plates, bolted to chassis rails using existing 4xbolt holes as mentioned.

I could see the benefit of the front 1/4 panel triangular braces and it seems they're pretty popular/widely used so will be looking into that further too.

The B-pillar/floor brace - i get it in principle, as in using a 20?cm section of chassis rails either side joined to reduce twist, but given overall length of car/chassis rail, could see it making minimal difference.

[niZmO_Man]

My mate's Spec S has the extra bracing.

[Trex]

http://www.skylinesaustralia.com/forums/topic/435782-nsw-r33-skyline-agi-roll-cage/#entry7215430

$500 half cage... Would go well with the floor brace

[warps]

Problem is, OP says his 33 is a lot sloppier than others he's driven (IIRC - a while since I read the full thread). If that's the case, then start with bushes and joints as they're consumable items and likely to wear out. If it isn't the bushes, and the chassis is indeed as flimsy as OP says, then we (he) have a big problem. Why is the chassis so loose? Putting in "cheap, bolt-on" braces will only partly mask the underlying problem, and will treat the symptom but not the root cause. This will never end well and I strongly suggest finding the root cause of the problem before it can be properly fixed. The bolt on braces may improve the car, but it will still be only as good as a standard car. Where's the fun in that?

/reliability engineering

[hardsteppa]

that chinese place I can't remember the name of (KLS maybe?) also have r33 cages on ebay for $450ish new. No idea of fit/quality but if it was more for bracing purposes, it would be a good price.

even tho OP has said multiple time he doesn't want a frickin cage;) ...just putting it out there tho..

[C4a0s]

To the OP... if the chassis is as bad as u make it out to be... then braces may not work. a case of being "pound foolish penny wise" ?

if its really THAT bad, maybe u shd take a long hard in-depth look and figure out the problem before spending $$ on cheap braces. although cheap, they are not free and costs will add up eventually...plus... it sounds kinda unsafe to drive in if it flexes that much...

[Trex]

Would be cost effective to pay someone on here to have a look at your car.

They will be able to give you a run down sheet on what needs fixing and what will give you the best bang for buck and where to start.

From what you said about your wheel alignments and steering wheel shake, you REALLY NEED TO CHANGE YOUR BUSHES. Please just trust us on this. Start from the basics, which is to have somebody on here who knows skylines and who is a mechanic who will give you a list to get you to where you want the car to be. Once this is done, brace up.

[junkie]

I been reading this and heres my 2c:

Something isnt right with this car. If its actually flexing as much as described, its either been badly bent and not repaired properly, has huge mileage or been hammered over bad roads for a long period of time. Skylines are pretty robust in general and take a lot of punishment but any car has its limits. Even my 35 sedan flexes a tiny bit, but lubricating the door seals gets rid of all the noises

As suggested above, take it to a pro first before buying bracing bits. A decent panelbater would be a good place to start, chuck it up on a hoist and check the rails, floors, subframe mounting points, rust, cracks, bad repairs etc. A lot of stuff can be hidden under sound deadener

And if it really is that bad, the cost of fixing wont be worth it. Part it out and scrap the shell instead

[junkie]

another idea for some bracing, not hugely popular here, is sill/rail rigid foam injection. nissan did this with the infiniti Q45 back in the 90s

this stuff is meant to be good for it - http://solutions.3m.com/wps/portal/3M/en_US/Marine/Home/Products/Catalog/?PC_Z7_RJH9U5230GE3E02LECIE20S4K7000000_nid=GSLTMTP63TgsQH8HT14PGTglJ3XN7JWC1Cbl

[hardsteppa]

slight hijack, but since relevant to the thread topic - after not finding the chassis braces I want, thinking I will just make my own. My understanding is, given an equal diameter and wall thickness, square tube will be stronger and flex less than round tube, is that right?

[GTSBoy]

No. Two things need to be considered. When you say "equal diameter and wall thickness" you have to declare whether you mean the length of a side on your square is the same as the diameter of your round, or whether you mean "the same equivalent diameter".

If you mean the exact same dimension, then the square tube actually has more material in it (the perimeter of the square is 4.D but the perimeter of the round is only Pi.D, or about 3/4 of the square). This gives the square an advantage simply from having more material. If you mean the same equivalent diameter, then you're effectively making the square smaller so that the perimeter is the same and the amount of material is the same. Then the square should be weaker.

Square tube has corners. Corners are weak. Round tubes transfer load like an arch, all the way around.

[hardsteppa]

No worries, so what would be yr tecommendation as the best tu use for bracing?

[GTSBoy]

Round cromolly tube. But it is an engineering exercise. You have to know what sort of loads will be put into the braces you want to make in order to know how heavy you have to make them. If you just guess you will most likely end up with one of the unacceptable solutions rather than falling into the narrow acceptable range. The unacceptable solutions are a) you underdo it and have a brace which deflects under the load applied or b) you overdo it and the brace is far too strong and therefore far too heavy for the benefit gained.

As most of these braces are intended to go between two (or more) points that are actually not supposed to move relative to each other and are not supposed to have loads running between them, it's a little hard to know how to go about working out what the real loads are so you can design for them. So you probably have to fall back on guessing, and so you don't end up with unacceptable solution a) which is totally useless, you need to overdo it. But whether that means that you need 1" 3mm wall tube or 1.5" 5mm wall tube (or any other size that comes to mind), I dunno.

cheers

[hardsteppa]

Lol...since the weight difference we're talking will be a matter of 100g, not even kilos, the weight i don't think will really become a factor. If we look at the stock strutbraces fitted front/rear as an example, i don't think it even has to be that thick-walled, so will use them as a comparitve starting point and see hos it goes.