Cars (DATA REPLACEMENT) BMW M3 E30 Improved Physics by Arch

[Kyuubeey]

Alright. If you could explain better what *exactly* you think is wrong, it'd be more useful.

If it's roadfeel, not much we can do. Wait for scanning technology to get better and simulation physical meshes to catch up. Probably need some better rack simulation for that too, to nail the roadcar feeling.

If it's slip based, we could maybe influence it. I still wouldn't compare a DTM car to a roadcar; compare the roadcar to a roadcar. Even there is plenty of inaccuracy in the unknowns.

 

[Akinastyle]

No, no, I already told you that, and no, it's not a circuit problem. I don't see why you're saying that.
The problem comes inevitably from the car why I feel better the one made by kunos?
With yours I don't feel the slip if the rear axle slips and the steering wheel stays still.
I'm exaggerating, but there's a delay compared to KUNOS.

PS: I use a translator maybe my translations are wrong.

 

[Kyuubeey]

Okay, well, you said you haven't driven an E30 but an E36, which are known to have better, stiffer rack feel than E30s, so...

It's almost maybe like Kunos fakes feel into their cars to please people like you.

 

[ReZ]

Mellow greetings, i am a former E30 owner (did not have a M3 as you can imagine... but a 325e with shorter springs and m-tech sport dampers) and have to agree with Akinastyle, something feels weird with the steering, it feels a bit like the camber is flipping mid corner or something. i checked with the ingame apps and noticed 2 things that do not seem alright for me ...

- max turn angle of inner / outer front wheels at full lock ... is 39/30 ... but should be more like 39/33.
there is point when you turn the wheel where the outer wheels dont gain any more steer ratio and get to far behind in angle compared to inner side.

- another thing that seems wrong is the KPI value --- it shows 35° in CM showroom , KS_version has 19° ... iirc it should be more like 14° or i interpret / translate something wrong.

 

[Kyuubeey]

Mellow greetings, i am a former E30 owner and have to agree with Akinastyle, something feels weird with the steering, it feels a bit like the camber is flipping mid corner or something. i checked with the ingame apps and noticed 2 things that do not seem alright for me ... did not have a M3 as you can imagine... but a 325e with shorter springs and m-tech sport dampers

- max turn angle of inner / outer front wheels at full lock ... is 39/30 ... but should be more like 39/33.
there is point when you turn the wheel where the outer wheels dont gain any more steer ratio and get to far behind in angle compared to inner side.

- another thing that seems wrong is the KPI value --- it shows 35° in CM showroom , KS_version has 19° ... iirc it should be more like 14° or i interpret / translate something wrong (KPI should be "Spreizung" in german i think).

Hey,

The front geometry is pixel measurements from a schematic from BMW, and the steering is close to spec. And anyway, IRL cars' steering varies by +-30deg or so at the wheel, steering stops are in different condition and so on. Even with cars where I got a laserscan, the steering is not 100% exactly within spec, so I didn't see it an issue. Although this is outer wheel angle, which concerns me a little. Usually it's the inner wheel which is allowed to be out of spec.

I will be improving most of my cars at a later date, so I can take another look. Small inaccuracies will affect the steering geometry quite a lot.

Don't use showrooms for anything. Go ingame or put it into a real suspension software. The KS software also shows the SAI as broken for strut and axle is completely broken.

M3 also has offset front bushings and some other **** which IIRC will change the steering.

For example here is some data which doesn't all add up, of course because of different parts and probably one typo. So I'm inclined to believe the 38~ and 32.8~, although I doubt you will find a car which is exactly to spec. Like I said, actual laserscans aren't always. due to various reasons. But it's worth a look because it's not exactly to spec. If it's 39/30 ingame, the ackerman should be less, and the weird feeling is probably the outside wheel being very incongruent with the inside.

 

[ReZ]

aye , thanks for clearing up the difference between showroom and ingame apps ... i thought ingame was wrong and shows a middle-value of front and rear because there is only one KPI readout.
i think the KS E30 has the correct values at full lock steering ... for both front wheels(edit: nope it doesn't^^)

maybe that difference in front wheel turn-in gives that weird feeling in the wheel at a certain angle.

btw. your effort in reworking the KS cars was really inspiring and i am digging hard into AC physics moddings since a few weeks and fix awful mod cars that deserve it

 

[Akinastyle]

@ReZ
No no no! I do not question the geometry because I am not able to prove that it is false, having no technical documentation on the dimensions of the front axle.
What I regret is the feeling at the wheel that this new geometry provides, although more precise as our dear friends claim.

 

[Kyuubeey]

I had a suspicion perhaps the front knuckle geometry was changed in the M3, and by lining up the tie rod with the lower balljoint laterally, I achieve basically exactly the 38 and 32.8 degree steering angles, in accordance with spec. So perhaps I figured out the thing with the steering geometry in M3 cars. Normal E30 doesn't appear to be like this and IIRC those did line up better to spec.

Still some time until an update, though.

 

[Kyuubeey]

Kyuubeey updated (DATA REPLACEMENT) BMW M3 E30 Improved Physics by Arch with a new update entry:

Load curves, aero, ARBs, setups

04.12.2019 Version 1.6

- Implemented custom load curves to tires
- Tire tweaks
- Changed ARBs and ARB setup
- Changed M3 front knuckle geometry
- Changed rear toe deflection
- Changed brake bias
- New aero
- Added yaw drag fin
- Reverted S2 to stock M3 rack
- Bunch of small suspension changes, spring angle multiplier etc.
- Updated UIs

Read the rest of this update entry...

 

[Kyuubeey]

Update coming up at some time.

I've determined some causes for the steering feel issue, and decided it's more proper to adjust the trail axis a bit forward from IRL. It barely disrupts anything else at all so it should only really influence steering feel and hopefully fix the issue.

IRL a lot of BMWs seem to have bad self centering and will even steer in to the turn slightly, but simulators often decrease the steering feel in slip dramatically compared to IRL, so it can cause very large issues and a disconnect in kinesthetic feel compared to IRL if scrub is approaching negative, I suppose.

 

[Kyuubeey]

Kyuubeey updated (DATA REPLACEMENT) BMW M3 E30 Improved Physics by Arch with a new update entry:

Drift, sta-bars, steering feel

04.02.2020 Version 1.7

- Added Drift version
- Derived more accurate front sta-bar MR
- Adjusted wall thicknesses for sta-bars
- Moved trail axis of front suspension forward to combat issue with steering forces
- Figured out E36, Z3 etc. steering racks, refitted to S2 properly
- Minor tire changes
- Maybe minor suspension changes that I've forgot

Read the rest of this update entry...

 

[Leonardo Ratafiá]

good, now the S1 drives good again, nice fbb all the way from lock to lock of the wheel.
S2 is garbage, worse than facebook mods, can't think of anyone liking this one honestly.makes no sense to drive.

 

[Kyuubeey]

Nice update coming later. I redid the rear entirely; it wasn't completely wrong, but my approach was off. Fix was pretty simple actually, and it benefited the behavior on paper and on track a lot. Not sure how I didn't notice earlier.

Now it's just down to what the testers think.

 

[Kyuubeey]

Kyuubeey updated (DATA REPLACEMENT) BMW M3 E30 Improved Physics by Arch with a new update entry:

Rear geometry, normal M3, E30s, fixes

17.02.2020 Version 1.8

- Added M3 E30 AK01
- Added 325i E30
- Added 325is E30
- Redid both rear suspension layouts
- Changed Sport Evo dampers
- Changed M3 rear spring to "Late" type spring as per 1987 data
- Found more accurate damper travel ranges for E30, M3 from BMW manual
- More accurate motion ratios for sta-bars from BMW manual
- More accurate steering ratio for M3 from BMW manual
- More accurate E30, M3 front geometry
- Changed S14B25 rev limit from 7250 to 7800 as per new data; old...

Read the rest of this update entry...

 

[GTAce]

Awesome! I used this mod for your 325s: https://www.racedepartment.com/downloads/bmw-e30-325i-coupe.18782/

 

[Leonardo Ratafiá]

Awesome! I used this mod for your 325s: https://www.racedepartment.com/downloads/bmw-e30-325i-coupe.18782/

yeah it's a great idea, not an "easy" swap though but if you are careful enough you'll get it working

 

[GTAce]

yeah it's a great idea, not an "easy" swap though but if you are careful enough you'll get it working

Haha, yeah, just noticed that it doesn't work because of the LODs.
Too bad, because an M3 body doesn't really fit.

 

[Kyuubeey]

You're free to open the data and modify LODs for personal use.

 

[GTAce]

You're free to open the data and modify LODs for personal use.

Thank you mate!

 

[Twister80]

thanks to share