Car broken. No real work on my part to fix it. But I expect you to solve my problems.

[Bumnah]

Well, it's not a 100% accurate description of what's happening.

I made a post a while back about a binding in my front suspension. I'm still sort of fighting the issue.


The problem:
The front end does not feel stable.
"Stable" defined: At low speeds I hold the steering wheel tightly. The car feels as if it will snap to any side, any moment. When the speed increases, the problem seems lessen.

Symptoms:
01.) The wheel doesn't self center as well.
02.) Less than confident driving feel
03.) Worse initial turn in steering feel.
04.) One traction arm is longer than the other. Noticed when I installed the new tension rods. One arm was longer than the other.
05.) During a back road spirited drive, I noticed severe bump steer (first time ever) when I went over a rough road surface.
06.) Well composed at higher speeds, no weirdness under braking, and most bumps.

Cause:
Minor accident a while back. Car popped the curve. I am thinking some may be bent, but nothing looks bent at all. Heck, I drove it home. When taking it to get aligned, you can get it to spec. Since everything is adjustable, that may not be saying much.

Questions:
01.) OEM S13 tension rods are 12.4" or 12.7" from the center of the bushing to the front stud that goes into the FLCA? I got two different lengths during my search.
02.) The tension rods are suppose to be the same length at all times right?
03.) The toe is set properly, but caster and camber has not been reset after new tension rod install and lowering. How much could those two be affecting my handling? The camber was adjusted at my last alignment, but I have since lowered it. It shouldn't be off by that much just by lowering; it should still be pretty even left to right, or am I wrong?
04.) I have not realigned it yet, because I want to be sure I fix this before I spend money aligning it. Bad idea?

Possible remedies:
01.) Go back under the car and look carefully for a bend. I've done this, and I haven't seen jack.
02.) If I see a bent frame or suspension part. Replace it.
03.) Take the car to a frame shop and have them check to see if the frame is straight if I can not see a bent suspension piece.


Any feedback is appreciated. I haven't had time for my track events this year, but I would like to have this thing ready for late August event.

Sorry for the novel.

[Def]

How's your lower front core support? There aren't many spot welds holding it on, and it gets a lot of beating from the tension rods. It'll definitely give vague handling and all kinds of weird behavior since it changes your caster and toe as it moves around.

[josh18_2k]

i was thinking broken/split bushing somewhere (kinda along the same lines)

[Matt93SE]

bad alignment and bump steer will cause those issues. my Maxima had HORRIBLE bump steer- i.e. 2-3" of toe change from full compression to droop.
I couldn't drive it at 60 on the street due to the bumpsteer, but on the track it was no problem since the only way to make that car turn was to trail brake and throw the thing into the corner. car would take a set and bumpsteer would be somewhat constant through the corner during steady-state cornering. it was VERY twitchy while driving on the street and if you'd start to turn in, the car would continue turning sharper and sharper as the body started leaning from the turn. with more body lean came more bumpsteer, which caused the car to turn in more and lean more. and more bumpsteer. sweepers at "normal" speeds on the highway were nearly impossible.


Traction rod lengths should be same on both sides.
T/C rod lenghts don't really matter- use them to set your caster correctly for the front end. your core support is likely tweaked like Def said so the TC rods likely won't be the same length. just get the caster in spec.

and yes, lowering the car some will change camber. not a ton but enough. get the car on an alignment rack, and set caster, camber, THEN toe. do the same for the rear, then go back and check the front.

[Ando]

Alignment shops are generally not worth the cost. A much better investment is an Alignment gauge, (like this http://www.summitracing.com/parts/SPS-91000/ )

Then do the alignment yourself. Much better then waiting around at the alignment shop. Very easy to use, once you do the initial setup. I use a laser level and industrial floor tiles to make level pads in the garage, then just atach the gauge and measure. Then you can check your alignment after minor curb damage or lowering.

[Bumnah]

I'm starting to lean towards core support as well. After the accident I notice the turbo spooling sounds different. I think it's off just the slightest. I also just replaced a bunch of hardware in the front suspension. Replacing the bolts on the front of the Nismo Power brace proved to be a difficult job. I figured it was because all the suspension was bolted together. Perhaps that is where the tweak is.

I had it on a lift today, but I did not notice anything out of the ordinary. I'm thinking about putting it on a frame machine, but the local shop wants $250 just to diagnose it.

Driving it around today, there is definitely something out of whack. I was holding the wheel very tightly. No amount of alignment could cause it to be feel like that.

It's def. not the bushings or ball joints. Those were all replacement recently. Plus when the wheels are off the ground they do not have play when you shake them.

[Def]

The core support is easy to tell if it's tweaked. It'll be just hanging there, with the spot welds ripped off. Peak under the front of the car. The spot welds are all on the frame rails, which is only a few inches from where the front tension rod brackets/power brace bolt onto the front core support.

[Def]

BTW - if you have lots of adjustable arms - check the jam nuts on them. They can come loose and screw your alignment up pretty badly.

[Bumnah]

Yeah I'm going to try and finish the M3 asap, and get wrenching on the 240.

[a_ahmed]

sub'd to see whats up