In my quest for a better understanding of suspension basics, I've been doing some online research. My goal is to figure out how to significantly improve the steering and handling of my '05 Sedan. I'm doing some tweaking (sways, springs, dampers) but I'm continuing to struggle with understeer and the tendency of the car to fight turn-in, even at relatively slow speeds. I'd kill for some crisp "point and shoot" turn-in!

Anyway, I came across this article (excerpt below) and am interested in your collective experience/feedback with improving G handling with some strategic alignment adjustments to overcome the factory-programmed understeer.

"To maintain the ideal camber relative to the road, the suspension must be designed so that wheel camber relative to the chassis becomes increasingly negative as the suspension deflects upward. If the suspension were designed so as to maintain no camber change relative to the chassis, then body roll would induce positive camber of the wheel relative to the road. Thus, to negate the effect of body roll, the suspension must be designed so that it pulls in the top of the wheel (i.e., gains negative camber) as it is deflected upwards.

While maintaining the ideal camber angle throughout the suspension travel assures that the tire is operating at peak efficiency, designers often configure the front suspensions of passenger cars so that the wheels gain positive camber as they are deflected upward. The purpose of such a design is to reduce the cornering power of the front end relative to the rear end, so that the car will understeer in steadily greater amounts up to the limit of adhesion. Understeer is inherently a much safer and more stable condition than oversteer, and thus is preferable for cars intended for the public."

It's clear to me from my driving experience so far that Infiniti has done this exact thing - even on the "sport tuned" models like mine - and it's obviously a detriment to true sport handling. I'm curious if any of you have had success improving the steering response of your G's by going against "factory recommended" alignments settings? If so, can you share some specifics? I don't want to start messing with Camber, Caster, Toe, etc without understanding how others have benefitted from certain adjustments.

Thanks for the help. -T

 

for your fast turn-in, removing push-under...

try slight toe out front, -2.2 camber.
rear -1 camber.

set your rear swaybar to stiff

 

Thanks Kenchan. The Sedan is about to lowered roughly 1.3" in front and .9" in back. Can I expect that amount of drop will introduce an "appropriate" amount of negative camber? Also, will the drop necessarily affect toe?

 

im sure you'll get plenty of negative camber.

yeh, you will need to get the toe adjusted as it will toe-out too far from
the lowering and cause instability. i would play around with your
swaybar settings first after your alignment. i don't need any toe out
on my car and it does not push under at all... turning at wot, it will
either turn tighter or mildly drift