We're getting some wierd inside wear out of the azenis this season. Basically seems like we are spinning a wheel out of turns so much, its eating up the inside. Looks like a STS Celica tire :)

We might have *too* much camber, but I've already taken 0.5 degree out and don't know about taking any more out. I will take a couple of pics tonight and show you guys what I'm talking about. The tire temps show around 5-10 degrees more inside then outside temps, but with the outside shoulder wear, it seems like we have the perfect camber....

Only theory I have is the extra caster is giving me too much camber change for fast turns and I'm killing the inside of the tire because of this. I'm thinking about backing the caster out a few tenths and leaving the camber the same... (5.8 caster,-2.6 camber)

As far as the # of runs.....We have about 90 runs on the falkens so far this year and they are *almost* done. We will get 12 more runs out of them for the Atlanta SEDIV and they will probably be corded or real close to it. Are you guys seeing more runs out of the falkens or is this about right?? Kind of funny as we bought these first week in Feb. We might go through 4 sets of street tires this year :eek: :eek:

-Tom

Tom,

This wear seems excessive to me. I'm seeing roughly TWICE that much wear life from Azenis, plus a fair number of road miles. You may be on the right track, regarding the caster. I've been running approx. -3.1 degrees front camber, and don't see the same level of inside wear you're experiencing. Another factor - are you still running some big a$$ anti-sway bar? If so, that could be a factor as well.

-Steve

p.s. If the issue is wheelspin, don't discount driving style either - smoothly applying the throttle, versus simply stomping on it can make a big difference. Does your co-driver have a lead foot? ;) :lol:

200 runs??? Wow.....

About 60 of these 90 runs were on concrete though, maybe thats got something to do with it. If we weren't getting the inside wear, we could get another 40-50 runs out of these I bet.....

As far as the swaybar, I'm only very slightly bigger then what you are now. I tried your settings, but I switched back, as the car felt better to me with my settings...

The driving style could very well have something to do with it. I know that for a full practice day he was way overdriving the car, getting it loose and then getting on the gas causing wheelspin. Thats when most of the wear happened. I'm definetly a lead foot myself though. I'm very smooth with the steering wheel, but could definetly work on the right foot smoothness. We did about 40 runs saturday with two bigass sweepers and you could definetly light up the inside tire coming out. It was just like that last turn at Oscoda last year where you were LIGHTING the inside. Maybe those two cases were just it. Since we don't see manuevers like that at most events, maybe I shouldn't worry about it :)

[obligatory **** talking]
The car felt great though, I beat out eric peterson in their new 04 LSD spyder by 0.3 on a 30 second course, and then GH Sharp got me by 0.2 in his AS Boxter S on a 50 second course :) Raw not pax ;)
[\obligatory **** talking]

-Tom

Tom,

I would really like to see the pics of your tires. I am seeing the same thing with mine. Lots of inside tire wear. I run about -2.8 camber in the front, but can't dial it back that much more, because the outside shoulder just gets killed if I do. I run about 47-49 lbs in the fronts.

Not much inside tire spin for me, so I don't think that's a huge factor.

About 120 runs on my tires and they are shot. 30 of those were on concrete.

Corey #89 STS

Yep, I get more wear on the inside, too - most noticeable at Laurinburg, where they wear faster. The inside half of the tire will be worn about the same as the outer edge, while the 25% or so in between those two areas doesn't get that much wear.

-2.2° camber in front, ~ 3.5° caster

It's the same on 205/55/16, 215/45/16 and 225/45/17

I'm nowhere near in the same league, but I took my STi down to Wendover (ProSolo location) for a school and autocross, with a co-driver. We decided to save the race tires and run on brand new Falkens instead (Wendover's concrete eats tires). At that time I was running front +4.5 caster, -1.2 camber front, rear -2.6 camber and 0 toe all around (camber plates hadn't arrived -- I'm up to +5.7 caster and -2.5 camber front with the plates).

We got 12 60 second runs in on Sunday, spraying the tires between runs. Saturday saw 6 autocross runs and a huge amount of school driving (20 runs down a 6 cone slalom, sweeper, 5 cone slalom; 40 runs through an increasing radius corner with pretty big diameter; 40 runs through two Chicago boxes; etc.). Add 700 miles of highway driving. Wear was great - the insides look fine and there is lots of tread everywhere except the outside inch on the front tires where the tread is gone. My RA-1's wore much, much worse when I took them to Wendover and particularly thrashed the outside couple inches of the fronts. My guess is that the added caster and camber on the front will help some with that wear pattern.

Tom,

I'd bet on a combination of the concrete surface & driving style. Almost all my events are on asphalt. A couple weekends ago, I was getting a fair amount of wheelspin coming out of a similar fast sweeper in Milwaukee, but didn't notice any undue wear. Note - the surface at Miller Park is relatively slick asphalt.

-Steve

Thanks for the opinions.

Originally posted by Corey
Tom,

I would really like to see the pics of your tires. I am seeing the same thing with mine. Lots of inside tire wear. I run about -2.8 camber in the front, but can't dial it back that much more, because the outside shoulder just gets killed if I do. I run about 47-49 lbs in the fronts.

Not much inside tire spin for me, so I don't think that's a huge factor.

About 120 runs on my tires and they are shot. 30 of those were on concrete.

Corey #89 STS

That sound the same as me. We'll get right close at 100 out of these, but almost twice as many as you on concrete....

I'm running 44 cold and gets up to 46 hot. That seemed to work the best on concrete. I'd probably take that down a couple psi on asphalt.

The inside half of the tire will be worn about the same as the outer edge, while the 25% or so in between those two areas doesn't get that much wear.

Exactly.

Seems like this might not be a wheelspin thing as the uberpowered RS guys are getting it too :confused:

At that time I was running front +4.5 caster, -1.2 camber front, rear -2.6 camber and 0 toe all around ...snip.... Wear was great - the insides look fine and there is lots of tread everywhere except the outside inch on the front tires where the tread is gone.

That sounds about right. A lot less camber and youre getting that far outside tire wear but probably losing out on the contact patch. (well not anymore with your new settings) How is your tire wear with the new camber plates?

I'd bet on a combination of the concrete surface & driving style. Almost all my events are on asphalt. A couple weekends ago, I was getting a fair amount of wheelspin coming out of a similar fast sweeper in Milwaukee, but didn't notice any undue wear. Note - the surface at Miller Park is relatively slick asphalt.

I think youre right. Sealed asphalt is VERY nice to tires while the asphalt lot we tested on is tough and the concrete surface we have is very rough (although its *exactly* like topeka :devil: )

I'll have pics for you guys tonight when I get home.

-Tom

tom, are you running the 8k/10k setup now? i've noticed a similar wear pattern on my car as rear spring rate increases relative to front. my early conclusion is that the higher yaw angle/rate combined with the cummulative effect of ackerman and toe-out is the culprit. ie, you're "dragging" the inside front tire through the early phases of the corner.

btw, theoretically you can flip the tires to no ill effect. my fronts are mounted inside out and they seem to feel the same, but i've only had 2 events so far, and the only one at devens was 40* and rainy. add to that the tires are the same ones i've had since late may of last year and they've never been on the rear of the car...

nate

Yup, the good ol' 810.

As far as rotating tires. The rears wear the outsides a tad more because of the low negative camber, so I *might* be able to cancel this out by rotating a lot. We didn't bother with these tires before "uhhh shawn, looks like the inside is toast" :lol:

Can you give me a quick "for dummies" version of ackerman. I'm for some reason unable to understand it.....

-Tom

Have you considered how much toe out you might have: http://forums.nasioc.com/forums/showthread.php?s=&threadid=546830

on the other hand ... is it true that our (WRX) excessive toe out is partially negated during loaded cornering?

I have been seeing the same kind of wear, but I figured it was due to excessive amounts of toe out when I add camber.

I assume you guys trailer your car anyway, and have your toe set right where you want it...so this probably does not apply to you.

Kevin

You'd be suprised at how many of them don't trailer their car. ;)

I drive, but I'm currently on 200 lb/in springs (STi V5/RA) with Konis. I also have my alignment set the way it is all the time - no adjusting before runs or anything (toe is zero front & rear). The Hoppemobile is a trailer queen, though. And it looks mighty good up there with the new graphics. Very "race car."

Originally posted by Fred
The Hoppemobile is a trailer queen, though. And it looks mighty good up there with the new graphics. Very "race car."

Only as of this year if I remember right; as of last year he drove it everywhere. ;)

Originally posted by trhoppe
-snip- Can you give me a quick "for dummies" version of ackerman. I'm for some reason unable to understand it.....


ackerman is the term used to describe a difference in steering angle between the inside front tire and outside front tire. positive ackerman, what a wrx has, turns the inside front at a faster rate then the outside front. for example, you turn your steering wheel enough so the outside front turns 7 degrees. the inside front would turn 12 degrees.

toe-out could be considered "dynamic" ackerman. lets say you are using 1 degree of toe out on both front tires for 2 degrees total toe out(you never would use that much, but it works for the example). now you have to turn the wheel a bit more to get the same 7 degrees on the outside front. all that extra toe will result in the inside front being turned more then 14 degrees. (the 12 degrees from before, plus the combined toe out, which was an obscene 2 degrees total toe out, plus the ackerman effect on that additional degree you had to turn the wheel to get the outside front to the same place).

nate

*edit* i forgot to mention. the numbers i used are just random numbers plucked from thin air. they have no accuracy beyond illustration.

All this talk of excess tire wear and no mention of toe settings. :confused:

Originally posted by wrx2.0 555
All this talk of excess tire wear and no mention of toe settings. :confused:

Well we have been talking about toe settings :) Read Nate's post. We're just talking about dynamic toe rather then static toe. I don't know if I already mentioned it in the thread, but I run 0 toe all around.

-Tom

With zero toe ... does your steering feel a bit dead? Do you have the Whiteline steering rack bushings in ...

Nope, those are illegal.

I have poly everywhere else up front though, so the steering is FAR from dead.

-Tom

Hey Tom,

Do you have poly bushings installed in the front control arms? If so, where did you get them? It would be nice to install something to complement my Whiteline caster bushings.

-Steve

Originally posted by MNbiker
Hey Tom,

Do you have poly bushings installed in the front control arms? If so, where did you get them? It would be nice to install something to complement my Whiteline caster bushings.

-Steve

Energy Suspension

-Tom

Originally posted by trhoppe
Energy Suspension

-Tom

I thought they only had bushings for the back of the front control arms.:huh: hmmm...I'm sure Energy Suspension would be a LOT less expensive than the Powerflex bushings Rallispec carries.

-Steve

Nope. They got the front ones too. I don't know the price as I got that whole kit they had.....

-Tom

I bought mine used, and if I remember correctly, the guy said he had maybe 5 events on them. I have personally done maybe 20 events or so, plus an Evo school. Add in maybe 400 miles for the few times when I drive on them to/from events.

They are still in great shape. I'm obviously not pushing them hard enough, because I probably still have 2 seasons left on them.

Update. We pretty much figured out it was wheelspin that is causing the tire wear.

On local courses as well as the toledo pro with the turnaround, we are destroying the insides. In DC with no tunraround and no wheelspin issues the entire weekend, the tires wore perfectly.

I'm going to deal with the tire wear this season, but next year if for some wierd reason I keep my car, we'll figure out something with the front bar/springs to eliminate the wheelspin.

-Tom

I'm going to deal with the tire wear this season, but next year if for some wierd reason I keep my car, we'll figure out something with the front bar/springs to eliminate the wheelspin.

Front LSD and move to ESP:D

Originally posted by BSLICKOH
They are still in great shape. I'm obviously not pushing them hard enough, because I probably still have 2 seasons left on them.

Or you're just a really smooth driver.

Originally posted by ratt_finkel
Or you're just a really smooth driver.

I'd bet on "not pushing them hard enough" ;)

25 events with enough tread left for 50 more is a bit much ;)

We are getting 100 runs out of each set and I consider myself pretty smooth.

-Tom

Originally posted by trhoppe
I'd bet on "not pushing them hard enough" ;)

25 events with enough tread left for 50 more is a bit much ;)

We are getting 100 runs out of each set and I consider myself pretty smooth.

-Tom

True, I'm just saying he may already be riding the ragged edge, and pushing them further would be both slower, and detrimental to tire wear.

Originally posted by Corey
Tom,

I would really like to see the pics of your tires. I am seeing the same thing with mine. Lots of inside tire wear. I run about -2.8 camber in the front, but can't dial it back that much more, because the outside shoulder just gets killed if I do. I run about 47-49 lbs in the fronts.

Not much inside tire spin for me, so I don't think that's a huge factor.

About 120 runs on my tires and they are shot. 30 of those were on concrete.

Corey #89 STS

Corey can attest to to the crazy amounts of inside wear I had last year. I was running full negative with FLEXs (in the -3+ range, I guess) I ran alot last year but only one national and no concrete. I guess I had less then 200 runs.

I backed camber out to -2.5 and am running RAs this year. There is no noticable uneven wear, I've only got about 50 runs on them max so far however.

Jeremy
(glad he didn't bother bringing the Falkins to the Dragon since the car broke and just sat all week in front of the hotel room)


read your update, makes sense. I'm pretty fond of the romp it out of the corner method too. It just doesn't work for me as well as others

me = not smooth