New Front End Alignment - Not what I was hoping for

[Zipper]

11 hours ago, socorob said:

Techno Toy Tuning or Apex Engineered have the tie rods.

Slow reply - Yep, I used TTT tie rods too. They have both right/left and right/right thread options, so check what's on the car. Have to drill steering arms.

Adding parts could help, but you need a patient alignment tech too. Problems move around as you add parts (compromises).

I also have out-of-whack rear toe, too much and uneven left/right. I think I can feel that at the track. I'm interested in adjustable arms rather than bushings.

[Leon]

On 7/25/2018 at 7:22 AM, jgkurz said:

 

I have checked the car thoroughly but I could have missed something. If a better mount or bushing was available I have upgraded it. 

 

Back to the toe conversation. My understanding is the toe-out in the front would cause more dartiness but better turn-in at the track. Toe-in minimizes the dartiness/tramlining affect especially on the freeway. Is that not true?

 

Regarding rear toe, any suggestions on reducing toe-in with stock lower control arms? I could loosen up the mounts and try to tighten the LCA's while prying on them. 

 

 

 

In a vacuum, both toe-in or toe-out would cause dartiness as single-wheel inputs will steer the car one way or the other. I also don't agree with toe-out being better for turn-in, as it decreases your yaw rate gain, i.e. you need more steering input per given corner radius.

 

Now if we take ourselves out of the vacuum, there are other effects that influence static toe settings such as suspension compliance (mostly controlled by bushings) and kinematics (bump-steer). I haven't seen any published K&C test results on an S30 chassis but if you've installed poly bushings everywhere, keeping toe close to zero with a dab of toe-in, as you have it, is a safe bet.

 

The cheapest way of adjusting rear toe with stock arms is eccentric bushings. I've never used them but I don't see any other way around that other than adjustable arms or doing a bunch of fab work to slot the transverse link supports and splice in a turnbuckle into the transverse link brace (this has been done and can be found by searching).

[Leon]

On 7/25/2018 at 8:01 AM, socorob said:

What would be a good maximum caster for the Z assuming everything was adjustable, and nothing would rub or run out of thread length? I know some newer cars run fairly high caster.

 

"Good" depends on your use case. Are you tracking it and how strong are your arms?

 

Take a look at John Coffey's recommendations, they're in the first post of this thread.

[jgkurz]

On 7/26/2018 at 9:45 PM, Leon said:

 

In a vacuum, both toe-in or toe-out would cause dartiness as single-wheel inputs will steer the car one way or the other. I also don't agree with toe-out being better for turn-in, as it decreases your yaw rate gain, i.e. you need more steering input per given corner radius.

 

Now if we take ourselves out of the vacuum, there are other effects that influence static toe settings such as suspension compliance (mostly controlled by bushings) and kinematics (bump-steer). I haven't seen any published K&C test results on an S30 chassis but if you've installed poly bushings everywhere, keeping toe close to zero with a dab of toe-in, as you have it, is a safe bet.

 

The cheapest way of adjusting rear toe with stock arms is eccentric bushings. I've never used them but I don't see any other way around that other than adjustable arms or doing a bunch of fab work to slot the transverse link supports and splice in a turnbuckle into the transverse link brace (this has been done and can be found by searching).

 

I bit the bullet and ordered some Techno Toys rear arms and tie rod ends. I hope to have them installed so. I am also considering going back to stock steering knuckles. My car sees about 50% street duty so it might make the car more enjoyable to drive around town. Remind me, what rear toe should I put on the rear arms if I'm going with slight toe-in on the front?

 

[Leon]

Go for slight toe-in at the rear, 0.10-0.20 degrees total.

Edited July 28, 2018 by Leon

[jgkurz]

I upgraded to adjustable lower control arms and was able to fix the rear toe. Below are the new alignment specs. Drives and steers much better. Thank you for all the help on this one. Can't wait to get it to the track for some real testing. 

 

Edited August 10, 2018 by jgkurz

[Leon]

Glad to hear! That front toe setting really wasn't doing you any favors either, I wonder if it was incorrectly measured last time or if something had been changed since. That looks nicely dialed in, you'll want more camber depending on how much you track it. 

[JMortensen]

Agree on front camber, needs more if you're getting serious on the track. More caster would be nice too, but there are issues with tire/airdam clearance that pop up pretty quickly.

[jgkurz]

The car is on the street most of it's life. I occasionally participate in track days, autocross, and even drag racing on a rare occasion. If I find my self doing more track days I'll add more neg camber. The caster @ 3.5deg is already getting close to my front fender. I might be able to get to 4deg but that's probably the max. 

 

How much neg camber would you run for a car like mine that sees both street and track time? Just curious. 

 

This weekend I have been invited to a drift event which will be entirely new for me. I will probably be the oldest one there at 50. Ha! I don't plan on ragging on my car too much but I might enjoy sliding around a bit with some friends and family doing the same. I need new tires anyways so I figured why not give it a try. 

Edited August 10, 2018 by jgkurz

[Leon]

It really depends on your duty cycle on track and how hard you drive on the street. Your tires' wear pattern will be the tell since you have such a mixture of use cases.