Center of Gravity


Apollo

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Aug 5, 2006
2,512
Pahrump, NV
I am curious, has anyone determined the approximate center of gravity, or center of balance for the car as a point (i.e. in line with the side scoop front edge or some other landmark)? I have been trailering my car quite a bit and with Kendall's help I feel I have the GTs weight distributed well but wondered where this balance point actually is.
Thanks in advance,
TC
 

Kayvan

GT Owner
Jul 13, 2006
4,782
43/57 front/rear weight distribution
 

centerpunch

ex-GT owner x2
Mark II Lifetime
Sep 16, 2005
952
OH/NC
So with a wheelbase that's 106.7 inches, I think that means the CG would be 57% back from the front axle, which is the same point as 43% ahead of the rear axle.

In other words, the CG should be 60.8" back from the center of the front axle, which is also 45.9" ahead of the center of the rear axle.
 
H

HHGT

Guest
When Kendall is a passenger the C.G. shifts to the right....
 

RALPHIE

GT Owner
Mar 1, 2007
7,278
When Kendall is a passenger the C.G. shifts to the right....

The actual amount of the shift depends upon where his glasses are located at the time...:lol
 

PL510*Jeff

Well-known member
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Nov 3, 2005
4,900
Renton, Washington
So with a wheelbase that's 106.7 inches, I think that means the CG would be 57% back from the front axle, which is the same point as 43% ahead of the rear axle.

In other words, the CG should be 60.8" back from the center of the front axle, which is also 45.9" ahead of the center of the rear axle.

CP - as usual way too technical. Indy GT would have taken 275 words to describe this subject.

But I digress, as the original question was referencing cg rather than weight distribution. I suggest that the cg is approx. 6.5" above the point equi-distance above the center line of the rear axle in corelationship to the ground. Unless it is a TT GT with good traction with the front tires off the ground at the Texas Mile in two weeks.:eek
 

HeritageBruce

GT Owner
Mark II Lifetime
Mar 13, 2006
748
Southern CA
Can someone jack up his car using one jack in the centerline of the car and look for the balance point and report back?
Took Kendall out one time in the car, his weigjt didn't affect my lap time at all so he can't weigh much more than 160. :biggrin
 

DRIVEBY

GT Owner
Mark II Lifetime
Mar 17, 2006
253
Las Vegas
I jack it up just in front of the doors' rear edge - works like a charm.
 

centerpunch

ex-GT owner x2
Mark II Lifetime
Sep 16, 2005
952
OH/NC
The question was about the balance point- where you would position the car so there was equal weight front and back. My answer was correct.

I've scaled the point 43% in front of the back axle on this photo, this yellow line should be about right.
.
 

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nota4re

GT Owner
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Feb 15, 2006
4,281
Bruce, you are my friend.... I think my ONLY friend!
 

centerpunch

ex-GT owner x2
Mark II Lifetime
Sep 16, 2005
952
OH/NC
Basic physics lesson.
.
 

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HeritageBruce

GT Owner
Mark II Lifetime
Mar 13, 2006
748
Southern CA
The question was about the balance point- where you would position the car so there was equal weight front and back. My answer was correct.

I've scaled the point 43% in front of the back axle on this photo, this yellow line should be about right.
.

So it looks like the balance point (yellow line in the picture) is where the driver's spine is. Hum... that's got to be why the car feels so "balanced" to the driver.
 

Apollo

GT Owner
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Aug 5, 2006
2,512
Pahrump, NV
The actual amount of the shift depends upon where his glasses are located at the time...:lol

Shift happens...
 

Apollo

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Aug 5, 2006
2,512
Pahrump, NV
The question was about the balance point- where you would position the car so there was equal weight front and back. My answer was correct.

I've scaled the point 43% in front of the back axle on this photo, this yellow line should be about right.
.

This is what I was looking for! I was a bit further back in my guestimation.
You guys are awesome!:thumbsup:thumbsup:thumbsup
 

centerpunch

ex-GT owner x2
Mark II Lifetime
Sep 16, 2005
952
OH/NC
Of course, for towing, you don't want the trailer balanced, you want (I think) 10% of the weight on the hitch.

Whenever I get a new car, I load up my trailer with tools, tires, and other misc. stuff, then put the car in its approximate position, then level the trailer with the tongue on a big scale. I then move the car back and forth until the tongue weight is right (marking that location for future reference), then hook up to my tow vehicle, put on the weight equalizing bars, and adjust them to get the trailer back to level.
 
Last edited:

Mark McGowan

Ford GT Team Alumni
Jul 31, 2006
148
If you want to be precise for a stock GT, try @ curb loading:

GG height 18.5 inches high
Longitudinal CG 60.32 inches rearward from centerline of front axle
Lateral CG -0.26 inches (left of longitudinal centerline)
 

PL510*Jeff

Well-known member
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Nov 3, 2005
4,900
Renton, Washington
Words from The Master

If you want to be precise for a stock GT, try @ curb loading:

GG height 18.5 inches high
Longitudinal CG 60.32 inches rearward from centerline of front axle
Lateral CG -0.26 inches (left of longitudinal centerline)

Doesn't get any more precise than that. :thumbsup
 

Apollo

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Aug 5, 2006
2,512
Pahrump, NV
Of course, for towing, you don't want the trailer balanced, you want (I think) 10% of the weight on the hitch.

Whenever I get a new car, I load up my trailer with tools, tires, and other misc. stuff, then put the car in its approximate position, then level the trailer with the tongue on a big scale. I then move the car back and forth until the tongue weight is right, then hook up to my tow vehicle, put on the weight equalizing bars, and adjust them to get the trailer back to level.

Thanks! :thumbsup
 

Apollo

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Aug 5, 2006
2,512
Pahrump, NV
If you want to be precise for a stock GT, try @ curb loading:

GG height 18.5 inches high
Longitudinal CG 60.32 inches rearward from centerline of front axle
Lateral CG -0.26 inches (left of longitudinal centerline)

Let me guess, engineer? :biggrin I love it, thanks!
 

centerpunch

ex-GT owner x2
Mark II Lifetime
Sep 16, 2005
952
OH/NC
If you want to be precise for a stock GT, try @ curb loading:

Longitudinal CG 60.32 inches rearward from centerline of front axle

Hey, I calculated 60.8" in the third post- only a half inch off.........