[zeke]

So, I just had my steering bushings upgraded to the polyurethane ones and it's much better overall. IMO, slightly more noticable on a long freeway drive than regular street driving.

Quite a bit of the steering play is gone, the steering wheel now self centers much more easily and as a result holding the wheel in turns is now much easier.

I noticed it did nothing for direction changes caused by bumps in the road (twichiness?). I've been thinking about this and what the Whiteline Anti Lift Kit does and find it might be the solution.

So, I put them on today and the result is almost all unwanted direction changes over rough pavement are gone. My drive home was almost twitch free. I could have kept one hand on the steering wheel the entire trip if I wanted.

I know that too little caster angle can cause easy wheel deflection and the lift upon throttle application due to too much leverage over the shocks - all things the ALK addresses and talks about. Apparently, the stock shallow caster angle is a direct result of finding ultimate grip for offroad. After reading about it, everything about the way the car handles made sense.

By increasing the caster angle you get less deflection of the wheel upon hitting a bump, more negative camber when the wheel is turned for better steering response, the increased shock angle from the caster decreases the leverage working on the shock upon acceleration (lift).

You might give up the ultimate offroading ability this almost direct contact with dirt during turns would give you, especially given the driven front wheel power but, I'm thinking I don't really drive offroad.

I've got to say that you can learn directly all about suspension changes and how it will affect handling from high end Radio Control cars. I've seen the direct effects of altering camber, caster, long suspension arms verses short, unequal length control arms, toe in and out on either front or rear, anti roll bars, bump steer caused by steering tie rods not in parallel to the suspension arms, rising rate camber angles due to suspension arm geometry. They can do it all and you will see the results on how the car handles and turns.

So...summing up, I feel my STi Whiteline Anti Lift Kit install was a success for me. A minute enough change that resulted in a lot more steering feel without being twitchy.

The part is commonly found for about $150 and install is straightforward. It's easily reversable if you don't like it.

There's my contribution to the handling issue.

[subawayne]

Awesome information zeke. Believe it or not, I have learned about suspension changes from playing the Gran Turismo series. By the way, do you autocross? If so, please post results of before/after the ALK.

[t00h0t]

Sounds like what I have been looking for... where did you purchase this?

[Jon]

If bumps in the road are causing bumpsteer (toe changes) how would adding more caster help, other than numbing the steering a bit?

Try using a bumpsteer kit--then you'll have no wandering over bumps AND keep the precise steering.

[zeke]

I've owned a 94 TT supra, 98 Integra Type R among others. I've also driven 996 bodied 911s, a 911 Turbo, a Renault Turbo2,an M coupe. None of them really slacking in the handling department. While this is the first 4WD I've owned and driven for an extended period of time I felt it wouldn't hurt to emulate the same feel as the above cars.

All I was trying to do was to decrease the slight sudden steering corrections I had to make caused by rough pavement.

I've driven at Thunderhill in CA as well as Laguna Seca. I've ridden my bike at Infineon (Sears Point). There's my limited pedigree.

Personally, I like it.

Technology wise I found a good site explaining what I thought the increase in caster would do and it did. I'm happy. (again, RC cars...)

http://www.rctek.com/handling/caster..._advanced.html

BTW, I chose the comfort version ALK, I've noticed no real increase in NVH (since there's enough to begin with).

Oh yeah, as far as track times before and after. I'm not so good that I HAVE times consistent enough to measure any benefit.

It's all subjective. If you do it and don't like it, like I said, easy enough to change back and not that expensive to experiment. I'm satisfied with it.

[Jon]

Some real problems with that RC car site. Lots of misinformation about how caster works. ALL cars, FWD, RWD or AWD have postive caster. The STI already has lots of positive caster compared to most cars. Big, RWD, luxo-barges have more caster to help the wheels center in spite of the overboosted power steering. Porsche 911s also have a lot, but they don't follow many of the rules that other cars must go by.

[zeke]

As illustrated in the site I linked to (which is for Radio Controlled cars, not full size cars), it demonstrates GROSS changes to caster and what some of the possible effects are.

As far as I know, the talk of negative caster doesn't even exist for RC cars let alone full size. I believe it was for illustrative purposes.

I found a much better site describing the effects of caster. While I understand it's basics, I find it hard to describe effectively.

Try this and look under "caster".

http://www.ozebiz.com.au/racetech/theory/align.html

Here's an exerpt:
"...the steering axis pulls the wheel along, and since the wheel drags along the ground, it falls directly in line behind the steering axis. The force that causes the wheel to follow the steering axis is proportional to the distance between the steering axis and the wheel-to-ground contact patch-the greater the distance, the greater the force."
"...it is possible to create castering by tilting the steering axis in the positive direction. With such an arrangement, the steering axis intersects the ground at a point in front of the tire contact patch, and thus the same effect as seen in the shopping cart casters is achieved."

And if after all that, you still think my comments about the kit are crap, so be it. I'll just be motoring along...

[SS-Sti]

Zeke, Thanks for the contribution to the forum. I live in NH where we have lots of frost heaves and mostly crappy roads. For $150 its worth a try as cornering on the bumpy roads around here is quite a hand full in anything but a land yacht.

got-a-love those twisty road signs by the rivers and around the mountains

Where did you purchase the ALK?

[zeke]

I got mine from http://www.mpjperformance.com/main.html because they're local. Anyplace online that has Whiteline should have similar prices. There was a post with the same looking thing made by Perrin also in the handling forums.

Just as with the steering bushings the change won't be drastic because the suspension is so good already. Change is definitely enough that I'm am very pleased I did this mod.