Formula One 1958 [RF1] by O.R.M.

Release over on F1Classics.

http://f1classic.your-talk.com/t18560-formula-one-1958-rf1-by-o-r-m

Haven't had to test it out, because Christimas, but dying to do so.

To drunk to test right now, but hey, F1 '58? A little dream of mine come true!

I'll just copy and paste the post here, so you won't need to register there

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These cars supposed to be impossible to drive in a straight line? Acceleration is all but impossible, but when I lift to shift gears the car pitches right, every time.

I realize these cars were difficult to drive fat, but this difficult?

Jason Fitch wrote:

These cars supposed to be impossible to drive in a straight line? Acceleration is all but impossible, but when I lift to shift gears the car pitches right, every time.

I realize these cars were difficult to drive fat, but this difficult?

Did you install all of the patches?

I installed everything posted int he thread, Mod v2.3, 2.5, and 3.5.

Jason Fitch wrote:

I installed everything posted int he thread, Mod v2.3, 2.5, and 3.5.

So, to get it straight: it slips right every time you try to accelerate? I'd like to know which car is giving you this problem, so I can try to fix it up more easily.
From the looks of it, seems like a DropOff value being off in the traction section.

Nice effort, good models and lots of attention to detail. The suspensions are however not to my liking, but I understand all is a matter of personal interpretation of how you simulate them. 

I created a proper DeDion rear axle with watts linkage instead of the questionable solution employed here (Originated by Kangaloosh as a crutch to fix the lack of it in rFactor) and also a proper rear swing axle instead of the solution you guys employed here, which is not a real swing axle but still a double superimposed triangles one. Both correct solutions are used in our 1937 GP physics patch 

Alberto Ibañez wrote:

Nice effort, good models and lots of attention to detail. The suspensions are however not to my liking, but I understand all is a matter of personal interpretation of how you simulate them. 

I created a proper DeDion rear axle with watts linkage instead of the questionable solution employed here (Originated by Kangaloosh as a crutch to fix the lack of it in rFactor) and also a proper rear swing axle instead of the solution you guys employed here, which is not a real swing axle but still a double superimposed triangles one. Both correct solutions are used in our 1937 GP physics patch 

Thanks for the kind words, Alberto: for the suspensions, we had to rely on what was known amongst the modding community about 3 or so years ago... and we've used the PM files (a bit modified, to be honest) that would've seen their debut in the 55F1 Teamplayers mod. If I knew you guys were using a better suspension model, I'd have gotten all the way up to Everest just to ask the permission to at least have a peek at it!

This said... can I have the links for the patches please? The links in the archives seem to be broken...

Gabriele Maruca wrote:

Jason Fitch wrote:

I installed everything posted int he thread, Mod v2.3, 2.5, and 3.5.

So, to get it straight: it slips right every time you try to accelerate? I'd like to know which car is giving you this problem, so I can try to fix it up more easily.
From the looks of it, seems like a DropOff value being off in the traction section.

Maserati 250/F Specifically, It was the Buell? team car, Carroll Shelby's car.

Here you go, you are welcome to benefit from anything useful you find there: 

http://www.mediafire.com/file/pvuc2vwvxcjv31x/37GP+Physics+Beta+0.9c+FULL.rar

Giving credits or permissions or whatever, I do not care about it, I just hope people can benefit from all I do and produce more historic stuff for the community to enjoy 

Note that the trick to adjust the stability of the swing arms suspension is by moving the control arms horizontally. The closer they are to the point where the swing arms articulate, the more oversteer you will get. If they are further away, the result is some toe in when the suspension compresses, which stabilizes the car. I guess many earlier attempts to do a proper swing axle in rFactor missed that and just produced undriveable cars.

Your cars have also IMHO less inertia than they should (rFactor has an internal bug where it won't work properly with the physical correct values, you need to raise them by some considerable %), and some front suspension will have bump steer (Porsche), though I guess in the late 50s that was normal still, as they had not much clue about it. 

Cheers

Alberto Ibañez wrote:

Here you go, you are welcome to benefit from anything useful you find there: 

http://www.mediafire.com/file/pvuc2vwvxcjv31x/37GP+Physics+Beta+0.9c+FULL.rar

Giving credits or permissions or whatever, I do not care about it, I just hope people can benefit from all I do and produce more historic stuff for the community to enjoy 

Note that the trick to adjust the stability of the swing arms suspension is by moving the control arms horizontally. The closer they are to the point where the swing arms articulate, the more oversteer you will get. If they are further away, the result is some toe in when the suspension compresses, which stabilizes the car. I guess many earlier attempts to do a proper swing axle in rFactor missed that and just produced undriveable cars.

Your cars have also IMHO less inertia than they should (rFactor has an internal bug where it won't work properly with the physical correct values, you need to raise them by some considerable %), and some front suspension will have bump steer (Porsche), though I guess in the late 50s that was normal still, as they had not much clue about it. 

Cheers

Oh, that's really nice of you! I'll credit you nonetheless... it's not in my style to pick up things and not give credit where it's due

So, I've been testing with the PM and TBC files you've sent me and all is working way nicer than before, but somehow the Porsche and Renault give me an error, apparently the Inertia is too low is one of the directions and needs to be corrected: thing is, I don't know how much higher should be respect to the real values. Seems like I was wrong in trusting rF not to be so stupid ^^;

The TBC files also? Those are good for 1937, but probably one would expect some more grip in 1958 tires though I have not really studied that era. The loads are likely not perfect as the 1958 cars were lighter. 

Other things I noticed: 

- The rebound values in the dampers are probably too low, you can have only up to 2300 in the stiffest setting, but I think they should go up to 3500-4000.  

- The brakes have the same power front and rear is that OK?   Normally you would expect stronger brakes in front. 

- Some cars are supposed to be leaf sprung if I understood it correctly, but they have rear antirollbars which I am not sure if it is correct. 

- Any cam and pawl differential should have zero coast. They lock only under power, when coasting they are open.

Alberto Ibañez wrote:

The TBC files also? Those are good for 1937, but probably one would expect some more grip in 1958 tires though I have not really studied that era. The loads are likely not perfect as the 1958 cars were lighter. 

Other things I noticed: 

- The rebound values in the dampers are probably too low, you can have only up to 2300 in the stiffest setting, but I think they should go up to 3500-4000.  

- The brakes have the same power front and rear is that OK?   Normally you would expect stronger brakes in front. 

- Some cars are supposed to be leaf sprung if I understood it correctly, but they have rear antirollbars which I am not sure if it is correct. 

- Any cam and pawl differential should have zero coast. They lock only under power, when coasting they are open.

The TBCs I've had a go with just the curves, so it's not a very thorough test... just a "Let's see what happens".

About the rest...

- Bump and Rebound were a bit of a cr**shoot, to be honest: I couldn't find anything about what values they used in the era, not even a ballpark figure... so me and Ozpata went in the dark and tried something. Yes, highly scientific from a chap studying mechanical engineering ^^;

- ARBs were used because the "Kangaloosh" De Dion model doesn't model the tube's stiffness, and let the tires go all around the rotational axis. It was something funny to see, really: you gave a little bit of gas, the tyres went sideways... almost like a Scalextric.
So we decided to put a patch on it and at least moderate the issue this way... but with your model looks like it's not needed anymore.

- For the brakes, I've used the formulas I've been taught during my courses: problem is rF doesn't like that and I've had to diminish the values a bit, or the car would lock immediately. Don't know why though.

- Well, on the last point, it depends: cam'n'pawl diffs were quite the finnicky little "bioproducts". It all depended on the pawls: the more those were used, the more they would slip and lock in even under coast, causing a behaviour not dissimilar to that of a Salisbury diff. But the literature about that, for what I've seen and I might be mistaken, was somewhat vague.

Quote :

- Bump and Rebound were a bit of a cr**shoot, to be honest: I couldn't find anything about what values they used in the era, not even a ballpark figure... so me and Ozpata went in the dark and tried something. Yes, highly scientific from a chap studying mechanical engineering ^^

The cars both pre war and after the war were generally stiffly sprung and not so well dampened. The leaf springs had little refinement and were usually stiff, and they also allowed little suspension travel. In fact a reduced travel was the key to have the cars behave more or less decently, because with the poor knowledge they had, a long travel suspension (more than 5 cms) basically sent to hell the geometry and caused weird effects. A good amount of soaking the bumps came then from the tires, which were not nearly as stiff as the modern ones. I haven't researched figures about the 50s cars, but you can usually tell quite well how stiff the bump/rebound is if you can see some footage of the cars, sometimes even from pics. Look for the gap between wheels and arches, body roll, and similar indications of how the car moves, and if there is footage, check how quickly it does. 

BTW in the Porsche (Haven't checked the other cars) the fast damping ion the front will never come to play as the transition speeds exclude them. I have used that many times to disable fast damping and create simple single effect dampers, as used in classic cars. However the logical thing to do is make both front and rears equal. 

Quote :

So we decided to put a patch on it and at least moderate the issue this way... but with your model looks like it's not needed anymore.

It works yeah 

Alberto Ibañez wrote:

The cars both pre war and after the war were generally stiffly sprung and not so well dampened. The leaf springs had little refinement and were usually stiff, and they also allowed little suspension travel. In fact a reduced travel was the key to have the cars behave more or less decently, because with the poor knowledge they had, a long travel suspension (more than 5 cms) basically sent to hell the geometry and caused weird effects. A good amount of soaking the bumps came then from the tires, which were not nearly as stiff as the modern ones. I haven't researched figures about the 50s cars, but you can usually tell quite well how stiff the bump/rebound is if you can see some footage of the cars, sometimes even from pics. Look for the gap between wheels and arches, body roll, and similar indications of how the car moves, and if there is footage, check how quickly it does. 

I'm not sure about the "stiffly sprung", to be honest... I've followed what Costin said in his books (and I quote):

"The next step is to plot the movement of the wheel at full bump and droop, allowing something in the region of 3 1/2 inches bump and 2 1/2-3 inches droop. These figures could be slightly higher on a road car and rather less on a single-seater racing car."

"Vehicle spring steels for laminated and coil springs - Si-Mn - En. 45A"

So there was almost 20-21 cm of movement and the EN45A alloy was quite soft (it had a 190 GPa as Young's Modulus) even for the era...

But again, I'm always open to new sources: to live is to learn

Alberto Ibañez wrote:

BTW in the Porsche (Haven't checked the other cars) the fast damping ion the front will never come to play as the transition speeds exclude them. I have used that many times to disable fast damping and create simple single effect dampers, as used in classic cars. However the logical thing to do is make both front and rears equal. 

Alright, got it. I just wonder how did you calculate the damping for rFactor, as all of the formulas I've used always seem to fail. Even calculating the damping via the "z" coefficient doesn't work :/

Quote :

I'm not sure about the "stiffly sprung", to be honest... I've followed what Costin said in his books (and I quote):

"The next step is to plot the movement of the wheel at full bump and droop, allowing something in the region of 3 1/2 inches bump and 2 1/2-3 inches droop. These figures could be slightly higher on a road car and rather less on a single-seater racing car."

"Vehicle spring steels for laminated and coil springs - Si-Mn - En. 45A"

So there was almost 20-21 cm of movement and the EN45A alloy was quite soft (it had a 190 GPa as Young's Modulus) even for the era...

Like I said, I haven't done any research on suspensions from the 50s. I know in the 60s and 70s they had long travel and soft springs (Is that likely what Costin is referring in his book?), until the downforce era started and they had to go to stiffer springs and shorter travel peaking in the 80s with the ground effect F1s which had travel of less than 2 cms. But I also know that the 1937 Mercedes W125 had an abnormally long (For the era) bump travel of 7 cms, and the previous W25K had just about 4 cms and was so stiff that when losing a wheel in tests, the car went on on three wheels with no problems as a bike with sidecar. The Auto Union also had around 5 cms of bump and was quite stiff (The wheels cambered absurdly otherwise because of the horrible swing axle geometry change), and the famed Bugattis didn't have much more because of the solid axles front and rear on leaf springs, the latter reducing rebound considerably. 

Quote :

Alright, got it. I just wonder how did you calculate the damping for rFactor, as all of the formulas I've used always seem to fail. Even calculating the damping via the "z" coefficient doesn't work :/

I usually start by setting the springs I want, which is easier as you can calculate weight transfer and know how much you want the car to roll. Use historic pics to see how much the cars rolled and if you know or can guesstimate the G forces they were able to pull around a corner you will easily find what springs they were using. Consider obviously the type of track and corner to know if that is the softest or hardest they would ever go, but you get the idea. Of course there are also the roll bars there (Well not in older cars) but still it gets you in the ballpark because you can divide the roll resistance between springs and roll bar in some arbitrary proportion -again experience or knowledge about real data will obviously help. 

Then for the damping a rule of thumb is to start with bump in the exact middle range of what you will finally have, setting 1.5x to 2x as much rebound.  There are formulas around to calculate the damping needed for each spring rate, Kangaloosh carfactory gives you already a decent approach, but once you have done many cars you tend to have a feel for how much is needed. Obviously rfactor has its limitations and absolutely correct real life values don't always work exactly as intended.

One thought that comes to my mind, though it is not taken into account in rF: its not just the suspension and tires that spring a car, but the whole chassis acts as a spring as well, and that should make the whole thing a good deal softer and give some extra travel (though not controlled by kinematics) than the numbers discussed here. Even more true so with typical prewar platform frames, that didn't built particularly high and thus prone to twisting and flexing. That makes IMO the limit very narrow with these old cars, as the tires follow longer the predetermined path along the kinematics, whereas I'd think they'd already gradually loose grip, as additional force wouldn't go into the tire, but deforming the car.

Wanted to follow up on my original post, I'm having the issue I laid out in some for or other with all the cars, it's not as bad in the Cooper though(engine placement probably having to do with that.)

Anyway, I THINK, it's steering related and that it's on my end. I'm using the "Standard rFactor FFB" setting in the upgrades menu, I don't use RealFeel. However, the steering feels like RealFeel is fighting with rFactor to control the car. I dunno how to describe it. I'll do some fiddling with it later. Try removing the RealFeel ini file and see what it does.

@Alberto: Costin's book is dated 1962, and he was referring to cars made up to 1960. I still have to check with more sources, but according to Nye, Rudd and Lawrence seems like that was the case back in the day.
As a matter of fact, the most recent car it analyzes is the Lotus Elan 26R. Maybe Moss's and Pomeroy's "Design and Behaviour of the Racing Car" will be of more help, but it's still being restored digitally by me and my brother (a graphic designer with a penchant for working with paper... I'm not flattering him when I say he definitely knows his stuff) since it's a 1963 book with some nasty water damage. Not gonna lie, it felt bad having to break it to scan the pages

For the inertia values, I've had a look by calculating the Alfa 12C/36's real values and checking them with the values you've put in... talk about some "considerable percent"! It's almost 3 times more in the worst case (1050,1066,106 vs 1770,1810,360), are you sure it should be that high? Not judging, just asking.
I have to admit that with the real inertia values the 718 with your new PM file had a rear that was hellishly jittery, the simplest turn and the ass would shake like a broken F150's. Getting a higher 3rd value (so far it was +10%) alleviated the problem, and getting it higher would eliminate the problem definitely (at around +20%), but it was harder to steer.

@Michael: Exactly what mechanical automotive engineers always say: get a stiff enough chassis or you'll lose grip and the car will deform. Too stiff and the car is undriveable. It's a delicate balance.

@Jason: If it means "Each time I steer, the tyres go where they want", I can relate: I've tried everything to fix it, even to reverse the force, but it seems realFeel and rF don't want to give the control to one another over FFB. I'm honestly baffled and don't know how to solve it... I'm sorry.

hi mate , glad you stroke down here and sharing the thoughts
its great to see and read, you all high skilled engineers combined to brew the best phsyics for this high quality mod that we entirely embrase.



your friend
François

Here is my take on the Porsche 718, correct rear swing axles and what I believe is a more accurate front strut. Beware that this is a quick starting job, I have not fine adjusted the front camber curve properly, nor does the steering have any Ackerman built in. I also tweaked several things in the HDV, springs, damping, etc

http://www.mediafire.com/file/ynbq852lqapvne5/Porsche_718.rar/file

As the real car, the tail is quite happy and you must brake in anticipation in straight line, then enter the turns at the perfect speed with smooth throttle and never off the gas. If you nail it, the car will be very fast and quite agile, if you screw it you will end up looking the way you came from 

Quote :

are you sure it should be that high? Not judging, just asking

No I am not sure, but that is how the cars feel as I want them. The 1937 cars had long wheelbases and narrow tracks, they were rigged to cope as well as possible with the acceleration, not with cornering, because the tires were shit and needed all the possible help. If you look well at the silhouette, you will quickly see the similarities with a modern dragster, which again is not for turning but for traction. 

Also, despite being relatively light (Around 900 kgs with driver and fluids, barring fuel) they were of a heavy chassis construction and the wheels weighed a shitload which expands the inertia box. 

But again, that is my personal take on them 

EDIT: Oh and the tires have too much initial tension, which makes the car too responsive because of its light weight. That curve was for a heavier one, with stiffer sidewalls.

@Alberto, that's absolutely great! Thank you!

I've been studying your file and I've been probing around in it to check what your changes do, and I'd like to ask you a couple of things:

1. Why did you set the Porsche's pressures to 30/30psi instead of 34/37 Front/Rear? I've got some ballpark figures from Moss, Costin and Nye about formula cars in dry weather being around 34/37 in that era (up to 1960), with peaks of 45+ with heavy cars or Endurance racing (GTs, TCs...).

2. I've tried the PM file on the Dauphine and it left me a bit perplexed... made me think I kinda did a crap job on that car , because it always kept squatting (looked like a JDM) on moving. So I've put both rear wheels as:

PushrodSpindle=(0, 0, 0.000)
PushrodBody=(0, 0.500, 0.000)

Now the car doesn't squat anymore, but under traction the tyres converge toward the front of the car, making it understeer and jack like a Chevy Corvair... until it smashes unto something or you release the gas. In that case, the car automatically reverses a bit and the back tyres go back as they should.
How can I fix this?

Oh, and last thing, I've raised the Porsche of 3 cm and added the same amount in packers, the rear tyres were poking through the wheelwell

Hi mate

Quote :

1. Why did you set the Porsche's pressures to 30/30psi instead of 34/37 Front/Rear? I've got some ballpark figures from Moss, Costin and Nye about formula cars in dry weather being around 34/37 in that era (up to 1960), with peaks of 45+ with heavy cars or Endurance racing (GTs, TCs...). 

I did not change anything in the pressures as far as I know 

Maybe I did some copy paste that changed it, but it was unintended 

Quote :

Now the car doesn't squat anymore, but under traction the tyres converge toward the front of the car, making it understeer and jack like a Chevy Corvair... until it smashes unto something or you release the gas. In that case, the car automatically reverses a bit and the back tyres go back as they should.
How can I fix this?

That should not happen, if the tires move around wildly it's because you did not correctly implement all suspension rods, and the wheels are not fixed properly. 

Quote :

Oh, and last thing, I've raised the Porsche of 3 cm and added the same amount in packers, the rear tyres were poking through the wheelwel

It probably needs some less suspension travel. One thing about rfactor is, the tracks are absolutely smooth unlike in real life, so suspension seems conceived for modern formula one with less than 2 cms of travel on silky smooth surfaces. I was once in the Valencia F1 circuit after they disassembled it and was absolutely amazed at the pavement ... smoother than my desk table, really    The F1 guys won't race in anything else, (except Monaco )  it's incredible compared to a normal road, no wonder they can go down to such precision. 

But, classic cars on open roads are obviously somethiny VERY different 

track smoothness its my department , i can make it bumby as hell or flat just
i remember all 65 tracks uses higher bumb values then any other in rfactor
they finetuned for the 65 mod and there tires aswell suspension

but guys what a awesome team this can be for the future
Alberto , Richard, Gabriele , and who knows Duke then we have 4 masters of physics at HSO!
inlcluding a brilliant car modder in the name of Gabriele