Odd track tire wear?

I am looking for advice on track tire temps and alignment. I have Kumho Ecsta V730 tires on my car. I got 3 track days (about 6 sessions each) on them before the edge started falling off. It happened on the tires at the same time. I rotated side to side and front to back.

My car is a 2023 Audi RS3 - 3600 lbs and 58:42 weight distribution. -2.9 degrees camber and about 8 degrees of caster front, with about -2.2 camber rear, and about .1 degree of toe in. For suspension mods, I have 034 camber plates, rear upper control arms, and rear sway bar.

Pics of the worn tires here. they're almost a cone now. The outside edge is gone on all tires, showing the cords in some parts. I still have 4.5-5.5 mm of tread in the middle though, so really just the outside is gone. I bought another set because they are cheap. They're supposed to be great on wear though. The sidewall wear looks normal though. It is right up the the triangle marker on the tire.

Anyone have similar issues? Any advice? I think my tire pressure might be off. Any thoughts on what I should aim for for hot tire pressure? I am in the low 40s front and high 30s rear right now. Outside wear usually means that pressures are too low, but mine is odd enough that I think too high is possible as well. I don't think I'm overdriving much, but I am doing longer sessions. I'll start doing cool down laps mid session from now on.

It could be a number of things.

You need to get tire temps as a first step.

Are all the tires wearing like that, or just the front?

Looks like not enough camber to me.

I would agree that tire temp readings will reveal all.

40 psi seems really high!  My track car has similar tires but only weighs 2400#.  We run 27psi cold and target 32 to 34 hot.  

I also run about 3.5 degree front camber (but that is with a strut front end).

A good tire temp probe is cheaper than a set of tires.

It does look like insufficient camber, definitely not insufficient pressure with what you're running. But that's strange because the car seems to have a healthy amount of static negative camber right now, and the V730 isn't the kind of tire to get chewed up too easily either.

You can piece together a tire temp probe for under 3 digits rather than paying $300+ for one from a racing equipment company, like this:

https://www.amazon.ca/gp/product/B07H5H1YV9/

https://www.amazon.ca/Thermometer-Thermocouples-Dual-Channel-Backlight-Temperature/dp/B07Z66F4HG/

(I'd bet you could get that exact same reader for a good bit less on AliExpress too)

With that amount of static camber, I would guess you are struggling with understeer due to the awd system and are overdriving the front end trying to bring the nose around. 

Does the wear happen much more drastically on the front tires which is why you are rotating then to the back?

More camber less overdriving. But it's a heavy fwd based platform, to some extent you're just going to have that. More front spring/swaybar might help too.

GameboyRMH said:

It does look like insufficient camber, definitely not insufficient pressure with what you're running. But that's strange because the car seems to have a healthy amount of static negative camber right now, and the V730 isn't the kind of tire to get chewed up too easily either.

You can piece together a tire temp probe for under 3 digits rather than paying $300+ for one from a racing equipment company, like this:

https://www.amazon.ca/gp/product/B07H5H1YV9/

https://www.amazon.ca/Thermometer-Thermocouples-Dual-Channel-Backlight-Temperature/dp/B07Z66F4HG/

(I'd bet you could get that exact same reader for a good bit less on AliExpress too)

Oh, perfect. I've been hoping to find a tire probe that wasn't hundreds of dollars. Thanks!

Front tires are definitely wearing a bit faster, which is why I rotated them. But that is expected with a front heavy car. The issue with the chunking on the outside edge happened to all four tires at about the same time. I don't think it's understeer. The car was actually prone to oversteer stock, because it came with reverse staggered tires. I went to square 265s, but added the rear sway bar and increased front camber by -1.4ish. Now it's more stable and pretty balanced. I'll understeer midcorner if I'm going in way too hot, but there is a slight tendency to oversteer on corner entry and midcorner. I might overdrive a bit on corner exit. It's hard to determine when that is happening sometime because AWD will grip either way on corner exit.

I do have some videos on youtube if anyone wants to check those out. I don't feel like I'm torturing the tires like the wear would have you believe.

Before I rotated, the wear difference was about 1mm or less in the middle (where I can actually measure the wear). So about 4.5 mm compared to 5.5 mm. New they are 6.75 mm, so tons of life if the outside wasn't shredded off.

Most feedback I've gotten is that my tire temps seem high. I've been lowering them pretty much every time out, but maybe I'm still not there. I never had wear like this on my Focus RS with MPS4S tires, which is only about 200lbs lighter, but I'm also running about 10 seconds faster now compared to that car.

Oh, on tire pressure, one more thing to note is that I did switch from factory 19s to 18s. So my track wheels are 18"x9" and tires are 265 35 18s. I think switching to a smaller wheel usually means lower pressure, right? Factory pressure is 44PSI on the door. Ranges in the manual from 44/36 at low load, 44/44 full load, to 49/49 if you're trying to hit 180 MPH. That is for the 19s with 265s front and 245s rear though.

I'll probably try out the pyrometer and put a gopro recording the wheel on a skid pad and see what happens. No idea what pressure I should be targeting though. Especially if I end up with an extremely hot outside again.

From your videos it looks like your negative camber isn't enough for the amount of body roll you're getting, you need harder springs to keep the car flatter in the corners.

265s are kind of a lot for 9" wheels especially with tires that run wide. That's certainly not helping the outer edge wear.

I was thinking of switching to 255s actually. The factory setup is 265s on 9s front, so I stuck with that, but yeah, I may try dropping to 255s.

The videos are from before the rear sway bar. I haven't uploaded my most recent sessions. That might be part of it. I did have like 12 or so sessions on these tires with the factory bar. I also have new bar set to the soft setting. I might need to switch it to the stiffer one.

I considered springs but I'll probably hold off unless I still have this wear issue. 

You've changed multiple things; wheels / size, sway bars, pressures, ???, without having done any tire temps. From what I can tell there is no baseline to compare the changes to. STOP and get a GOOD baseline so you will have a clue as to what each individual change results in. 

So I watched a couple of the videos; your not over driving it the car seems pretty balanced so two things come to mind.

1. you may indeed need more camber but without tire temps we cna't be sure.

2. this may be a "feature" of the car and set up.  My Datsun 1200 gets this really bizarre tire wear in the rear (the inside edge cups out). It's down to the leaf spring rear suspension having limited droop travel............there is no fix beyond rotating the tires or flipping them on the rim.

Even if you use an cheap infrared gun it will at least give you an idea of what the temp difference is across the tire. You're looking to see if the outside edge is higher than the rest of the tire. 

Yep, I bought a pyrometer already. My local track has a skidpad so I'll get a few cones and test it out. I also reached out to Kumho to see if they have any advice.

Following up on this. I went to the track took some temps. Unfortunately, a drift event occupied the skidpad, so I took temps after parking on track sessions. I have the TPMS pressures and temp data as well.

I started at about 30 PSI cold (after driving there), and I settled on about 36-37 hot front and 35 hot rear. This gave a pretty even reading on the outside and middle of the tire, however, the inside was actually the hottest in this scenario. For example, if the outside and middle were about 160f, the inside would be 170 or 175ish. TMPS temps on the fronts were about 210f. It was a 100 degree high day.

I'm guessing the increased inside temp is from the negative camber while braking, or when the inside tires are turning. Camber is at -2.7 front and -2.1 rear right now. Is this something to be concerned about if the tire wear ends up being ok?

No other heat issues at all, so pretty happy about that so far. I think I'm just a little down on power due to the heat, judging by the max speeds on the straights.

xeonoex said:

I'm guessing the increased inside temp is from the negative camber while braking, or when the inside tires are turning. Camber is at -2.7 front and -2.1 rear right now. Is this something to be concerned about if the tire wear ends up being ok?

These will both cause inner tread heating when you're running static negative camber and it's nothing to worry about as long as there's no wear issue.

This item from our back catalog might help set tire pressures: How to set tire pressure, align your chassis and more proper set up tips.

I'm going to go against the grain here...I almost never take tire temps.  I just read the tire wear (noted IMSA engineer Jeff Braun does the same) and use a skid pad (see above story linked by David).

I see not enough camber and too much tire width for the wheel width.  I'd be researching wider wheels.  I personally put 265's and 255's on 10's, minimum.  The GLTC front-running S2K's all run 255-18 V730's on 10.5's.

Note that the wider the wheel/tire combo, the less camber you need (think of a barrel rolling).  So you kill two birds with one stone.

You could also run a different tire that needs less camber and has a stiffer sidewall, such as the RE71RS.

FYI, most of the modern Super-200's run optimally in the 28-34 range for hot pressures in most applications, assuming proper wheel width fitment.  Pinched fitments need to run on the high side of that range, and maybe even more.  They will deliver similar pace throughout the range (think of a bell curve), but feel and wear will be different at each end.

Hey Andy. Thanks for sharing. I actually just read your article on wheel width too. 

Since my car had the odd staggered setup stock, it's hard to find any wheels that aren't custom. Especially 18s. I think I should have gone to a 9.5" wheel or possibly a 10" wheel all around. I initially assumed that Audi knew what they were doing at the time, since they did set the small sedan Nurburgring record with the car. I also didn't want to dramatically change the ride height or rake much just from switching wheels.

It seems like based on the ~.5" wider than tread width rule in your article, I should probably be on the 245/40/18s. I'm curious what it will do to my lap times. I am not racing though, just doing track days, so I'm more concerned about tire life than outright speed. These would also be cheaper, which is nice.

I do think part of it was alignment and tire pressure though. I did drop them pretty significantly on my last track day and ran like 6 sessions in 100 degree weather.

Pics of current wear after 1 track day. I think it looks ok. But the outer tread block is pretty hard to read because it's just a big chunk of tread.

I bought the 265s again, mainly to see if the pressure or alignment was the issue. They didn't really fall off towards the end of the sessions, despite the heat, which is nice. 

If I have the issue again, my plan was to go to 255s, but I think 245s may be the better option now. I'll keep the RE71RS in mind too. They're actually pretty similar in price at the 245 size.

xeonoex said

If I have the issue again, my plan was to go to 255s, but I think 245s may be the better option now. I'll keep the RE71RS in mind too. They're actually pretty similar in price at the 245 size.

If you are running in 100 degree ambients, you should also consider the revised 2023 Nankang CRS.  It has similar heat characteristics to the V730 (needs some, tolerates lots).  And...accomodates pinching better than most (upcoming GRM story).  RE71RS are not found of lots of heat.

As for sizing, yes, rake and such are important, so keeping the OD close to stock is important.  Modern cars can also have ABS and Stability Control challenges with too much deviation from stock stagger %.  That's why wider wheels is usually the best option.

In reply to xeonoex :

I also have a RS3 8Y, springs and rear sway bar. Same issue like yours with my left rear tire (Cup2) after 2 days at Grandsport in Houston. No issues at MSR track both directions. Tire pressures at 32/37 cold/hot. Cups2 front and R888R rear, stock wheels. 

RS32023HOU said:

In reply to xeonoex :

I also have a RS3 8Y, springs and rear sway bar. Same issue like yours with my left rear tire (Cup2) after 2 days at Grandsport in Houston. No issues at MSR track both directions. Tire pressures at 32/37 cold/hot. Cups2 front and R888R rear, stock wheels. 

Are you on stock wheels and tire sizes? And have you done a performance alignment? You might just have a toe issue. Factory has some significant toe in. I went to 0 toe front and 0.5 degrees rear. You can also increase the camber on the rear quite a bit just with the bolt.

The only other theory I've heard is that the bushings are so soft that the wheel/tire shakes under heavy load and braking. Kinda sawing itself.

Also, thanks again Andy for the tire recommendation. Will definitely keep that option in mind when it's available. I try to avoid doing many summer days because of the heat here, but it can be hard to resist sometimes.

@xeonoex apologies for reviving an old thread, but did you ever figure out the cause and solution? I have the exact same problem. I've worn out 4 sets of V730s the exact same way - outside edge is destroyed but the center still has 4-5 mm of tread left. Car is 2016 BMW M235i with -3.5 degrees of negative camber up front, -2.5 in the back. All four tires show the same wear pattern. Running 255 width V730s on 9 inch wheels. Pictures of tire wear and how the car looks loaded up in a corner can be found here https://drive.google.com/drive/folders/1G0V5ER773YOgjVSLld8WhxPVvr5ws7cB?usp=sharing

Video of my driving style here https://www.youtube.com/watch?v=CavIx_4IyYc

Thanks!

Robert

I was about to resurrect this myself actually. My next setup I tried was 245 Conti ECF (before I had the 265 V730s) on my 9" wheels. These pics are after one day. The top tire is my outside front. One below is inside front. The top of each tire is the outside edge.

I thought the outside edge looked bad, but then I took them off and say the inside and they are destroyed. I am at -2.7 camber front and -2.2 rear. Looks like the main issue is braking due to the wear I have here. I thought the more endurance focused ECF should hold up better, but it doesn't seem so. My front tire pressures were in the mid to high 30s hot here. It does seem like a bit of a different issue though.

My theories are:

• Too much heat. I'm usually doing 20-30 minute sessions.
• Track surface. I notice your video is also at MSRH. The track is definitely rough.
• Suspension - Springs and bushing in particular. I've heard issues that the OEM bushing I'm my car are so soft that they move/vibrate under braking and hard cornering. I'm on stock suspension other than the rear swaybar.

I don't think it's tire pressure or camber. Maybe overdriving is a part of it, but our driving seems pretty similar looking at the videos. I don't think either of us are overdriving to the point it would cause wear like this. I've rode with mustang drivers who don't have this issue.

There aren't a lot of people who track their 8Y RS3, but some that don't have this issue do have coilovers. Though I can't say if they're running at the same pace (or how much an issue track surface at MSRH might be).

In other news, I have a 2019 Miata Club on the way. I'm keeping the RS3, but I need something cheaper to run. I have everything else on the RS3 sorted except this tire wear issue.