Inside fronts heating up mid corner?

[Tim.Wright]

Ok guys, don't post much on here but this was interesting for me to see.

For me this phenomenon is down to suspension geometry. Red bull and other teams are most likely running upright mounted pushrods, meaning it is possible to move weight to the inside wheel when turning the steering wheel, and shift it in large quantities (more than maybe required for certain points on the track). The dallara f3 car runs the same system and I have experience with this type of setup. This weight transfer takes opposite effect at rear axle. Now, if you go back to the start of the race you will hear Riciardos engineer tell him 'no excessive steering inputs when the lights go out' this for me retierates the upright mounted pushrod (ump) because this causes a loss of rear grip and thus traction.

So I don't think Ackerman or Toe angles are playing a part here, I think the inside tyre is actually doing more work than what we are lead to believe.

As for the advantages of UMP that is a different topic altogether.

I doubt this very much since there is only about half a degree of steer angle on the front wheels in the tunnel.

[Jersey Tom]

i'm thinking that the toe out introduces an inside tire drag, rotating the car about its yaw axis. thoughts?

If you want yaw moment you will get a larger one by pointing the tire's force laterally, acting on half the wheelbase, than you would pointing it backward acting on half track width.

The yaw center isn't always exactly halfway between the axles is it? Actually, this may be a relevant question, but at the instant when you begin to turn in, would it not be approximately at the rear axle?

Yaw center? Forces and moments always act on the CG.

[Powerslide]

Wheel pointing against each other does not make any sense other than heat generation. Maybe the front and rear tyre run similar compounds and engineers want to get as much heat on the front as rear. While the rear sees more action, being the one that carry the most weight, downforce and the driven wheel, they might have ran anti-ackerman to balance this out.

[Tim.Wright]

Wheel pointing against each other does not make any sense other than heat generation. Maybe the front and rear tyre run similar compounds and engineers want to get as much heat on the front as rear. While the rear sees more action, being the one that carry the most weight, downforce and the driven wheel, they might have ran anti-ackerman to balance this out.

I can assure you that the primary reason for toe and ackermann isn't to generate heat even though that might be a side effect.

While the tyres are "fighting each other" in a straight line, in a corner its a different story. There are many reasons to have non zero toe throughout the cornering phase.

[Powerslide]

I can assure you that the primary reason for toe and ackermann isn't to generate heat even though that might be a side effect.

While the tyres are "fighting each other" in a straight line, in a corner its a different story. There are many reasons to have non zero toe throughout the cornering phase.

I don't think the wheels have toe in a straight line nor when the suspension is at dive position. Heat generation shown massive increase in temperature only at corner, since we are discussion steering wheel angles and not braking. So you are saying its how the tyre surface twist itself towards the tarmac is what they are targeting for? It could an interesting point if they want flat contact patch during braking where minimal camber change occur yet get camber through steering wheel angle.

[Powerslide]

If the point is to create yaw by dragging the inside wheel, over Ackerman would be far more effective also giving more castor to angle camber.

[olefud]

If the point is to create yaw by dragging the inside wheel, over Ackerman would be far more effective also giving more castor to angle camber.

The front tires appear to have gobs of static negative camber. So leading with the outer edge of the inside tire, i.e. antiAckerman, would seem to be the better approach. And I agree that wedge would work as an explanation.

[Jersey Tom]

[handwaving intensifies]

[Tim.Wright]

Bugger this, I give up...

[Powerslide]

If the point is to create yaw by dragging the inside wheel, over Ackerman would be far more effective also giving more castor to angle camber.

The front tires appear to have gobs of static negative camber. So leading with the outer edge of the inside tire, i.e. antiAckerman, would seem to be the better approach. And I agree that wedge would work as an explanation.

With the amount of castor, the attack angle on the inner wheel can get good enough contact patch to generate friction and pull back the inner part of the car but this is obviously not the case as to why anti Ackerman is being utilized as the inner wheel will be pointing against the targeted direction of travel would be counter productive. I still believe is tyre temperature management.

[olefud]

With credit to Markush, antiAckerman appears to be demonstrated at
http://i27.tinypic.com/1570gti.jpg

If so, this would be useful at low speed, low down force sections and tolerated during higher speed sections.

[thisisatest]

That is not anti-ackerman being demonstrated. It is an optical illusion. With the amount of toe out they run, I doubt any amount of anti- would have them point towards each other.

[SiLo]

As an interesting point, I just noticed that that inside tyre WALL was heating up, about two inches from the surface of the tire. Im guessing this is from lateral load pulling the tire and flexing at that point around the tyre causing it to heat up.

[Powerslide]

Now we are getting somewhere

[Tim.Wright]

Now we are getting somewhere

I'd argue that we "got somewhere" back on the first page when I more or less proved that what we saw was due to the static toe angle...