Grand Prix Legends

Logitech® MOMO® Force and Grand Prix Legends

Grand Prix Legends, better known as GPL, is a legendary car simulator that is known to be very accurate.  Properly set up, it is a pleasure to drive with the Logitech® MOMO® Force wheel.  However, there are a few pitfalls on the way to GPL heaven, which are pointed out below.

 

Requirements

If you want to use your Logitech® MOMO® Force with GPL, it is highly recommended that you have at least WingMan® Software 4.11C installed.  The 4.10 and earlier 4.11 releases had a number of problems with this wheel, which resulted in bad force feedback effects or imprecise centering.

Note - it is recommended in general to have at least WingMan® Software 4.11C installed if you have a Logitech® MOMO® Force wheel.

 

Settings for core.ini

GPL does not support force feedback out of the box.  It requires a patch, along with modifications of one file, core.ini, in the install directory of the game.  After updating GPL with the 1.2 patch, there is a file called core.ini.sample, which needs to be renamed to core.ini, and then edited to manually enable force feedback.

While you're at http://www.papy.com, it might be a good idea to get either the D3D patch or the OpenGL patch, which will enable your 3D-accelerated graphics card to assist drawing the game's images. Without those patches, GPL will draw with software rendering which looks a bit antiquated, to say the least.

In regards to the configuration file settings, there is a wealth of knowledge on the web.  The force-related parameters depend on device, system, and also to a big extent, personal preferences.

For Logitech® MOMO® Force, the following parameters in the [Joy] section of core.ini are recommended as starting values:

[ Joy ]

allow_force_feedback = 1                ; Use FF if device has it

force_feedback_damping = 40.000000      ; force feedback damping coefficient

force_feedback_latency = 0.001600       ; force feedback latency (secs)

max_steering_torque = 225.000000        ; steering torque in N*in giving max device force

Some people find the following settings better

[ Joy ]

allow_force_feedback = 1 ; Use FF if device has it

force_feedback_damping = 200.0 ; force feedback damping coefficient

force_feedback_latency = 00.001 ; force feedback latency (secs)

max_steering_torque = 250.0 ; steering torque in N*in giving max device force

 

Your mileage may vary. Start out with one of these settings and look if it works for you.

 

Settings for Logitech® Control Panel / Profiler

In the control panel, Settings page, it is recommended to start out with the default settings for the force levels (100% everywhere, Centering  Spring in Force Feedback games unchecked), but separate pedals.  While the 100% settings will give you nice, strong forces, they might be a bit too much for some people.  In that case, it is recommended to use the Overall Force Gain to reduce the forces to fit one's particular taste. 90% or even 70% are values that some people are using.

GPL has essentially two types of forces - dynamic forces that get updated with the ongoing vehicle physics, and a damper that gives a certain amount of resistance to the wheel.  Some people like the damper, some people find it taking away from the pure "driving forces". If the damping effect on the wheel feels disturbing, it can be reduced or completely annihilated by using the control panel's Damper Gain slider.  0% will get rid of the damper altogether, while values between 1 and 99% will reduce its intensity.

In general, it is not recommended to go above 100%, as this starts to distort forces, and forces like the ones GPL produces are very true to the simulation.  If they get distorted, they don't feel "right" anymore and tend to get disturbing.

 

Some recommendations from Ernie Smith / GPL Foolishness

We would like to thank Ernie Smith for the following entry.  It is information like this that helps make our FAQs useful.

One reason I got the MOMO® Force was the use of ball bearings in critical areas of the wheel, my WingMan® Formula™ Force (red wheel) is getting quite lose in its plastic bushings.  When I got the Logitech® MOMO® Force I was disappointed with it's performance.  It had force feedback, but I couldn't feel the front wheels when they were losing their grip as I could with the WingMan® Formula™ Force.  Also when going down straight sections of track the Logitech® MOMO® Force would move the wheel from side to side, (spiking I guess), with the addition of the modeling of the mass and inertia of a swerving car caused by the spiking making it hard to drive in a straight line.

First some of my system specs, Windows® 98SE,  DirectX® 8.1, WingMan® Software 4.11c w/411c update installed. Also, my Logitech® MOMO® Force was 1 or 2 degrees left of center when at rest.  I used "MOMO® Force Center Adjustment Utility" to correct this initially and so far it has kept the wheel centered.

This is the procedure of how I set up my Logitech® MOMO® Force in GPL and should help others struggling to do the same.

To make initial Logitech® MOMO® Force setting adjustments.

1. In WingMan® Profiler set the Strengths as follows:

 

2. In the GPL folder, Core.ini, initial file settings:

[Hack]

steer_ratio= 0

[Joy]

allow_force_feedback= 1

force_feedback_damping= 0.0

force_feedback_latency= 0.0

max_steering_torque= 100.0

 

3. Set "force_feedback_latency" in the GPL core.ini file first.  This is the most critical and hardest to get right.

A good track to use is Monza.  Stop the car on a wide piece of track.  Engage first gear and turn wheel to full steering lock, left or right.  Take your hands off the wheel and slowly add power.  The car should straighten up under gentle acceleration.  Try again, but add power more rapidly.  The car should straighten up and may spin around although in my case it didn't.

Adjust "force_feedback_latency" in 0.025 increments until the car ceases to go into a wild fit of divergent instability or oscillate from side to side with the wheel chasing the suspension under acceleration.  This setting is more critical for smaller values of max_steering_torque.  Don't worry if the car and wheel oscillates from side to side under de-acceleration, we will deal with this later.

To fine tune latency further go to the first turn of Monza which has a curb on the right.  Change to the F10 view (out of car) and drive over the curb at a 30 to 45 degree angle.  Watch each wheel as it goes over the curbing.  Change the force_feedback_latency to get an independent thump from the Logitech® MOMO® Force that coincides exactly with the rise or fall of each wheel as it goes over the curb.  Also note the number of thumps you feel, there should be four.  Thanks goes to Giovanni Tifosi for coming up with this method.

Remember the final core.ini latency setting will only apply to your specific setup.  No other users should be affected.  Small variations in manufacturing and your hardware speed, will all influence this variable.

4. Now make some "max_steering_torque" setting adjustments in the GPL core.ini.  Try some laps at Monza.  If you decrease the values of max_steering_torque the effects become stronger until they start to become "clipped".  Increasing the value makes the effects more subtle, to the point the car won't straighten up under acceleration.  If your setting results in clipping or the car won't straighten up under acceleration or coming out of a corner when you take your hands off the wheel you have gone too far.  Try a value of 300 to begin with and slowly decrease it to a setting you like best.

5. Finally, increasing "force_feedback_damping" in the GPL b helps to damp out the "jerks" that you sometimes get with the wheel, but at the expense of numbing some of the feeling.  This setting DOES NOT influence the damping force applied to the wheel.

6. In the force feedback wheel world "damping" means the effect that gives the sensation of "moving an object through viscous fluid".  With heavy damping, the wheel will feel sluggish or unresponsive because damping resists quick movement.  The faster the wheel moves, the stronger the resistance you will feel.

To set the Logitech® MOMO® Force wheel "damping" go into Windows® Control Panel->Gaming Options->MOMO® Force Properties->Settings window.

I adjusted this setting until the wheel would stop oscillating when de-accelerating and would only make one small oscillation in the opposite direction of the initial wheel movement when straightening out when driving at a moderate speed and steering left or right and then letting go of the steering wheel.  I tried to make this action mimic what happens in the car I drive in the real world.  Although it's not a race car it should act similar in a general sort of way.

7. At this point there was still a very noticeable side to side bumping force generated from the wheel when driving in a straight line, making it difficult to not weave side to side down a straightaway.  So, there is one other thing to do!

Experiment this setting till you get the best result that you can with an acceptable center dead zone.  Then try different values of the "Sensitivity" setting and adjust to your taste.  You probably should leave the "Range" setting at 100%.

I now have very similar forces with the Logitech® MOMO® Force as I did with the WingMan® Formula™ Force wheel and no excessive oscillations in the Logitech® MOMO® Force wheel at lower speeds.  The wheel will straighten out and center itself at lower speeds without any oscillations at all until you apply enough throttle to break the rear wheels loose.  Then the wheel will react as it should, IMHO, as the car begins to slide sideways.  At higher speeds if you turn the wheel left or right and then let go there are oscillations similar but less than those when you used the beginning settings.  However, who lets go of the wheel at speed?  Not me!  Changing the dead zone from the 0% default setting drastically reduced the wheel bumping side to side when going in a straight line.  I can now drive in a straight line and I can steer the car on the line that I want to travel on the track, speed permitting!

Here are my settings but I suggest that you go through the above procedure, your latency setting will most likely be different that mine.

Settings in the GPL "core.ini" file:

[Hack]

steer_ratio= 0

[Joy]

allow_force_feedback= 1

force_feedback_damping= 20.0000

force_feedback_latency= 0.10000

max_steering_torque= 250.0000

 

Settings in the Control Panel/MOMO® ForceProperties/Settings Window:

Overall Effect Strength= 90%

Spring Effect Strength= 0% (GPL doesn't use this)

Damping Effect Strength= 15%

Center Spring= OFF or 0%

 

Settings in the WingMan®  Profiler "Adjust Sensitivity, Dead Zone, Range and Mapping" window settings:

Sensitivity = 60%

Dead Zone= 4%

Range= 100%

 

I tried enabling the "steer_ratio" may be able to be enabled (=1, this enables variable steering ratio, you can turn sharper at slower speeds) and it did change the feel some.  If you want to use it, some further tweaking needs to be done.  I may try to increase "Overall Effect Strength" in the MOMO® Force control panel settings.  This is probably not the final configuration.  I found a web site  that has some alternate views about the Core.ini file settings, (i.e. that force feedback damping actually sets force feedback strength and max steering torque sets force feedback  damping in the GPL core.ini file.  Going to fine tune my settings and investigate the other matters also.

I want to give credit where it's due.  Most of the info came from the "GPL Foolishness" web site in the Hardware section with some things that were added by myself.

Hope this helps someone get there Logitech® MOMO® Force settings in the ball park,

Ernie

I am experiencing spiking problems with Logitech® MOMO® Force:

A user who had this problem suggested running the game under Windows 2000 compatibility mode.

Some additional links on GPL configuration

http://www.slottweak.com/gamesettings.htm

http://website.lineone.net/~richardn/Dampers.html