Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB

Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB (https://www.ft86club.com/forums/index.php)
-   Suspension | Chassis | Brakes -- Sponsored by 949 Racing (https://www.ft86club.com/forums/forumdisplay.php?f=59)
-   -   Help figure out this uneven tire wear. (https://www.ft86club.com/forums/showthread.php?t=141590)

Irace86.2.0 07-23-2020 09:38 PM

Help figure out this uneven tire wear.
 
I'm looking for advice to fix the uneven tire wear, if it is even a symptom of something other than my driving style. My driving style is commuting 3-5 miles to work. I pretty much drive aggressively and hoon a little with sliding the car around. I don't know if I am hooning more to the right or to the left, which could explain the uneven wear. I do notice under heavy acceleration that the car seems to torque more to one side than the other, as if the motor is twisting and loading up one side, which is the passenger/right side, or maybe it feels as if the right rear is thrusting the car more than the left rear, such that the car always seems to kick the rear out to the driver's/left side (if I can remember correctly).

On my short commute, there is a sweeping reverse 'S' shaped turn I take pretty fast, and it is a right hand turned followed by a left that requires hard braking if the light is red. Nothing too crazy.

Besides commuting and hooning, I go on canyon runs several times a month. The car doesn't see too much long, highway, road trips any longer, but there were some in there.

My car has a Harrop SC with E85 at 12-13 psi. The car is lowered 0.9'' on Eibach Pro springs, but my tires are slightly larger than stock by 3% because I wanted to fill out the wheel well more for aesthetics. I have bushings and other mods available in my build thread (link in my sig). Wheel and tires are staggered as follows with slight tuck in the front and slight poke in the rear:

-XXR 530 Black Chromium 18x7.50 +38
-BF Goodrich Sport Comp 235/40/18
-XXR 530 Black Chromium 18x8.75 +33
-BF Goodrich Sport Comp 265/35/18

I am planning on getting Michelin Pilot Sport 4S when I need a new set of tires, but until then, I want to have a plan to dial in my setup because I don't want such uneven tire wear if I can avoid it, so the tires last longer.

The tires have 30-35k miles on them. Mounted during March of 2016.

Right/Passenger front
https://i.imgur.com/28XPQT9.jpg
https://i.imgur.com/2PRu0rx.jpg

Right/Passenger rear
https://i.imgur.com/hxEHarM.jpg
https://i.imgur.com/J9NbX0j.jpg

Left/Driver front
https://i.imgur.com/WUEOpBr.jpg
https://i.imgur.com/JSqkZnn.jpg

Left/Driver rear
https://i.imgur.com/wECQSh4.jpg
https://i.imgur.com/g0dui44.jpg

Just in case the pictures aren't clear. The rears have inside wear. They aren't horrible, but the outsides look much newer than the insides, and the right rear is slightly worse than the left rear. The fronts are worse. The inside versus outside wear ratio on the right front looks pretty bad like it will need replacing soon, yet oddly, the left front looks pretty good in overall wear and in the difference between the inside and outside of the tire. Again, it seems odd that the front has a one tire in the best shape and one tire in the worst shape.

I never had an alignment, so I suppose I could start there, but I'm not entirely sure if a proper alignment can be done on tires that have uneven wear. Can it? I considered having the tires swapped right to left by having them remounted and rebalanced, which will cost about $160 and could be done because the tires aren't asymmetric. I don't know if this is worth the money, or if I should just drive until I need new tires. What do you think?

Everyone is going to have a different opinion on what alignment settings I should have from those that like a stanced/camber look to guys that are going to get on my case for not having a square setup because square is the best for the track. If you could set your own preferences aside then what would be a good setup to balance the performance of my driving style with tire longevity and what would you recommend to achieve such a setup? Is the tire wear typical, and I need to not do anything--perhaps an alignment at most? Does the wear patterns look like I have a toe problems? Do I need to buy some LCA or something to fix the camber?

Thanks in advance :thanks:

Jdmjunkie 07-23-2020 09:45 PM

I would suggest to find a knowledgeable alignment shop and have it done. Any time you change out anything in the suspension you at least need to have the tire alignment checked.

Ohio Enthusiast 07-23-2020 10:26 PM

Definitely check the alignment, and check all suspension part while at it for play. I don't think the current state of the tires should impact the alignment measurements (it's measured against the rims, not the tires). If you want to be 100% sure, leave the setup as-is for now (although current tires look worn out completely), and get an alignment done right after getting new tires.
Inner edge wear is typically due to negative camber, which is both beneficial for spirited driving and is a consequence of lowering (although a 0.9" lowering should barely introduce 0.5 degree of negative camber). If all the camber you have is the stock camber plus the lowering camber, I don't think it should have had such an impact on unevenness of wear, though.

Tanstin 07-23-2020 11:18 PM

Like Ohio said, my immediate first impression was that you might be running too much negative camber

Definitely recommend checking your alignment though.

Sent from my SM-G950U using Tapatalk

redlined600 07-24-2020 12:20 AM

If you only have springs there isn't much you can do in terms of camber. You likely have some toe change from lowering which is wearing the inside of the tires. Take it to a reputable race shop, or at least a shop that will work with you to hit your targets. Have them check/adjust to zero toe/thrust front and rear, or maybe a small amount of toe in in the rear if you feel you need to stabilize the car.

Additionally, you could have around negative 1.5*ish of negative camber in the rear from lowering, if you're mostly accelerating hard in a straight line that's having a negative effect on the inside of the tires too. Probably not horrible but it all adds up over time.

Or take your car to an autox or track day and then complain about killing the outside edges.:bellyroll:

churchx 07-24-2020 06:32 AM

Tires don't affect alignment. Their uneven pressure though might (if measurements are taken with car weight resting on tires). Hence alignment procedure in competent suspension shops include checking/evening tire pressures prior alignment.

As to OP, first thing to fix car tendency to always slip to one side and not tracking roughly straight even with rear wheels slipping, would be toe, get it precise & even (that is if all is ok with tire pressures. Once i had unnoticed low pressure in one wheel, and it also tended to go to one side under gas).
More inside wear = too much negative camber for type of driving you typically do. Unfortunately stock our cars have only toe adjustment, not camber. For rear camber adjustment one needs adjustable aftermarket LCAs. Hmm, but stock our cars have ~ -1.1 rear camber, which shouldn't add noticeable camber wear. I guess more camber wear comes due you being lowered and thus have more rear camber (eg. -2 or more) and thus it is probable culprit of rear inner tire wear.
As i don't use tires >3 years even if they still have sufficient thread, i wouldn't bother much, just get next new set of tires. And you can rotate tires to even out wear (that is if tire setup is square). Right now rear right seems past evening wear by rotation, but you can do that/apply to next tire set, every year driving with different tire there.

DarkPira7e 07-24-2020 07:55 AM

Sounds like the camber is eating away at the inside. Something note worthy is that just because the springs are the same height on both sides, it will affect camber differently.

Just for fun, check the condition of the roads where you're stopping and making a right hand turn. Maybe there's dirt that's allowing your DR tire to spin if you're getting on it there, our limited slips are not great under those conditions. I know in my E36, there was a left hand turn that I had to stop for. It was down a hill, so I could never resist letting the back end come out as I pulled onto it. It caused me to go through a couple sets of rears in short order until I got over it and decided to increase my grip in the rear so I'd stop being able to spin them

Breadman 07-24-2020 08:22 AM

the first 2 look like camber wear but it could be toe too. it is hard to tell in the pic. the next one is over inflated tires since the center is wearing faster than the outside. next 2 are definately camber because you can see how the tire is wearing into a cone shape. the last 2 look fine.


you need an alignment and look up a load rating chart for your new psi

N_Raged 07-24-2020 09:35 AM

1 Attachment(s)
Looks like a combination of toe wear and camber wear.

Yoshoobaroo 07-24-2020 09:51 AM

Help figure out this uneven tire wear.
 
You’re not cornering hard enough.

p1l0t 07-24-2020 09:52 AM

I had a similar issue (much worse on the tires though) I got a new set of tires and an alignment. Problem solved. You probably don't need new tires just yet though.

Sent from my SM-G975U using Tapatalk

Racecomp Engineering 07-24-2020 10:08 AM

If you haven't gotten an alignment since installing the springs, you need an alignment.

And if you had an alignment before you need an alignment again just by looking at the tires.

Even tire wear on a street car with -2 or so degrees camber front and rear is not hard. Toe is the tire killer.

- Andrew

Yoshoobaroo 07-24-2020 11:35 AM

Quote:

Originally Posted by Racecomp Engineering (Post 3351650)
Even tire wear on a street car with -2 or so degrees camber front and rear is not hard. Toe is the tire killer.

- Andrew

But it’s impossible if you don’t ask for a custom alignment. If you go to a shop and just ask to align it they will set the toe to factory, which is too much for -2* camber.

You need to align the front to zero or near zero. Only way to reduce the feathering on the inside. Keep in mind the inside will still wear more quickly to a certain extent. That is how camber works.

Irace86.2.0 07-24-2020 01:03 PM

I’ll make an appointment for an alignment then report back.

Tire pressure is usually 38-42 in front and 34-38 in rear. It never is higher unless the tires are getting hot. Typically it is lower.


All times are GMT -4. The time now is 04:18 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2026, vBulletin Solutions Inc.
User Alert System provided by Advanced User Tagging v3.3.0 (Lite) - vBulletin Mods & Addons Copyright © 2026 DragonByte Technologies Ltd.


Garage vBulletin Plugins by Drive Thru Online, Inc.