wparente

Would anyone happen to know where you can get a sample test session for a MXL2 or MXG dash. Just looking to play with it in RS2 and RS3. I have the MXL tests, I'm just looking for the latest dash to play with the differences between GPS_Acc and the _Acc coming out of the three axis in the dash.
Bill P

ProCoach

Ok. EVO4 data will work also, because of the tri-axial accelerometer, but almost every install of an EVO4, Solo DL, MXL2 and MXG have NOT had the units calibrated on level ground with drivers weight in the car! So unless someone can with SURETY tell me that they've calibrated the accelerometers in the dash correctly, the data that you seek is going to be suspect.

Now, with the above information, YOU are going to be able to calibrate your unit and read the data produced within Race Studio Analysis, seeing the extra sensors as extra channels. But, until they're calibrated, they're not going to agree...

What filtering are you using? What sample rate?

wparente

Peter -Good questions on filtering and sample rate. From some of the reading I have done, some state that "some" data collection systems have default filters on the three axis units. I however have not read anything that leads me to believe that the MXL2 has that. I believe that it was you and Matt in a prior thread that made it clear about the fact that you must be on the level and calibrate with the driver in the car. Right now it about 10 deg above zero in my garage so I haven't played with that yet accept to play with the auto calibrate.
Because of my lack of knowledge on the subject, I was going to start at 50hz sample rate and compare to 20hz and 100hz on future test sessions. Then I plan to play with the filter rate in the software until I got something that looked close to a line on the graph. After that I have to convince myself that I know what I think I know or start over!
Do you know if there is any prefiltering on the raw data, I see filter steps default to 0 in RS2. Is there anything magic (harmonic tuning) about the rubber dash mounts or are OEM mounts as good or better than the next? I'm guessing that all cars are different for filter requirements depending on many individual variables in the engine and drive train.
Bill P

Matt Romanowski

Every system has an analog to digital converter and that has some bias in it as to how the programmers handle things. That is at a very, very deep level and not really important for 99.5% of people. The MXL2, MXG, and MXS all have different A/D converters than the prior MXL, Evo4, and Solo DL. The new A/D converter is better, but it's not something that would affect many people.

The "raw" data you see has very little filtering. Filtering is a bit of an art in that you want to take out the extraneous info but keep the important parts. In accelerometers, this is especially important.

The mounting method has some variability depending on the car it's going in. In an open wheel, purpose built race car like a Formula Continental or Formula F, the cars shake a lot and solid mounting gives bad data. Their, the rubber mounts or a good Velcro mount works great. In anything but the toughest car (tube frame or production based), the supplied rubber mounts are about perfect.