tire temp distribution vs camber

[Haifisch M3]

any formulas for this?
E36m3 nitto 01 255/17/40 square setup
had 5 deg F difference
outside 150
inside 145
same difference on back tires
maybe dial another 1/4 degree of negative camber in?

[dominator293]

Sounds like a plan to me. May also be slightly incorrect tyre pressures too depending on what the temp in the centre of the tyre read.

[Haifisch M3]

Sounds like a plan to me. May also be slightly incorrect tyre pressures too depending on what the temp in the centre of the tyre read.

center temp was average between the others so pressure was about right

[aeronaut]

FYI, you want inner edges higher than outer.
Those temps are low, are you measuring after you pull into pits? With what?

[golgo13]

 The goal is to get all four tires with a as close to perfect heating pattern as possible. Occasionally, I briefly manage that for a given track condition. Those settings always coincide with my fastest laps. Expect it to take a few sessions of tuning if you are starting from scratch. Highly recommend keeping a notebook will all your measurements, brief driving impressions, car set up and of course, lap times.

• Without a cool down lap, get the car stopped safely but quickly in the pits
• Start with the tires on the outside of the track, example: left tires on CW track
• Start with the inside and work out; Inside, Center, Outside.
• The shoulder measurement must be in the scuffed an heated part of the tread, usually 1/2~ 1" inboard of the extreme edge of the tread. Not the shiny unused outer corner.
• Put the probe into the exact same area of the tread on each tire and push in the same amount.
• For a given car, always use the same sequence.
• You should see a 5~10° drop from inside to center, then the same drop from center to outside shoulder. The total gradient that works best for radials on the loaded side of the car (outside of track) is usually 15-20° in even steps.
• The outside tires (left side on clockwise course) are the important ones. It is possible for the more lightly loaded inside course tires to display a greater temp delta of 20-30° on cars with a lot of static camber and stiffer suspensions (more than OEM specs). This is normal and usually doesn't need to be corrected.

Center too hot - example: I 170° - C 180° - O 170°
Too high air pressure. This can be too high cold or "starting" pressure or excessive heat caused by sliding due to car setup or driving style.

Center too low - example: I 180° - C 160° - O 170°
Too low air pressure. This can be too low cold or "starting" pressure, car setup or driving style.

Inside high or low - example: I 190° - C 175° - O 160°
Too much toe out or negative camber can cause excessively high inside edge temps. The way to differentiate is if both LF and RF have the same delta, it's toe. If the outside course tires have a much different delta than the inside course tires, it's usually camber. Also, excessive toe out will usually show a scalloping or feathering of the tread where camber will not.

Outside high or low - example: I 170° - C 180° - O 200°
This is the pattern most commonly seen on production based cars and is usually caused by insufficient negative camber. One band-aid fix is to help make it through the day is to overinflate the tires to raise center temps. This can help reduce the workload of the overheated outside shoulder

With the pyro, you're seeing vehicle configuration, weather, setup, and driving style.

Example: Too much front sway bar/spring and not enough camber? Front tires significantly hotter than rear, outside shoulders hotter than inside.

Example: Rears like 50° hotter than fronts? Too much drifting

Example: All tires low temps? First session, cold day on old tires

[ScotcH]

Yup, camber too low. 1/4" won't do it probably? What are you at? Min 3.5 ... closer to 4.5 if on proper race suspension.

Edit: really nice breakdown, golgo!

[Haifisch M3]

FYI, you want inner edges higher than outer.
Those temps are low, are you measuring after you pull into pits? With what?

yes after pitting measured with infrared reader. Also read that inner should be warmer than outer, so more camber needed.
I have Turner plates and could add washers to get me there. Currently just under 3 degrees front and about 2.5 rear

[Haifisch M3]

 The goal is to get all four tires with a as close to perfect heating pattern as possible. Occasionally, I briefly manage that for a given track condition. Those settings always coincide with my fastest laps. Expect it to take a few sessions of tuning if you are starting from scratch. Highly recommend keeping a notebook will all your measurements, brief driving impressions, car set up and of course, lap times.

• Without a cool down lap, get the car stopped safely but quickly in the pits
• Start with the tires on the outside of the track, example: left tires on CW track
• Start with the inside and work out; Inside, Center, Outside.
• The shoulder measurement must be in the scuffed an heated part of the tread, usually 1/2~ 1" inboard of the extreme edge of the tread. Not the shiny unused outer corner.
• Put the probe into the exact same area of the tread on each tire and push in the same amount.
• For a given car, always use the same sequence.
• You should see a 5~10° drop from inside to center, then the same drop from center to outside shoulder. The total gradient that works best for radials on the loaded side of the car (outside of track) is usually 15-20° in even steps.
• The outside tires (left side on clockwise course) are the important ones. It is possible for the more lightly loaded inside course tires to display a greater temp delta of 20-30° on cars with a lot of static camber and stiffer suspensions (more than OEM specs). This is normal and usually doesn't need to be corrected.

Center too hot - example: I 170° - C 180° - O 170°
Too high air pressure. This can be too high cold or "starting" pressure or excessive heat caused by sliding due to car setup or driving style.

Center too low - example: I 180° - C 160° - O 170°
Too low air pressure. This can be too low cold or "starting" pressure, car setup or driving style.

Inside high or low - example: I 190° - C 175° - O 160°
Too much toe out or negative camber can cause excessively high inside edge temps. The way to differentiate is if both LF and RF have the same delta, it's toe. If the outside course tires have a much different delta than the inside course tires, it's usually camber. Also, excessive toe out will usually show a scalloping or feathering of the tread where camber will not.

Outside high or low - example: I 170° - C 180° - O 200°
This is the pattern most commonly seen on production based cars and is usually caused by insufficient negative camber. One band-aid fix is to help make it through the day is to overinflate the tires to raise center temps. This can help reduce the workload of the overheated outside shoulder

With the pyro, you're seeing vehicle configuration, weather, setup, and driving style.

Example: Too much front sway bar/spring and not enough camber? Front tires significantly hotter than rear, outside shoulders hotter than inside.

Example: Rears like 50° hotter than fronts? Too much drifting

Example: All tires low temps? First session, cold day on old tires

great write up, very informative!
My main focus was on the outside tires (left side cw track)
running 0 toe
camber just under 3 degrees front and about 2.5 rear

- - - Updated - - -

Yup, camber too low. 1/4" won't do it probably? What are you at? Min 3.5 ... closer to 4.5 if on proper race suspension.

Edit: really nice breakdown, golgo!

eibach springs with bilstein shocks struts
also street car so 4.5 seems a bit much?

[ScotcH]

eibach springs with bilstein shocks struts
also street car so 4.5 seems a bit much?

Yeah ... but I guarantee it'll be faster

Also, the laser pyrometers kinda suck. Get a probe one (or borrow one) to really get an accurate reading.

[aeronaut]

NT01s love camber.
If you're going to optimize for the track, you're going to run a lot of camber.
If you only have an IR gauge, it's even more important to get temps IMMEDIATELY after a HOT LAP.
Get a friend to meet you in the pit-in lane. Exit track, stop, record temps. (Do not even get out of the car).
(As a courtesy, I tell the pit control folks if I'm doing this, just so they don't think it's an emergency.)

EDIT: And/Or, borrow a tire pyrometer.

[Haifisch M3]

the Turner plates came with shims as well

I wonder if I install them at the track how much the tow will change?

[ScotcH]

the Turner plates came with shims as well

I wonder if I install them at the track how much the tow will change?

You will gain toe out ... that's a good thing, to a point. Toe plates are cheap ... or free to borrow

[Haifisch M3]

You will gain toe out ... that's a good thing, to a point. Toe plates are cheap ... or free to borrow

Thanks will look into toe plates

[Haifisch M3]

Yeah ... but I guarantee it'll be faster

Also, the laser pyrometers kinda suck. Get a probe one (or borrow one) to really get an accurate reading.

so i dialed it -4 camber in front
what should I set the rears at? 3-3.5?

[ScotcH]

I would not go more than 3 in the rear ... you'll start to suffer on corner exist and acceleration. Even when we run 4.5 or more front, I think we've never had the rear past 3.2 or so (going from memory).

[Haifisch M3]

Great thanks on the lift right now, will check

[golgo13]

FWIW, I dialed out some camber because my car wasn't taking advantage of it. My car is so light and doesn't have a big wang out back or splitter to push down on the front/rear of the car.

I'm now -3*F and -2*R and my car is faster.

[aeronaut]

Hmmmm....good point. My car has lost a lot of weight since I last did tread temps. I'd better get on that.

[ScotcH]

Testing is always the answer of course! If it's faster with less, great! As a data point, our e46 is 2801 lbs with driver at end of race.

[aeronaut]

That seems pretty light for an E46!

[ScotcH]

That seems pretty light for an E46!

We had it down to 2750 at one point (200 lbs driver), but added air jacks and stuff since. It's a motorsport chassis, so the cage in it is very light compared to most. Love the car ... probably never get rid of it

[MINIz guy]

FWIW, I dialed out some camber because my car wasn't taking advantage of it. My car is so light and doesn't have a big wang out back or splitter to push down on the front/rear of the car.

I'm now -3*F and -2*R and my car is faster.

How light is light? My car is probably 3100+ with me in it and I run over 1 degree more negative camber on both axles.

[Haifisch M3]

I would not go more than 3 in the rear ... you'll start to suffer on corner exist and acceleration. Even when we run 4.5 or more front, I think we've never had the rear past 3.2 or so (going from memory).

Ok got 4.5 front and 3.0 rear with aggressive angle big wing ...will report back after WG

btw always thought that the same reason you mention affects corner exit would affect hard, straight braking with the front...meaning that in theory you should be able to decelerate better without camber ?

[MINIz guy]

Ok got 4.5 front and 3.0 rear with aggressive angle big wing ...will report back after WG

btw always thought that the same reason you mention affects corner exit would affect hard, straight braking with the front...meaning that in theory you should be able to decelerate better without camber ?

Yup, more front contact patch will help you stop quicker, given your tires have the grip and your brakes have the stopping power.

[Haifisch M3]

Yup, more front contact patch will help you stop quicker, given your tires have the grip and your brakes have the stopping power.

question is how cornering gains are offset by braking losses...