Koni Yellow dampers rebound range in N/m/s?

[BMW135pls]

Apologies if I am not allowed to ask this, but for a relatively silly reason, I would like to know the ACTUAL rebound range of the Koni Yellow dampers for the 135i in N/m/s, or some statistic that could be converted to that format.

The reason I would like to know this is just because I play a racing simulation game with a 1M in it, and I would like to tune it so that it has the digital equivalent of my up and coming 135i build of Swift Spec R and Koni Yellow. Swift was nice enough to put their estimated spring rates out there (even though it is just a rough estimate of a progressive spring) but I can't find any details about the Konis at all. If anyone has their range for front and rear, that would help me a lot. And it may help me to decide on a stiffness setting myself for when I get around to installing the ones I have purchased.

Even without actual stats, if someone with experience could estimate how stiff 1 turn from soft is on front and rear just to give me a starting point at all, that would be helpful as well.

[dtla1]

Do you have a driving simulator at your disposal also? This sounds like a fun racing game.

[BMW135pls]

Originally Posted by dtla1

Do you have a driving simulator at your disposal also? This sounds like a fun racing game.

Yepp, I play Project Cars occasionally if I get the chance. It's a great simulator, but the stock tuned 1M in game does not drive well at all, luckily the game gives you a fair bit of tuning power. I was actually able to get in touch with someone who works at a factory that builds BMWs and he said that the stock tuning for the 1M in game is not at all close to what it should be, and he was able to give me some of the important numbers to put. A definite improvement, but he wasn't able to get data on the stock dampers and was only able to estimate the LSD figures. Dampers are so important to how a car drives and handles, but I have no starting point and the starting point they give you in game sucks a bit.

[dtla1]

Start by reading this thread, it may be in there somewhere... http://www.1addicts.com/forums/showthread.php?t=956039

Maybe fe1rx has some data he can share?

[Yeineken]

Originally Posted by BMW135pls

Yepp, I play Project Cars occasionally if I get the chance. It's a great simulator, but the stock tuned 1M in game does not drive well at all, luckily the game gives you a fair bit of tuning power. I was actually able to get in touch with someone who works at a factory that builds BMWs and he said that the stock tuning for the 1M in game is not at all close to what it should be, and he was able to give me some of the important numbers to put. A definite improvement, but he wasn't able to get data on the stock dampers and was only able to estimate the LSD figures. Dampers are so important to how a car drives and handles, but I have no starting point and the starting point they give you in game sucks a bit.

You should post the numbers you have so far! I play project cars as well and would be nice to have that data.

[BMW135pls]

Originally Posted by Yeineken

You should post the numbers you have so far! I play project cars as well and would be nice to have that data.

I will just post the entire message that the guy sent me. I don't know if he works for or just on BMWs, but he was able to provide a lot of the stock OE stats to apply to the game. Goes by JapImports on the PCars forum.



These should be used with street tires - UHP in Pcars, for baseline setup testing. Using slick will need a tweaks to support the lateral loads and tire pressure changes.


Tire Pressure: Front 2.2, Rear 2.1

F 2.2 R 2.1 is stock 1M for street on 18 inch wheel

For 19 inch wheel : F 2.3 R 2.2 street

You can adapt the M3 E92 specs ( Competition Pack )

F 2.4 R 2.5 ( street )

F 2.8 R 3.0 ( above 100mph / high speed track )

I would advise to try 2.3 / 2.2 first and increase it slowly.

Car & Driver BMW 1M Michelin Test Track Tire Pressure

F 2.3 R 2.4 ( 33 Psi / 35 Psi )



Brake Pressure: 90%
Brake Balance: 70%
Steering Ratio: 12.5:1 ( similar to E92 M3 )

Spring Rate: Front 26 Rear 88 ( 1M OEM Rate )

Sway Bar: Front 34, Rear 19.6 or 20
For sway bar, I used E92 M3 OEM sway bar rate, both E82 1M and E92 M3 uses very similar anti roll bar ( diameter and appearance )


Bump Stop: Front/Rear 25mm
Slow Bump: Front 4600, Rear 5000
Slow Rebound: Front 11000, Rear 14500
Leave these alone for now.


Differential: Accel 30%, Decel 10%, Preload 45N-M

GKN ViscoDrive, just rough estimate, try and see if it works.



Alignment Options :

Eibach 1M Test Car
Caster: +7.1
Camber: Front -0.5, Rear -1.8
Toe: Front +0.3, Rear +0.3

Sport Auto 1M Super Test ( 1M BMW Courtesy Press Car ) Track : Hockenheim and Nordschleife

Caster: +6.90
Camber: Front -1.5, Rear -1.3
Toe: Front +0.5, Rear +0.3

Car was driven by Horst Von Saurma, 8:14.9 lap at Nordschleife and 1:14.1 at HockenheimRing.

reference online article :

http://www.auto-motor-und-sport.de/s...f-3891517.html

1M weights 1513kg with full tank when tested, 51.5%/48.5% distribution


Settings Range According to BMW OEM Specs:

Front Axle:
Caster from 6.9 up to 7.9, Toe from 0.03 up to 0.30 and camber from -0.90 up to -1.75

Rear Axle:
Toe from 0.03 up to 0.30 and camber from -1.50 up to -2.00

Most 1M has 6.9-7.1 caster from factory, some has 7.3 caster. Higher caster, the better the turn in.

Real 1M benefits from zero toe on front wheel, better response for turn in entry. Set the spring rate, and alignment first ( try both Eibach and Sport Auto alignment ), lower both front toe in to zero and see if it improves. Then raise caster slowly to max 7.9. Find the sweet spot that you like.

The real 1M can run up to 3.0 camber front with close to zero toe and good tire wear. Toe out eats up tire.

+ toe is toe in, - toe is toe out.




For LSD, real 1M has GKN Visco Drive ( speed sensing viscous coupling LSD ), I suggest to start with 30% on accel, and 10% on decel, with 45Nm preload. The GKN has been said to have high preload on the M cars, often can be felt from low speed driving at parking lot, the resistance and the noise


1M 6-speed

1st: 4.110:1
2nd: 2.315:1
3rd: 1.542:1
4th: 1.179:1
5th: 1.000:1
6th: 0.846:1
Final Drive: 3.154:1

[fe1rx]

Originally Posted by dtla1

Start by reading this thread, it may be in there somewhere... http://www.1addicts.com/forums/showthread.php?t=956039

Maybe fe1rx has some data he can share?

A single damping number has no real world meaning. The rate varies with damper shaft velocity and is different in the compression and rebound directions. The shape of the damping force curve gives the damper its characteristics, not a single value.

This should give you an idea of what I am talking about:

http://www.1addicts.com/forums/showp...&postcount=156

[John_01]

Is the driving simulator complex enough to take into account the suspension (or wheel) velocities for rebound and compression?

To make it simple maybe its possible to assume a figure of damping ratio which is dimensionless number, then calculate backwards to get the damping coefficient.