Chuck S

Properly aligned the tires will not wear unevenly but there's "road alignment" and maybe "autoX" or "track" alignment which abuse the tires but handle better in specific situations. I'm not racing at all. I got 14K mines on my Bridgestone RE-11A tires with even wear. I was expecting half this so I'm not driving as aggressively as my wife claims! New set of Bridgestone S-04s on two months ago. Like your car mine will hibernate soon until April. I did put 255mm tires on the rear out of curiosity (see the "understeer" thread). They handle as wonderfully as the RE-11A tires did. No hydroplaning thru some vicious puddles here in the past couple of weeks.

Tires are only good for about 4 or 5 years before they naturally deteriorate. I replace my travel trailer tires about that time. Flat tire on a holiday weekend in East Bubba is not the place to be. No local tire place here in Cleveland had S2000 size tires either.

-- Chuck

ZDan

You can run a decent amount of camber and get good tire life if you keep toe minimized. I'm running the max camber I can get on my stock AP1, -1 front -2 rear, with 0.15 degrees total rear toe-in (half of minimum spec, one quarter of max spec). I got 18k miles out of Hankook RS-3s (with one 2-day track event)

I use the same alignments for road and track on the S2k and FD RX-7 without excessive wear rates on the street (though the ~550hp FD does go through rear tires at the track...). -3 front and -2 rear camber on the FD.

"Track alignments" are not necessarily overly abusive of tires on the street. Unless you run a lot of toe, in which case tire life will be dramatically shorter in any case.

Jah2000

Now you have me concerened. Got an alignment done a couple days ago (along with new tires), but my rear toe is 0.41º.

After the alignment, the specs that were really off were: the Front Toe (-0.35º Toe-Out) and the Rear L-R Cross-Camber difference (0.8º difference).

Ever since I got the car, it had a bit of tram-lining on the freeway; with my car always easily catching slight grooves on the freeway and pushing/pulling my car along with it unexpectedly (and moving my car 1-2’). I always thought this was normal and a trait of the S2k, because I’ve always read that S2k’s had super sensitive and twitchy handling. So, I just wrote it off in my head and thought it was totally normal.

Drove around 100-150 miles on it so far, mostly freeway. And, I can totally feel the difference with the new alignment. It doesn’t tram-line at all now!!! Wow, so much easier and more predictable to drive. I don’t need to worry about those darn little grooves on the freeway anymore. So, I guess the previous Front Toe alignment being pretty off was the main culprit to my tramlining issue. But, idk if the rear toe is good, because of what you've mentioned.

B serious

Your rear toe is fine. You've got .42 total. It says 0.41...but 0.24+0.18= 0.42. So...rounding error on the machine, maybe.

...Anyway, it puts you in the lower/middle of the range. The side to side difference could be better than where it was set.....but you almost for sure won't notice a pull to the left with .06 deg more left side toe in.

0.24 degrees is about 0.10" of toe on the left.
0.18 degrees is about 0.07" of toe on the right.

Sin(X)*25 = answer in inches

**at the tyre...assuming 25" diameter tyres. 255/40/17 is ~25" diameter.

rpg51

This is really interesting stuff. i'd like to learn more about alignments and the impact they have on both performance and tire wear. If you know of a good read on the general topic please post a link.

Also, this mention of "tram-lining" is also interesting. I have the original S02 tires and wheels for this car and I have driven them some. The rears are toast. The fronts have tread. They have about 9K miles on them. They are 15 years old and at this point I plan to use them purely to store the car over the winter. But, I have driven them a bit (carefully) and I notice something like what you describe as "tram-lining" especially when these old tires are mounted. The car seems to track on its own a bit one way or the other as I go down the road (no preference for which side) and it require steering slight steering input to keep it straight. I can't tell if it is related to the road surface but it feels that way. I figured, like you, that this was just the nature of the beast, or that maybe it was just the old worn out tires.

I now have a set of good S04s 17" on front and rear. The rears are brand new. The fronts are 8K miles old but they have a lot of tread left with apparently good even wear. I have these tires and wheels mounted now. It seems that most of that "tram-lining" for lack of a better word is gone now. But, there is still a very small bit of it I think. Not a big deal at all. But if I could eliminate it with my alignment without any negative impact on the other characteristics of the handling and tire wear I would do it. Keep in mind I did just have the car aligned at a reputable shop but unfortunately I did not get the numbers. I was told that it was out, especially the right rear which show by far the most tire wear, and that they put it all back to OEM specs whatever that means.

What is this "tram-lining" thing? Is it the nature of the beast so to speak? Is it a function of the alignment?

Lastly, for folks like me, (spirited street drivers with little understanding of alignments but who want to put their cars in the best possible state for handling and tire wear etc.), what alignment specs should we try to establish for our cars in your opinion?

ZDan

For sure getting the front toe-out dialed out should have made the car a lot more stable for ya!

Regarding rear toe, I think the AP1 spec range is way too high. For sure the max 0.64 degrees is a ridiculous amount of toe, and results in weird nonlinear handling (poor turn-in, car moves around over asymmetric bumps/undulations in the road and over asymmetric wet or other low-grip surfaces), AND kills tires twice as quickly vs. more reasonable toe settings.

For me, 0.41 degrees total is a bit high, but not a total disaster and nowhere near as bad as 0.64. If you want alignment within spec, I'd go with the minimum 0.32 degrees total. Outside the spec, 0.2 degrees is a good place to be. I'd say anything from ~0.1 degrees to 0.25 degrees is fine and will give better more linear handling characteristics and longer tire life. That said, if you are happy with the way the car handles and feels now, you might just leave it.

I have on purpose and inadvertently tried a wide range of toe settings on my AP1 and 240z on the road and at the track, and for me, a lot of rear toe in sucks, bad, for absolutely everything. And running minimal rear toe feels better, more responsiveness and more linear response, on the road and at the track, and gives a lot more rear tire life.
Part of it *might* be driver preference, but I can't imagine any reasonable sports car driver who would *want* the car to be less responsive at turn in while also being more unstable/twitchy over road irregularities and variable-grip surfaces...

(regarding 0.41 total: you can be sure that they get 0.24 + 0.18 = 0.41 because it's something like 0.236 + 0.177 = 0.413 degrees, not that 0.42 vs. 0.41 is anything...)

Jah2000

Cool. Thanks for tips.

Next time I get an alignment, I'll try to get them to do 0.10º to 0.25º Total Rear toe for sure ...because I think that's why my last previous Rear tires became bald so quickly. I remember when I bought the car almost exactly 1 year ago, the Rear tires (even though they were just cheapy Chinese budget tires) had a decent amount of tread on them, maybe only 1/4-1/3 way through its' life. Then when I checked my tires a month ago, they were already completely bald. The Fronts had about the same amount of tread as the Rears when I got the car (maybe even a bit less), but the Rears balded much more quickly (the Fronts had a bit of life left in them still).

B serious

Tram lining is the tendency for the car to follow grooves and irregularities in the road. It can be caused by uneven or excessive alignment angles...as well as by bump steer from suspension deflection...or by tyre characteristics. Some tyres follow grooves more than others.

Alignment settings should'nt be set based on speculation. But, I also agree that I like rear toe setting to be set at the "small" or "straight" end of spec.

Toe specs are often given in totals with permissible crosses. Like 0.50deg total (for example), with a permissible cross of 0.1. Meaning that the total of both sides must equal 0.50...but with a max side-to-side difference of 0.1.

So:
A reading of 0.3 Right and 0.2 Left is acceptable. They equal 0.5 together. And the cross (0.3-0.2 = 0.1) is also within spec.

0.4 right and 0.1 left equal 0.5...but the cross (0.4 - 0.1 = 0.3) is too great and the car will pull to the side with the most positive REAR toe.

It is extremely rare to see negative rear toe as a spec on any car. That causes oversteer and high speed instability. Most cars come with some positive rear toe specd in.

Positive toe = toe IN.

Alignment specs also have tolerances. So and example of the range may be 0.3 to 0.5 total with a max cross of 0.1. As mentioned earlier, I like to tell them to shoot for the smaller end of toe spec. I prefer 0.3 to 0.5 in this example.

Remember...POSITIVE toe.

Camber and caster also have similar min/max and cross specs.

Each angle can be tuned either seperately or in conjunction with other angles to tune the car a certain way.

For a spirted street car I'd recommend:
-Front Camber set to MEDIUM end of spec. If spec is 0.0 to -2.0, I shoot toward -1.0.

-Front toe 0. Or slightly positive. I'm talking like 0.05 deg. Don't go crazy. Try for as close to a 0 cross as possible or the steering wheel will be off.

-Caster as POSITIVE as possible with a max cross of 0.5 deg.

-Rear camber: Toward NEGATIVE end of spec.

Rear toe: Smaller end of POSITIVE. if spec is 0.3 to 0.5, shoot toward 0.3 or so. Keep cross within factory recs or the car will pull.

Rule of thumb: if using negative camber, use a little more positive toe....and NEVER use negative toe and negative camber together...or you'll chew the inside tyre edge.

B serious

Keeping it simple, my ideal street AP1 S2000 would look like (degrees):

Front:
-Camber -1.5 to -2.
Toe: 0
Caster: 5.5 to 6 (being realistic with achievable numbers).

Rear:
Camber: -1.5 to 2.
Toe: 0.3ish TOTAL.

rpg51

Thanks. Very helpful.

I can across this piece for beginners like me - Caster, Camber, Toe