G meter discrepancy

boggie1688 · Post by **boggie1688** » Fri Jun 02, 2017 5:22 am

Some of you may have seen the video I posted from my recent Autox event. I was looking over the video and notice the g meter seems off. Particularly in the 180 turn towards the end if the run.

I've attached a raw datalog and was hoping someone could help. Is it the datalog? Meaning the RCP needs to be recalibrated? Or does it have something to do with how racerender is calculating the g?

https://drive.google.com/file/d/0B-Udn3 ... p=drivesdk

boggie1688 · Post by **boggie1688** » Fri Jun 02, 2017 3:26 pm

I did a basic Pythagorean calculation on x and y; g= ( x^2+y^2 ) ^ (1/2). Created a column in the log, and loaded it into the app. The calculated G seem more in line with what is expected.

Anyone have the formula for calculating G with x,y,z with yaw, pitch, and roll??

I figure it would be best to calculate this, then compare with race render.

Post by **brentp** » Fri Jun 02, 2017 4:57 pm

How do you have the unit oriented during mounting? is it different than natural orientation (flat, upright, connector facing forward) ?

Also, did not see the video. Got a link?

boggie1688 · Post by **boggie1688** » Fri Jun 02, 2017 5:42 pm

Hey Brent,

Natural orientation. It is not on the center of rotation, but mounted under the driver seat. It has the 24 pin connector facing forward and the sd,led,usb connector facing the rear.

Here is a copy of the video:

https://drive.google.com/file/d/0B-Udn3 ... sp=sharing

Post by **brentp** » Fri Jun 02, 2017 5:54 pm

I watched the video, and the 180 degree section around 0:53. What were you expecting to see in the video? Looks like in the 180 degree section you had some consistent lateral G's.

boggie1688 · Post by **boggie1688** » Fri Jun 02, 2017 6:07 pm

The actual value seems low.

I admit, I'm red/green color blind. Given the size of the g meter, and the color, I'm having a hard time seeing the tenths place. But to my eyes, it says 0.0X mid turn.

Am I seeing this wrong?

Post by **brentp** » Fri Jun 02, 2017 6:15 pm

Did you check out the data in the app?

Looks like you were pulling about 1G in that turn-around.

Agree, RaceRender seems to be doing something with the actual g-force calculation.

boggie1688 · Post by **boggie1688** » Fri Jun 02, 2017 6:41 pm

Thanks for confirming Brent.

I did check the data, but I wasn't 100% sure what I was looking at. The data log seemed correct, but I was trying to figure out where, if any, errors were being introduced.

I'll post on the racerender forum.

Your help is always appreciated.