I get lots of questions about what exact parts to install etc. Truth is there is no one right answer. I have built the same cars lots of different ways. The goal with modifications is the improve the cars feel and performance ability in the drivers view. Sometimes this can be just more tire pressure, others full custom springs etc. This is a long one…
For the fist step on the NG900/9-3 chassis is upgrading the rear sway bar from stock 14mm to 22mm bar. This will have the most improvement for the least investment and easy install. Roll is reduced so that both front tires stay planted improving straight line acceleration. The second benefit is keeping the car flatter during cornering to help overloading the outer front tire. Even my shop loaner cars get the 22mm bars. There is another article in here about the other sway bar sizes. Read that before thinking of the 25mm bars.
Assuming there are decent sport tires on the car the next step is to help the steering feel. The sway bar helped some of this but the next step is to hold the steering rack more solidy. The point to do thing this is eliminating the deflection that occurs laterally in sthe steering rack when you initially correct the steering. The second part is when you have corrected but there is this stored energy in the steering rack mounts causing an overshoot back. While we eliminate this deflection from the stock rubber bushings we also brace the rack mount on the firewall to the sturdy frame. The rack appears to mount on the firewall shear plane but actually is mounted on 2″ tall flexible standoff. Rack brace is a simple bolt on part. 1 hour max with basic hand tools.
From there it gets a bit tricky balancing install difficuly and retunr on investment.
For Convertibles we install the 6-point brace to triangulate the front chassis. This helps by reducing the cowl shake/scuttle that is more apparent with the CV top lowered. The same applies to the hardtops but they are less compromised to start with so you get a decent improvement just not OMG that you get on a vert. 6-point install is still quite basic. Some people with less patience will fight the rivets. Just 6-bolts. Again under an hour to install. No compromises either No more harshness etc.
Shocks and springs help with the vehicle dynamics. This is the first place there is a hint of compromise comes in since stiffening the shocks or bushings will add some ride harshness. The reward is greatly improving the vehicle dynamics. The kit we build most of the cars with in our workshop is the Koni Sport shocks and Koni or Vogtland shocks. Nice stance and the shocks have adjustable rebound to tune it to you the driver. Fitting Konis to stock springs helps. Not the best setup for max performance but a viable option for some people. Fitting lowering springs to stock shocks is a bad idea and results in underdamped and bouncy suspension. The koni kit has matched dampers and springs so it all works great together.
While you have the front struts out it is a good time to save some labor and throw suspension bushings in. The outer bushings are replaced to help with wheel hop off the line and stability under braking. Basically the fore/aft location of the wheel. The inner bushings will help with side chatter during aggressive cornering and also helps the outer bushings do their job. Usually replaced in full sets of both bushings. Will need a press to get the old bushings out. Some people pull them then take it to a local machine shop. You may notice I don’t make/sell the rear bushing in the front arms. The stock is perfectly capable and actually stiffer than the “purple” bushings out there. No reason to replace it with aftermarket.
This is usually where most stop. There are other mods to address certain deficiencies as those bother the driver. Again back to no need to replace the parts unless it fixes what the Driver feels is the issue. Not just bolt every single part on the car because.
The Brakes The first brake upgrade is not with the brakes. Its better TIRES! Brakes cannot do anymore work once the tires slide. The stock brakes do an adequate 1 time stop. The problem comes when you ask for more before they have time to thermally recover. This can be from using the wrong pads or not enough brake diameter. Sport pads are a first step. Hawk HPS or similar. Next is to fit the 308mm “Viggen” fronts. After that or for Viggens is to add the “9-5″ 300mm vented rears. This helps with lots more cooling and also more brake torque. The extra rear brake torque helps to pull the rear down on hard high speed braking. One of the best felt upgrades on a Viggen. I had goodridge make custom lines to add the 9-5 style sliding rear calipers. The best part with this upgrade is that the spare parts aside from lines are available at ever Saab dealer.
From there we move on to power. Will add the rest of the chassis mods and expand this based on your feedback.