Rear weight bias ?

So which way is it? Loose car- ie.rear-end hits the wall before the front ;o/- more rear weight bias or less?? I believe it should be more but I keep seeing advice to use less. Is this a sim issue with the sim being different than actual racing? Or am I just interpreting the weight transfer wrong? Thanks, AKH

More rear bias. When your car accelerates, it forces weight to the rear of the car. If more weight is in the rear to begin with the effect is less dramatic. It also depends on if your car is loose entering or exiting turns. Shocks and tire pressures as well as cross weight can also cause the car to be loose. What track r you at ? Need more info to help u.

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> So which way is it? Loose car- ie.rear-end hits the wall before the > front ;o/- more rear weight bias or less?? > I believe it should be more but I keep seeing advice to use less. Is > this a sim issue with the sim being different than actual racing? Or am > I just interpreting the weight transfer wrong? > Thanks, > AKH

I have always used the rear weight bias adjustment to correct how my car is turning in the center of the corner. If I'm loose - I decrease rear weight bias. Seems to work for me. Don Clawson DonC - Hawaii

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>So which way is it? Loose car- ie.rear-end hits the wall before the >front ;o/- more rear weight bias or less?? >I believe it should be more but I keep seeing advice to use less. Is >this a sim issue with the sim being different than actual racing? Or am >I just interpreting the weight transfer wrong? >Thanks, >AKH

Depends on the track, you can overload the rear tires in acceleration. There is a great tip book called NASCAR racing tips and strategies. Go Big Chief. RACING TAKES BALLS GET OUT OF THE WAY LOSERS

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>So which way is it? Loose car- ie.rear-end hits the wall before the >front ;o/- more rear weight bias or less?? >I believe it should be more but I keep seeing advice to use less. Is >this a sim issue with the sim being different than actual racing? Or am >I just interpreting the weight transfer wrong? >Thanks, >AKH

I assume your talking about the Papyrus NASCAR sim. If so, to tighten up the car, you move weight forward, but not too much. I get the impression that the Papyrus sim doesn't take into consideration that more load on a tire generates more lateral force, but instead only model the change in the center of mass when you move weight around. For a more detailed explanation of setting up a car, see: http://www.sequoia-dev.com/Hawaii/Features/setupguide.html Dave (davids) Sparks Late Night League http://www.sequoia-dev.com/Hawaii/latenite.html

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> >So which way is it? Loose car- ie.rear-end hits the wall before the > >front ;o/- more rear weight bias or less?? > >I believe it should be more but I keep seeing advice to use less. Is > >this a sim issue with the sim being different than actual racing? Or am > >I just interpreting the weight transfer wrong? > >Thanks, > >AKH > I assume your talking about the Papyrus NASCAR sim. If so, to tighten up > the car, you move weight forward, but not too much. > I get the impression that the Papyrus sim doesn't take into consideration > that more load on a tire generates more lateral force, but instead only > model the change in the center of mass when you move weight around. > For a more detailed explanation of setting up a car, see: > http://www.sequoia-dev.com/Hawaii/Features/setupguide.html > Dave (davids) Sparks > Late Night League > http://www.sequoia-dev.com/Hawaii/latenite.html

Hi Folks, I don't normally post, but this one hit home for me. I have puzzled over this point for about a year now. Since NCR came out, I have used thought I was running fast until hawaii went open... Last June I went to the 3 day skip barber school, had a great time and learned some things. The lesson that applies here really was about weight transfer, but I applied it to the F/R bias. Bruce McGinnis (great guy) was always talking braking once and accelerating once per turn. Why are you lifting at the exit of the turn?? The reason you are lifting is not to slow down enough to make the turn, it's because when you lift weight is transfered to the front giving more cornering force. Yes you do slow some which fits the speed=radius*grip(G), but the extra load on the front is what keeps you from dropping two wheels or slapping the wall. I learned this lesson the hard way, I spun my formula car on the first day after doing a pedal snap when the car got a little out of shape. The other lesson I learned was "if you spin, both feet in", it works! I'm not very good at creating setups from scratch, but a friend put together a good Atlanta setup for me. While I could manage 185-187mph race laps, I was still getting passed in the middle of the turns. For some reason the weight-transfer lesson came to mind about two weeks ago. After changing the Rear bias from 50.4 down to 49.5, I can now run 175mph in the middle of the turn instead of the 171-2 I was doing before. I have since moved my atlanta setup to every single track, and with the exception of the road-courses and phoenix, I run faster than I ever have before. Even at Marty with the gears same as Atlanta, I can run 99mph after a few laps. Tally was about the same speed, but the TRI became very drivable. I don't know if other people can drive the setup with the same results, but I'll email the basic building block to anyone who wants it. John Mullins jmullins/vortex on hawaii

>> I get the impression that the Papyrus sim doesn't take into consideration >> that more load on a tire generates more lateral force, but instead only >> model the change in the center of mass when you move weight around. I think they did it right - see below. > Last June I went to the 3 day skip barber school, had a great time and >learned some things. The lesson that applies here really was about weight >transfer, but I applied it to the F/R bias. [rest deleted...] Folks - these are two different things... In fact, weight transfer has the *opposite* effect of static weight distribution. Here's why: (For in-depth explanations see the *** to Win series by the author whose name I'm blanking out right now) - Static weight: All other things being equal, shifting the center of gravity of the car should have no effect on the balance - you've got increased lateral force required, but you've got the same amount of vertical force; should be a wash. What actually changes the balance is the effect of the extra weight - The weight deforms the tire, which in turn deforms the contact patch... As a result the coefficient of friction of the tire goes down... Thus, more front weight for a tighter car, more rear weight for a looser car. - Weight transfer: Weight transfer, on the other hand, is a dynamic effect which operates only in one axis - By decelerating, more normal force is applied to the front contact patch, but the center of gravity is not shifted forward. As a result, no additional lateral force is needed to turn that end of the car, and the front grips harder (despite the fact that the tire deforms as a result of the extra force). The rear wheels, of course, are "lightened" by the equivalent amount, and thus may start sliding. -- Ulrich

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>>> I get the impression that the Papyrus sim doesn't take into consideration >>> that more load on a tire generates more lateral force, but instead only >>> model the change in the center of mass when you move weight around. >I think they did it right - see below. >> Last June I went to the 3 day skip barber school, had a great time and >>learned some things. The lesson that applies here really was about weight >>transfer, but I applied it to the F/R bias. >[rest deleted...] >Folks - these are two different things... In fact, weight transfer has the >*opposite* effect of static weight distribution. >Here's why: (For in-depth explanations see the *** to Win series by the author >whose name I'm blanking out right now) >- Static weight: All other things being equal, shifting the center of gravity >of the car should have no effect on the balance - you've got increased lateral >force required, but you've got the same amount of vertical force; should be >a wash. What actually changes the balance is the effect of the extra weight - >The weight deforms the tire, which in turn deforms the contact patch... As >a result the coefficient of friction of the tire goes down... Thus, more front >weight for a tighter car, more rear weight for a looser car. >- Weight transfer: Weight transfer, on the other hand, is a dynamic effect >which operates only in one axis - By decelerating, more normal force is >applied to the front contact patch, but the center of gravity is not shifted >forward. As a result, no additional lateral force is needed to turn that >end of the car, and the front grips harder (despite the fact that the tire >deforms as a result of the extra force). The rear wheels, of course, are >"lightened" by the equivalent amount, and thus may start sliding. >-- Ulrich

Can you give me the name of the author. I have a book that says similiar, but apparently isn't as clear as yours. Please pass on and thanks for the info. Weekend Racer. Gotta Lovitt work hard and spend your money racing. Go 24