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The current 9-3 and all of the NG900's have suspension flaws. Some well meaning designer, or idiot, created or included hollow oil filled bushings to connect the radius arm to the lower control arm. So what was the point of that? They could have used a spherical bearing for this bushing and used a rubber radius arm and gotten similar problems.
I can see the intent if the bushing were to create some road surface vibration isolation, but that is clearly not the case. The road surface noise vertical component goes up through the wheel, hub and strut. That oil filled bushing is not in this vibration path. The ball joint only serves to keep the bottom of the strut anchored to the lower control arm, and provides a steering pivot.
Under lateral loads, the radius arm is meant to keep the ball joint stationary relative to the subframe etc. The oil filled bushing allows the geometry to distort under load. Small deflections react with the steering tie rods, which then means that steering angles distort under lateral loads. So steering sucks.
Under acceleration and braking, the same bushing distortion will create changes in toe-in angles.
I expect a big improvement in the NG9-3, whatever that is. This way, they can introduce a corrected suspension, without, as others have pointed out, been seen as correcting a serious flaw in an existing model.
I installed the Viggen rescue kit from Abbott on my 95SET. The suspension had been serviceable, but got very bad at 100000 miles or so. The change is very good. It only serves to show how crappy it was. Putting such features into new production should be a zero cost issue. It cost me more than 1100 US$ by the time things were installed. When I hear that the brand new Viggens have very crappy handling as new, this pisses me off. Yes, there is class action lawsuit if people would get organized.
They (Saab) will not make changes, almost as if they have an ego problem. Take the engine. An engineering marvel. Some idiot put a step ID transistion into the throttle body transistion casting in 1994, and is it was uncorrected until model year 2000. So the engine performance and smoothness was buggered up for all of those years. And HP and torque ratings that were developed on an engine dyno? You can bet that they did not feed the engines on the dyno through that throttle body casting. I bet that there are folks in the engine and turbo charging engineering group that were fighting over that blunder that compromised their work.
Back to the suspension. Then there was the dummy that attached the front roll bars to the radius arms for the 1994 and part of the early 1995 production. This applied bending moments to the radius arm, which was silly, but worse, the forces have to go through the oil filled bushing to have any effect at all. Well guess what. The oil filled bushing then also partially decouples the roll bar from wheel deflections. Hmmmm and what was the point of a roll bar in the first place.
Back to the Viggen recue kit. What it feels like. I get better cornering now on my 15" blizzacks than I was getting with high performance 16" tires on the stock suspension. And the vehicle seems to corner flatter, less body roll. It is as if the steering system distortion was making the inboard tire simply track the curve, instead of having it help pull the vehicle around and into the curve. This is like reducing the one wheel and tire to a passive caster. Perhaps the distortion would allow that inboard tire to generate negative instead of passive efforts. Hard to tell. In my mind I try to figure out how having the outboard tire do all of the work would develop greater body roll. No answer to that. I freely admit that the oil filled bushing was probably degraded and not representative of as new condition. But the way that is was, in its extreme, did amplify and demonstrate the designed in flaws in a fashion that make them very observable. My tie rod and ends and ball joints are original and tight. So the improvments cannot be attributed to those items. The steering and high speed manouvering flaws were also very evident under mild lateral loads. So subframe and steering rack distortion are not issues. So the whole thing amounts to a lesson on the effects of having a radius rod that has a mushy coupling to to the lower control arm, which lets the ball joint location deflect under lateral loads. You do get to appreciate, (or hate), what the dynamics are, when it gets really bad.
, Fri, 5 Jan 2001 14:32:33
, Fri, 5 Jan 2001 17:59:22
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