gtroth

Does anybody happen to know the center of gravity (front to back) relative to the lift points?

I am cutting my slab to sink my BendPak MD-6XP mid rise scissor lift below grade and I want to be sure I can get the center of gravity as centered as I can on the lift, so determining where to cut.

Many thanks.

Butters944

The center of gravity is the point under the little diamond shaped dents under each door. If you jack the car from that point (the best jack point anyway), the front and rear will raise together

HICKS

+1

gtroth

Not jacking. Lifting from the proper lift points. When I do that I want the center of gravity of the car to be centered on the lift. And i want the car not to interfere with the garage door or take up too much space in the shop in back. And of course must simultaneously work for the Carrera. Once I cut my slab, the lift wont be moving so i want to get it as right as I can.
If you fellas are sure the diamond is at the actual center of gravity then the diamond gets centered on the lift and the arms reach for the lift points.
Are we sure?

87 944 C

look along the bottom of the car, behind the front wheels and in front of the rear wheels, there are supports that have holes in them(for the factory jack) they are good lift points if you can get the lift to match up with them you'll be set.

Fara

.... except the front ones.
Lift from the chassis reinforcement just in front of the rear tyres and the chassis rail at the front.
Denting/deformation of the chassis rail is normal.

gtroth

Well, the front lift points are on the inner frame (those bumps behind front wheels are not to be used for lifting). Hitting the proper lift points is simple. Hitting them with the car's CG centered on the lift and not interfering with the garage door is the challenge. I want to be as close to the garage door as I can (6", say) so I have as much shop space as possible on the other end.

Add to that I am considering front in and back in orientations, and all this for two very different cars and you can see why it's complicated. And the lift won't move once it's below grade.

I'll never hit all the constraints perfectly of course. Just looking to get the best balance.

Cheers.

UltimatE157

If the center of gravity is indeed the diamond on the rocker, then use the 4-point suggested lift locations and center the lift under the diamond.

gtroth

Should be no issue placing the lift for perfect centering of 944S CG:





What's tricky, and what will drive placement is the 993:

https://rennlist.com/forums/993-foru...ml#post9469197

gtroth

Fini:

gtroth

Here's where I ended up - 52" in from the garage door. I chickened out just before the pour and added 2" to my 6" gaurd band (margin from door to the cars). Better to loose some shop space in the back than not be able to close the door with the cars up:





More build pics over on the 993 forum if interested:

lift w/ 993