rec.autos.simulators

>> You've come to the same conclusion I have it seems.***
>> temperatures, camber is king seems to be the order of the day(in F1C).

>If you look at modern day F1 you'll see that this is actually the case -
>camber *is* king.

>> "Magnus Svensson" said:

>>> You've come to the same conclusion I have it seems.***
>>> temperatures, camber is king seems to be the order of the day(in
>>> F1C).

>> If you look at modern day F1 you'll see that this is actually the
>> case - camber *is* king.

> Actually, I have watched it very carefully, and they do not always
> apply that much camber as is done in F1C. Some have a little more than
> others, some have a little less. Check out this pic for example, it's
> Kimi going out for his qualifying lap at hockenheim last GP:

> http://www.racesimcentral.net/

> Compare that to -6.0deg front camber in F1C in outside view. That's
> just the fronts, all RL cars seem to have very little to no camber to
> the rear tyres, and they almost seem to get positive camber on the
> outside rear when cornering hard. Hotlapper setups in F1C often have
> heavy camber at the rears too!

> Just for kicks I modified the .hdv of the Ferrari to allow much
> greater camber. I went out with -14deg on the fronts and -12deg at the
> rears!!! And it drove extremely well! I put in a 1:16.0 at Hungaroring
> with a scorching 192/140/85 temperature on the LF tyre... I could
> brake at exactly the same points as usual and forward traction also
> seemed unaffected.

>> Technology has evolved to such a point where modern F1-cars have
>> virtually 0 degrees of lateral roll. Not only that, but with
>> no-droop suspension and a geometry (pararell equal-lenght wishbones)
>> that calls for very small camper changes in bump/rebound too.

> Well, Renault and Michelin incorporated a variable camber suspension
> which works by deflection and body roll... So supension dynamics still
> matters, I guess.

>> By looking at some of these cars you'll see
>> that run "huge" amounts of front-camber for sure.... 3-4 perhaps
>> even 5 or 6 degrees of negative chamber at times. I think much of
>> this is due to camber-thrust and their relatively small and wide
>> tires with big fleixng sidewalls.

> As for camber thrust, see my reply to Greger. I don't agree on that
> camber thrust is the reason why camber is applied, I think the camber
> they are using is applied because the *** is optimally exploited at
> that angle in cornering. And that they don't apply camber to the rear
> because that would make them lose longitudinal traction and add a lot
> of scrubbing, especially with toe-in.

>> Add to that the fact that what we see in our sims is just a tiny bit
>> of how real tire physics work. It's a very complex task.

> No kidding... :-\

> I was just hoping that the model was a little bit more advanced than
> this and that they had 'fixed' it by now.

>A quote from F1 Racing magazine interview with Bridgestone:

>"The tyres do look very different. How does your tyre work with it's rounder
>construction?"
>"We use 'camber thrust' so that when you lean a tyre inwards it wants to
>turn in that direction. That generates some cornering force. When you look
>at the front suspension of the Ferrari, for example, you can see that it has
>negative camber settings to use our tyres' camber thrust.
>But the Michelin would like to stand up vertically and be used in that
>position. So they could not be using camber thrust, but instead using
>maximum cornering power.
>So I guess their tyre has very high cornering power. We believe Michelins'
>philosphy of cornering is different because they use cornering power only
>and do not adopt camber thrust at all"

> I knew that camber thrust is a pretty vital part in motorcycle
> physics, but the premise is very much different, although the rounded
> vs. square tyre above is vaguely related.

> Well, back to the drawing board.

> >> "Magnus Svensson" said:

> >>> You've come to the same conclusion I have it seems.***
> >>> temperatures, camber is king seems to be the order of the day(in
> >>> F1C).

> >> If you look at modern day F1 you'll see that this is actually the
> >> case - camber *is* king.

> > Actually, I have watched it very carefully, and they do not always
> > apply that much camber as is done in F1C. Some have a little more than
> > others, some have a little less. Check out this pic for example, it's
> > Kimi going out for his qualifying lap at hockenheim last GP:

> > http://www.racesimcentral.net/

> > Compare that to -6.0deg front camber in F1C in outside view. That's
> > just the fronts, all RL cars seem to have very little to no camber to
> > the rear tyres, and they almost seem to get positive camber on the
> > outside rear when cornering hard. Hotlapper setups in F1C often have
> > heavy camber at the rears too!

> > Just for kicks I modified the .hdv of the Ferrari to allow much
> > greater camber. I went out with -14deg on the fronts and -12deg at the
> > rears!!! And it drove extremely well! I put in a 1:16.0 at Hungaroring
> > with a scorching 192/140/85 temperature on the LF tyre... I could
> > brake at exactly the same points as usual and forward traction also
> > seemed unaffected.

> >> Technology has evolved to such a point where modern F1-cars have
> >> virtually 0 degrees of lateral roll. Not only that, but with
> >> no-droop suspension and a geometry (pararell equal-lenght wishbones)
> >> that calls for very small camper changes in bump/rebound too.

> > Well, Renault and Michelin incorporated a variable camber suspension
> > which works by deflection and body roll... So supension dynamics still
> > matters, I guess.

> >> By looking at some of these cars you'll see
> >> that run "huge" amounts of front-camber for sure.... 3-4 perhaps
> >> even 5 or 6 degrees of negative chamber at times. I think much of
> >> this is due to camber-thrust and their relatively small and wide
> >> tires with big fleixng sidewalls.

> > As for camber thrust, see my reply to Greger. I don't agree on that
> > camber thrust is the reason why camber is applied, I think the camber
> > they are using is applied because the *** is optimally exploited at
> > that angle in cornering. And that they don't apply camber to the rear
> > because that would make them lose longitudinal traction and add a lot
> > of scrubbing, especially with toe-in.

> >> Add to that the fact that what we see in our sims is just a tiny bit
> >> of how real tire physics work. It's a very complex task.

> > No kidding... :-\

> > I was just hoping that the model was a little bit more advanced than
> > this and that they had 'fixed' it by now.

> The McLaren uses Michelin tyres, they need less camber to work than the
> Bridgestone. Take a look at the camber on the Ferrari.

> A quote from F1 Racing magazine interview with Bridgestone:

> "The tyres do look very different. How does your tyre work with it's
rounder
> construction?"
> "We use 'camber thrust' so that when you lean a tyre inwards it wants to
> turn in that direction. That generates some cornering force. When you look
> at the front suspension of the Ferrari, for example, you can see that it
has
> negative camber settings to use our tyres' camber thrust.
> But the Michelin would like to stand up vertically and be used in that
> position. So they could not be using camber thrust, but instead using
> maximum cornering power.
> So I guess their tyre has very high cornering power. We believe Michelins'
> philosphy of cornering is different because they use cornering power only
> and do not adopt camber thrust at all"

> --

> Ian P
> <email invalid due to spammers>

>> A quote from F1 Racing magazine interview with Bridgestone:

>> "The tyres do look very different. How does your tyre work with it's
>> rounder construction?"
>> "We use 'camber thrust' so that when you lean a tyre inwards it
>> wants to turn in that direction. That generates some cornering
>> force. When you look at the front suspension of the Ferrari, for
>> example, you can see that it has negative camber settings to use our
>> tyres' camber thrust.
>> But the Michelin would like to stand up vertically and be used in
>> that position. So they could not be using camber thrust, but instead
>> using maximum cornering power.
>> So I guess their tyre has very high cornering power. We believe
>> Michelins' philosphy of cornering is different because they use
>> cornering power only and do not adopt camber thrust at all"

>> --

>> Ian P
>> <email invalid due to spammers>

> >> A quote from F1 Racing magazine interview with Bridgestone:

> >> "The tyres do look very different. How does your tyre work with it's
> >> rounder construction?"
> >> "We use 'camber thrust' so that when you lean a tyre inwards it
> >> wants to turn in that direction. That generates some cornering
> >> force. When you look at the front suspension of the Ferrari, for
> >> example, you can see that it has negative camber settings to use our
> >> tyres' camber thrust.
> >> But the Michelin would like to stand up vertically and be used in
> >> that position. So they could not be using camber thrust, but instead
> >> using maximum cornering power.
> >> So I guess their tyre has very high cornering power. We believe
> >> Michelins' philosphy of cornering is different because they use
> >> cornering power only and do not adopt camber thrust at all"

> >> --

> >> Ian P
> >> <email invalid due to spammers>

> I'm only quoting what the guy from Bridgestone said in the September 2003
> issue of F1 racing magazine. I would hope he knows at least something
about
> tyre technology.
> Which part(s) *exactly* is (are) codswallop ?

> --

> Ian P
> <email invalid due to spammers>

> Radius=0.325                          // Radius of tire
> RadiusRPM=4.65e-6                     // Increased radius per unit RPM

> SpringBase=54500.0                    // Base spring rate with no pressure
> SpringkPa=1331.0                      // Spring rate per unit pressure

> RollingResistance=1435.0              // Resistance torque (Nm) per unit
> deflection (m) on ground

> The first two lines indicate that there is a base radius that is RPM
> dependent.  The next two indicate that there is also a spring rate that is
> pressure dependent.  The spring acts against deflection from the base
> radius.  The next line indicates that there is a rolling resistance torque
> that depends on the deflection.  So not only is rolling resistance
modelled,
> but it is also clearly pressure dependent.

> Regarding camber sensitivity, well I don't know how realistic it is, but
> here is the data from the same file:

> CamberLatLong=(2.99, 0.121, 0.11)     // Peak camber angle, lateral gain
at
> peak, longitudinal loss at 90 degrees

> This appears to indicate that the optimum *dynamic* camber angle for the
> Michelins is 2.99 degrees, that at this angle it gains 0.121 in lateral
> friction coefficient, and it loses longitudinal friction coefficient at a
> rate of 0.11/90 per degree of camber.  So first there is a small,
realistic
> camber angle at which you get the maximum lateral friction.  Secondly
there
> appears to be very little loss in longitudinal friction for any realistic
> camber angle.

> This means that the typical soft suspensions that many people are using in
> F1C will require greater than 3 degrees of static camber, but probably not
> more than 5 or so.  A harder suspension would require less, but the
minimum
> you would need would be 2.99 (the above is for the front tires btw).

> I don't know how much camber gain is built into the suspension, but they
do
> have shorter upper arms so probably not much.  Someone with more patience
> than I could figure it out by plotting out the values in the f1susp.pm
file.
> I'll pass.

> Since we are talking about tires with a base friction coefficient of
around
> 1.9 that means there is only about a 6% lateral friction gain at most from
> playing around with camber.  Too much isn't going to cost you much, but
> neither is too little.  Too much isn't going to cost you much in
> longitudinal grip either, in fact it is negligible.  And in my experience
> this is confirmed by telemetry.  More camber feels better but doesn't have
a
> huge effect on lateral grip or speed on the straights.  It seems to affect
> the transients more than anything else, i.e. more camber (up to a point)
> seems to make it more drivable.

> Is that realistic?  I don't know, but if nothing else the file shows
clearly
> that there is no need for huge camber angles unless you are using
> unrealistically soft springs and bars (and many people are).  For a
> realistic setup somewhere around 3 to 4 degrees of static camber in front,
> and about a degree less in the rear, should be optimal.

> For the record, here are the optimum dynamic camber angles for the 2002
> season soft compound tires:

>                                Front           Rear
> Michelin                 2.99             2.07
> Bridgestone            3.17             2.17

> Seems the reverse of what I would expect, but that's what's in the files.
> If you are making a setup for F1C, it makes absolutely no sense to deviate
> far from these values.

> > The ISI sims are not realistic in this regard.  The Papy sims are much
> > closer to RW experience.  In F12002, etc., yes, camber is king - the
more
> > neg cam you add, the greater the tire temp diff...and the greater the
> grip.
> > WTF.   In N2003, you aim for a lower temp diff: maybe 4-8 deg. betw.
inner
> &
> > outer.

> > Also, Papy models roll resist (and has since Indy 500); ISI, AFAIK,
> doesn't.
> > That is, you can increase yer Vmax 3-4 mph by running the tires on edge
> > (common sense dictates the inner edge, but if yer not cornering, pos cam
> > works just as well).  Overinflating the tars also significently decr.
the
> > roll resist.

>> I guess what I'm asking is for other people's take on this. Does everyone
>> experience this? If so, and offset tyre temps are required, what setup
>> rationale do you use to decide on the degree of camber. What's the
>physics
>> behind it all?

>Once I've got each tyre balanced if the temps are too high I stiffen the
>shocks, if they are too low I soften them.

> >> I guess what I'm asking is for other people's take on this. Does
everyone
> >> experience this? If so, and offset tyre temps are required, what setup
> >> rationale do you use to decide on the degree of camber. What's the
> >physics
> >> behind it all?

> >Once I've got each tyre balanced if the temps are too high I stiffen the
> >shocks, if they are too low I soften them.

> This I don't quite understand.  Maybe my logic is a bit off.  I take it
> that you are talking about 'wheel rate' in GPL, yes?  I've just checked
> this in GPL at Kyalami and the temps did go up, though not by much, when
> I softened the wheel rate, but I don't understand why.  I thought if you
> stiffen a wheel's suspension then you're making that wheel do more work
> because the suspension is less able to dissipate the energy/load as
> easily.  If the wheel is having to absorb more energy/load then surely
> its temperatures should rise not fall.  What is is that I am missing
> here?