I figured I could review this as to help other people who may be interested in the same setup. I decided to upgrade the suspension on my '11 Base + Sport coupe and wanted to stick with OEM parts to avoid any NVH or questionable craftsmanship. My car is daily driven but also goes to the track and autocross. Shortly after I purchased the car I replaced the sway bars, and just today installed the rest of the suspension. No other suspension modifications on my car. Current tires are Hankook V12 Evo 245F 275R.
Nismo Sway Bars
I purchased the front and rear swaybars from Z1, they were currently overstocked and had a killer deal going on. Quality of the parts and fitment was excellent as they were OEM. Overall diameter is just a slight bit more than stock but they are thicker and significantly heavier. Installation was very simple, although did require unbolting some chassis-stiffening bars in the rear.
Driving Impressions
No extra NVH (not that I was expecting any from swaybars). Turn in was improved slightly and the car felt more stable in the corners. The car still felt fairly neutral and I could not detect any extra oversteer or understeer with these. The one downside is that the swaybars are not adjustable, but I am happy with them as is. The car still rotates around fine for autocross and doesn't try to push through corners.
Used Nismo 370z Struts/Springs
*Note that the image is of S-Tune suspension. The Nismo suspension that comes equipped on the Nismo 370Z does not have printed on it "nismo" and the struts are not coated silver at the bottom mount.
I purchased these from a forum member, they had been removed from a Nismo 370z. To the best of my knowledge, these are a different part than the S-Tune struts and springs. Again, quality of the parts and fitment was excellent being OEM Nissan/Tokico. I could not find the exact spring rates for either the Sport or Nismo springs but was told the struts/springs are around 20% stiffer. Installation was very simple using impact tools and I will not go into an install procedure here. There are several in the DIY section. For those asking how much this will lower the car, my suspension has yet to settle but it appears to have lowered it very little if at all.
Driving Impressions
I have yet to take the car to a track with these struts/springs. I will hopefully get it to VIR and CMP in next coming months. On normal city roads, there is a fair amount more "bump" while driving. However, this is not spine jarring and the suspension seems to soak it up very well. It's just firmer. In spirited driving around some backroad twisties, the car sticks to the ground even better than before. There is less body lean while cornering. It is also much more confidence inspiring going through turns than the sport struts/springs. The car had little nose dive before under braking but now there is none. Over rough surfaces in the corners it did struggle for traction a bit more (TCS off). Overall I am very happy with my upgraded OEM suspension.