1968 Plymouth Barracuda 440 6-Pack V8

[luthobu]

(more screenshots at Alge)

I have done alot of work on RyanT's 1968 Barracuda 340cidV8, most which basically means that it is an entirely different car, but with the same "chassis". I replaced the 340cidV8 with a 440-6packV8 (yes, I know that this particular engine was first released for the Barracuda in 1969 and not 68, but I really wanted it) and adjusted torque, brakes, steering, suspensions, replaced wheels, steeringwheel (not really satisfied with it yet), and replaced the 3D driver. Also I have changed the textures - interior and exterior, altered the shaders and added some new features by overriding the default dofs in the original *.ar file.

Now, this car is absolutely amazing to drive! Instant reaction on both brakes and steering, and it could turn on a dime or a nickle if it had to, and the brakes are perfect - they behave just as they should and that really makes driving fast both a pleasure and even secure (as breaking is more accurate than with the original). On Some1's track Speedest2 this car had an avarage speed of 242.3 km/h! The dials stopped at 150MPH while the car justed blasted on down the track :tongue:

Since I have done so many changes I reread the Instructions.rtf included with RyanT's original Barracuda, and as far as I can tell, no changes have been made that violate his requests, which in turn means that I can release the 440-6pack version - as an add-on or mod - without asking for permission. But it is going to be a while, still a lot to do before it is really perfect.. but stay tuned.. it might even be worth it.. :veryhappy:


From the original Instructions.rtf:

"Feel free to publish your INI.s as different setups. Since I.ve
included all the files you need, your re-releases need not be
more than car.ini. Also, you may include other wheels and/or
accessories if you like. I just make one request: no spoilers
or 22. rims!"


UPDATE: FIRST INITIAL RELEASE!

READ the README! Yes! Now.
Here: http://alge.anart.no/projects/racer/releases/README_440-6pack.txt


Read it? Now you can download..
Download here: http://alge.anart.no/projects/racer/releases/plymouth_barracuda_440-6pack_1968.7z


Enjoy

 

[KS95]

Mmm.. looks good, I just hope it drives as good

 

[FiftyOrange]

Now, this car is absolutely amazing to drive! Instant reaction on both brakes and steering, and it could turn on a dime or a nickle if it had to, and the brakes are perfect - they behave just as they should and that really makes driving fast both a pleasure and even secure (as breaking is more accurate than with the original). On Some1's track Speedest2 this car had an avarage speed of 242.3 km/h! The dials stopped at 150MPH while the car justed blasted on down the track :tongue:

Have you ever driven a Barracuda? Sharp responsive fast race machines they are not.

 

[luthobu]

Have you ever driven a Barracuda? Sharp responsive fast race machines they are not.

It all depends on the configuration.. ref:

 

[Tiberius]

Nice, I love classic American cars, I had a lot of the original versions of Ryan's cars a long time ago..

I think that what Fifty means is that they're not agile and quick through the corners like a good European car would be, more of a fast car for long straights. Like some people import US cars into the UK and then get a shock because the cars don't like the camber and more twisty nature of our roads.

Nice car though, if I ever had that amount of money (LOL), I'd love at least one piece of classic American metal in my collection, probably a vintage Plymouth or Pontiac

 

[FiftyOrange]

Brakes are drums all round, aren't they?

Still, it's great to have an update for this car. If I can drag myself away from this Jag Cab, I'll see if this can dance.

 

[luthobu]

I think that what Fifty means is that they're not agile and quick through the corners like a good European car would be, more of a fast car for long straights. Like some people import US cars into the UK and then get a shock because the cars don't like the camber and more twisty nature of our roads.

Ah, of course. That makes perfect sense, and it is all eventually in the interpretation of the text. It is not as fast, quick or even stable as many other cars, but compared to the /original/ (Ryan´s) it is a lot better - or rather - it behaves more like I want it to Glad you like it!

 

[Stereo]

Brakes are drums all round, aren't they?

Probably disc front, drum back if it's more a performance car. By the late 60s most muscle cars had an option for disc brakes, eg. http://www.tocmp.com/brochures/Plymouth/1968/Barracuda/1968PlymouthBarracudaBroch/68-11_JPG.html mentions front discs.
Interestingly that brochure also lists spring rates and torque curves...

 

[luthobu]

Interestingly that brochure also lists spring rates and torque curves...

Hm. Could not read the text, but.. I thought torque was based on engine.. not car make. So if I replace the standard 340cid with a 440 it would have an effect on the torque curve.. right? And even the brakes, and the steering..

Maybe I do not know enough yet to be able to release a car.. even though I am very satisfied with it..

 

[Harey]

Hm. Could not read the text, but.. I thought torque was based on engine.. not car make. So if I replace the standard 340cid with a 440 it would have an effect on the torque curve.. right? And even the brakes, and the steering..

Maybe I do not know enough yet to be able to release a car.. even though I am very satisfied with it..

Changing an engine would change the torque curve, but not necessarily the brakes or steering, it might also change your weight distribution, like putting a 440 6 pack into a Cuda would put quite a bit more weight into the front end of this thing causing it to be more prone to understeer, and big healthy burnouts, naturally lol

 

[luthobu]

Changing an engine would change the torque curve, but not necessarily the brakes or steering, it might also change your weight distribution, like putting a 440 6 pack into a Cuda would put quite a bit more weight into the front end of this thing causing it to be more prone to understeer, and big healthy burnouts, naturally lol

*Whew* So I was at least on the right track (pun intended). Thanks

 

[Tiberius]

Hm. Could not read the text, but.. I thought torque was based on engine.. not car make. So if I replace the standard 340cid with a 440 it would have an effect on the torque curve.. right? And even the brakes, and the steering..

Maybe I do not know enough yet to be able to release a car.. even though I am very satisfied with it..

What's the problem?

Springrates are a nice find but Racer uses the actual wheelrate so you can't actually use them directly unless you know the suspension geometry (motion ratio I think it's called - it's been a while since I set up a car).

Yep, your engine torque is independent of the car - however, sometimes (especially nowadays that engines have management systems), the same engine might be used in two cars but have slightly different power outputs and torque curve in both, it depends on how the ECU is set up, parts like drivetrain losses (from what I could find out, usually around 12% for RWD manuals, rising to around 20% for RWD autos) and also down to smaller things such as air intake which could sap a few hp where it creates air resistance at high RPM. But usually, as long as you get the peak torque and peak HP in the correct places, you should be fine.

Regarding performance, the most important things to get right are the aero drag and frontal area and amount of body lift/downforce, they will have a large effect on the performance of the car at high speed. Also, bear in mind that physics in Racer have changed quite a bit since that car was originally created, so you might need to change more parts of the physics setup to get it behaving how you think it should.

 

[Stereo]

What's the problem?

Springrates are a nice find but Racer uses the actual wheelrate so you can't actually use them directly unless you know the suspension geometry (motion ratio I think it's called - it's been a while since I set up a car).

Possible mis-speak, I'm not really familiar with suspension terms. It lists the rate at the wheel, in lb/in. ranging from 95 to 115 front, 105 to 150 rear depending on the engine. I think those correspond to about 1600 to 2500 kg/m. With an even bigger engine though you'd probably not keep them stock.

 

[luthobu]

Possible mis-speak, I'm not really familiar with suspension terms. It lists the rate at the wheel, in lb/in. ranging from 95 to 115 front, 105 to 150 rear depending on the engine. I think those correspond to about 1600 to 2500 kg/m. With an even bigger engine though you'd probably not keep them stock.

Interesting. I have changed the wheels, and the suspension, just so that is made clear. The main "problem" here is that the 340cid has mass=250 while the 440-6pack has mass=333.39 - now /that/ makes a huge difference. While driving smaller tracks with shorter roads, like Small City or Monaco, my settings work really great. But try larger tracks with longer staights.. like Badlands.. once you come off the bridge and hit the sharp curve at approx. 140MPH you can practically "feel" the engine pull you off the road.. unless you pump the brakes for all your moneys worth.. so it is a matter of /knowing/ how heavy the engine is.. and you do not hit a 45 angle at 140MPH at any rate, because you simply /know/ it's gonna "kill" you.. right? But I still have to find a way to reduce the force of the engine from pulling the car too much.. if any one has suggestions I am most happy to receive them

 

[Tiberius]

Interesting. I have changed the wheels, and the suspension, just so that is made clear. The main \"problem\" here is that the 340cid has mass=250 while the 440-6pack has mass=333.39 - now /that/ makes a huge difference. While driving smaller tracks with shorter roads, like Small City or Monaco, my settings work really great. But try larger tracks with longer staights.. like Badlands.. once you come off the bridge and hit the sharp curve at approx. 140MPH you can practically \"feel\" the engine pull you off the road.. unless you pump the brakes for all your moneys worth.. so it is a matter of /knowing/ how heavy the engine is.. and you do not hit a 45 angle at 140MPH at any rate, because you simply /know/ it's gonna \"kill\" you.. right? But I still have to find a way to reduce the force of the engine from pulling the car too much.. if any one has suggestions I am most happy to receive them

As far as I know, the engine 'mass' is just dumped at the origin and added to the overall body mass, making the engine lighter or heavier won't have any other effect than changing the overall weight of the car - I still add the engine weight separately, in case the separate engine mass is used for something else later on, but you don't actually need to.

Sounds like you might need to check the weight distribution, if you press CTRL+ one of the number keys while ingame, you get a series of readouts, one of which will give you info about the weight distribution.

It could also be the suspension, wrong camber settings or even the wrong slip angles/ratios in the tyre pacejka can make a car really drive badly. Also check the roll centres, I have no idea where they should be on that particular car but usually if you just want good cornering, around 5cm above ground for the front and around 20cm above ground for the rear works well, you can change them from there if you find the real data.

 

[luthobu]

As far as I know, the engine 'mass' is just dumped at the origin and added to the overall body mass, making the engine lighter or heavier won't have any other effect than changing the overall weight of the car - I still add the engine weight separately, in case the separate engine mass is used for something else later on, but you don't actually need to.

Sounds like you might need to check the weight distribution, if you press CTRL+ one of the number keys while ingame, you get a series of readouts, one of which will give you info about the weight distribution.

Well, RyanT added the engine weight separately, so I followed that example. Seems to make sense to me. About the overall weight.. I printed out the telemetry of the car, maybe someone can tell me if there is something wrong.. See image: http://alge.anart.no/projects/racer/mods/1968_Barracuda/telemetry_440.jpg

Oh, this was taken at the bottom of the first bridge... at over 140MPH.. just before I hit the brakes.. and went flying off into oblivion..

EDIT: for comparison I added a screenshot of the 340cid telemetry at the same spot, here: http://alge.anart.no/projects/racer/mods/1968_Barracuda/telemetry_340cid.jpg

 

[Stereo]

The .30 front .40 rear RC (Roll Centre) heights could probably do it, even on a solid rear axle the roll centre should be either at the centre of the axle or below it. I'm not sure exactly what tires it uses but you could check their radius and try to adjust the rear roll centre to a similar number. I would expect it to be more like 0.3 or so.

Front roll centre really depends on the suspension geometry, but if you adjust it down to 0.1 to 0.2 above the road you should get a much more stable ride. I believe the roll centres are defined relative to the car's null point, so adjust accordingly.

 

[luthobu]

The .30 front .40 rear RC (Roll Centre) heights could probably do it, even on a solid rear axle the roll centre should be either at the centre of the axle or below it. I'm not sure exactly what tires it uses but you could check their radius and try to adjust the rear roll centre to a similar number. I would expect it to be more like 0.3 or so.

Originals were radius=0.2865 but I replaced them with Eagles with radius=0.326. I'll adjust the RC and see if it helps. Thanks

 

[Tiberius]

Yep, I agree with Stereo, roll centres up that high would certainly cause some handling issues - especially with turn-in. When I did the Capri (live axle/leaf rear, MacPherson strut front), I think from the advice I got on RSC that I set the rear roll centre just below the centre of the axle (say 0.25m), after some driving I think I ended up with the front at about 0.15m. So try dropping each roll centre by about 0.15m and see if it's any better. As I mentioned before, these aren't absolute values but it should be a ballpark figure to get better handling.

From what I can see, weight distribution looks OK, CG height looks fine too (usually they say between 35-40% of roof height is a good ballpark value for centre of gravity height).

Other than that, you're really talking about changing the pacejka if the tyres still behave badly, and that's a can of worms in itself

 

[luthobu]

Thanks to everyone for all the help.. seems like the settings are about as perfect as they can be now. I reduced the radius of the wheels from 0.326 to 0.3005, changed RC from .35 to .34, changed mass=15 to mass=20 (original setting) and the car is now very stable and alot better to drive. I passed the Chevrolet Van (Alex's) at the curve just before the bridge (Badlands) at aprox. 80MPH and the car was purring like a kitten

Screenshot of telemetry here for those who are interested: http://alge.anart.no/projects/racer/mods/1968_Barracuda/telemetry_440_perfect.jpg