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Discussion Starter #1 (Edited)
Has anyone figured out where the balance point is on a 115 GTV? This would be useful when lifting on a two post lift. An important point to consider is where to set the lift points. The weight distribution at the tire contact points will be different from placing the lift arms to contact on the frame rails. --TIA

Bruce Sharer
Raleigh, NC
 

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Don't most folks put the lift pads under the jack points, if strong enough? The frame rails get so mangled from lifts and jacks.
You could probably calculate if from the weight distribution, like 55/45 or whatever it is, favoring the front? Old R&Ts would list in road tests.
Andrew
 

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Discussion Starter #3
Andrew, It would seem logical to align the lift points with the jacking points. After all the Italian engineers selected where they would be located, but weren't those points only for lifting a corner to change a tire? On the other hand, many jacking points have deteriorated. My jacking arms have rubber pads, so I'm not worried about damaging the frame rails. Looking closely at the location of the front and rear jacking points, it seems that the weight distribution would be significantly biased towards the front because of the engine and part of the transmission being ahead of the front point.
 

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Discussion Starter #5
My lift instructions state that it is important to balance the load on the lift arms. I've used the lift numerous times, but always did a seat of the pants guess as to where to set the lift pads. It may not make any difference, but I would like to know the optimum lift points.
 

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Bruce, most 2-post lifts are rated for at least 8000 pounds. With something as light as our Alfas, the balance between the forward and rear arms isn't that critical. I use the stock jack points on my cars with no issues. Even with rubber pads, the frame rails can get bent. After all, on the Alfa, they are just stamped steel.

I pay a little closer attention to the balance when I put my 8,000 pound pickup on the lift and get under it!
 

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Discussion Starter #7
Erik, You are correct. However for the sake of math and physics, how about this? Find the midpoint between the front and rear contact points. using the weight distribution of 55/45 front to rear. Find the midpoint of the weight distribution. Center that point of the vehicle on the centerline of the posts. Place the lift arms so they are equidistant from the weight midpoint. QED?
 

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You can spend your Saturday guessing at the CG and measuring lever arms. Or you can spend it working on your car. Your choice :)
 

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Discussion Starter #9
Actually, I haven't let this exercise keep me from ay work on the car. However, to answer my own question: Per R&T, stated wheel base is 92.5; weight distribution is 56/44 f-r; calculating the approximate mid-point of weight distribution 92.5" x .44 determines that the mid-point is 40.7" to the rear of the front axle center. This mid-point is roughly at the bottom rear of the wing window post. Therefore, placing the lift arm pads equidistant from that point should place the same weight on each arm - given that there will be some variation from car to car.
 
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