I’ll go first. Haven’t taken mine to the track yet, so don’t judge me. 😁

 

I’d say those are very healthy numbers for the street! My buddy cracked 2g lateral at HPR on stock Pirellis and factory alignment.

 

Ha great launched it, peak acceleration of 12.35ms-2 - the joys of new rubber

 

Can someone explain those numbers and the yellow ***** what they mean please

 

On Goodyears:

 

G forces

 

Its what is known as a friction circle - it is level of g force generated by the car during acceleration, braking and turning (both left and right). The top number is braking g force, the bottom number is g force generated by acceleration and the left and right numbers are the cornering forces.

An ideal, friction circle is literally that a circle - when driving round a track at race pace a good driver generates a circular pattern (the orange ball moves in a circular pattern) meaning he or she is making the maximum use of the cars grip. A novice driver tends to make a star shaped pattern - meaning they brake and accelerate well but corner poorly (don't use all available grip)

So the example posted by the OP indicates his left and right cornering is similar but he isn't using the maximum grip available to him whilst braking (or the top number would be around 1.8). The bottom number ~ 1.3g is close to the maximum accelerative g for this car which occurs ~ at around 33mph, in first gear at ~ 6000 rpm. The fact that he achieved this and had a number below 1.8g means he likely had little wheel slip when he launched.

You can download this data and more from logging set ups or the Porsche Track app when it works.

 

Thank you for the mature and detailed answer. Much appreciated!

 

Superb

 

What am I doing wrong?? These are on on and off ramps.. Tires aren't squealing yet so maybe go faster?!

 

You will reach your limits way before the car's limits. Tire pressure, temps etc matter of course too. I believe that guys who are getting those huge g force numbers are doing it at a high speed during elevation changes with a turn at the bottom which will maximize your normal force and hence g-forces. My GT3 is getting up to 1.35 on a totally flat track with factory alignment, and CUP 2s. Max g forces will occur just before loss of traction.

 

Here is my max G force. Not bad considering 3 point and sofas. haha. I don't track the car though. Took it out a couple times for 3-4 laps just to try it out. I'm sticking to fully caged race cars for track duty.

 

210 mile estimated range left on half a tank based on your driving?

Get on it gramps.

 

Thank you for the educational post! Such a breeze of fresh air to gain further technical knowledge through the community amidst all these 'value threads', cheers to you!

 

I guess not all cars are capable of generating a circle if it is not powerful enough to have the tire's traction be the limiting factor to forward acceleration (something like a Miata). So the bottom of the circle would be truncated. Even my GT3 experiences less forward acceleration than the other 3 vectors (I live at high altitude, so well less power and torque than at sea level)