Real inertia values--For VEH file tweakers

There's been a lot of tweaking of inertia values lately! Here's some real, tested values for an Indy oval car. They ought to be fairly close to an F-1 car, or perhaps these may be a little higher? Indy Oval Track Car--- One tested baseline configuration Tire rate (front corner) 36,000 lbs/foot Tire rate (rear corner) 36,000 lbs/foot Spring rate (front corner) 19,200 lbs/foot Spring rate (rear corner) 25,000 lbs/foot Of course, these are probably actually a progressive value in real life, but they should give anyone who is interested a sense of scale. Roll inertia ---- 13.7 lb-ft-sec^2 Pitch inertia ----252.5 lb-ft-sec^2 I don't have published data for the yaw inertia, but in my simulation experiments, it seems 500-800 lb-ft-sec^2 would be about the right range for the yaw axis. Concerning flywheel inertia and wheelspin in F12K: The flywheel inertia in a real car is perhaps only 1/10th of the total rotating inertia for the driveline. It's possible that for calculation speed purposes, these are summed together in F12K and simply used as "flywheel inertia". A rough estimation for an American V-8 musclecar for flywheel would be about 3 lb-ft-sec^2, while the rest of the driveline is on the order of 30 lb-ft-sec^2. An F-1 car should be considerably lower than this. I'd guess 1/2 to 1/3rd? Just a guess, but hope these values help. It's up to you folks to convert these to proper metric form for F12K, sorry!! The oval track Indy car this data is from has a wheelbase of 9 feet and weighs 1600 lbs. This information was taken from Milliken and Milliken's "Race Car Vehicle Dynamics" Hope this helps! Todd Wasson --- Performance Simulations Drag Racing and Top Speed Prediction Software http://PerformanceSimulations.Com

James Pickard wrote:

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> > Will these values work for SCGT, you think? > > Interesting... > > James >

Interestingly enough, when I recently tweaked the SCGT files (see another thread of mine), the values for inertia were very reasonable, and even lower than those in F1 2000. So I left them as they are, and only tweaked the tires/steering. -Gregor

Will these values work for SCGT, you think? Interesting... James "J. Todd Wasson" <[email hidden]> wrote in message news:[email hidden]... > There's been a lot of tweaking of inertia values lately! Here's somereal, > tested values for an Indy oval car. They ought to be fairly close to anF-1

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> car, or perhaps these may be a little higher? > > Indy Oval Track Car--- One tested baseline configuration > > Tire rate (front corner) 36,000 lbs/foot > Tire rate (rear corner) 36,000 lbs/foot > Spring rate (front corner) 19,200 lbs/foot > Spring rate (rear corner) 25,000 lbs/foot > > Of course, these are probably actually a progressive value in real life,

but

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> they should give anyone who is interested a sense of scale. > > > Roll inertia ---- 13.7 lb-ft-sec^2 > Pitch inertia ----252.5 lb-ft-sec^2 > > I don't have published data for the yaw inertia, but in my simulation > experiments, it seems 500-800 lb-ft-sec^2 would be about the right range

for > the yaw axis. > > Concerning flywheel inertia and wheelspin in F12K: > > The flywheel inertia in a real car is perhaps only 1/10th of the total > rotating inertia for the driveline. It's possible that for calculationspeed > purposes, these are summed together in F12K and simply used as "flywheel > inertia". A rough estimation for an American V-8 musclecar for flywheelwould > be about 3 lb-ft-sec^2, while the rest of the driveline is on the order of30 > lb-ft-sec^2. An F-1 car should be considerably lower than this. I'dguess 1/2 > to 1/3rd? Just a guess, but hope these values help. It's up to you folksto > convert these to proper metric form for F12K, sorry!! > > The oval track Indy car this data is from has a wheelbase of 9 feet and > weighs 1600 lbs. > > This information was taken from Milliken and Milliken's "Race CarVehicle

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> Dynamics" > > Hope this helps! > > > Todd Wasson > --- > Performance Simulations > Drag Racing and Top Speed Prediction > Software > http://PerformanceSimulations.Com

I'm actually a big fan of SCGT. Not the default installation that you get with the CD, but when you 'tweak' it up with all the add-ons on the net. With the Advanced Options Editor it is actually really good. not perfect, but a really fun Simulation. James "Gregor Veble" <[email hidden]> wrote in message news:[email hidden]...

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> James Pickard wrote: > > > > Will these values work for SCGT, you think? > > > > Interesting... > > > > James > > > > Interestingly enough, when I recently tweaked the SCGT files (see > another thread of mine), the values for inertia were very reasonable, > and even lower than those in F1 2000. So I left them as they are, and > only tweaked the tires/steering. > > -Gregor

I wish I knew what you guys were talking about.......seems really heavy. "James Pickard" <[email hidden]> wrote in message news:_Sp%5.23702$[email hidden]...

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> I'm actually a big fan of SCGT. Not the default installation that you get > with the CD, but when you 'tweak' it up with all the add-ons on the net. > With the Advanced Options Editor it is actually really good. not perfect, > but a really fun Simulation. > > James > > > > "Gregor Veble" <[email hidden]> wrote in message > news:[email hidden]... > > James Pickard wrote: > > > > > > Will these values work for SCGT, you think? > > > > > > Interesting... > > > > > > James > > > > > > > Interestingly enough, when I recently tweaked the SCGT files (see > > another thread of mine), the values for inertia were very reasonable, > > and even lower than those in F1 2000. So I left them as they are, and > > only tweaked the tires/steering. > > > > -Gregor > >

What formula do you use to convert the real world into the number in the VEH files ? Regards Mike On 18 Dec 2000 01:29:49 GMT, [email hidden] (J. Todd Wasson) wrote:

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> There's been a lot of tweaking of inertia values lately! Here's some real, >tested values for an Indy oval car. They ought to be fairly close to an F-1 >car, or perhaps these may be a little higher? > > Indy Oval Track Car--- One tested baseline configuration > > Tire rate (front corner) 36,000 lbs/foot > Tire rate (rear corner) 36,000 lbs/foot > Spring rate (front corner) 19,200 lbs/foot > Spring rate (rear corner) 25,000 lbs/foot > > Of course, these are probably actually a progressive value in real life, but >they should give anyone who is interested a sense of scale. > > > Roll inertia ---- 13.7 lb-ft-sec^2 > Pitch inertia ----252.5 lb-ft-sec^2 > > I don't have published data for the yaw inertia, but in my simulation >experiments, it seems 500-800 lb-ft-sec^2 would be about the right range for >the yaw axis. > > Concerning flywheel inertia and wheelspin in F12K: > > The flywheel inertia in a real car is perhaps only 1/10th of the total >rotating inertia for the driveline. It's possible that for calculation speed >purposes, these are summed together in F12K and simply used as "flywheel >inertia". A rough estimation for an American V-8 musclecar for flywheel would >be about 3 lb-ft-sec^2, while the rest of the driveline is on the order of 30 >lb-ft-sec^2. An F-1 car should be considerably lower than this. I'd guess 1/2 >to 1/3rd? Just a guess, but hope these values help. It's up to you folks to >convert these to proper metric form for F12K, sorry!! > > The oval track Indy car this data is from has a wheelbase of 9 feet and >weighs 1600 lbs. > > This information was taken from Milliken and Milliken's "Race Car Vehicle >Dynamics" > > Hope this helps! > > >Todd Wasson >--- >Performance Simulations >Drag Racing and Top Speed Prediction >Software >http://PerformanceSimulations.Com