noddaz
noddaz Reader
11/24/12 8:18 a.m.

The subject: 1997 Jetta GT The Mod: Eibach Sportline springs #4.5485

Springs are on the car. Springs are mounted on Koni STR.T struts purchased spring 2012. Car is back on the street. Lower control arms were replaced at the same time to take care of worn bushing/balljoints.

The problem: (Perceived or otherwise) Maybe the car sits too low? When I view the front suspension sitting on the pavement the ball joint end of the arms are slightly higher than arm inner pivot end. The arms are not sitting flat at rest. (see bottom picture page 30 of VW sport Tuning by Per for example) So far the Jetta is not exhibiting any bad manners during street driving. The car has not been driven hard yet. Should I be concerned? Should I try to find spacers to put under or over the springs to pick the car up about 1/2 inch? Inquiring minds want to know.

DeadSkunk
DeadSkunk Dork
11/24/12 9:12 a.m.

The ultimate handling in mid-corner will be compromised by being that low. For street driving it will have minimal impact. It depends how you going to use the car.

noddaz
noddaz Reader
11/24/12 10:22 a.m.

The car would be used for normal DD and Auto Cross when I can...

mad_machine
mad_machine MegaDork
11/24/12 10:35 a.m.

unless you are getting weird camber issues... I would not worry about it for a DD and occasional cone killer

92CelicaHalfTrac
92CelicaHalfTrac MegaDork
11/25/12 11:45 a.m.

I don't think it'll be worth worry about even right now. While common thought with MacStrut cars says the arms should be parallel at the most or with the ball joints pointing down, all of my cars have gone the opposite way, and i've never noticed anything bad.

That said, i haven't really pushed the hell out of any of them but the MX6. (Which is also the worst offender. It handles great.)

series8217
series8217 New Reader
11/25/12 11:53 a.m.
noddaz wrote: Maybe the car sits too low? When I view the front suspension sitting on the pavement the ball joint end of the arms are slightly higher than arm inner pivot end. The arms are not sitting flat at rest. (see bottom picture page 30 of VW sport Tuning by Per for example)

The angle of the arms to the ground is not relevant; you need to measure the angle vs. the strut axis.

The closer the arms get to being perpendicular to the strut axis, the less camber gain you will get from a given amount of body roll. If the angle goes past 90 degrees (i.e. the arms are angled way up), camber will go more positive with any further body roll. This is bad.

Ideally, your suspension should gain at least 1 degree of negative camber for every degree of body roll, and maybe a bit more depending on tires (and if you need to make up for some lost due to steering axis inclination).

With MacStrut suspension, its possible (perhaps likely) for a car to handle worse when lowered than at the factory ride height. The camber curve will invariably be worse, and you can even end up getting more body roll since the roll center may drop. That compounds the camber problem...

Travis_K
Travis_K UltraDork
11/25/12 12:18 p.m.

The springs are junk, they are too soft and short, and unless you like crashing against the bumpstops hard enough to rattle the windows on the freeway and skipping sideways in a corner everytime you hit a tiny bump and use up the little suspension travel that is left, get rid of them and get some different springs. They will also wear the struts out way faster, and likely help crack the strut towers like vws like to do.

Grassroots Motorsports Magazine

Subscribe Today

Also get your instant access to the digital edition of Grassroots Motorsports Magazine!

Learn More
Q1r7JDffsTT5DL12DGvX0SMOeXnMn9Rb