Cars NFS Tournament Class B 1.6

[Kyuubeey]

Yes, that's okay if the values are correct. I gave Jason my data and template.

There's already a 2:1 ratio of rear to front lift in the car with the wing down, and when you put the wing down, it turns to something like 8:1. Old 911s have a ratio of like 1.5:1~ due to the front lift. The front lift will make it have less overall grip, but technically more stable because the loading is more even and closer to static. Although IRL neither of these high lift situations will feel as stable as in the sim.

 

[Błażej Wianecki]

So the aero balance of the old 911 is only 25% more favorable than the 993 with the wing down? I expected something more dramatic considering the terror of driving it at high speed. Also those values seem alarmingly rounded...
Oh well, all I can do is to believe you if you are sure about the data. Thanks!

 

[Kyuubeey]

I dunno how Jason implemented it, I haven't verified it, but based on what we know, yes the 993 aero is much better and it should overall have less lift in the rear in absolute load than it does in the front relatively. 993 should oversteer less at speed with the spoiler down compared to older 911s + have more grip because it has less lift overall.

The thing is that if you keep the very low lift front, but introduce the 50 - 70kg~ of lift back into the rear, the balance goes off. You kind of need the spoiler.

 

[Błażej Wianecki]

Ok, thanks! I get it

 

[aphidgod]

Yeah... there's not much data on the aero with wing-down, but what little we were able to find did indicate that this is the situation. Best advice is to leave the wing alone or lock it in the up position unless you're just driving around town.

 

[Kyuubeey]

Yeah... there's not much data on the aero with wing-down, but what little we were able to find did indicate that this is the situation. Best advice is to leave the wing alone or lock it in the up position unless you're just driving around town.

At least my understanding of the wing-down option or wing-up option being there is because A: IRL you can lock it out by pulling some plugs and B: For screenshots. Leave it at 1 otherwise.

 

[Avo77]

Speed 250km/h
Spoiler open 26kg of lift
Spoiler closed 137kg of lift

Drag coefficient with spoiler open 0.61
Drag coefficient with spoiler closed 0.69 (this is the cause of lower top speed).

 

[Błażej Wianecki]

Speed 250km/h
Spoiler open 26kg of lift
Spoiler closed 137kg of lift

Drag coefficient with spoiler open 0.61
Drag coefficient with spoiler closed 0.69 (this is the cause of lower top speed).

Where is this data from? From the game, right?

 

[Kyuubeey]

Here's one chart to get an idea.

 

[Avo77]

Where is this data from? From the game, right?

From game.

 

[aphidgod]

Oh, and here I thought you were trying to actually be helpful. Yes, I'm aware of the existence of the wings app too, but thanks for that. Back to the list...

 

[RJRacer]

these cars show up as their respective manufactures for me after install, they work, they are present in game, they function etc, but they are not in a group called NFS Grp A etc? Any ideas why?

 

[Avo77]

Oh, and here I thought you were trying to actually be helpful. Yes, I'm aware of the existence of the wings app too, but thanks for that. Back to the list...

Ok, if you want, from the table posted by Arch the car with spoiler open should have 56kg of lift instead of the 26kg it has now.
In addition to me it's not clear how the front and rear lift coefficients are calculated. They already take into account the load transfer induced by the drag or not?

In both cases your lift distribution about 7% front seems to be wrong (always taking Arch table as reference).

 

[Kyuubeey]

It's good to actually read the chart you're referencing before you say something. You'll see what I mean if you take a look at the column names.

Data just about always takes drag load shift into account, as it's nearly always from a wind tunnel.

Wings app shows only wings split %, not wheel loading from drag and lift. Use telemetry to get actual wheel loading.

 

[Avo77]

It's good to actually read the chart you're referencing before you say something. You'll see what I mean if you take a look at the column names.

Data just about always takes drag load shift into account, as it's nearly always from a wind tunnel.

Wings app shows only wings split %, not wheel loading from drag and lift. Use telemetry to get actual wheel loading.

I’m quite good at reading and understanding.
So, ‘it’s good to actually read the chart you're referencing before you say something’...

From your table from the bible:
@56m/s (201km/h) the 993 has 23+54lbs of lift alias 35kgf
so at 69.4 mph (250km/h) the car would have 35*(69.4/56)^2 kgf of lift, alias 54kgf of lift instead of the 26kgf I read in the aero app at 250km/h with spoiler open.

 

[Kyuubeey]

Ah, I see what it is now. The base 993 with the spoiler up is probably making 993 Turbo aero, not 993 Carrera. Adds up to 15kg at least. Jason probably did an oopsie while copypasting.

@aphidgod

 

[aphidgod]

Yeah, my local files are fine, so...

 

[Avo77]

Ah, I see what it is now. The base 993 with the spoiler up is probably making 993 Turbo aero, not 993 Carrera. Adds up to 15kg at least. Jason probably did an oopsie while copypasting.

@aphidgod

Looking further at the table I won't be so sure about how the data are calculated (or their overall consistency).
The drag induced load transfer alone for this kind of cars would cause about 50lbs of lift at 200km/h.
How could a standard 964 compensate for that and arrive to 8lbs of downforce at the same speed is a mystery to me.
The 964 RSA is even stranger: with an huge wing added on the rear it's listed at 187lbs of lift on the back instead of just 15lbs for the standard 964.

 

[Kyuubeey]

Some of it's a bit suspect, could even be signage typos or misunderstanding from the person making the chart. RSA likely is reversed signage and they just put it in as-is: so lift front, downforce rear in reality, but the signage is opposite to the chart and they just took it at face value.

However I buy the 964's front downforce if we consider it in context with other cars. It's not a completely open bumper setup like it'd look, it's closer to the R34 GT-R. The only reason those make miniscule front lift and not downforce is because of the rear wing. R33 same thing. R32 has a way less efficient front design, so it actually seems to make real lift irregardless. MR2 SW20 is also downforce in the front, only barely making front lift because of the rear wing, and that doesn't even look as effective as the 964. For reference, MR2 SW20 with spoiler is
-0.004 CLF
+0.05 CLR
so almost zero lift front and some downforce rear.

Everywhere I look I only find sources citing front downforce. If you have some sources saying 964 made lift, post them.

EDIT: If the MR2 data is presented as "for normies" and not proper, then you could also interpet it as slight downforce front and slight lift rear.

 

[Avo77]

You missed my point.
If, as you said, the values in the table take into account the load tranfer due to the drag, the 964 would need at least about 60lbs of downforce generated by 'something' on the front to reach the final -8lbs result at 200km/h.

Not being able to find this 'something' on a standard 964 design I'm not so sure about how to use the data you posted and about their reliability in general.