15 replies to this topic

[Kneifzange]

Hi, folks,

some thoughts about how the F1 teams manage the tyre temperature.

toe-in:
if toe-in is increased, temperature should go up by more friction ?

Ackermann:
does have Ackermann any influence to tyre temperature?

I think track temperature is not that essential, because the heat tranfer area is too small.
But what´s with the air around the tyre?
Can they cool the tyre by directing air to the tyre or through the wheel over the rim (from inside; but there is the hot break?...)

Any comments welcome for a deep dive discussion.

cheers!

Michael

[MatsNorway]

More toe inn more work sounds right to me. Ive heard this about RC cars. Making one model slower on the straights. http://www.3racing.h...akurafgx_02.jpg
(the others where straight axle models http://www.competiti...-conversion.jpg

Directing natural airflow around the tire will not have a effect on temp on a open wheeler. its just to much air. exhaust gases however...

Mclaren was or is able to adjust some temp by directing brake heat onto the rim. they could adjust this during pitstops.

Edited by MatsNorway, 10 November 2012 - 22:22.

[munks]

I think track temperature is not that essential, because the heat tranfer area is too small.

Track temperature will noticeably transfer with the tire temperature. It's just that you can't do much to change the effect. If you change tire pressure, for example, that's going to affect a lot more things and more significantly than it will change the transfer area.

[jimclark]

Ackermann:
does have Ackermann any influence to tyre temperature?

Ackermann is essentially the toe-in/out whilst turning....;)

Edited by jimclark, 11 November 2012 - 04:42.

[Powersteer]

Think its about the difference in turning ratio between left and right wheels to cater for the difference in perimeter width makes on two inner and outer curve.

[Lee Nicolle]

More toe inn more work sounds right to me. Ive heard this about RC cars. Making one model slower on the straights. http://www.3racing.h...akurafgx_02.jpg
(the others where straight axle models http://www.competiti...-conversion.jpg

Directing natural airflow around the tire will not have a effect on temp on a open wheeler. its just to much air. exhaust gases however...

Mclaren was or is able to adjust some temp by directing brake heat onto the rim. they could adjust this during pitstops.

I have never met a racecar that uses toe in. Toe out always, more nervous, drags on straights but steering reaction is always better. Toe in is for the tow car!!

[Greg Locock]

I have never met a racecar that uses toe in.

Front or rear axle?

[MatsNorway]

Front or rear axle?

exacly. I was taking about the rear axle. Hence the picture of rear suspension.

That said. Toe in at front is supposed to give a quicker initial turn in.

[Ross Stonefeld]

I thought that was toe out? Because you're using the mechanicals to pull the car into the corner before the suspension and tires load.

[MatsNorway]

I think its because the outer wheel is allready pointing in the direction you want to go. load it and boom!


More toe-in
Lengthen the front steering link
• More nervous off centre
• Car wanders more on straights
• Decreases overall steering
• Makes the car more difficult to drive

More toe-out
Shorten the front steering link
• Car track straighter
• More stable in high speed sweepers
• Increased overall steering
• Makes the car easier to drive
Less Toe-in

More toe-in
REAR TOE
Decreases the spacing at the front of arms
Increase the spacing at the rear of arms
• Increased rear grip
• Increased stability
• Increased understeer

Less Toe-in
Increase the spacing at the front of arms
Decrease the spacing at the rear of arms
• Decreased rear grip
• Reduced stability
• More rotation, decreased understeer


http://www.hudy.net/...1b7b5cf543ef3bd

Edited by MatsNorway, 12 November 2012 - 15:51.

[Greg Locock]

A miscellaneous list

Those might be good trends but they are not rules. Any amount of roll steer, ackerman, and lateral compliance may make a mockery of that list.

[John Brundage]

I have never met a racecar that uses toe in. Toe out always, more nervous, drags on straights but steering reaction is always better. Toe in is for the tow car!!

It depends upon the car and driver. What are the characteristics of the car, i.e. Ackerman, bump steer etc ? Driver preference for feel of the car is also key.
There have been real race cars through the years that used front toe-in when raced in period.

[Kneifzange]

Ackermann is essentially the toe-in/out whilst turning....;)

Ackermann and toe-in toe-out of racecars with race tyres

http://www.smithees-...u/ackerman.html

I have the feeling that here the the big difference is buried between the teams.

What do you think? Do they play with these parameters?

cheers!

Michael

[MatsNorway]

Those might be good trends but they are not rules. Any amount of roll steer, ackerman, and lateral compliance may make a mockery of that list.

Let me know what you think about this one. page 54 is a priority list for setting up a RC car.
http://cosmobomb.com...set-up_book.pdf

Edited by MatsNorway, 13 November 2012 - 16:13.

[gruntguru]

Ackermann and toe-in toe-out of racecars with race tyres

http://www.smithees-...u/ackerman.html

I have the feeling that here the the big difference is buried between the teams.

Nice article. Well worth a read.

[munks]

Nice article. Well worth a read.

Agreed. I found it interesting that the "line of peaks" should guide your Ackermann setting. Honestly I don't remember seeing a slip angle graph with decreasing peaks at higher loading before.