Wear on outside of tires - suggest suspension upgrades?
 

Hi all,

Had my first HPDE course and noticed that my tires (Michelin PSS) were exhibiting quite a bit of uneven wear toward the outside. I'm running camber bolts up front right now (-1.3). I noticed that my friend's twins were all running less wear than mine (guessing the extra grip from the PSS giving it more roll).

Was wondering what mods you guys would suggest to combat this issue / increase camber. Wondering if it's worth spending money on camber plates / RLCA or just save up for proper coilovers that come with plates. I have my eyes set on Ohlins R&T but not sure I want to drop that kind of money right now. The other option is that I could just put stock wheels/tires back on for now and save my PSS from getting chewed on the outside.

Appreciate any advice / comments you may have. Thanks!

could be case of overdriving the car/tires


do you have any video of yourself driving (specifically your hands)


while more camber and stiffer anti roll will always help, driving beyond the limits of the tires will have them wear down sooner.


did you log your pressures and tire temperatures? Which track was this and how long were your stints?


doing 15 hard laps on street tires is bound to burn through the rubber much faster than doing 3 sessons of 5 with only 1 or 2 being aggressive laps.

A lot of what I've been reading on this forum says that ~2 degrees of camber gives you the best wear pattern

^ to many variables. There is no magic number that fits every tire, spring, swaybar, ride height, track situation.

-Hot tire pressures when coming off track?

-any suspension mods other than the camber bolts?

-As 7thGear said, video preferably in car?

Next time log tire pressures, and if possible tire temperatures at at least 3 points across the width of the tire (inner shoulder, center and outer shoulder).

If you're overdriving the tires you'll get similar wear to not enough camber or too little tire pressure, but the data will look very different.

Thanks for the suggestions guys - I've got footage, will upload tonight. Suspension is stock other than camber bolts (set at roughly -1.3 all around). It was my first time out on the track so a lot of it definitely has to do with driver experience / perhaps over driving.

It was at the new Mosport DDT, ~15 minute sessions.

Between sessions, I was reading ~37 PSI.

stiffer side wallz! :p

More negative camber is the answer.

I agree with above, could be overdriving, could be wrong pressures, could be lack of camber. Could be a combination of all.

Also pics of tires before and after event please.

Will post tonight. Before pictures - tires were new, possibly ~300KM of city driving.

How long after you got out of the car were they reading 37 psi: immediately, some time later, just before going back out again?

Read 37 probably ~45-1 hour after a session. Probably should've been more diligent during the day to take readings right after.

Yeah, if you want to stay on top of tire temps, you check them immediately after you come in, if only to record them and then come back later to adjust them. On a course as twisty/turny as DDT is, they could have been as much as 8 psi higher out on the course than they were when you checked them.

Hey guys, here's some pics. For info, these were essentially new coming in to mosport DDT. Lapping done in 15 minute sessions, 5 sessions in the day. Tires were 33 psi cold in the morning. Video footage of driving to come (with steering inputs)

http://imgur.com/MumbHTN.jpg
http://imgur.com/ZAHrxe7.jpg
http://imgur.com/Kq0R2UN.jpg
http://imgur.com/OR6e76i.jpg
http://imgur.com/6lwbCsA.jpg
http://imgur.com/rB6gUvr.jpg


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That's nothing :D That's not really uneven wear at all, just using more of the tire width. It doesn't look bad at all. If you see a major difference in tread depth, or are wearing way over onto the shoulder then you should change something, but based on the pictures I wouldn't worry at all.

From last year, I've got some wear another 1/4" into the triangle now, camber bolts maxed out, swift sport springs, running about 37psi cold.

https://scontent-a-ord.xx.fbcdn.net/...12525523_n.jpg

If anyone's interested - here's some gopro footage of one of the later sessions that day. Remember, I'm a complete noob!

[ame="https://www.youtube.com/watch?v=y-pGmDUDMbE"]New 2014 MOSPORT DDT | Scion FR-S | Gopro footage - YouTube[/ame]

You're not wearing the tires too badly, but you definitely need more camber.

RaceSeng camber/caster plates for the front, SPL LCA for the rears. You won't outgrow either one, and you'll get the camber you need now.

High end dampers are available as just dampers without top hats; all you need is the spring perch, bushing/bearing, and top nut ($160 total), and you continue to use your RaceSeng plates.

Please don't wear motorcycle helmets, get a proper Snell approved helmet designed for cars..and, the outside wear looks normal considering the amount of camber..

I'm far from convinced that, short of a HANS-equipped helmet, anything over a cheap DOT helmet is really going to make a difference. I don't have a roll bar. I don't have a turbo or flex fuel kit to burn the car to the ground. SA helmets cost more, usually have less visibility, and definitely offer less choice. I HATE my SA2005 Pyrotect. The only reason for a beginning driver to get an SA is, from what I can tell, to allow them to drive in events that require an SA helmet. It just sounds like a marketing scam more than anything. Not like Snell has a perfect history of testing. The 2005 designs are supposedly unsafe in smaller helmets.

you don't need to have a roll bar to benefit from a helmet specifically designed to take multiple hits (as opposed to one single impact with motorcycles) and even stock cars can catch a fire in an accident..:)

The HJC AR-10 he's wearing is an SA Snell rated helmet that has attachment points built in for HANS device; the logo on the back is specific only to the HJC automotive racing helmet line - hence HJC Motorsports moniker. Know your helmets... :slap:

Tire wear looks absolutely normal...barely scuffed in.

OP... one suggestion would be using your gearbox more. Is there a particular reason you really didn't shift at all after getting on track, going into slower turns with the engine in the absolute worst part of the torque dip? Being in the correct rpm range makes a difference in how the car sets the chassis to turn in. The car won't turn as well when bogged down verses when you are in the power band and able to control the yaw much better. You need weight transfer to better control turn in...whether under braking or acceleration - being in the torque dip range is not good for weight transfer.

The two go through the same testing; unless you're in a race car, there's no appreciable difference.

The difference in testing standards is fire resistance (non-issue unless you mess with your fuel system), and multiple impacts (to simulate hitting your cage/roll bar).

The difference in design is the opening for the visor; motorcycle helmets typically have superior visibility.

@Vracer111 thanks for the comments - Yup, didn't shift much, this was my first time out, and decided to work on lines and keep it simple :) that's a a great point you bring up about how it affects balance and turn-in, hadn't thought about that.

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wear doesn't seem that bad


but given the amount of offs you had it did seem like you scrubbed yourself off the course a number of times... curious why you simply didn't apply brakes and went on your way?


keep an eye on those hot pressures. Too much air in a street tires for many laps (and it was also a hot day) will wear them much quicker.

Interesting point on the triangles. I noticed the other day that the triangles on my front tires are almost worn out, and I've got some chunking on the outer tread blocks.

I think I need to put some camber bolts on my car before my next track day and probably inflate my tires higher as well.

I'd attribute it just to inexperience, wasn't comfortable slamming I the brakes. ABS was kicking pretty hard during the day, I'm still on stock brakes and lines. Will look to upgrade these before I heard out again. Thanks for your comment!

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not ABS, it was your traction control, which you've left on, if you look at your own video you can see the thing blinking every time it engages.. which was a lot


while it can certainly keep you safe in a structured environment, I would suggest you start practicing with it off as soon as possible, those counter-steer skills and feeling the back end coming loose are absolutely vital




having said that my first time in the car at MIR I left everything on, lol

@7thgear thanks man - gobbling up all the advice I'm getting, this is why I love this forum community.

No offense to either you, or the OP, but I 100% disagree here. If someone can't hit the turn in, apex and exit 100% of the time, as well as rolling on the throttle correctly, then downshifting is the last thing they need to be worrying about. At 60-70% of the limit that's really not a factor either.

Plus, you can't tell from the video, but most of the corners where you might drop to 2nd end up forcing you to shift at really bad places (either short shifting, shifting mid corner or riding the rev limiter until it's straightened out).

That track in these cars are perfectly happy to blast around in third all day long.

Same track, me driving. Laps were picked so I could look at where downshifting helped and where it didn't.

[ame="https://www.youtube.com/watch?v=ZvIRxuxcLe8"]ATTS Lapping - May 24th 2014 - YouTube[/ame]

Upgrading pads/lines/fluid won't stop ABS, if anything it'll make it easier to trigger ABS than on stock pads.

Honestly, I wouldn't worry about modifying anything else just yet, just get more seat time. Add more camber if you want, but I wouldn't let that hold you back or get into your head too much. IMO, you need to work on being smooth with inputs and hitting reference points more than more mods.

If you're going off and having TC/VSC kick in at less than 100% speeds then the best "upgrade" is more practice. My video is with VSC in sport mode, and it didn't intervene at all. There's still LOTS of time left on the table in my laps, but that wasn't my goal for the day.

I totally agree that playing around with VSC totally off is crucial for developing driving skills, but I would do that in a lower speed environment first. A driving school or autox is a much better setting than an open track (even a slower track like the DDT) for a beginner.

Check out the OTA or BMW club (don't need a BMW) schools, they're a full weekend and include in class, skidpad and track sessions.

right, apparently when I saw the passenger's helmet I didn't pay attention to his ..enough hijacking back to topic :)

@wparsons, I completely agree with you - my #1 concern is to get in more practice. I could tell the huge difference run between runs #1, 3, and 5 during the day so it's clear to me that more seat time will yield the greatest results at this point. Regarding camber - I don't see it as hindering my performance (as I have much to learn), it's more so to protect the tires - PSS isn't cheap on my budget and might consider doing more learning on my stocks until I get better. Thanks for taking the time to write all that - greatly appreciated!

At track temps, the stock tires supposedly grip the same as MPSS. At street temps, the MPSS are leagues ahead. The MPSS are also cheaper when new.

I wouldn't worry too much about the wear, even if you're wearing the outer edges more on the track, you'll be wearing them less on the street so it'll even out unless you spend A LOT of time on the track.

Once you go beyond ~2* you'll start seeing more wear street driving, so it's all a balance.

What school was this with? It seems odd that even with putting two wheels off the instructor wasn't really saying a whole lot. Did the instructor show you the line with them driving before you got behind the wheel?

Was with Hanson, instruction was pretty good - had a chance to ride with the instructor as well mid-day. I would have liked to have a chance to learn the line in car with an instructor before heading out myself but it was new to even most of the instructors it seemed. To his defense, this was later on in the day - he was much more instructive earlier on and knew that was a corner that I struggled with (turn 3, always coming in too hot on first lap). Let's just say my exhaust was loud and he wasn't exactly yelling into my ear.

From the schools I have done, if you're making big enough mistakes to go off (even two wheels off), you're forced to slow back down and prove you know the line and reference points at ~60% speed again before you're allowed to run faster again.

Until you can nail the turn in, apex and exit at 60% it is extremely counter productive to go any faster. Once you have it nailed at slower speeds, progressively add speed but make sure you're still nailing all the reference points.

I don't even see any wear on those tires. I can show you what wear on the outside of a tire looks like if you want, haha.

Yep. Generally tire pressure is used to determine how much of the sidewall you are using while camber will correct the wear pattern across the tire.

That's good to know for the future. Tough this time as I have nothing to compare the experience to. Got flagged first session for not letting people pass fast enough (think it was an error in judgment by one of the marshals as we were letting cars pass in droves) - that kinda lit a fire on my ass to go a bit faster and it definitely pushed me to keep a faster pace than I would like to practice re: reference points.

Don't let something like that light a fire under your ass man. You will get the red mist and bad things will happen. Drive your pace and follow the passing rules. Make sure you feel comfortable and sneak up on improvements. Don't go out there and drive other people's line or get upset when you are giving point byes. Speed will come with time.

Got it, thanks for the info. After adding whiteline camber bolts, ~3 psi tire pressure, and doing a tire rotation, I'm hoping to see better wear on the front tires.

The rears are wearing about the same rate as the fronts, but with much more even wear pattern across the tread. Thank you multilink rear suspension? :)