hsmith

I am very impressed with my GTS lateral grip. This was at Lime Rock on MPSC2's

Churchill

That is impressive.

Roosell

Seriously. 1.7 seems like just below being t-boned by a Hyundia. I haven't been above 1.1

GTOWN83

WOW!, Impressive numbers. Evidently, I'm driving my Pcar like a grandpa......Oh yea, I am one.

Fred2

Published tests show a skid pad value of 1.04
Is the G meter accurate?
or
How do you explain the high numbers?

amre

I'm not sure if this is correct, but I believe the lateral grip test is performed on a circular track and the car is accelerated slowly till it starts to lose grip or deviate from its path. At that point, the max G-Force is recorded.

The G-Force meter that's on the car can record instantaneous measures so you don't have to be constantly accelerating or going at speeds to get a high number on our installed meters. You can just take one sharp 90-deg turn at 25mph and record a number above 1.0 easily. It's not the same as constant grip at speed.

subshooter

A couple of reasons.
1. Different tires than test set up.
2. Different tire/track temperatures than test set up
3. They actually hit something and caused a high g force to be recorded.
4. Spin etc or jolt when sliding across uneven surfaces or surfaces that have an abrupt change in friction coefficients.
5. Hills/angles (not flat)


The skid pad values are determined by turning the car at constant radius on a flat surface while increasing speed until the outer most tires begin to slip. That speed is then placed into a formula to calculate the lateral g force. Anything that deviates from that methodology will produce different results.


I believe that the G force meter in our cars is an instantaneous measurement and not based on the above methodology which will produce higher values.

mwar99

Downhill right-hander onto the front straight at LRP can carry a lot of grip, as evidence by this G meter post. I've seen someone with over 1.8 before on a GT3 with a similar situation providing extra physical grip.

Churchill

This is key. Even a slightly banked turn on the track will allow a good deal more lateral grip than a non-banked turn.

Karl911

that 1.73 g , you were definitively sliding in a sideways drift !!

RonD

This is from a Laguna track day. C2S with PDCC on MPS Cup2.

budrichard

+1
Once you exceed the friction force keeping your vehicle from sliding in a corner, the G Force increases dramatically and is not related to any maximum G Force representing constant tire grip.-Richard

hsmith

Not sliding/drifting. I assume it was at the downhill that i achieved that figure.

Grunty

In a driving school I did, the gmeter would show a sustained 2.5 - 2.7 for the majority of a particular long turn. However, there would be a spike each time that was much higher. What causes this? I assume it's a false reading. these were formula cars which is why the readings are higher.

subshooter

Sorry but you guys are mistaken on this point. The coefficient for static friction is > than the coefficient for kinetic friction.


In other words, once your tires start to slide, the g forces will decrease. I'd be happy to go through all the math and newtons equations at the risk of being a nerd and boring everyone.


He either hit something or it was on a steep decline and turn.