Dog Tracking

[abisc]

Recently I heard an argument and someone mentioned dog tracking(related to toe at the rear), I looked for it online, but couldnt find anything about it, can someone help me here?
Is it applicable to FSAE vehicles?
Thanks!

[abisc]

Recently I heard an argument and someone mentioned dog tracking(related to toe at the rear), I looked for it online, but couldnt find anything about it, can someone help me here?
Is it applicable to FSAE vehicles?
Thanks!

[exFSAE]

Look at some recent pictures of a Sprint Cup car going down a straightaway. You'll see that the car is driving slightly sideways even when going in a straight line. Happens when you run rear toe in one direction (ie right, instead of in, or out).

I'll let you figure out if it's something you want to tune into your FSAE car.

[abisc]

I was thinking of implementing toe-in at the rear to improve straight line stability while braking, will dog tracking come into the picture?
And how has this not been discussed before in the forum, isnt this observed in FSAE?

[Hector]

No, it isn't seen in FSAE (at least not intentionally http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif) . Dog tracking isn't toe-in or toe-out, it's toe-left or toe-right. In NASCAR all the cars turn left. Guess which way their toe is?

[Edward M. Kasprzak]

"Crabbing" is another name for the "dog tracking" exFSAE describes.

[PatClarke]

Abisc,

Dogtracking or crabbing is where, when the vehicle is driving in a straight line (no steering input), the centreline of the vehicle does not align with the direction of vehicle travel.
Toe-in at the rear is advisable for directional stability and will not cause dogtracking if the toe is equally split between both rear wheels.

Inaccurate manufacture of the chassis may cause dogtracking, so be sure to adjust the toe (front and rear) relative to the vehicle centerline, (which may or may not be the chassis centreline)

Cheers

Pat

[DougMilliken]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Inaccurate manufacture of the chassis may cause dogtracking, so be sure to adjust the toe (front and rear) relative to the vehicle centerline, (which may or may not be the chassis centreline)
</div></BLOCKQUOTE>

Tire asymmetry is another cause of dogtracking, see RCVD p57,
"...Two non-symmetries which occur in steady state testing are conicity and plysteer which displace the measured curves from zero. On the vehicle this gives rise to steering/vehicle "pull" and "dog tracking"...."

Next time you drive on a straight & level (and low traffic) road, line your eyes up so you can sight down one side of the vehicle in front. If the driver moves close to the centerline in the road all the better to see dogtracking. To make sure you are not being fooled by differences in front and rear track widths, move your car over and sight along the other side.

[abisc]

Got it!
Thanks!

[Tim.Wright]

When its caused by compliance then it is commonly referred to as compliance steer.

That is your axle (front or rear) tends to "steer" off to one side under lateral loads.

Tim