gtroth

Does anybody happen to know the center of gravity (front to back) relative to the lift points for a 95 C4?

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.

vincer77

Between the front and rear wheels. Closer to the rear.

User 122821

The key is to space the front end of the transmission from the center cross beam of the bendpak so the trans and engine will slide out on the lift.

Bill Verburg

The factory put the lift slot in line w/ the CoM on the early cars, it hasn't moved a whole lot from there on 993s

The black removable plastic cover in the rocker of this '74(directly below the leading edge of the door handle ) shows where the CoM will line up

gtroth

^^^ that's helpful, thanks. By calculation, for the 993, the door handle front is right around 60% of the way between F & R axles (ie 40/60 weight distribution).

jimq

I have had a Bend pack scissor lift for 5 years on a regular 4" slab and has not done any damage from weight. its good to put a piece of metal under the rear rollers to keep the concrete from being marked up. It doesnt need to be over engineered.
Placement of the car on the lift is not the same every time as the arms can slide quite a bit.

gtroth

Yeah, for the 993, it seems that if you put the CG on the center of the lift, you won't be able to reach the front lift point because the stops (circled) limit the end-overhang to ~4" max:



Still will be centered enough:





944S has no issue:

https://rennlist.com/forums/924-931-...ml#post9468066

Bill Verburg

Do your lifts have a target on them for where the CG ought to be? It's sort of hard to see but mine has the target area indicated by the 2 color circle just forward of the oe lift point, our cars are so light relative to capacity that it's ok to be off by a bit, here's my C3 ooched back a bit to allow more room to work w/ under the trans and engine

gtroth

No center mark on the BendPak. Manual just says 'Center of balance should be midway between adapters and centered over the lift'.

Bill Verburg

This is the best I have from the side w/ 993, it's ooched back from CoM just about the same distance as the C3, the lift ctr pt is ~4-5" ahead of the door handle

gtroth

Fini:

Flying Finn

This gives you an idea that it ain't 50/50...
Where the jack is in this pic, is not where the center of gravity is (because when you jack from the rear, front raises a bit later) but I'd guess it must be around 150-300 mm forward from it.

Anyone have their corner weight numbers? With those, we could figure out the exact location.

Magdaddy

I ended up rotating my mid-rise 180 degrees after the first season. I had limits on how close to the existing slab I could(wanted to) put the recess. It was always gonna be tight, but when initially installed with the hydraulics forward, I was too close to the overhead dood to walk around the car when the car was up.

Flop the lift around, and I gained about 18". My lift doesn't have those stops, so getting to the lift points has not been an issue.

A great investment, makes waxing/detailing the car lots easier also.

RocketJohn

can a 993 drive over that lift without the lift being sunk into the slab?

gtroth

Even an SUV height 993 cannot drive over the Benpak MD-6XP without recessing the lift or raising the car on ramps.