Ride Heights in Garage vs in Motec

[Koray Can]

On the 2007 BMW E90, after I set ride heights in the garage to 11cm on all four sides (with 0 degree camber & toe and equal tire pressures), while stationary in the pits motec i2 pro shows 11.8 cm ride heights on all sides. That's acceptable..

But, when I set them to 10cm in the front and 11cm in the rear, motec shows 10.7 on all sides. 11cm in the front and 10cm in the rear gives 12.0 cm on all four sides in motec.

Ride heights are adjustable from 8cm to 13cm with 0.1cm increments for this car, and even though I didn't expect 0.1cm accuracy, I thought that I could get reasonably close to 10cm in the front and 11cm in the rear. What's the deal?

This sort of thing happens on the 2007 Chevy Lacetti as well.

 

[Pieter Theron]

I don't have much input for you regarding the discrepancies but do have a question if you don't mind:

Is it worth the time to analyze Motec data when it comes to setup? Guess the reason I am asking is because I am genuinely interested in finding a way of getting cars setup properly but don't know if Motec in Sim racing bears the same weight as in real life.

Thx

 

[João Andias]

From my point of view there is no "short answer" for the immediate above question... but I will try it (a short one) anyway :smile:

Basically if you enjoy physics/engineering/simulation you will like MoTeC I2 pro and likely the software will give you some help "understanding" and "improving" your enjoyment of the simulation.

​

Will it make you go faster (an often question)?

Yes & no...
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• Yes it might... but more likely it will help to go "safer"; useful information for non-sprint racing (simulation aspect).

• No... in the end, they are all just games, you will survive, also likely do quite well too with a "poor" control set ("poor" game wheel /a joystick or whatever), with no or very little FFB, "throwing the car" at every corner and doing quick laps abusing both chassis, tyres and engine... and in no way you need MoTeC for that.

It is all a game... that can be taken higher up by improving some of its simulating aspects (if you want/like).

*Edit*
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Regarding K. Can observation; I really don't have an answer now... I don't give much attention to absolute values in MoTeC, I kind just keep in an eye for "relative ones" (differentiation/integration).

For game physics sake, from start I would trust more MoTeC "real" values ... if all the data is being collected and calculated/analyzed correctly. The in garage absolute values can be just for show or might not have been updated from some previews game modification.

Anyway, will keep an eye for this since I will be using 2008 WTCC car in the nearing RD WTCC champ...

 

[Dave Stephenson]

Tyres are a possiblilty, when you set of on your run they heat up, expanding the air and raising the profile of the tyres. 7mm is probably not an excessive amount for this.

Another possiblity is that the ride height adjust ment is not a measure of the car from the ground, with adjustment for suspension stiffness and tyre pressures. If that where the case the adjustment could be a measure of the tension on the load bolt of the springs, which is used to adjust the ride height. The cm value could merely be an rough guide to display the information in a meaningfull manor to players.

 

[Koray Can]

Dave,

To be clear I didn't expect the logged values to match to the settings perfectly, either. I also didn't really set off on a run; I just sat in the pits and went back in. So whatever happens should happen pretty much the same way as everything else was held constant.

Ride height means ride height. We already have control over tire pressures, suspension stiffness and packers. There's really no point in making the player go to motec after every change to confirm that he's getting the ride heights he intended.

Here's more data: on the Mini the following ride heights in garage produce the following in Motec:

• 13.0 cm front; 13.5 cm rear : 13.8 cm on all sides
• 13.0 cm front; 14.0 cm rear : 14.0 cm on all sides (13 cm is the max for front in garage)
• 11.0 cm front; 12.0 cm rear : 11.6 cm front; 11.4 cm rear
• 10.0 cm front; 12.0 cm rear : 10.5 cm front; 10.4 cm rear (12 cm is the min for rear in garage)

Pieter,

If Motec logs from the game are to be trusted, I don't see why not. In simracing they could be even more important as drivers are deprived of a lot of sensory inputs. Especially if the garage setup doesn't match the reality. Also there are things that you just can't discover otherwise, e.g. damper velocities, tire temperatures at different parts of the track, etc.

 

[Dave Stephenson]

I've just read back what I wrote as I think our wires are crossed on what I meant, my fault, wrong choice of words. Corrected below.

Another possiblity is that the ride height adjust ment is not a measure of the car from the ground, with compensation for suspension stiffness and tyre pressures. If that where the case the adjustment could be a measure of the tension on the load bolt of the springs, which is used to adjust the ride height. The cm value could merely be an rough guide to display the information in a meaningfull manor to players.

I was refering to how the car mechanics are implemented in the programming of the game and wether or not the real world adjustment is simulated or wether it truly is an absolute adjustment. I don't know the answer though, which is a shame.

 

[Marco Boemi]

Personally I stopped using the Motec after I found a bug (see the topic "Ride Height + MOTEC"). Since then, I stopped trust Motec data.

 

[Koray Can]

Marco,

If you're referring to this thread, then it's not a bug if the particular car's suspension has more than 100% anti-lift. See this newsletter:

Anti-lift exceeding 100% will be evident in data acquisition outputs or trackside observation: the rear will drop rather than rise when the car slows.

It may be a sensible set-up to have as it reduces forward load transfer.

 

[Marco Boemi]

Koray,
sorry but it can't be. I didn't know this anti-lift technology (thanks for the info :-D) but for me there is no doubt it is a bug. Why? Because when I start brake on a flat surface I see the "Damper Pos" front channels go down and the rear channels go up which is ok. In the mean time I see the "Ride Height" front channel go down as well as the rear ones which is not possible.