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RELEASED-wip Mercedes-Benz W125 0.79

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Just a heads up, seems to spawn in the AC showroom about 50m in the air.

Edit*

Just spent a little time with it at Feld - what a total blast! Real sense of occasion, the monstrously long bonnet is intimidating in VR, but offers one of the best views out of a motor car. Particularly enjoy the lack of rev limiter with the indicator on the tachometer, just an added challenge to avoid damage.

One thing I would note (outside of 3d model things, I know you don't want to hear those!) is the tachometer on the dash seems really inaccurate, with an indicated 6000rpm actually being around 5400rpm.

Also the collider - I get its a WIP but I notices the front wheels are completely absent, so you can kinda cut corners a little bit near walls where the front wheels should collide. Otherwise its a lot of fun, really fantastic WIP.
 
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mantasisg

Active Member
Thanks, those are some good points. For the showroom, it is probably because of the "ground" object which I chose not to be renderable, it was helpful in editor. CM showroom works a bit differently, so it tricked me a bit.

Don't know about the tachometer limiter very well, I also haven't spent very much effort to make it completely precise, there just are yellow and red stripes painted on the face. I don't know how much damage it should be able to take, but Uhlenhaut said that after a while crankshaft would begin to crack, and it was possible to tell from engine sound getting smoother. They used to race for something like four hours with them in each GP, so I suppose it shouldn't be very severe, although drivers could have been told to be gentle. But they should have been to save the tires in the first place, after 4-5 laps of Nordschleife it will become almost undrivable, and will loose ton of pace, unless driven with lighter foot.

I totally forgot about collider, I should have tried racing an AI... mod is not very well tested yet overall, my main concern was to get the handling as authentic as we can.
 
Thanks, those are some good points. For the showroom, it is probably because of the "ground" object which I chose not to be renderable, it was helpful in editor. CM showroom works a bit differently, so it tricked me a bit.

Don't know about the tachometer limiter very well, I also haven't spent very much effort to make it completely precise, there just are yellow and red stripes painted on the face. I don't know how much damage it should be able to take, but Uhlenhaut said that after a while crankshaft would begin to crack, and it was possible to tell from engine sound getting smoother. They used to race for something like four hours with them in each GP, so I suppose it shouldn't be very severe, although drivers could have been told to be gentle. But they should have been to save the tires in the first place, after 4-5 laps of Nordschleife it will become almost undrivable, and will loose ton of pace, unless driven with lighter foot.

I totally forgot about collider, I should have tried racing an AI... mod is not very well tested yet overall, my main concern was to get the handling as authentic as we can.
I played around a little with the tacho and STEP=0.0398 seems to get it pretty accurate, enough to use the yellow and red stripes properly.

Regarding the handling, its really pure joy to wrestle it around. Only feedback I have in that area so far with my limited testing is brakes - they overheat fairly quickly and are hard to reduce temps - no idea if this is correct or not. My feeling is they cool slowly which is probably correct (being drums with pretty primitive cooling solutions), but I think they generate too much heat considering how low powered they are. But again, its just a feeling, no idea if its right or not.

Also I'd consider increasing the front ARB quite a bit - right now when turning the inside rear tyre load drops significantly compared to the front. I think this is because the front has a softer roll stiffness than the rear. By increasing the front ARB (I quickly tested at 14000Nm), you see that the inside front and rear reduce load much more evenly. You still have oversteer with that huge power and low tyre grip, but the rear is less likely to have issues with the inside rear spinning up.
Increase the front ARB further and you would potentially have the scenario where the inside front tyre load drops faster and in extreme cases lifts off the ground - not sure if this is something observed in pre-war cars or not, I haven't really looked.

Anyway just a few thoughts, haven't done any research on this type of car so it could well be useless. I am preferring it to drive over the Jag though, making me want to make another pre-war racer now!
 

mantasisg

Active Member
Thanks :)

I haven't really looked at brakes temps or tire actual loads values. As for brakes IDK but I think it might be ok. As for ARB you are probably right, in the past I was told that it is believable issue, I used to think that it is differential related and was a bit weird for me. I don't remember if we had data for ARB right now. Could also be that front has softer geometry comparing to rear. I'll try your value of ARB, I wonder how much it will change the pace, if it will improve too much on pace, I will probably have to tweak tires a little bit.

Good idea, I think there are some pre war cars that would be equally or even more exciting to drive :)
 

hal4000

New Member
Hi Mantas,

Congrats on the release. What a beauty. Love the way it drives now. So much better than the old version I had. Thanks!
 
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mantasisg

Active Member
@garyjpaterson

Thats pretty cool study, I don't have time to really look well into it (nor knowledge probably), but thanks for it, epic stuff, crazy to see that Type C had some sort of attmpt to gain some downforce. I don't know what lengths Aphidgod went for W125. I think there are great chances that he saw that, however I haven't really paid any attention to aero, I don't really know whats up with it. I mainly worked with tires, tire temps lut, tire wear lut, fuel consumption, engine damage and few other little bits... all the rest is done by Jason, we hadn't much conversation about W125 lately.

Type C would surely be an exciting car, afaik it was more difficult to drive than W125.
 
@garyjpaterson

Thats pretty cool study, I don't have time to really look well into it (nor knowledge probably), but thanks for it, epic stuff, crazy to see that Type C had some sort of attmpt to gain some downforce. I don't know what lengths Aphidgod went for W125. I think there are great chances that he saw that, however I haven't really paid any attention to aero, I don't really know whats up with it. I mainly worked with tires, tire temps lut, tire wear lut, fuel consumption, engine damage and few other little bits... all the rest is done by Jason, we hadn't much conversation about W125 lately.

Type C would surely be an exciting car, afaik it was more difficult to drive than W125.
Your aero seems reasonably good, looking at that study I'd say it should have about 10% more drag.

Im pretty busy at the moment but I have a folder of the aero data ready for the Type C in case I ever make it, would love to, such a great iconic car.

---

Quick update on that aero data - Just done some quick testing with some basic Auto Union Type C data, I'm pretty sure the data cannot be correct, at least not in absolute values (actual behaviour/characteristics are probably more trustworthy, such as balance and changes with AoA/yaw etc). With the quoted drag figure and the claimed 520bhp, its simply too draggy to be accurate (speed is far too low).

So yeah, I wouldn't rush to make your aero match that study. I'm keeping the same behaviour, so what it does in yaw and pitch etc but just scaling it to ensure its as fast as it should be.

I hear quite a lot that CFD overestimates forces, so this is probably very much the case.
 
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mantasisg

Active Member
It could possibly be that too narrow track at front makes it too soft (too big weight transfer), so too much of load transfer would happen at the rear. It is a bit confusing.
 

Willy Wale

Member
Your aero seems reasonably good, looking at that study I'd say it should have about 10% more drag.

Im pretty busy at the moment but I have a folder of the aero data ready for the Type C in case I ever make it, would love to, such a great iconic car.

---

Quick update on that aero data - Just done some quick testing with some basic Auto Union Type C data, I'm pretty sure the data cannot be correct, at least not in absolute values (actual behaviour/characteristics are probably more trustworthy, such as balance and changes with AoA/yaw etc). With the quoted drag figure and the claimed 520bhp, its simply too draggy to be accurate (speed is far too low).

So yeah, I wouldn't rush to make your aero match that study. I'm keeping the same behaviour, so what it does in yaw and pitch etc but just scaling it to ensure its as fast as it should be.

I hear quite a lot that CFD overestimates forces, so this is probably very much the case.
Yeah, I didn't want to jump in and poo poo that study but by the authors own admission the resolution of the mesh was very low. when I was last working in an aero role in 2012 we were running models with upwards of 130 million cells, 10 times the study here (I'm sure things have moved on). In general I've found CFD drag is more reliable than lift. The shape of most cars have a smaller frontal area than plan area. small errors in calculated pressure give greater force errors on the large plan area than the front and rear face.

WW
 

mantasisg

Active Member
^ Also it is really easy to make big mistakes in such curvy shapes... so they should have laserscaned models.

I am looking at the specs, and Aphidgod has made no typo, the trackwidth is correct. There could be some possibilities - data in the interent is wrong, my model is wrong, or perhaps they used different sized wishbones.

I don't know if i should try to match the track width to model, or use ARB setting which Garry suggested. Probably will try both options.
 

386

New Member
I gave you a nice review, and I pointed out a little flaw. Yet you have to respond with a sarcastic message like that.
 

mantasisg

Active Member
I put quite some effort in it, there was a little bit of sarcasm, but I don't consider that disrespectful. I even placed a smiley face to avoid looking mean as it is informal communication anyway.

I also seriously suggested for you to try to write a description, that line wasn't sarcasm. I don't have time myself, and I shouldn't be writing this detailed response, or any detailed posts that I did in near past, it doesn't work anymore.
 
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