Re: GPL - Performance differential with Hi-Fuel.

I once tested the influence of fuel level on car performance when a league I am involved in (MARA) was toying with the idea of adding a weight penalty system through start line fuel level. I will reproduce my conclusions below (if anyone's interested I can post the lap exports to alt.binaries.simulators.autos as well). <start quoted text> Fellow racers, I have now tested the premise of assigning weight penalties to top finishers in each of the rounds and, IMO, it is not going to work. Which is a pity, as I thought it was a good idea before I started testing it. I have done the following: driven each chassis at Silverstone with a 15, 25, 35 and 45 gallon fuel load (Brabham takes only 43 gallons) for five laps. Lap time exports for each session attached. Please note I sometimes lost count, so there's some 4lap and 5+lap stints, also, with the first 3 chassis (Ferrari, Eagle, Cooper), I started the session with a 5 gallon stint. Which I later dropped as I realised this is actually less fuel than required to finish a MARA race, so that was rather silly. I tried to drive at a constant level of effort and commitment as to not influence the results. So, after gone through this, why do I think it won't work? -Well.... It's not very straightforward. The time difference is different between marques AND it's not linear (i.e. no added 1/10th per gallon or somesuch). As I drove I found the weight affected the acceleration, braking and handling but it also made the car more stable, more predictable, allowing for some sections to be driven faster with the same amount of commitment. With certain cars and fuel load combinations I lost the balance a bit, but with some setup tinkering I'm sure I could make most combinations handle reasonably well. Secondly, if I'm a fast driver (pretend, ok? ;-)) and there's a weight penalty system in place there's no incentive for me to choose a slower car out of chivalry (on top of that they're more affected by the weight penalty system). This could be bad for competition (the differences between marques are greater than the difference between fuel loads) and bad for diversity as I would choose either a Lotus or a Brabham. Their nice, fat powerbands mean their accelleration is virtually unaffected. The Brabham IS unaffected, the 43 Gallon stint being significantly slower was a balance problem. The Lotus starts running out of brakes at 35 gallons and more, but as it's inherently faster than the Brabham I think it remains the car of choice. Anyway, that's my take on the matter after having tested the assumption for myself. If one's accustomed to running sub 1m30's at Silverstone the weight situation might be an entirely different proposition. I would encourage others to do a similar test, perhaps just with the car/track they're most comfortable with to see if this system is not too driver dependant to implement, but I'm afraid it is. <end quoted text> Jan. =--- Maxx wrote... > > Below is an email from a friend. Just wondered if anyone has > any comments/further insights. > <snip>

Below is an email from a friend. Just wondered if anyone has any comments/further insights. Maxx [EMAIL] Maxx One other thing i've noticed that i would like you to comment on: my laps with low fuel loads for qual are not much different from my full race loads - regardless of length. today at monaco in practice with fuel for 5 laps i ran a 1:32:7 during the race with fuel for 100 laps i ran 1:32.8 in the first 20 laps! is this signifigant of something? i make no other changes to the setup. keep in mind the pole for the race was 1:26, but i don't believe the racers were much quicker than 31's... any isite? all input appreciated- Bruce [REPLY] Bruce, I can't tell you categorically if there is any GPL specific reason for this but it happens in real life (and as GPL does a damn good job of modelling real-life, I suspect it is the GPL reason too). Whilst a higher fuel load means the car is heavier, hence more weight to full, hence "slower", the extra weight is ALSO gives the car more grip (there is more weight on the tires, hence more grip). More grip = slightly better cornering performance and slightly better traction exiting corners. Also, the fuel load will stabilise the car more during cornering i.e. it will not be so "lively", plus a very slight lowering of the centre of gravity (owing to the extra weight, may help) Also of course the handling characteristics will change slightly as the car is heavier which MAY be beneficial or vice-versa. I would imagine Monaco in particular would benefit from this owing to the number of slow corner where you need maximum traction out of. It's an interesting point and I would like to post your question and my answer to r.a.s. and possibly High Gear Forum etc. to see what the general consensus is .. is that OK with you? Cheers

[email hidden] (Maxx) wrote in <[email hidden]>:

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> >Below is an email from a friend. Just wondered if anyone has >any comments/further insights. > >Maxx > >[EMAIL] > >Maxx > >One other thing i've noticed that i would like you to comment on: >my laps with low fuel loads for qual are not much different from my >full race loads - regardless of length. today at monaco in practice >with fuel for 5 laps i ran a 1:32:7 during the race with fuel for 100 >laps i ran 1:32.8 in the first 20 laps! > >is this signifigant of something? i make no other changes to the >setup. keep in mind the pole for the race was 1:26, but i don't >believe the racers were much quicker than 31's... > >any isite? all input appreciated- > >Bruce

I would guess the difference it makes goes up exponentially as you approach the limit, and the limit at Monaco is in the 23s. Driving in the 32s it's probably a lot harder to sense. Even at my level, when I mistakenly enter a race with default/full fuel setup, I notice it in a big way. You won't find any WR setups at Schubi's that have more than a couple laps of fuel in them. -- Don Scurlock Vancouver,B.C. GPLRank -5.09 Come see how you rank, at the GPLRank site http://gplrank.ringlord.com/

Maxx <[email hidden]> writes: > Whilst a higher fuel load means the car is heavier, hence more > weight to full, hence "slower", the extra weight is ALSO gives the > car more grip (there is more weight on the tires, hence more grip). Not true as far as I know. The tires coefficient of friction is supposed to decrease when you increase the load on them. This is the reason you want to avoid lateral load transfer; 50% of the weight on each of the left and right tire gives more total grip than e.g. 70% + 30%. Hmm, is the reason people tell me that you should actually lean to the _outside_ of the turn when driving a kart that those things have so little load on the tires that the opposite (i.e. increasing coefficient of friction with increasing load) is true? _ Mats Lofkvist [email hidden]

More weight might mean more grip, but more mass means more momentum, so that more grip is required to take a corner at the same speed. That's why aerodyamic downforce is so nice. Increased weight without the increased mass. "Maxx" <[email hidden]> wrote in message news:[email hidden]...

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> > Below is an email from a friend. Just wondered if anyone has > any comments/further insights. > > Maxx > > [EMAIL] > > Maxx > > One other thing i've noticed that i would like you to comment on: > my laps with low fuel loads for qual are not much different from my > full race loads - regardless of length. today at monaco in practice > with fuel for 5 laps i ran a 1:32:7 during the race with fuel for 100 > laps i ran 1:32.8 in the first 20 laps! > > is this signifigant of something? i make no other changes to the > setup. keep in mind the pole for the race was 1:26, but i don't > believe the racers were much quicker than 31's... > > any isite? all input appreciated- > > Bruce > > [REPLY] > > Bruce, > > I can't tell you categorically if there is any GPL specific reason > for this but it happens in real life (and as GPL does a damn good > job of modelling real-life, I suspect it is the GPL reason too). > > Whilst a higher fuel load means the car is heavier, hence more > weight to full, hence "slower", the extra weight is ALSO gives the > car more grip (there is more weight on the tires, hence more grip). > > More grip = slightly better cornering performance and slightly better > traction exiting corners. > > Also, the fuel load will stabilise the car more during cornering > i.e. it will not be so "lively", plus a very slight lowering of the > centre of gravity (owing to the extra weight, may help) > > Also of course the handling characteristics will change slightly as > the car is heavier which MAY be beneficial or vice-versa. > > I would imagine Monaco in particular would benefit from this owing > to the number of slow corner where you need maximum traction out > of. > > It's an interesting point and I would like to post your question > and my answer to r.a.s. and possibly High Gear Forum etc. to see what > the general consensus is .. is that OK with you? > > Cheers > >

In article <[email hidden]>, Mats Lofkvist <[email hidden]> wrote: > >Hmm, is the reason people tell me that you should actually >lean to the _outside_ of the turn when driving a kart that >those things have so little load on the tires that the >opposite (i.e. increasing coefficient of friction with >increasing load) is true? I think the reason why you should lean to the outside in a kart is, that karts don't have rear differential (they have solid rear axles), so both rear wheels are always spinning at the same speed. It's much easier to get a kart around a corner when the inside rear wheel is off the ground, or at least giving as little friction as possible. Coefficient of friction probably decreases a little when the load increases, but it's not as significant as getting rid of they understeer the rear end is causing. Or so I've been told by a friend who used to drive karts. tax -- Samuli Takala [email hidden], Finnish GPL Championship: fgplc.figc.net

The Ferrari tends to handle bit better with more fuel onboard therefore producing faster lap times in race sounds possible ... or is it just my setups? Didn't notice that with Lotus... Also how many people achieve their maximum while in practice? and how many do it seriously? -- Oliver Nikolic BeoRocket Racing www.beorocket.co.yu Jan Verschueren <[email hidden]> wrote in message news:[email hidden]... > I once tested the influence of fuel level on car performance when a league I > am involved in (MARA) was toying with the idea of adding a weight penalty > system through start line fuel level. I will reproduce my conclusions below > (if anyone's interested I can post the lap exports to > alt.binaries.simulators.autos as well). > > <start quoted text>

U�ytkownik "Maxx" <[email hidden]> napisa� w wiadomo�ci news:[email hidden]... > > Below is an email from a friend. Just wondered if anyone has > any comments/further insights. [..] In my opinion it's bacuse you are driving 1.32 on Monaco when you will be able to make 1.25 u'll see the difference betweeen full of fuel car and empty one for sure ! :) I drove about few thousand laps on Monza with Eagle, now I have 1.26.98 and ONLY on last lap I can drive record or 1.26 times on empty car, with 8laps fule it's not possible -- Pozdrawiam Richie ( Piotr Oblicki ) [email hidden] http://gpl.pulse.pdi.net http://oj.gad.pl

In article <8seli1$7mo$[email hidden]>, Richie ( Piotr O. ) <[email hidden]> writes

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>U�ytkownik "Maxx" <[email hidden]> napisa� w >wiadomo�ci >news:[email hidden]... >> >> Below is an email from a friend. Just wondered if anyone has >> any comments/further insights. > >[..] > >In my opinion it's bacuse you are driving 1.32 on Monaco > >when you will be able to make 1.25 u'll see the difference betweeen full of >fuel car and empty one for sure ! :) >I drove about few thousand laps on Monza with Eagle, now I have 1.26.98 >and >ONLY on last lap I can drive record or 1.26 times on empty car, with 8laps >fule it's not possible > >

I agree. Whenever I've driven the Lotus with full or large fuel loads - no matter which track - and then review my lap times afterwards, there is a very marked, general trend towards faster lap times the lighter the car becomes. As a for instance, I would be in the high 1:29 seconds for the first 5 to 10 laps of a GP length race at Silverstone, but would be expecting to put in a couple of 1:26 laps towards the end of the race if I'm driving well. Even when checking my lap times in those short length races on VROC I can easily see the improvements timewise as the race progresses. I even was at a Glen race where someone who was out was giving out the current fastest lap. As I was the quickest driver in that race he was giving out my time and with less than 10 laps to go I was able to drive consistently enough so that, at the end of each of my laps, the fastest lap improved by a couple of tenths each time over a spate of 5 laps or so as my fuel load lessened. I have no doubts at all that a heavier car means a slower car once you reach a point where you can put in reasonably quick and consistent laps without too much variation. -- Peter Ives - (AKA Ivington) Remove ALL_STRESS before replying No person's opinions can be said to be more correct than another's, because each is the sole judge of his or her own experience.

Put two laps (full - empty) together with spygirl. you should see a difference if there is any. JensSchumi On Sun, 15 Oct 2000 17:09:04 GMT, Maxx <[email hidden]> wrote: > >One other thing i've noticed that i would like you to comment on: >my laps with low fuel loads for qual are not much different from my<snip> --------------------------------------------- LWFF Ball Bearing conversion at: http://members.xoom.com/JensSchu/ GPLRank: -2.61