OK here is my BMW 1M Coupe tune
Please do not kill me for the zero camber
This is not the tune that
@Ridox2JZGTE send me.
Here is what he send me:
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 ) - Also electronically variable - not possible in Pcars, 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 ( Pcars is correct )
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
These are just starting values, try to use the springs, ARB + alignment, tire pressure, and steering ratio
and I may be able to give you real car OEM data setup if you are interested to adapt it on Pcars ( use UHP tire ) For reference Horst Von Saurma did 8:14.9s at Nordshcleife and 1:14.1s at Hockenheim Ring in 2011 Sport Auto Supertest. I have test car + BMW factory range alignment data too ( detailed in the magazine article ), the 1M weighs 1513kg & 51.5/48.5 full tank of fuel in the test, the Pcars 1M is way heavier. Also need to lower steering ratio, the real 1M has 12.5:1.
👍
