How Low Can You Go?, Have I gone too far? Options

[Joseph Mills]

It never ends... (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

Corner balanced my car recently and acheived a "cross" reading of 50%. (IMG:http://www.914world.com/bbs2/html/emoticons/wub.gif)

However, instead of my front A-arms being level, they now angle downward towards the center of the car. I have read that you do not want to go beyond "level" to maintain correct steering geometry. How does this adversely affect geometry? For that matter, what is"correct steering geometry"?

Where do you check for levelness? The arms get thinner as they go out towards the wheel. Measuring under them with a level , I'm about a 1/4" too low. But measuring under the "seam" of the arm I'm level (By seam, I mean the flange on the side of the arms where the upper & lower halves of the arms are joined). Which does one go by?

My steering rods are also tilting down a bit going towards the center.

Here is the current ride height with Kumho V700s measured at the doughnuts:

LF 3 5/8" RF 3 6/8"


LR 4 2/8" RR 4 3/8"


Anyone else running this low to the ground? What are some of your measurements?

I'm sure I can achieve the same "cross" with the car slightly higher, although it will mean losing some of the current rake (not all).

Suggestions? Observations?

Have I just gone over the edge? (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[Brett W]

Since a 914 uses a McPhearson strut in the front, there are several complications when radically lowering the car beyond what the factory design for a ride height. The factory designed the car to ride at a certiian ride height. The relationship between the roll centers, steering axis, ackerman, roll couple, and cg were all factored into the equation. When you lower a strut car you increase the distance between the roll centers and the CG. This creates more leaverage to induce body roll. When radically lowered, (I know looks cool as hell) you have to increase the roll stiffness significantly to keep the car from rolling beyond the acceptable range of roll center movement. Most 914 owners will not accept the penalty of the required increase in roll stiffness on ride quality.

Another factory in lowering the car is where do the roll centers go when you travel through roll. The factory decided the suspension should operate within a certian set of parameters when you lower the car, by adjusting the suspension, you move the roll centers close to and even under the ground. Close to teh ground is OK but under the ground is bad. None of these is as bad as what happens in bump to the lateral location of the roll centers. It moves all over the world when you go droppin' your ride into the weeds. When the roll centers move this much you get weird handling and the car is much harder to drive.