Hi! I found a website where is some useful suspension data of Porsche 911.
So, could somebody "convert" these values and make a setup for FZ50, please?

http://www.pca.org/panorama/sample_article_3.html

Hmmm it has some big bumpstops on the suspension. I wonder if LFS even has some bumpstops simulated? Those are very useful... and I think LFS feels like it has just normal suspension, because it bottoms out quite often.

I found some more information and I tried to make RoW Sport and GT3 setups by myself:

RoW Sport:
Front ride height: 138mm
Rear ride height: 148mm
(I don't know how to convert the spring rates (front 170lbs/in rear 260lbs/in)to kN/m...
...so I guessed them)
Front spring rate: 60kN/m
Rear spring rate: 75kN/m
I don't know the anti-rollbar stiffness but I know the ratio between front and rear - 0.436. (I calculated from it from the table 2) So, if the front stiffness is lets say 35kN/m the rear stiffness is 15.3kN/m.
You can calculate the damper values from the chart 9 and 10. I can't...
Steering lock:
(911 GT2: ratio: 16.9:1, turns, lock-to-lock: 2.98)
So it's nearly 32 degrees which is quite low actually...
LSD:
(Again from 911 GT2)
40% power, 60% coast
Camber:
Front -0.5 degrees
Rear -1.25 degrees
Toe-in:
Front ~0.1 degrees
Rear ~0.2 degrees
Tire pressure (for Boxter 17" wheels):
Front 29psi ->2 bars
Rear 36psi->2.5bars

GT3:
Front ride height: 112mm
Rear ride height: 125mm
I don't know the spring rates so I guessed:
Front 75kN/m
Rear 90kN/m
Both of them are very stiff but GT3 has very harsh ride I think..
Camber:
Front -1 degrees
Rear: -1.83 degrees
Tire pressure:
Front 32psi->2.2bars
Rear 39psi->2.7bars

Sources:
http://www.pca.org/panorama/sample_article_3.html
http://www.pca.org/tech/tech_q ... B-4BAC-8DE2-5762DAAB1EC6}
http://www.pca.org/tech/tech_q ... 8-422B-851C-5BBD4A3E2B8B}
http://www.pca.org/tech/tech_q ... 7-4DC1-8B36-9BFB817DF141}
http://www.pca.org/tech/tech_q ... 9-4A20-BDFB-2351E45810E1}
http://www.automobilemag.com/r ... pes/0104_porsche_911_gt2/
http://www.motorsportscenter.com/article_124.shtml


Comments and corrections please!

I uploaded my current setups. You'll have to have a full gas tank and a "drop" before the camber values match with the real ones.

argh, double post

Quote from Antsa :

(I don't know how to convert the spring rates (front 170lbs/in rear 260lbs/in)to kN/m...
...so I guessed them)
Front spring rate: 60kN/m
Rear spring rate: 75kN/m
.

You guessed too high, I make them:
Front spring rate: 29.78 kN/m
Rear spring rate: 45.55 kN/m

That's almost exactly 1.6Hz front and rear - which is spot on for a road sportscar.

For damping values see how 3.8/7.3 R and 3.1/4.3 F works.

For anti-roll bars, I wouldn't have thought they would be much stiffer than 20 kN/m with suspension of that stiffness. So use about half of the values you guessed at before.

Fast google search tells that 1lbs/in = 0.175 kN/m

Does the car handle any better? Or what?

Or does it feel like a real car (something comparable to how a road car would feel? I've never driven a Porsche before, thats all )

Thanks!
How about the ride height? It can't be 0.138m/0.148m in LFS. Should I first stiffen the springs to max and put those values (0.138m/0.148m) and then put the right spring rates (29.78 kN/m 45.55 kN/m) and then increase the ride height with an eye until the actual ride height is as high as at beginning?

BTW I found some information about sway bar stiffnesses and GT3s sway bar specs:
http://www.optionimports.com/sitemap.html

GT-3/996 Front bar: 26.8mm, 5-way adjustable with adjustable droplinks and bushings
GT-3/996 Rear bar: 20.7mm, 4-way adjustable with adjustable droplinks and bushings

Here's my updated setup. Now the spring rates are correct and anti-roll bars are softer. I'm not so sure about the ride height.. Gear ratios are GT3's because FZ50 engine specs are the same as GT3's. Gear ratios seems to be very wide but they are real.
Now FZ50 has the porsche feel. The steering balance is almost neutral when you warm up your (rear)tires.
¨

Quote from Tweaker :

Hmmm it has some big bumpstops on the suspension. I wonder if LFS even has some bumpstops simulated? Those are very useful... and I think LFS feels like it has just normal suspension, because it bottoms out quite often.

I'm pretty sure it does, wasn't it added a long time ago (S1 ?!). I think they are more of the 'ball of rubber' variety then the more
modern progressive bumpstops. Like a spring at the end of the suspension travel to keep the car from 'jumping' when it bottoms out.
I think the suspension height adjustment is just that in LFS, the bumpstop height, the suspension travel stays the same.

Interesting stuff!

Ironically I have been looking for the same data but didn't really find a lot in the 30 minutes I googled.. But sadly I'm not alone in this LFS Fz50 world

Driving Antsa's setup almost makes LFS 'acceptable' but still the Porsche death rate would be rather high if it was real. I did a quick experiment of taking Antsa's setup and doing two laps with the exact setup and two laps with normal front tyres, which has helped a LOT in improving LFS for me.

IMO the setup is not nicely balanced whichever tyre used. Of course I'm just driving my first laps with them but you can see the oversteer is much more violent and frequent using the super fronts. With normal fronts it still oversteered at places where I didn't really think it should, but it also had pretty bad understeer. I've attatched the two replays for those interested.. Overall I get the feeling that the tyres lack 'bite'. They give up grip without a fight (i.e. a tiny little peak in grip) it seems, making the experience a bit 'floating' and not as 'tight' as I would imagine it to be.

You really get punished with understeer if you're on the gas too early with normal front tyres but I'm quite sure you're *really* punished, everywhere, using the super front tyres.. Perhaps worth a try to swap the front tyres and have a go? Needs much more slow in fast out but once you get used to it..

About the gear ratios, they are correct according to Antsa, but is the final drive as well? Then the engine max torque and max power rpm should be close to the real car as well for it to work in LFS.

Some things I think are not really known is how the LFS suspension geometry matches a 911. Perhaps real life camber and parallel steering are different. I think tuning those to match the LFS suspension could help quite a bit. Also the damping seems quite 'firm' but I really have no idea if that would be realistic or not..

All in all an interesting experiment! (and I want a porsche for real now..)

mV^2 ?

thanks for bumping. anyone going to continue Porsche setup project?

Quote from pasibrzuch :

mV^2 ?

That's kinetic energy, not moment of inertia.

Quote from sengab87 :

hi guys i need helppppp does any one know how to calculate a moment of inertia of a 996 car

Yep, I've got a big spreadsheet that I plug numbers into and out spits an estimated moment of inertia tensor for the whole car. I've not got it polished to a state that I'd be willing to release, but if you give me the exact model of car, I can look up the data and tell you what gets spat out.

Quote from Bob Smith :

That's kinetic energy, not moment of inertia.

:doh:

Now I have no idea what this moment of inertia is... and what for.

Quote from sengab87 :

for 996 c2 2004

I find this a little confusing.

I can find:
2001 Porsche 911 Carrera [996]
2004 Porsche 911 Carrera [997]

Which is it you want?

Update:
I figured you're rushed so I did both just to be safe.

2001 Porsche 911 Carrera [996]:
Yaw: 2360 kgm²
Pitch: 2280 kgm²
Roll: 440 kgm²

2004 Porsche 911 Carrera [997]
Yaw: 2580 kgm²
Pitch: 2480 kgm²
Roll: 490 kgm²

Figures include a 70kg driver

HTH

Quote from sengab87 :

if u dont mind can u just tell me how u got these caluclations

Using the dimensions of the car, it's mass, weight distribution, and the size and position of the wheels and brakes, the spreadsheet calculates the inertia of each wheel, and their inertia from the centre of mass. Subtracting the mass of the wheels from the body, the dimensions of the body are split into four sections of equal mass but unequal size, with their common centre at the centre of mass. The inertia for each block is calculated separately (as if a solid block), then their inertia from the CoG, then these figures are summed, scaled using coefficients to make it closer to a car (as a car is neither a solid body, nor rectangular in shape), then finally the inertia of the wheels is added back on.

If you still wish to see the spreadsheet at work, I'll tidy it up and PM you a link.

Quote from sengab87 :

bob if u dont mind do u have the unsprung mass of the 996 car

No I don't have that figure, sorry.

Usually, because of the engine weight, the track that carry the engine need to be stiffer... (...irl) if you refer to lfs setups, this may sometimes help to balance the handling...

Quote from sengab87 :

by the way it has nothing to do with weigth distribution

You'll have to explain that, as I would have thought it has everything to do with weight distribution.

Quote from Thread Title :

Porsche 911 (FZ50)

FZ50 isn't even close to be a Porsche 911.

:dnfnoob:

Quote from Danny LFS :

FZ50 isn't even close to be a Porsche 911.

:dnfnoob:

Apart from the fact its rear engined, RWD, has a boxer 6 engine with 350+ bhp and has a nose bearing strange similiarity, you're right, yes.

well, MAYBE the headlights.