1968 Plymouth Barracuda 440 6-Pack V8

  • Tiberius

Hi. Barracudas had a live rear axle, right? Ideally you want to add that to the weight of the wheels.

This is how I set my cars up for weight - if anyone else wants to correct me here, feel free - setting up car weight isn't clearly documented on racer.nl, this is how I worked out how to set up the weights so that the total car mass in the telemetry appears correctly, there's no guarantee that this is 100% accurate but it works for me:

You need to know:

Kerb weight of car (in Carfolio or whatever)

Weight of a full tank of fuel (AFAIK, I *think* Racer allows around 60kg for a tank of fuel, so you'll want to subtract this from your car's body mass)

Weight of the driver (AFAIK, Racer allows 60kg for a (very skinny) driver, you'll want to subtract this from the car's body mass too)

Unsprung weight - that is, the weight you enter for each wheel in the car.ini. As a ballpark guide, a 235/55 R16 wheel+tyre from the Jag weighs a perfect 20kg, a 185/65 R15 steelie from our Mondeo weighs 15kg, an old skool 185/70 R13 from the Capri weighs 13kg (yep, I weighed the wheels off every car we had here, I need to get out more :)) . Ideally to that you want to add the weight of any part attached to that end of the spring/damper, that means the brake disc/caliper, the hub etc. Also, if you've got a live rear axle, you want to add half the weight of that too to each wheel's mass (a live rear axle from the Capri weighs about 60kg, on your car probably a bit more - so for the Capri you'd add half of that to each rear wheel mass).


So, you end up with:

Wheel mass = weight of your wheel plus any bits attached to the suspension on that corner. So, if on each front suspension you have a 20kg wheel you might then have a 7kg brake disc, 3kg caliper, 2kg for the hub, bearing etc. That would give you a total wheel mass of 32kg. for the rear you might have the same 20kg wheel but a 8kg brake drum assembly and half of a 60kg solid rear axle - that would give you a total wheel mass of 58kg for each rear wheel

Then your body mass would be:

Body mass = kerb weight - 60kg driver, -60kg fuel, - engine mass - total unsprung mass for all wheels (weight of each wheel/suspension, as above - wheel, brake suspension parts etc - in the example that would give you a total unsprung weight of 180kg)

Engine mass = Whatever you allowed for engine mass above

That *should* work out correctly I hope :)
 
Then your body mass would be:

Body mass = kerb weight - 60kg driver, -60kg fuel, - engine mass - total unsprung mass for all wheels (weight of each wheel/suspension, as above - wheel, brake suspension parts etc - in the example that would give you a total unsprung weight of 180kg)

Engine mass = Whatever you allowed for engine mass above

That *should* work out correctly I hope :)

Ehm.. ok.. I am a bit confused now.. just to be sure.. body.mass=whatever is the total weight of.. what? If I subtract fuel, driver, engine mass +++... then the total weight would be the mass of the chassis ++.. and the rest of the weight, driver and fuel ++.. is that ignored? Or.. heh.. really confused now.. I thought I should /add/ the weight of driver, fuel, wheels and so forth..

EDIT: Ok.. here's what I found.. (http://auto.howstuffworks.com/1967-1969-plymouth-barracuda.htm/printable)
1967, 1968, 1969 Plymouth Barracuda Specifications: Weight (lbs): 2,793-2,940
I chose 2,940lbs which is mass=1334 and that is what I entered in the body.mass field.
The 440 engine has size=0.25 and mass=333.39 and the wheels have mass=20 (x4=80).
What to do with all this information? Since the mass now is defined in the proper places,
I see no need to alter the body.mass any more as the weight of the other parts are defined.
I also added mass=75 to the driver.dof.. if that makes any sense at all..

EDIT 2 (13.Jan): mass=1334 is much too light.. the car felt like a "car-toon" (pun intended).
So I added the weight of the wheels and the engine and now it feel "natural". Go figure..
 
For those who are interested.. this car is totally wild..

The 440 Cuda appealed strictly to the go-fast, straight-line
dragstrip addicts, as such a beast was almost undriveable on
most public roads
(http://wikicars.org/en/Plymouth_Barracuda)

255Km/h on Speedest2 (image)
Current car.ini (Don't simply replace your current car.ini with this one,
it WILL NOT work as the additional files are not yet included. WAIT
for the official release
:) )
 
  • Tiberius

Weight of a full tank of fuel (AFAIK, I *think* Racer allows around 60kg for a tank of fuel, so you'll want to subtract this from your car's body mass)

Weight of the driver (AFAIK, Racer allows 60kg for a (very skinny) driver, you'll want to subtract this from the car's body mass too)

Grrr, looks like I was wrong here, sorry to mislead you and confuse you for no reason. Seems that now Racer only adds the weight of the wheels and engine, no need to subtract the weight of the driver or fuel. The part about unsprung mass is still correct though, in the mass= field for each wheel you just put whatever the total of your wheel+brake+hub would be at that corner.

I'm certain Racer used to need the driver and fuel mass subtracted, but now the overall weights seem to come out correct if you just subtract your engine and wheels from the listed kerbweight of the vehicle.

So, body mass = kerbweight - total of all wheel masses - engine mass

The CTRL+9 debug screen gives you all the useful stuff like centre of gravity and weights, the overall car mass is on that screen..it's in Newtons but you can convert that straight to kilos or pounds.

I don't think you're able to add weight to models like the driver, would probably just give a Qlog error? The only way I know of to simulate extra points of weight would be to add the extra mass to the body mass, then move the centre of gravity around to try and simulate where your extra weight would be.

It's the same situation with fuel, we can add a fuel tank but all it does is cuts the engine when it runs out of fuel. I did ask Ruud a while back if there were plans to add fuel weight/inertia and he said maybe, I don't think it's happened yet. That's the one major thing rFactor has over Racer, get a light car like a Caterham or open wheeler and the fuel mass is added to the physics as a sprung mass, when you fill up at the pits you can notice the extra mass of fuel into the first few corners.

Also, I don't think the 'size=' feature for parts like the engine works anymore, as far as I know it used to be a placeholder for graphics models in the early days. Anything you put as engine mass is merely added to the overall body mass by Racer, it would work fine if you just added that mass to the body mass and set engine_mass=0..but it's better to add the engine mass in the proper place, in case Racer uses engine mass for anything later on.

Finally, body inertia has a big influence on how a car handles too, try setting the inertia really low and then really high and get a feel of how it affects the feel of the car. If your car feels too heavy or light, it might be the inertia that's wrong. The inertia calculator that Engine of Darkness posted on my 'lost physics data' thread will calculate that for you.

Thought I better set the record straight :)
 
Bump.. been working on the Cuda. A bit tired of track-making at the moment so I put it on hold for a couple of weeks. Need one or two beta-testers for the Cuda.. anyone interested?
 
Hi dude...
hmm...got strange reflektions....not sure why...
screenshot248.jpgscreenshot247.jpgscreenshot246.jpg
 
hmm...are you sure the engine should rev up to 30000 1/min. ?!

It should probably not.. thats why splashonda made an alternative torque. It's in the car directory.. I kept that one because I am used to it.. with the new one the car seemed to slow down.. and I did not want it too :p

EDIT: Well, I now have made splashonda's torque the default.. it maxes at 7000RPM. If you want more, just use torque.crv_luthobu instead. Ok? :)

Archive updated.. again..

EDIT2: Thanks for the info Dream Factory! Really helpful.. I want this car to be as perfect as possible as it might be the only car i ever release.. I really appreciate it! :)
 
ok, first..sorry..the updated shader was the same problem...but finaly i got it^^ i made cg- shaders for him and it works....but the "mopar" label on the driver seat and backseat is mirrored...see the pic...rest is ok...i like the handling...will see if i get a nice time for the Polish- Roads Contest^^

screenshot255.jpgscreenshot256.jpgscreenshot257.jpg
 
@Dream Factory: Wow.. it looks beautiful! CG is the way to go.. I can't reproduce the problem here though.. so I can't really debug it either. Sorry about that. About the Mopar label, I'll just remove the text, it is faster and easier than remapping. Thanks for the feedback, and I really appreciate that you like the handling.. so do I.. love to drive that car :)

Edit: here is the inside.tga without the Mopar text, just the M. I'll make it the default in the archive and re-upload it. Preview below.
 

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@Dream Factory: Wow.. it looks beautiful! CG is the way to go.. I can't reproduce the problem here though.. so I can't really debug it either. Sorry about that. About the Mopar label, I'll just remove the text, it is faster and easier than remapping. Thanks for the feedback, and I really appreciate that you like the handling.. so do I.. love to drive that car :)

Edit: here is the inside.tga without the Mopar text, just the M. I'll make it the default in the archive and re-upload it. Preview below.
I know this thread is oooold, but any chance this mod is still available anywhere as the original link is no longer valid?
 

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