Chicago Motor Speedway was running track shaped, if that's helpful. I believe they are called bi-ovals.

anyone wanna hop in the server with me? im in it right now and i will be in it for like 30 minutes

I did get some of my data from here, could be interesting reading: http://www.racelinecentral.com/garage101.pdf

Although it contradicts itself about weight distribution, first saying less than or equal to 50%, but then says >=50%, talks about above 50%, and the screenshot shows 51.5% front. So I'm thinking I need to revise this is the mod. Some more tyre pressure info in there too.

I've also seen that the fuel tank is in the "trunk", behind the rear axle, so am moving that too.

The rear wheel horespower figures given here indicate that the drivetrain on these cars is more efficient than anticipated, about 90%, so I need to inflate the engine power in LFS as there is a fixed 85% efficiency on RWD cars.

Quote from Bob Smith :

I did get some of my data from here, could be interesting reading: http://www.racelinecentral.com/garage101.pdf

Although it contradicts itself about weight distribution, first saying less than or equal to 50%, but then says >=50%, talks about above 50%, and the screenshot shows 51.5% front. So I'm thinking I need to revise this is the mod. Some more tyre pressure info in there too.

I've also seen that the fuel tank is in the "trunk", behind the rear axle, so am moving that too.

The rear wheel horespower figures given here indicate that the drivetrain on these cars is more efficient than anticipated, about 90%, so I need to inflate the engine power in LFS as there is a fixed 85% efficiency on RWD cars.

Nice finds.

Hmm, I'm running in to a problem with this car. I've adjusted the suspension geometry at the front to be more agressive, based off some stock car diagrams I've found and a piece of text that loosely described the length of the instant swing arm. The side effect of doing this is a much higher roll centre at the front, which sounds great, but without being able to raise the roll centre at the rear (which I've read you can do with the live axle the real car uses), it creates massive understeer, which I then compensate for by using a very stiff ARB at the rear, coulped with a not overly stiff one at the front.

Perhaps, given that the rear suspension is essentially rubbish anyway, would it be less wrong to put double wishbones at the rear as well, which would reduce the need for large static camber on the rear wheels, and would allow me to raise up the rear roll centre so that the need for wacky spring and ARB rates disappears?

I hope someone else can give you advice on that, I don't have much of a clue.

id love to download but m not sure...or what the hell. downloading!. this looks so awsome, altrought it isnt patch Z

Well, I gave it a try and I've uncovered another curiosity - it seems that using double wishbones makes the tyres hotter. With trailing arms at both ends, the tyre temps are just above optimal after 5 laps (115 to 120 at rear, 120 to 125 at front), while with double wishbones all round, they're glowing red (over 140 at both ends). Now the car did seem a little quicker in the bends, shaving a few tenths per lap (if only for the first couple of laps until the tyres overheat), but I'm wondering what is causing this? There can't be that much lateral scrubbing going on surely?

I want to run some more analysis on the geometry but I need to get round to updating my analyser applet first to actual perform this extra analysis. So that's not happening anytime soon. :|

Shadowww votes to make bob smith developer (2/12)

P.S.: join the server, guys!

Quote from Bob Smith :

Well, I gave it a try and I've uncovered another curiosity - it seems that using double wishbones makes the tyres hotter. With trailing arms at both ends, the tyre temps are just above optimal after 5 laps (115 to 120 at rear, 120 to 125 at front), while with double wishbones all round, they're glowing red (over 140 at both ends). Now the car did seem a little quicker in the bends, shaving a few tenths per lap (if only for the first couple of laps until the tyres overheat), but I'm wondering what is causing this? There can't be that much lateral scrubbing going on surely?

What compound are you using? I don't know what sort of compound real life NASCAR machinery uses but I guess it's probably rather hard.

I'm using R4s.

Attached is an updated version of the car for people to test out. Please back up your existing data file if you want to race online still (these changes are not online compatible).

If all goes well, I'll make this an official update for the mod, and encourage everyone to get it.

Changes:

• Static weight distribution moved forward by 2%
  
• Fuel tank moved rearwards
  
• Body lowered, centre of gravity dropped by 2cm
  
• Inertia increased in pitch and yaw by 6%, decreased in roll by 3%
  
• Engine power increased by 7% to make up for drivetrain inefficiency in LFS (wheel horsepower should now be accurate), rpm reduced a little
  
• Aero distribution moved forward to maintain balance with new weight distribution
  
• Revised suspension geometry at front (shorter instant swing arm for more aggressive camber compensation)
  
• Replaced trailing arms at rear with double wishbones (should really be live axle, but at least this way excessive static camber isn't needed, and I can play with the roll centre)
  
• Maximum tyre pressures reduced
  
• Setup: Softer springs, even softer dampers, stiffened ARBs, reduced tyre pressures and switched to R4 tyres
  

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Thanks.

If it's any use, on the default set I got a front right failiure on lap 4, with the FL red and the others green/purple. Sadly I wasn't recording the replay. I was driving hell for leather in a wacky trail braking style which screws up tyres, so it might be a very good idea to ignore this result. My experience in other sims is that I can do superspeedways, I can do short tracks but anything in between I am useless at. I'll try the plate setup. If someone makes a road course setup it would be interesting to drive one on South City.

EDIT : It goes on lap 5 on the default plate setup.

4 laps? Impressive, it takes me 5 or 6 just to get them red. I don't brake at all at the oval, with the improved car I'm running laps in the low 37s / high 36s.

i did some search on google to!

here is some Bilstein shocks stockcar information, about setting up for ovals and how to solve problems:
http://www.stockcarproducts.com/bshoc3.htm

page with technical information about the whole car when i look at the list. also with problemslove information, with baseline setups and calculators.
http://www.stockcarproducts.com/techindx.htm

i hope you can use this to setup or change the nascar's physics.

I've had a go early on. Hopefully the more people become aware of this the more chance there will be having a few people on the server at the same time.

The times you can do with the car are slightly quicker than FO8, so that's pretty good.

As I see it there are two main issues holding back mods like this one:
a) in this case, not supporting the latest version of LFS, although this is cureable with some effort
b) That you can't flit between normal and modded servers without quitting and relaunching the app (again, only a case of extra hassle)

Also not helping is the limited number of players, that means taking advantage of the online racing permitted with a fixed mod is hard to realise.

there is an other isseu that is holding the developement, the number of unlocks, need to wait a full week again before i can unlock x10 again.

made a short oval today for the nascarmod and wanted to test it. i will post it these days

did you had any helpfull information out of my links bob?

good luck!

I had a fair read (thanks) but that site is full of explanations and tips, rather than hard figures, which is what I need.

Why do you need to unlock X10 again? Once should be enough surely?

i don't know exactly, because i made a copy version of lfs.; and in the copy version i installed x10. i thought you had to lock/unlock if you want to change te version you use. or am i talking crap here :P

Quote from henrico-20- :

i thought you had to lock/unlock if you want to change te version you use.

No. The LFS licence permits you to unlock LFS on two machines (per account). I've never been aware of any restriction on how many different copies/versions of LFS are unlocked on those two machines.

Duke, daytona (a super speedway) and talladega (another) are nascar tracks. They have MUCH MORE banking. Kyoto has probably the equivelant to Kansas Speedway.

Edit: Sorry thought i was on the last page LOL

Quote from Bmxtwins :

Duke, daytona (a super speedway) and talladega (another) are nascar tracks. They have MUCH MORE banking. Kyoto has probably the equivelant to Kansas Speedway.

Edit: Sorry thought i was on the last page LOL

Kansas equal to Kyoto?? Get real BMX!!

Dave, they both are similar banking right? Kansas a little less but not much. Daytona definately way more than KY1

Good job Bob. Didn't have time to test your mod properly before today, and I got to say it's quite awesome. With the 28% restriction on Kyoto GP long with h-gate it's such a riot. Haven't had such a smile on my face while driving LFS in ages.

My set was mostly rubbish, but great fun car.

Glad I found this! I'll give it a try in the next day or so.

IIRC, a couple years ago, the rear camber was limited to 1.5 degrees positive or negative- not sure if it was a limitation of a live rear axle or a NASCAR rule, and it may have changed since the onset of the Car of Tomorrow. From what I have observed, they use a lot of rear camber on the ovals but not a whole lot of rear camber on the road courses.

About tire compounds, they use varying compounds at each track, though Goodyear supplies the tires and the teams cannot choose what compound they will run. Makes re-creating them in a sim a bit difficult, but I would imagine they don't vary a whole lot between the major track catagories; IE, normal "cookie-cutter" speedway, super-speedway, short track, and road course. It was pretty normal to use very high pressures on the right-rear tire for the ovals and very low pressures on the left-front on the flatter tracks. I've also seen them talk about tire temperatures in the 200-degree F range at the extreme.

Of course, the oval cars are much different than the road-course cars- the oval cars have as much weight as possible on the left side. Even shifting the engine to the left side by several inches is common. I don't think the oval cars use a rear swaybar but the road course versions sometimes do. If you watch the road course races, many times the inside-front wheel will lift coming out of a sharp turn- so they must run pretty soft rear-ends even for the road courses. Like with any live-axle car, under heavy breaking and downshifting, the rear-end will tend to hop on you which means you will more than likely swap ends when entering the turn.

That's about all I know. I used to really be in to NASCAR but not as much any more. Sorry if I am re-posting previous information or if it's all stuff you already knew. I'll give your mod a try here soon and let you know how it feels. Thanks for your work though!!

Brendan