Cars WIP - 911 by Singer

[Dirk Steffen]

implemented Multilink

Ohhhh - really, did they?
I always thought one really only had to workaround with DWB ?

 

[Kyuubeey]

I experimented with Multilink for my GT-R, and I ran into some stuff like arm angles not matching up with suspension travel when lowering the car, toe going out of whack in the setup etc.

I believe there's a reason they don't use it.

 

[Dirk Steffen]

How do you define a Multilink system - I have never seen this documented ?

 

[Kyuubeey]

TYPE=ML

Remove everything that points towards DWB, STRUT or AXLE wheel points, add in:

;LCA Front
JOINT0_CAR=0.0000, 0.0000, 0.0000
JOINT0_TYRE=0.0000, 0.0000, 0.0000

;UCA Front / Toe arm
JOINT1_CAR=0.0000, 0.0000, 0.0000
JOINT1_TYRE=0.0000, 0.0000, 0.0000

;LCA Back
JOINT2_CAR=0.0000, 0.0000, 0.0000
JOINT2_TYRE=0.0000, 0.0000, 0.0000

;UCA Back / Camber Arm
JOINT3_CAR=0.0000, 0.0000, 0.0000
JOINT3_TYRE=0.0000, 0.0000, 0.0000

;Tie-rod / Steering Arm
JOINT4_CAR=0.0000, 0.0000, 0.0000
JOINT4_TYRE=0.0000, 0.0000, 0.0000

The parts in ; are just quoted out as reminders for myself.

 

[CobraCat]

It's not like I have laser suspension measurements, but they're done from schematics, and I double checked with some largely non-distorted images. Curves line up decently as well, although I will double check them later.

For sure, it is better than whatever Kunos made for their 911's and whatever mods have come out. Not a lot of people understand how to make a trailing or semi trailing arm with DWB. Kunos also got it wrong.

Interesting. Does that explain why the Kunos Carrera RSR 3.0 lacks character and feels so underwhelming ?

 

[Kyuubeey]

Interesting. Does that explain why the Kunos Carrera RSR 3.0 lacks character and feels so underwhelming ?

I don't know what they did to the racecar IRL, but for sure the rear camber curve is not accurate to the normal semi trailing arm setup. Especially on rebound: so it will retain too much grip when lifting off, most likely.

Porsche did a good job with the 964 and it's not like it slides constantly, but it's still a semi* trailing arm and shares the same weaknesses with all of them, like toe movements from G-forces, relatively high unsprung masses, very aggressive camber and toe curve when lowered and increasingly more squat the lower you go and so on. Generally decently high roll centers too and lack of proper anti-squat geometry to begin with.

 

[Dirk Steffen]

TYPE=ML

Remove everything that points towards DWB, STRUT or AXLE wheel points, add in:

;LCA Front
JOINT0_CAR=0.0000, 0.0000, 0.0000
JOINT0_TYRE=0.0000, 0.0000, 0.0000

;UCA Front / Toe arm
JOINT1_CAR=0.0000, 0.0000, 0.0000
JOINT1_TYRE=0.0000, 0.0000, 0.0000

;LCA Back
JOINT2_CAR=0.0000, 0.0000, 0.0000
JOINT2_TYRE=0.0000, 0.0000, 0.0000

;UCA Back / Camber Arm
JOINT3_CAR=0.0000, 0.0000, 0.0000
JOINT3_TYRE=0.0000, 0.0000, 0.0000

;Tie-rod / Steering Arm
JOINT4_CAR=0.0000, 0.0000, 0.0000
JOINT4_TYRE=0.0000, 0.0000, 0.0000

The parts in ; are just quoted out as reminders for myself.

Thanks a lot for sharing! This goes straight into my notes and I'll give it a good testing when I get back to one of the 996 or 997 Porsches I have in the backlog.

I remember I was a bit dissatisfied not being able to get close to what I wanted with that particular car.
Trying to get close in geometry with a DWB workaround to "replicate a multilink suspension does lead to bad results in suspension behavior.
Without testing much further that is the very reason why none of the Kunos 911 Porsche I have looked into are actually resembling their actual suspension geometry (the worst offender probably being the semi trailing arm rear suspension of the '74 RSR).
I guess what Kunos did there was simply to create a workaround that still has the traits of that car yet is very much driveable (just like the real car as I hear). So it is a difficult line to find a workaround that replicates the actual telemetry data results (camber, toe, roll behavior) rather than sticking to perfection to suspension pickup points and accurate geometry - that doesn't make building these any easier ;-)

Interesting. Does that explain why the Kunos Carrera RSR 3.0 lacks character and feels so underwhelming ?

I find the '74 RSR an excellent car. These naturally aspirated 911 with big meaty tires, low weight and moderate power output (by todays standards) are NOT the widow makers everyone and their mom makes them to be. These cars were not unpredictable and difficult to control by any means.

The Kunos 74 RSR although as described above does not have by any means an "accurate" suspension geometry resembling the actual cars semi trailing arm suspension but the characteristics of the actual car are retained nicely (squat on lateral load, cornering, lift off oversteer, massive traction on throttle weight shift, corner turn-in understeer, etc ... in driving dynamics it all makes sense.

Where the Kunos 911 RSR 3.0 lacks soul unfortunately though is in the sound department - the actual cars sound GLOOOORIOUS, the Kunos '74 RSR is a little ... understated shall we say. I wish we had a goo quality, throaty NA high compression 6cyl boxer sound on megaphone trumpets for these cars - they sound like nothing else on the planet.

 

[movo.]

Nice one Ben, looks fantastic already!

 

[mclarenf1papa]

For reference, DWB is the same thing as multilink and just puts two joints in the same spot... the suspension app doesn’t actually display the physics geometry (that goes for all suspension types), but rather a quickly generated (and usually wrong) visual version.

And Kunos don’t use it because every car they ever released was created before it was added.

 

[Kyuubeey]

I mean, the RSR is not *completely* off, but if it's supposed to be a stock rear arm, the curves and important traits are more off than they need to be. Longitudinal roll center is also *way* off (Unless I myself am misunderstanding something) and that's a bit important when we're talking about it being on the wrong side of the axle...

You're never gonna get it spot on, for sure, but I tried to put a little more effort into it.

 

[Mascot]

Hey guys, I am really happy to see another Porsche coming towards AC ... cant' have enough of them!

I was a console warrior for the whole time that EA had Porsche in their pocket. It's hard to imagine how starved we were for so many years, and what little use EA put the license to.

 

[AccAkut]

I was a console warrior for the whole time that EA had Porsche in their pocket. It's hard to imagine how starved we were for so many years, and what little use EA put the license to.

Just like how little EA does these days with the Star Wars licence... Jedi Knight II, you'll be missed

 

[Ben O'Bro]

Going into such details, it's hard to tell which has too many polygons or not enough at the moment...

wipers green 1400 tris
against red... 71000

exterior is fairly ok for now with 175k triangles, starting to sort the interior since few days...

.
no fancy renders today!

@AccAkut ; they actually might have ruined the starwars license for themselves as well with the battlefront2 drama

 

[Kyuubeey]

I myself have been practising some infidelity and have been aggressively cheating on the 964 with other cars for the past few days. What can I say, you gotta have variety.

 

[CobraCat]

Going into such details, it's hard to tell which has too many polygons or not enough at the moment...

wipers green 1400 tris
against red... 71000
View attachment 300894

exterior is fairly ok for now with 175k triangles, starting to sort the interior since few days...
View attachment 300895 .
no fancy renders today!

@AccAkut ; they actually might have ruined the starwars license for themselves as well with the battlefront2 drama

How long did it take Kubicki to create the original model? The level of detail is mind boggling. A testament to your skill level, the Singer still looks amazing after reducing it down to so few tris (compared to the original) How long until we can run a 4 million tris model in a racing sim ? HAHA

 

[Ben O'Bro]

serious progress tonight

 

[A3DR]

serious progress tonight
View attachment 300993

Seems legit

 

[aphidgod]

I almost don't see the van.

 

[Stereo]

Interesting choice to start with the 'Safari' model

 

[mclarenf1papa]

I almost don't see the van.

Van?