How many G's y'all gettin'?

[kart125]

I don't play a lot with instrument cluster but the other day while stuck in trafic I scrolled arround the different options and noticed the G's that got registered on my last track day.

I know the G-meter is not accurate but I thought it would be fun to post pictures/numbers of what our cars are capable of!

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[Txclyde1]

I don't play a lot with instrument cluster but the other day while stuck in trafic I scrolled arround the different options and noticed the G's that got registered on my last track day.

I know the G-meter is not accurate but I thought it would be fun to post pictures/numbers of what our cars are capable of!

After

 

[Txclyde1]

After running Hallett last year I showed 1:33 left
and 1:35 right.Totally stock 2015 TrackPack

 

[kz]

That's about a millionth thread about it and sorry to disappoint you but your numbers are below of what regular GT can do... Also, those numbers are largely meaningless as it's peak acceleration, not sustained.

 

[Tank]

After running Hallett last year I showed 1:33 left
and 1:35 right.Totally stock 2015 TrackPack

Tearing up a '15 GT350, nice....

 

[crazymayhem]

out of interest - sorry for a potential threadjack - but does anybody know if its possible to just replace the tach/rpm background to get the km if you need em? Or simply replace the gauge cluster?

 

[16GT350]

I haven't reset mine since I was at Road Atlanta with NT01 tires...





Fun track!

 

[Eric0w]

Not too much on lateral G, but acceleration is pretty good.

 

[PencilGeek]

I know the G-meter is not accurate but I thought it would be fun to post pictures/numbers of what our cars are capable of!

The accelerometers themselves are pretty accurate, but it's the car itself that induces spurious readings in the accelerometer. If you look at enough vBox files, you can see pretty clearly that road bumps and the like influence the accelerometer. If you think about it, of course they do because the accelerometer is measuring g-forces. The accelerometer is a 3-axis device (X, Y, Z), and even though hitting a bump or rough patch of road theoretically only affects the Z-axis, since the car is in motion there are side-effects of that bump that will pollute the X-axis as well.

Besides the Z-axis bumps, shifting gears very much influences to X-axis values. Dump the clutch or really make a speed shift and yes you'll see a very big spike in the positive X-axis.

A lot of those types of spikes can be smoothed with filtering. Most people don't use filtering though. vBox doesn't filter the raw values and lets you add a filter during post-processing. I'd bet Ford doesn't apply filtering either. The moral to the story, the spikes are a little bigger and probably lead to the impression that the car's accelerometer isn't accurate. The fact is, it really is accurate -- pretty darn accurate.

In case you're wondering, I just happen to run a software department that writes the low-level drivers for these types of motion sensors. IIRC, Ford uses a standard +/- 2g motion sensor for the track apps, but will have a separate +/- 16G (or larger) sensor for accident black box recording.

 

[C7 B8]

 

[xt6wagon]

I think that could be mine other than the right lateral G on mine is like .8x

 

[J_Maher_AMG]

The accelerometers themselves are pretty accurate, but it's the car itself that induces spurious readings in the accelerometer. If you look at enough vBox files, you can see pretty clearly that road bumps and the like influence the accelerometer. If you think about it, of course they do because the accelerometer is measuring g-forces. The accelerometer is a 3-axis device (X, Y, Z), and even though hitting a bump or rough patch of road theoretically only affects the Z-axis, since the car is in motion there are side-effects of that bump that will pollute the X-axis as well.

Besides the Z-axis bumps, shifting gears very much influences to X-axis values. Dump the clutch or really make a speed shift and yes you'll see a very big spike in the positive X-axis.

A lot of those types of spikes can be smoothed with filtering. Most people don't use filtering though. vBox doesn't filter the raw values and lets you add a filter during post-processing. I'd bet Ford doesn't apply filtering either. The moral to the story, the spikes are a little bigger and probably lead to the impression that the car's accelerometer isn't accurate. The fact is, it really is accurate -- pretty darn accurate.

In case you're wondering, I just happen to run a software department that writes the low-level drivers for these types of motion sensors. IIRC, Ford uses a standard +/- 2g motion sensor for the track apps, but will have a separate +/- 16G (or larger) sensor for accident black box recording.

They very well might be accurate to some degree, but it is wise to keep in mind that anything above ~1.10-1.12G thereabouts is superficial. Since essentially every car can overpower a tire's grip during full braking, braking tests (60-0, 70-0) can be used with basic physics to determine the absolute limit of adhesion for any specific vehicle.

2ad = V2^2 - V1^2, V2 being 0 since the vehicle is coming to a stop, distance d is known from the objective tests, V1 being either 60mph or 70mph converted to meters/sec; solve for acceleration (technically deceleration) "a".

Just a pointer really so that people don't honestly believe they are hitting 1.5+G's in the corners, and know that the data is flawed, as a vehicle literally cannot achieve the same maximum grip laterally as it can in a single plane/along a single axis (braking or acceleration, with braking being far more powerful). :cheers:

 

[PencilGeek]

They very well might be accurate to some degree, but it is wise to keep in mind that anything above ~1.10-1.12G thereabouts is superficial. Since essentially every car can overpower a tire's grip during full braking, braking tests (60-0, 70-0) can be used with basic physics to determine the absolute limit of adhesion for any specific vehicle.

2ad = V2^2 - V1^2, V2 being 0 since the vehicle is coming to a stop, distance d is known from the objective tests, V1 being either 60mph or 70mph converted to meters/sec; solve for acceleration (technically deceleration) "a".

Just a pointer really so that people don't honestly believe they are hitting 1.5+G's in the corners, and know that the data is flawed, as a vehicle literally cannot achieve the same maximum grip laterally as it can in a single plane/along a single axis (braking or acceleration, with braking being far more powerful). :cheers:

Agreed. I was explaining how the data gets flawed in the first place while saying the hardware itself isn't likely flawed.

 

[J_Maher_AMG]

Agreed. I was explaining how the data gets flawed in the first place while saying the hardware itself isn't likely flawed.

For sure, and you were spot on with your explanation. I just remember a few months ago a guy claimed he was able to "easily" eclipse 1.5G's in his car... just wanted to put a disclaimer for anyone else reading so they don't naively think that these spiked values are legit...

Last thing we want is some meatball bragging at a car meet about how of G's his car gets giving us more bad rep... we have a hard enough time already getting crowds of bystanders to trust us when we drive by :lol: :cheers:

Its too bad they don't incorporate these filters you spoke of though into the software; would love to know how they work. Would be really cool to have a gauge that couldn't be contaminated with false data points so easily.

 

[cking]

Yes you can -- bat turn -- throw out your anchor

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