General concepts in race strategy (GP2)

First of all, apologies for any double-aa's that creep into this text - my keyboard is a bit knackered! Couple of questions about race strategy, specifically aimed at GP2 but I suppose probably apply to ICR2 and NASCAR aswell. 1. Fuel Load - I accept that less fuel equals greater straight line speed, because the car is lighter. But, on twisty circuits where I would set up with a lot of downforce, would having a heavier load of fuel increase the grip of my car through the corners? 2. Tyre Wear - Subjectively, how much tyre wear is tolerable before performance suffers too much? The set-up screen shows tyre wear up to 4mm, but should I be looking for a change before this? 3. Pit Stops - Okay, so maybe this is a little unrealistic in GP2, as my pit guys can replace all four tyres, fit a new front wing and mend an oil leak in 8.8 seconds! Nevertheless, is there a formula or something similar that I can use to work out the relative benefits of one, two or three stops? How do the teams in real life judge this? 4. Race Position - How do the factors above vary with the position I qualify? If I get pole (yeah, right!) should I be looking to stay out as long as possible, or set up with a light load to race ahead as far as possible? Thanks in advance for any thoughts anyone is willing to share on this. Long live GP2 and God save Geoff Crammond! regards, Paul *********************************************************************** * Paul L. Finnemore - Apprentice Veterinarian * * "Auto-brakes? I don't need no stinking auto-braaaahhhhh....!" * ***********************************************************************

I'll try to answer in a general race strategy mode. As I had to work til the stores closed today and my USA copy of GP2 is still sitting in the store :( : Couple of questions about race strategy, specifically aimed at GP2 but I : suppose probably apply to ICR2 and NASCAR aswell. : 1. Fuel Load - I accept that less fuel equals greater straight line : speed, because the car is lighter. But, on twisty circuits where I would : set up with a lot of downforce, would having a heavier load of fuel : increase the grip of my car through the corners? In real life racing, it really would depend on the location of the fuel cells. But, I would hazard to guess that the benefits would be outweighed by the weight. Also your handling is affected by the "larger" weight shifting (trying to throw around extra weight). But how closely any of the sims model this is beyond me. The extra weight can also affect your tire wear. : 2. Tyre Wear - Subjectively, how much tyre wear is tolerable before : performance suffers too much? The set-up screen shows tyre wear up to : 4mm, but should I be looking for a change before this? When you begin to feel it. Some drivers can drive almost as fast on worn out tires as they do on fairly fresh ones. However, there does come a point where it's too dangerous. It used to be that it was always the driver's call in F1 to come in for new tires. But, I am sure this has changed alot with the "fuel" strategies being played out now days. : 3. Pit Stops - Okay, so maybe this is a little unrealistic in GP2, as my : pit guys can replace all four tyres, fit a new front wing and mend an : oil leak in 8.8 seconds! Nevertheless, is there a formula or something : similar that I can use to work out the relative benefits of one, two or : three stops? How do the teams in real life judge this? The actual time in the pits usually isn't what kills you. It's the slowing down to enter and the time it takes you to get back up to speed and warm up the tires that counts. That's why Schumacher always used to beat the pants off of Damon Hill. He's a master at entering and exiting the pits. He could even have a slower pit stop than Hill and still have a better overall lap time. God, what I wouldn't give to have a pit crew like GP2 does in Indycar or NASCAR. But, you also have to keep in mind that you can have 40 guys out there working on your car in F1, we're limited to the number of crew in the pits for Indy & NASCAR. : 4. Race Position - How do the factors above vary with the position I : qualify? If I get pole (yeah, right!) should I be looking to stay out as : long as possible, or set up with a light load to race ahead as far as : possible? There are alot of variables to consider. How well do you conserve your tires? How well do you enter and exit the pits? What game plan does your hottest competitor have in mind? Ah, that's why I'm glad they brought pit stops back into F1. They had to add some sort of suspense. -- **************************** Michael E. Carver ************************* Upside out, or inside down...False alarm the only game in town. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=<[ /./. [- < ]>=-=-=-=-=-=-=-=-=-=-=-=-=-=

[snip] |> 4. Race Position - How do the factors above vary with the position I |> qualify? If I get pole (yeah, right!) should I be looking to stay out as |> long as possible, or set up with a light load to race ahead as far as |> possible? I guess if you're on pole, go for a light fuel load so that you can open up a big lead. That's assuming you have a good start (you don't happen to be Damon "I won't win if I don't get the lead in the first corner" Hill, heh?). If you are not on pole, go for a heavier fuel load so that you can have less stops and stay out longer. Especially if you are stuck behind some mobile chicane which will diminish your advantages of a lighter fuel load. Can't wait anymore to get my hands on GP2! We Canadians are last! -- Isaac Wong (613) 763-6127 | Compiler Development, Public Carrier Networks

On Wed, 24 Jul 1996 18:03:41 +0100, "Paul L. Finnemore" >1. Fuel Load - I accept that less fuel equals greater straight line >speed, because the car is lighter. But, on twisty circuits where I would >set up with a lot of downforce, would having a heavier load of fuel >increase the grip of my car through the corners? There is a force which pulls outward in your car through the corner: Fa = m * v * v / r Then there is another force which ensures you have grip: Fb = m * g * y (+ downforce) where: r = radius of the curve. m = mass of the car. v = velocity of the car. g = gravitational constant y = friction coefficient (between wheels and track) If Fa is less than or equal to Fb, then you stays on track, otherwise you loose traction and skates of the track. or in mathematical terms: Fa <= Fb which equals m * v * v / r <= m * g * y (+ downforce) The mass can be left out on both sides, and then gives: v * v / r <= g * y (+ downforce) Conclusion: The mass has no influence on grip through corners. But increased mass will increase acceleration time and brake lenght, and also decrease top speed due to more friction in bearings, so you really don't want a heavy car. Hope this helped (...and someone tell me if I need to go back to school.....!) -- Lennart Gr?nlund http://www.pip.dknet.dk/~pip2351/

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> [snip] > |> 4. Race Position - How do the factors above vary with the position I > |> qualify? If I get pole (yeah, right!) should I be looking to stay out as > |> long as possible, or set up with a light load to race ahead as far as > |> possible? > I guess if you're on pole, go for a light fuel load so that you can open up > a big lead. That's assuming you have a good start (you don't happen to be > Damon "I won't win if I don't get the lead in the first corner" Hill, heh?). > If you are not on pole, go for a heavier fuel load so that you can have less > stops and stay out longer. Especially if you are stuck behind some mobile > chicane which will diminish your advantages of a lighter fuel load.

Find out the lap times of the slowest cars during the pre-race warm up. Then assume that by the end of the first lap, the slowest cars will be about 30 seconds behind the leader. From this you can work out what lap you will start to reach the backmarkers on. Plan your first pit stop for then, and you won't get caught in traffic too much. Julian _____________________________________________________________________ University of Oxford

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> : 1. Fuel Load - I accept that less fuel equals greater straight line > : speed, because the car is lighter. But, on twisty circuits where I would > : set up with a lot of downforce, would having a heavier load of fuel > : increase the grip of my car through the corners? > In real life racing, it really would depend on the location of the fuel > cells. But, I would hazard to guess that the benefits would be > outweighed by the weight. Also your handling is affected by the > "larger" weight shifting (trying to throw around extra weight). But how > closely any of the sims model this is beyond me. The extra weight can > also affect your tire wear.

In real-life F1, running a light fuel load is considered more advantageous at a twisty circuit than at on with a lot of flat out straights. The disadvantage of running with a heavy load at Monza or Hockenheim is not that great, but on tight circuits, where acceleration and braking in and out of the corners is critical to good lap times and being able to overtake, it carries quite a penalty. In GP2, fuel load doesn't seem to make much of a difference to car handling though, much less than In ICR2. F1 cars do carry less fuel than Indy though. Julian _____________________________________________________________________ University of Oxford

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>On Wed, 24 Jul 1996 18:03:41 +0100, "Paul L. Finnemore" >>1. Fuel Load - I accept that less fuel equals greater straight line >>speed, because the car is lighter. But, on twisty circuits where I would >>set up with a lot of downforce, would having a heavier load of fuel >>increase the grip of my car through the corners? >There is a force which pulls outward in your car through the corner: >Fa = m * v * v / r >Then there is another force which ensures you have grip: >Fb = m * g * y (+ downforce)

^^^^^^^^^^^^^ This is where you start to go wrong. To a (VERY (No flames!)) simple approx: downforce = k x v (I prefer x as a multiplication symbol instead of * and k is some fixed const). As you lightly skip over the problem of downforce, you neglect the fact that increasing the fuel load in a vehicle will increase the load down upon the tyres AND will increase the centrepetal force equally. BUT the aerodynamic downforce (do to wing+ground effect etc), will not vary, save possibly due to a slightly different ride height (as the car lightens, the springs reach equilibrium further from the ground - they aren't squashed as far). Therefore, as the fuel load decreases, the force downwards upon the tyres increases compared with the force outwards due to the mass of the vehicle. So as the fuel load decreases, the force Fb is proportionately larger than Fa. Conclusion: You can corner faster with less fuel in your vehicle. (Hint: since downforce=k x v you the fuel load changes handling more at high speeds than low ones. This also the reason why your brakes lock up more easily at low speeds. Downforce and fuel load are negligible in most road-cars. Ferrari F50 owners can***off...) Not so. See above. ^^^^^^^^^^^^^^^^^^^^ Probably not simulated. :-)

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>really don't want a heavy car. >Hope this helped (...and someone tell me if I need to go back to >school.....!) >-- >Lennart Gr?nlund >http://www.pip.dknet.dk/~pip2351/

Why haven't you seen me post before: You are few; we are many. -- Lurkers motto. -- Andy _______________________________________________________________________________ | "...the enemy of the market is not ideology, but the engineer."J.K.Galbraith|

: Find out the lap times of the slowest cars during the pre-race warm up. : Then assume that by the end of the first lap, the slowest cars will be : about 30 seconds behind the leader. From this you can work out what lap : you will start to reach the backmarkers on. Plan your first pit stop for : then, and you won't get caught in traffic too much. This brought up a question that I haven't thought of trying out. What happens if one calls a pit stop earlier than the pre-planned stop? Let's say your are mired in traffic and want to pit 5-6 laps early. If you planned on a 2 pit-stop strategy and this is your 1st stop, will the pit crew readjust the early pit stop's fuel load to get you to the next 2nd planned pit-window? -- **************************** Michael E. Carver ************************* Upside out, or inside down...False alarm the only game in town. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=<[ /./. [- < ]>=-=-=-=-=-=-=-=-=-=-=-=-=-=

On Sat, 27 Jul 96 22:09:32 GMT, Andrew Haigh

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>>There is a force which pulls outward in your car through the corner: >>Fa = m * v * v / r >>Then there is another force which ensures you have grip: >>Fb = m * g * y (+ downforce) >As you lightly skip over the problem of downforce, you neglect the fact that >increasing the fuel load in a vehicle will increase the load down upon the >tyres AND will increase the centrepetal force equally.

Actually, that is the fact I based the equations on. Mass is a part of both equations. You have opened my eyes :-) Fa <= Fb + downforce The equations I have stated is still true, but my conclusion was wrong. Fa and Fb is reduced equally when the mass decreases, but I ignored the fact that the downforce is independent of this fuel decrease. True, and my original conclusion: still goes for racetracks on the moon and other non-atmosphere places where downforce is off topic...... :-) -- Lennart Gr?nlund http://www.pip.dknet.dk/~pip2351/

>This brought up a question that I haven't thought of trying out. What >happens if one calls a pit stop earlier than the pre-planned stop? When your in the pits you can select the number of pit stops you still want to make and the fuel is adjusted accordingly. The selection is done on the steering wheel display in the same way as the tyre selection and leave pits etc. options when not in a race.

WHOOPS!!!! Your thing looked pretty good there until you dropped mass out of the equation. Downforce is as you said a force and therefore your Fa <=Fb where Fb =F(weight)+F(downforce) works well. When you devide out mass you get V^2/R <= g*y* [1+F(downforce)/M] So Mass makes a HUGE difference in a twisty course. Think of it this way. If the car weighed nothing but had 1g of downforce you could turn instantly (no mass to change direction but some force to create friction). So if the Mass is small compared to the Downforce the car handles well in corners. BTW not guaranteeing the rest of the equation just ensuring that it should have Mass in it when all is settled :) Eric Fesler

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>On Wed, 24 Jul 1996 18:03:41 +0100, "Paul L. Finnemore" >>1. Fuel Load - I accept that less fuel equals greater straight line >>speed, because the car is lighter. But, on twisty circuits where I would >>set up with a lot of downforce, would having a heavier load of fuel >>increase the grip of my car through the corners? >There is a force which pulls outward in your car through the corner: >Fa = m * v * v / r >Then there is another force which ensures you have grip: >Fb = m * g * y (+ downforce) >where: >r = radius of the curve. >m = mass of the car. >v = velocity of the car. >g = gravitational constant >y = friction coefficient (between wheels and track) >If Fa is less than or equal to Fb, then you stays on track, otherwise >you loose traction and skates of the track. >or in mathematical terms: >Fa <= Fb >which equals >m * v * v / r <= m * g * y (+ downforce) >The mass can be left out on both sides, and then gives: >v * v / r <= g * y (+ downforce) >Conclusion: >The mass has no influence on grip through corners. >But increased mass will increase acceleration time and brake lenght, >and also decrease top speed due to more friction in bearings, so you >really don't want a heavy car. >Hope this helped (...and someone tell me if I need to go back to >school.....!) >-- >Lennart Gr?nlund >http://www.pip.dknet.dk/~pip2351/

On Sat, 27 Jul 96 22:09:32 GMT, Andrew Haigh

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>>On Wed, 24 Jul 1996 18:03:41 +0100, "Paul L. Finnemore" >>>1. Fuel Load - I accept that less fuel equals greater straight line >>>speed, because the car is lighter. But, on twisty circuits where I would >>>set up with a lot of downforce, would having a heavier load of fuel >>>increase the grip of my car through the corners? >>There is a force which pulls outward in your car through the corner: >>Fa = m * v * v / r >>Then there is another force which ensures you have grip: >>Fb = m * g * y (+ downforce) > ^^^^^^^^^^^^^ >This is where you start to go wrong. To a (VERY (No flames!)) simple approx: > downforce = k x v >(I prefer x as a multiplication symbol instead of * and k is some fixed const). >As you lightly skip over the problem of downforce, you neglect the fact that >increasing the fuel load in a vehicle will increase the load down upon the >tyres AND will increase the centrepetal force equally. >BUT the aerodynamic downforce (do to wing+ground effect etc), will not vary, >save possibly due to a slightly different ride height (as the car lightens, >the springs reach equilibrium further from the ground - they aren't squashed >as far). >Therefore, as the fuel load decreases, the force downwards upon the tyres >increases compared with the force outwards due to the mass of the vehicle. >So as the fuel load decreases, the force Fb is proportionately larger than >Fa. >Conclusion: You can corner faster with less fuel in your vehicle. >(Hint: since downforce=k x v you the fuel load changes handling more at >high speeds than low ones. This also the reason why your brakes lock up >more easily at low speeds. Downforce and fuel load are negligible in >most road-cars. Ferrari F50 owners can***off...) >>where: >>r = radius of the curve. >>m = mass of the car. >>v = velocity of the car. >>g = gravitational constant >>y = friction coefficient (between wheels and track) >>If Fa is less than or equal to Fb, then you stays on track, otherwise >>you loose traction and skates of the track. >>or in mathematical terms: >>Fa <= Fb >>which equals >>m * v * v / r <= m * g * y (+ downforce) >>The mass can be left out on both sides, and then gives: >>v * v / r <= g * y (+ downforce) >>Conclusion: >>The mass has no influence on grip through corners. >Not so. See above. >>But increased mass will increase acceleration time and brake lenght, >>and also decrease top speed due to more friction in bearings, so you > ^^^^^^^^^^^^^^^^^^^^ >Probably not simulated. :-) >>really don't want a heavy car. >>Hope this helped (...and someone tell me if I need to go back to >>school.....!) >>-- >>Lennart Gr?nlund >>http://www.pip.dknet.dk/~pip2351/ >Why haven't you seen me post before: >You are few; we are many. > -- Lurkers motto. >-- Andy >_______________________________________________________________________________ >| "...the enemy of the market is not ideology, but the engineer."J.K.Galbraith|

JESUS CHRIST MAN !!! Am I going to have to go to Harvard to p[lay this sim ???

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>>On Wed, 24 Jul 1996 18:03:41 +0100, "Paul L. Finnemore" >>>1. Fuel Load - I accept that less fuel equals greater straight line >>>speed, because the car is lighter. But, on twisty circuits where I would >>>set up with a lot of downforce, would having a heavier load of fuel >>>increase the grip of my car through the corners?

This seems to be a very common misconception in car physics. I answered a thread a week ago about why weight and downforce had opposite effects in NASCAR racin. In fact, someone answered the question in that thread by saying that "moving weight distribution to the rear and adding rear spoiler should the same thing and the game and the manual is wrong". How do we rectify this situation, since this was always an idea completely taken for granted by me (and I thought most people)? If someone can spit out a formula for friction depending on normal force and coefficent but boggle this idea (remember Newton's laws?!?), we all need to pay more attention to HS Physics. Gregory Fung Vancouver, B.C., Canada

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>On Sat, 27 Jul 96 22:09:32 GMT, Andrew Haigh >>>On Wed, 24 Jul 1996 18:03:41 +0100, "Paul L. Finnemore"

[fancy technical stuff. Deleted] I don't think Mr Crammond went to Harvard. British doncher know? The mechanics was the Newtonian kind I learnt at school. Naturally, you don't have to know anything much about how to drive or setup in theory. Just change what you do until the the laptimes decrease. Also obtain setups from others who drive faster/know more on the web. In desperation, you can try bribing the computer. (Hint: This will not work.) Bye, -- Andy _______________________________________________________________________________ | "...the enemy of the market is not ideology, but the engineer."J.K.Galbraith|