Data acquisition analysis. Lateral acceleration

[Birel99]

Hi,

I am wondering what is the point of lateral acceleration when analyzing data? How can you determine oversteer or understeer from it? What do you look for in the graphs?

I am using AIM Race Studio 2, very very basic software.

a bit off topic but: I am looking for data acquisition for a low level formula car (Formula Enterprise). Does anyone have any suggestions for data, preferably under $4K USD with some sensors. (PI research, motec, are way out of my league!)

Thank you,

[sticky667]

http://www.efitechnology.com may have something to suit.

or racepak.

http://www.racepak.com/Drag_Racing/V300SD.php

[Jersey Tom]

You will not be able to determine under-/over-steer characteristics from lateral acceleration alone.

At a minimum you'll need steering angle and vehicle speed as well.

[Birel99]

I have wheel speed, but no GPS, or steering sensors.

I have seen on some CDS systems they use the GPS to plot theoretical lat accel and compare it to actual acceleration from the logger and get an Oversteer vs. Understeer.

Given that I only have wheel speed, what can lateral acceleration be used for? just bragging rights?

[sticky667]

ps. need to change your sig to the correct url to get more hits.

http://tylerwalsh.webs.com

you don't need the www.

[Birel99]

Thanks Sticky

[RacingManiac]

simplest I think is to look at your steering input vs the lat-G. As your steering increase without a corresponding rate of increase in lat-G, you should be experiencing understeer. Thats just the most basic way of looking at it though.

[Birel99]

Can anything be found from how bumpy the curve is? Or how quickly/ slowly it builds to maximum g load?

Thank you,

[Jersey Tom]

Can anything be found from how bumpy the curve is? Or how quickly/ slowly it builds to maximum g load?

Thank you,

I'd start simple and look at sustained corner loads...

[Mystery Steve]

Lateral acceleration would be useful for calculating your lateral load transfer so that you can analyze your roll stiffness (and ride stiffness) and determine your wheel loadings from that. If you have a yaw sensor included with your lateral/longitudinal acceleration sensors, you can start to look at understeer/oversteer and corner entry/exit characteristics. But, like JT said, start simple... most of your cornering is steady state, which is where the lateral acceleration is important.

[Jersey Tom]

I have seen on some CDS systems they use the GPS to plot theoretical lat accel and compare it to actual acceleration from the logger and get an Oversteer vs. Understeer.

Now that I read this again.. that sounds BS.

If anything, an on-board GPS sensor tells you your true lateral acceleration, in the ground plane. A frame-mounted accelerometer makes measurements in the rolling, constantly changing co-ordinate system of the frame.

Comparing the two traces won't tell you anything about oversteer or understeer that I can think of. It can give you useful information regarding the orientation of the car.

[Belatti]

Given that I only have wheel speed, what can lateral acceleration be used for? just bragging rights?

You can check if the AIM soft allows you to combine latG + longG and plot it.
Then you´ll have a "semi circle of traction".

Also, the lat acceleromneter can be used to check max lat G if you want to evaluate mech or aero setup.