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Discussion Starter #1
I have used a G-Force meter for many years to determine the "pull" (G-Force) that each of my cars has in the lower few gears. I maintain a spread sheet that I update periodically to compare the cars.

I find this very helpful when trying to determine if a particular car is still performing to its full potential, or whether it has lost some of its spunk.
I have several meters that I use and have found pretty good correlation between them. I typically do each "pull" while the car is locked in a particular gear, then roll-on the throttle and watch for the peak sustained G-Force that it sustains. For practical reasons, I usually record the force that I get when the car is operating in the "meaty" part of its torque curve. The turbo cars of course take about 1000rpm or so of roll-on to build boost, then typically max out at mid-range RPM and start to fall off in the highest ranges. (This is really easy to see in the GT-R since it has graphic display of G-Force built in to the console). The high revving cars tend to get their peak torque and hence pull stronger , closer to the upper reaches of their rpm range.

Note that I consider these numbers to be "approximate" given all the variables, so I would not get too hung up about differences of a few percent between the readings, but they are highly repeatable.

Assuming my attachment comes through as planned (since I have never tried to attach an excel table before), you'll see that the McLaren ties with the GT-R for the highest G-Forces in each gear. Note that G-Force in first gear for the rear drive cars is not all that meningful, as all are traction limited - in fact I have not been able to get a representative 1st gear pull on the McLaren yet given the cold road surfaces.

Given that I have been able to do this for a pretty large number of cars (including a bunch that are not on this list), it is safe to say that the G-Force is a pretty good representation of the seat-of-the-pants "pull" that one feels when driving the car. However, I have noted that cars that sound "strong" or that squirm around a bit under acceleration, can often feel as fast and satisfying beyond what you would expect from their raw numbers. (For example, the GT-R with all its noises and sounds, "feels" stronger than anything else on the page, but its pull definitely peaks in the 3500-5000rpm range, then starts to fall off). The McLaren is smoother and more linear, and sustains for a longer range of RPM. The SLS and 458 "feel" as strong as most of the other cars, because of the combination of their sound and squirming around under acceleration. The 599 was very fast, but not very thrilling unless you really wrung it out to highly illegal speeds. The ZR1 feels the most like a race car with an unending amount of power and torque, but was not all that thrilling. The Scuderia and the GT3 (which is not on this spreadsheet) are not nearly as fast as the other cars, but are pretty thrilling because they are so light, lively and noisy.
 

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Very, very cool, Thunder - thanks for sharing that and I especially like that you include the gear ratio. Would love to see you get your hands on a Veyron and see how its numbers look! A question, that you may choose not to answer: Where do you conduct the test?
 

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Very, very cool, Thunder - thanks for sharing that and I especially like that you include the gear ratio. Would love to see you get your hands on a Veyron and see how its numbers look! A question, that you may choose not to answer: Where do you conduct the test?
I just do it on quiet country roads or a quiet highway. That is what I meant about practical constraints. It is fine to wring it our in 2nd and 3rd gear, but beyond that I usually just record the reading I get while within the general range of safe, responsible speeds, and the corresponding RPM. So I have never tried to get a reading at 8000rpm in 4th or 5th!
 

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Very interesting chart. The number on the 599 caught my eye. Was that a GTB or GTO?
I noticed by the way that you had a 575. Here are the numbers for my 2004 575 as a matter of interest. (One of my all time favorite cars - a great blend of modern and classic.) That was one of the cars I was referring to in terms of "feel" of speed - since its suspension and traction were not nearly as good as modern cars, it always felt really strong and quick to me. Could break loose the rear tires at will - great fun.
1st .75 G
2nd .62
3rd .45
4th .34
 

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and have you ever done the process in reverse i.e. braking g?
 

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and have you ever done the process in reverse i.e. braking g?
I have not done it specifically.
However I have observed it on quite a few occasions, and it is very much a function of the tires and the road surface, and have noticed no obvious definitive differences between the cars.
 

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I noticed by the way that you had a 575. Here are the numbers for my 2004 575 as a matter of interest. (One of my all time favorite cars - a great blend of modern and classic.) That was one of the cars I was referring to in terms of "feel" of speed - since its suspension and traction were not nearly as good as modern cars, it always felt really strong and quick to me. Could break loose the rear tires at will - great fun.
1st .75 G
2nd .62
3rd .45
4th .34
Mine was also an 04 575, one of the few manuals with FHP. It was a great combination of old school/modern car.
 
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