Alignment or Suspension Related at 100MPH?

jchammond

May's;
It has been a learning experience for sure...no turn plates.
I tweaked a tad every day or 2 & kept up with all of my adjustments made;as the least incorrect adjustment & steering wheel can get mis-aligned.
Treadwear is very good on tires.

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MaysEffect

Yea that sounds a bit tricky. To make it a bit more accurate . A cheap alternative to professional turn plates would be to use a double stack of thick glossy pvc sheets on top of rubber mats and use oil or soap and water between the two plates.

This was recently covered by motoiq on a project drift car. This will yield better results compared to nothing but rubber to road surface. The downside is that you have to constantly check the alignment of the string.

Rusty

If you set the rear toe on the Z to zero or more negative toe. You'll get into a handling problem called snap-over steering. The settling is nice for getting the Z to rotate in a corner on the track, and the Z feels nervous going straight. But at max grip in a corner. There is no warning of the rear letting go. It just goes. Been there, survived that.

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MaysEffect

There are several other factors that would cause snap oversteer, not just toe-out in the rear. In most cases, toe out would actually limit snap oversteer or sliding as the inner tire is countering rotation depending on how much toe-out is set. If we are talking about 1 degree from zero, then neither case would be a primary reason for this issue. The Z being a multilink rear setup with rubber bushings like most cars, the design is set to reduce toe-out under load on the outside wheel. If you are getting snap oversteer you are most likely dealing with weight transfer problems.

Unless you have a solid/stiff bushings in the rear, the outer tire in most cases is gaining to in. Increased static toe-in would just create more understeer at the limit.

What was the situation where you were sliding or getting snap oversteer with toe out?

Rusty

How much actual track time you have with the Z. Because your answers sound like they're coming from a book, or google.

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MaysEffect

I have track time and driving experience with several cars, with varying suspension designs and chassis weight. Whether the information came from a book or experience, the dynamics behind the geometry of this car and my own are still factual, that's all i was saying. Not to mention i've gone through about 100 alignment changes over 3 cars in the past 2 years. All of which have different suspension designs and bushing materials. I'm not trying to blow smoke up anyone's rear. It's genuine passion in the subject.

You made a point about toe settings causing SNAP oversteer, when in reality this factor alone can't possibly cause this phenomenon. That's why i asked for you to recount the situation you have in mind. I'm willing to bet cash that several other factors came into play for you to have such a situation. I already agreed upon the fact said alignment can cause basic stability problems in certain situations.

But you're right though, i did get a lot of information from books and research. A couple thousand dollars worth of information and training to be fair :

Rusty

I'm pickin' your brains to see what you have up there. How much work have you done with the Z? What alignment settings you've tried? Have you switched out/changed suspension parts? And which parts? What tire/rim comb you using? If you have knowledge up there that can help us track rats. I'm going to pry it out of you.

I've gone through 20+ alignment settings on my Z to get where I'm at now. Have a killer setting for track but tires life isn't good for the street and the Z is nervous as sh!t. Have a street setting that won't work well on the track, but tire life is great. The setting right now is a compromise between the two. I can tweek farther if I want to. Which I may do over the winter.

Snap-oversteer. Have you ever experienced it? The Z is good at telling you on what's going on if you take the time to listen. I can load the rear to the point of loosing grip, and feel it start to slide. With the toe at zero, or a hair +. The Z tells me everything. But when I had the toe -. I loose that feeling. The rear will load. When I expect it to start to slide. It will hang a little longer, then let go right now without any warning. It's not good looking at the driver behind you. Eyeball to eyeball.

Alot of the track info for the Z that you read on. Was done by pro level drivers. Like BGTV8, clintfocus, Mike, Shamu, BJ, etc. I'm not up to their level, but I can hold my own.

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