## What is negative lateral G force

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I was just looking at the circuit map for Malaysia and it includes the g forces involved in some of the corners

http://www.fia.com/en-GB/sport/champion ... rcuit.aspx

Some of the corners show that there is negative lateral g. Now i understand lateral g force and i understand negative g, but i don't understand how you can pull negative g laterally. Can someone please explain.

Sorry if this is a simple/easy question.......even though i've watched F1 for years, its only recently i've taken an interest in understanding the more technical aspect of racing.
stu112

Joined: 1 Apr 2011

I think it just says left or right hand corner. So when you turn to the right you get negative G's.
mep

Joined: 11 Oct 2003
Location: Germany

mep wrote:I think it just says left or right hand corner. So when you turn to the right you get negative G's.

Yep. One direction is positive, other one negative.
timbo

Joined: 22 Oct 2007

Ok, thanks guys. There's me thinking it was gonna be complicated Is there a particular reason behind doing it that way or is it just for pure simplicity.......negative g means you are cornering to the right and thats it? You would think that people would know what direction lateral g was coming from by seeing to direction of the corner. Anyway, probably best i stop over thinking it
stu112

Joined: 1 Apr 2011

Could be yet another application of the infamous "right hand rule" used throughout basic physics. Depending on your coordinate system, it's useful to define acceleration this way to keep the sign-convention standardized.
volarchico

Joined: 26 Feb 2010

mep wrote:I think it just says left or right hand corner. So when you turn to the right you get negative G's.

Standard convention for graphing Lateral G's in data acquisition and is actually how track maps (in the data) are made. The track map is drawn using a wheel speed or GPS speed for distance (tire roll out per one revolution) and lateral G (left +, Right -) so the system knows which way the car is turning.

Long G is the same way only negative means acceleration and positive deacceleration, though the convention for this sensor may be reversed on some systems...

Steering also follows the same convention with left hand turns are positive numbers and right hand turns are negative numbers so that the relationship with Lateral G is maintained.
Last edited by speedsense on Sun Apr 10, 2011 5:15 pm, edited 1 time in total.
"Driving a car as fast as possible (in a race) is all about maintaining the highest possible acceleration level in the appropriate direction." Peter Wright,Techical Director, Team Lotus
speedsense

Joined: 31 May 2009
Location: California, USA

stu112 wrote:Is there a particular reason behind doing it that way or is it just for pure simplicity

Well, from pure physical standpoint, acceleration is vector, and if it's along the axis direction it's positive and vice versa.
I guess you can say it is for simplicity, so if you have the sign and axis you which direction object is accelerating.
timbo

Joined: 22 Oct 2007

speedsense wrote:
mep wrote:I think it just says left or right hand corner. So when you turn to the right you get negative G's.

Standard convention for graphing Lateral G's in data acquisition and is actually how track maps (in the data) are made. Steering also follows the same convention with left hand turns are positive numbers and right hand turns are negative numbers.

So I am right after all.
mep

Joined: 11 Oct 2003
Location: Germany

mep wrote:
speedsense wrote:
mep wrote:I think it just says left or right hand corner. So when you turn to the right you get negative G's.

Standard convention for graphing Lateral G's in data acquisition and is actually how track maps (in the data) are made. Steering also follows the same convention with left hand turns are positive numbers and right hand turns are negative numbers.

So I am right after all.

Absolutely....
"Driving a car as fast as possible (in a race) is all about maintaining the highest possible acceleration level in the appropriate direction." Peter Wright,Techical Director, Team Lotus
speedsense

Joined: 31 May 2009
Location: California, USA

stu112 wrote:Ok, thanks guys. There's me thinking it was gonna be complicated Is there a particular reason behind doing it that way or is it just for pure simplicity.......negative g means you are cornering to the right and thats it? You would think that people would know what direction lateral g was coming from by seeing to direction of the corner. Anyway, probably best i stop over thinking it

In the old days (before data system track mapping), there was a simple way to track the location of the car on the racetrack. That was if you walked across the screen above the Lateral G signal, to your left was a left hand corner and to your right was a right hand corner and allowed you to locate the position of the car for analysis. 0 g would the center of the graph indicating the car going in a straight line (the sensor is zero'd on the setup table as well), so lateral to the right would be negative numbers.
The track maps you see all the data systems using today, was invented in 1991 by Bill Mitchell (USA) when he was contracted by Competition Data Systems (USA) to design a new data acquisition program. It made analysis much quicker and greatly sped things up....
Last edited by speedsense on Sun Apr 10, 2011 6:01 pm, edited 1 time in total.
"Driving a car as fast as possible (in a race) is all about maintaining the highest possible acceleration level in the appropriate direction." Peter Wright,Techical Director, Team Lotus
speedsense

Joined: 31 May 2009
Location: California, USA

speedsense wrote:
mep wrote:I think it just says left or right hand corner. So when you turn to the right you get negative G's.

Standard convention for graphing Lateral G's in data acquisition and is actually how track maps (in the data) are made. The track map is drawn using a wheel speed or GPS speed for distance (tire roll out per one revolution) and lateral G (left +, Right -) so the system knows which way the car is turning.

Long G is the same way only negative means acceleration and positive deacceleration, though the convention for this sensor may be reversed on some systems...

Steering also follows the same convention with left hand turns are positive numbers and right hand turns are negative numbers so that the relationship with Lateral G is maintained.

Thanks for that info. It makes much more sense when its taken (or explained) in the context of data acquisition.
stu112

Joined: 1 Apr 2011