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Strange tyre temp behaviour
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(31 posts, started )
#1 - samjh
Strange tyre temp behaviour
I tried the tyre temp view yesterday while hotlapping in a FBM at Blackwood GP.

I noticed something strange with the tyre temperature which I hope some of the more experienced players here can explain. My front-right tyre runs hotter than my other tyres. The three other tyres peak at around 90C, but the front-right reaches over 100C.

Given the track configuration, I thought that the front-left or rear-left tyres will heat up more, but this doesn't seem to be the case.

As far as my driving is concerned, I occasionally seem to lock the rear-right at the first corner after the pit straight, and at the end of the long back straight. But that would mean my rear-right should be heating up, not the front-right.

What could be causing this?
#2 - JeffR
This could be related to which side the driver is on (left or right). I've noticed that the front tire on the side opposite the driver seems to get hotter than the front tire on the same side as the driver when braking.
#3 - samjh
It's FBM. The driver is in the centre.
Tire pressures in your setup might have a low pressure for your front-right. Tire pressures can effect both grip and temperature by a lot. It you could be locking it, although that doesnt seem to be the case as you mentioned you were locking the rear so naturally that makes me assume you've already checked that for the front...
#5 - Woz
It might just be your driving causing the load on one of the left corners on the track. Here are some possibilities.
  • If you have slight turning forces when you brake for a left corner it will cook that tyre more.
  • You might be touching the grass with your right tyre so next time you brake it is more likely to lock that wheel earlier than the other.
  • It might be caused by understeer out of a left bend as that would stress that tyre more.
Watch a replay and go into forces mode in a chase cam. (f key for forces and keep pressing v until in chase). You will now be able to see all the forces on the wheels to see if your technique or a certain part of teh track causing it.
answer is VERY simple, as I suffer from the same: if you watch your replays, you'll see your front right locks up on braking into t1. Then, in the last turn, it heats up quite a bit again, so both effects accumulate quite a bit of temp. the 2 other long left turns (in the first and second chicane) dont heat up, but prevent cooling down. End result is that tyre overheating. You can either raise temp a tad, lower brake power, push brakes to rear, stiffen front bump damper, stiffen rear rebound damper, or softe, front rebound+rear bump dampers. I'd suggest all of the above, but just 1 click each. Then choose one and add a tad more, and more till it is under control.
you might be turning the wheels to far in right had corners.
#8 - Gizz
hhmm strange, there are a few things it could be though....

most obviouse is pressures, some people like low presures on that wheel (for BL1) as in normal curcumstances its near impossible to get heat into it, so just guve that a quick check over (although you have probably already done that)...

parralel steer has caused me to get some strage heating cycles in the past this is normal if its very low (non paralel) ....

your camber could be WAY out and causing scrubbing in the bends and high temps...

but to me it sounds like you have understeer on exit, if the right rear seems pretty mutch ok thats what it normal is, BUT you say the front left is ok, soooooo, clutching at straws here but i would say its in that ballpark, personly i would take a look at your damper setup, that tire should not be getting that warm on that track...

as for braking for t1 you dont really lock up the front right for because the left will give first due to being on the rummble strip (if u use it) pluss 9x outa 10 you have less pressure in the right tires giving more grip under breaking .... so if any tire SHOULD give its the left.....

IMO its a BIG damper problem coupled with driving style

hope ya get it fixed
what!?!? I always have the right front tyre heating up on a track with many left hand corners. I thought that was normal. Easing up on locking tyres under braking is the first thing you can do.
blackwood is a right handed track, stigpt is correct its caused by you locking the front right hand wheel when braking for t1 and turning in its lifting the weight off that corner, theres only 2 real left hand turns on blackwood both are smooth turns with no braking required. just be careful when braking for t1
Quote from samjh :I tried the tyre temp view yesterday while hotlapping in a FBM at Blackwood GP.

I noticed something strange with the tyre temperature which I hope some of the more experienced players here can explain. My front-right tyre runs hotter than my other tyres. The three other tyres peak at around 90C, but the front-right reaches over 100C.

Given the track configuration, I thought that the front-left or rear-left tyres will heat up more, but this doesn't seem to be the case.

As far as my driving is concerned, I occasionally seem to lock the rear-right at the first corner after the pit straight, and at the end of the long back straight. But that would mean my rear-right should be heating up, not the front-right.

What could be causing this?

Check your setup... Do you have low parallel steering and/or big toe-out? It could be your right inside wheel is constantly scrubbing through the right turns...
#12 - Gizz
im sorry i fail to see how braking on t1 would cause that!, that wheel as got the best chance of holding under braking there, the weight is on that corner and lower presures hence way more grip!, TEST it and watch in forces view on a replay, its the most stable wheel of the car, unless you have 99% front brake bias!!...

as for the left handed turns on BL, ok theres no braking but the car is accelerating hence the exit oversteer...

looking at t1 your wasting your time unless you have 30deg camber on the right wheel, its near enough imossible to get that wheel to lock and and not the left wheel with it!

your understearing somewhere! is my thoughts
#13 - Gizz
Quote from bbman :Check your setup... Do you have low parallel steering and/or big toe-out? It could be your right inside wheel is constantly scrubbing through the right turns...

exactly
I was had assumed that samjh wasn't locking the tires.
Have it happen to me all the time, if you notice most of the corners except 1 on blackwood are right hand turns, so maybe there is more friction or more force being put on the right side front than the left side.
Thats what i thought it was.
Quote from Gizz :im sorry i fail to see how braking on t1 would cause that!, that wheel as got the best chance of holding under braking there, the weight is on that corner and lower presures hence way more grip!, TEST it and watch in forces view on a replay, its the most stable wheel of the car, unless you have 99% front brake bias!!...

as for the left handed turns on BL, ok theres no braking but the car is accelerating hence the exit oversteer...

looking at t1 your wasting your time unless you have 30deg camber on the right wheel, its near enough imossible to get that wheel to lock and and not the left wheel with it!

your understearing somewhere! is my thoughts

well without a replay its hard to say, but your statment "that wheel as got the best chance of holding under braking there" doesnt make sense to me, the rears will not lock with a good setup as the bias will be to the front, the left front has the most weight on it as it on the outside of the car so to me the right front is the one that will lock if any, i remember running fox and f08 round there right front were forever locking. but my thoughts are only based on those cars as i have not driven the fbm round there yet
Quote from bbman :Check your setup... Do you have low parallel steering and/or big toe-out? It could be your right inside wheel is constantly scrubbing through the right turns...

Other way round. High parallel steering will cause lots of scrub during tight turns. Try driving with 100% then with 33%. Apart from losing some understeer, you're front tyres should run cooler.
#18 - Gizz
Quote from andybarsblade :well without a replay its hard to say, but your statment "that wheel as got the best chance of holding under braking there" doesnt make sense to me, the rears will not lock with a good setup as the bias will be to the front, the left front has the most weight on it as it on the outside of the car so to me the right front is the one that will lock if any, i remember running fox and f08 round there right front were forever locking. but my thoughts are only based on those cars as i have not driven the fbm round there yet

ok i see where your comming from,

as regards brake bias your right if your just braking, but throw engine braking into the bowl and the rear's can lock pretty easy as the is no weight over the back, but again its all setup/driving style specific, some drivers downshift slow and some just dive down the box...

as regards the weight transfer, i was talking about the point when you first hitt the brakes, now for me at this time 9x outa 10 there is more weight on the right due to me slowly stearing onto the rumble, your talking about braking while turning into the apex, something i dont really like doing there personly as you get the problem you just mentioned and the car feels in a unstable state to me..


but i still stad by the the fact i dont belive for one second this is caused in t1,

Quote from Bob Smith :Other way round. High parallel steering will cause lots of scrub during tight turns. Try driving with 100% then with 33%. Apart from losing some understeer, you're front tyres should run cooler.

bob surely thats a 2 way thing? to low you get scrub to high you get scrub? i would have thought you would get more heat from the low P/S?
If you had too much toe out, then yes of course. By design though, that would require more than true Ackermann, or a -% of parallel steering. So it's not possible in LFS given the slider limit.
However, think of it this way:
  • The outer wheel is dominant in the corner, it dictates where the car goes
  • You're likely going to have some understeer while cornering, at least the downforce cars seem to have this notion of "steer more, turn more", even far beyond the point where you'd normally think the limit is
  • The inner wheel, which has barely any say in what happens can now be in two states:
Either
  • it is in Ackermann mode (toe out), which means it scrubs along the asphalt at an even higher angle than the outer wheel, or
  • it is in parallel steer mode, scrubbing the same amount as the outer wheel does
Or even think of an extreme example c) where the wheels have toe in. The outer, working wheel understeers slightly but the inner wheel just merrily rolls along not doing anything, but not scrubbing and generating heat either.

Does that make any sense?
It's lock ups in this case, almost guaranteed, into t1, the turn after the back straight, the turn before the tunnel. If you run into those corners deep on the brakes, you can easily cook the surface of the inside front. A result of too much brake force at the front, turning whilst still on the brakes, and possibly too much camber. It's so easy to do, and totally undramatic which makes it hard to tell that you're doing it.
Android, running parallel steering will scrub the inside tyre more than the outside. In theory, running Ackerman steering (without any toe) should cause them to scrub equally.
Quote from Bob Smith :...running parallel steering will scrub the inside tyre more than the inside.

Mystery of LFS: Just when you think you know something you get confused again.
That's not specific to LFS. Tyres run different lines through the corner. Parallel steering makes them try and take the same line. Hence scrub. Ackermann steering lets them take the lines they are actually going round. So minimal scrub.
I think he is refering to

Originally Posted by Bob Smith
...running parallel steering will scrub the inside tyre more than the inside.
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Strange tyre temp behaviour
(31 posts, started )
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