[SDSUsnowboards]

While bleeding my master cylinder and brake lines I noticed a few things. I'm looking for some help in interpreting my findings.

Tires.
I'm running too much camber as evidenced by uneven wear on the wheels. I know that there should be some uneven wear on strut-based cars that run negative camber, as some of the wear will happen while the car is going strait; however, this wear does seem abnormal.

As you can hopefully tell, the left edge of the tire is heavily slanted while the other has retained it's original profile.

I am running ~-3.8 degrees of camber in the front and ~-3.2 in the rear. The tire pictured below has traveled 2 track days on the front of the car, and 2 track days on the rear. As such, it is impossible to tell whether this uneven wear is happening on the front or rear or both. I do know, based on pictures, that the front sees very little body roll whereas the rear sees a lot. How much should I adjust camber?

Brakes.
After 4 track days, all of the brake pads look brand new with the exception of the rear outside pads. The rear outside pads have worn noticeably, maybe a full 1/4 of their total pad width. Is it normal for the rear outside pads to wear faster than the rear inside pads? The piston acts directly on the inside pads, so this seems counter intuitive.

 

[akomsr1]

Only way to know is by using a pyrometer

 

[HeelToeHero]

Brakes.
After 4 track days, all of the brake pads look brand new with the exception of the rear outside pads. The rear outside pads have worn noticeably, maybe a full 1/4 of their total pad width. Is it normal for the rear outside pads to wear faster than the rear inside pads? The piston acts directly on the inside pads, so this seems counter intuitive.

I can't comment on the camber/tire wear, but as for the brakes: I did one track day with dedicated front pads (HP Blue) and left my stock rear pads and about 15 autocrosses on the stock front and rear pads. My rear pads are very similar. I forget if it's the inside or outside, but one is at 25% and the other looks to be close to 75%. I've never greased the "caliper slider pins" or whatever they're called so I put it down to that, but that's a guess. I'm curious if someone can comment as to what's happening with confidence.

 

[sldnrck]

I have noticed that toe in or toe out causes more tire wear than excessive camber. If the wear was just from the rear I would say that it is possible you are getting wheel spin. With lots of rear camber and wheel spin, then you will get inside wear. What Toe setting are you running?

 

[SDSUsnowboards]

I have noticed that toe in or toe out causes more tire wear than excessive camber. If the wear was just from the rear I would say that it is possible you are getting wheel spin. With lots of rear camber and wheel spin, then you will get inside wear. What Toe setting are you running?

Zero toe angle front and back (I think...).

 

[rocwandrer]

Tires: That is a terrible picture, but the tire wear looks like the sort of wear that happens from a combination of a lot of camber with a toe error that is decently bad. My limited experience has been that with the same alignment, some tires will exhibit that wear really bad and feathering a little, where as other tire constructions will exhibit not much of that wear and a lot of feathering. I have been extremely frustrated by this issue with my wife's Mazda3. It took aligning the car with typical weight in the car and being super picky about the specs to fix the problem. Oddly, before we fixed the alignment, we has run summer and winter tires about the same miles, the winter tires had very slight feathering and a hair more wear on the inside 2" of the tread, but the summer tires looked like your tires.

Run your hand over the inflated tire around the rolling surface in one direction. Then do it the other way. Is there slightly more resistance or fetching up of your hand against the tire one way than the other?

Brakes: A stuck piston can cause more wear on the inboard pads. A sticking slide can cause more wear on the inboard pads, or it can cause more wear on the outboard pads depending on what is going on with it. I suggest checking your slide pins for radial sloppiness, and checking pistons and slides all around for ease of travel. I also suggest checking the thickness of your pads with a caliper. Is there even wear across the width and height of each pad (my bet is not).

Anybody have an idea on the amount of freeplay allowable in the caliper slides?

 

[SDSUsnowboards]

Tires: That is a terrible picture, but the tire wear looks like the sort of wear that happens from a combination of a lot of camber with a toe error that is decently bad. My limited experience has been that with the same alignment, some tires will exhibit that wear really bad and feathering a little, where as other tire constructions will exhibit not much of that wear and a lot of feathering. I have been extremely frustrated by this issue with my wife's Mazda3. It took aligning the car with typical weight in the car and being super picky about the specs to fix the problem. Oddly, before we fixed the alignment, we has run summer and winter tires about the same miles, the winter tires had very slight feathering and a hair more wear on the inside 2" of the tread, but the summer tires looked like your tires.

Run your hand over the inflated tire around the rolling surface in one direction. Then do it the other way. Is there slightly more resistance or fetching up of your hand against the tire one way than the other?

Brakes: A stuck piston can cause more wear on the inboard pads. A sticking slide can cause more wear on the inboard pads, or it can cause more wear on the outboard pads depending on what is going on with it. I suggest checking your slide pins for radial sloppiness, and checking pistons and slides all around for ease of travel. I also suggest checking the thickness of your pads with a caliper. Is there even wear across the width and height of each pad (my bet is not).

Anybody have an idea on the amount of freeplay allowable in the caliper slides?

I wonder if the mechanic did not trust my judgment and gave a more 'street' alignment than what i asked. He swore up and down he did it to my specs. Upon visual inspection, Silversprint doubted I had as much as -3.8 degrees of camber in the front, and he has a lot more time around cars than I do. So, now I am in doubt about my zero toe....

Does it change your assessment much if I told you that on both sides of the rear the inside and outside pads are worn the same? In other words, on both sides of the car the rear outters are more worn than the rear inners. They look about even. now that I think about it, i haven't greased the pins since I bought the car 80,000 miles ago. Welp, that seems to fit with your assessment.

Sorry for the picture. My brother took it with a camera, then we found we couldn't get it to a computer. So then he took a photo of the camera's display with his phone. It appears surface resistance is equal in both direction. What do you mean by 'feathering?'

 

[Cap Weir]

IF your picture represents an Inside Wear pattern for the tire being on the front..

I've had that problem from the start on my Spyder..

Did new Struts, and Front tires.. and the problem came back.. All is tight.. I just swap the tires on the rims to get the Inside to the Outside .. and let it wear there for a while..

This last set of tires will only go 1/2 the distance of my first set.. ( Only 50K Miles instead of 100K ).. I am blaming this on a 'Squishier' tread .. as my Goodyears are no longer made in the Size I want..

EDIT:..

I use these numbers from the Sticky.. My actuals are close..

Caster: 3.13 +/-.75, L-R diff .75 max (not adjustable, if this is out of spec, start looking for bent parts. Expect a perfect car to have more caster on the passenger's side than driver's side).
Front camber: -1.0 +/-.2 L-R diff .1 max
Front toe in total (total): .0 +.1/-.05 L-R diff only affects steering wheel centering
Rear camber: -1.0 +/-.2 L-R diff .1 max
Rear toe in (total): 0.1 +.1/-0 L=R diff .1 max (this is 1/4" error in tracking over the length of the car)

Cap

 

[Levi]

I can't really tell much from your photo but I will just say that I've never seen a car that sees autox/track duty wear the RS3 any where near even unless you flipped them halfway through their life.

http://www.s2ki.com/s2000/topic/839...gestone-re-11/page__p__20052794#entry20052794

I think your tire wear is normal but I'd really need a better pic to be sure. Maybe I'll take a photo of my RS3s tomorrow to compare they are at like 1/32 =)

 

[SDSUsnowboards]

I can't really tell much from your photo but I will just say that I've never seen a car that sees autox/track duty wear the RS3 any where near even unless you flipped them halfway through their life.

http://www.s2ki.com/s2000/topic/839...gestone-re-11/page__p__20052794#entry20052794

I think your tire wear is normal but I'd really need a better pic to be sure. Maybe I'll take a photo of my RS3s tomorrow to compare they are at like 1/32 =)

Yes, the wear exhibited by that RS3 in the picture is very similar to the wear I am seeing, except reversed. His outside edges are worn in the same manner in which my inside edges are worn. So, normal, then?

I don't own a camera, so pictures won't be forthcoming. If you could post yours then I can compare. Akomsr1 is correct, I probably need a pyrometer to gauge how my tires are being used.