Help with handling?
 

I just got a 2014 almost new 1600 mile 370Z coupe, Im coming from a 2010 Roadster. Both cars have sports package 6mt. The roadster Was one of the best handling cars I had ever driven. Nice tight steering massive front end grip really confidence inspiring and Cornered really Flat. My 2015 is nice but much different not as Tight steering nowhere near the sure footed front end. The only difference is the tires My old car had Conti extreme contact the new one has the Potenza tires which look great but dont stick as well, With the bridgestones Im getting a ton shimmy and wag coming out of corners I have been leaving the VSC on (always off on the roadster). I think Im gonna put a set of Extreme contacts on the New car (285-35-19 rear and 255-35-19 front) Hoping that will help.

any other ideas?

Also I read vague posts about turning a bolt on the Steering box that will increase the tension on the steering. Anybody know about this?
Old:
http://i43.photobucket.com/albums/e3...psoweu1ksd.jpg


New:
http://i43.photobucket.com/albums/e3...psimoh0sta.jpg

I think you meant 255/40/19 right? I would suggest getting a printout on your current alignment first.

No, I want to stay at a 35 Profile

Edit, you are correct

I think I will go with 175 35 19

Im very curious about that turning of the bolt statement. Sub'd

sub'd for the possible bolt adjustment. I hit an unmarked speed bump at 30mph and even after alignment and visible inspection I have some play in the wheel and car pulls to the right.


As far your coupe handling different than the roadster, I am sure the weight difference has something to do with the "feel" of the car. I'd maybe try some wider rubber in the front or a stiff front sway /stock rear sway setup to bring the rear around. This is just secondhand scuttlebutt from what I have read as I am not to the point of tuning the balance of my car yet, but It is what I would personally try in your situation.

Regarding tightening the rack and pinion nut, I too have a 2014 coupe and was experiencing "loose" steering, as evidended by the steering wheel doing a quick left-right-left-right shimmy when I hit bumps in the road that affected only one front wheel.

I brought the car to the dealership, and the tech tightened that nut about one full turn. That made an immediate huge difference in steering feel. On-center feel was much more pronounced, and the steering generally had more heft and resisted the aforementioned shimmy. HOWEVER, the steering would no longer self-center when making a turn; I had to manually guide the wheel all the way back to center. So I returned to the dealership and had them loosen the nut 3/4 turn, which cured the new problem and caused the old problem to return.

I spoke to a Nissan master tech who works at an independent shop, and he said never to tighten that nut, as it casuses the gears in the steering to bind, which is obviously detrimental long-term. So yes, this is yet another case of a dealership's service department not knowing its products well enough to implement the proper solution, which in this case may be replacement of the steering rack.

Sounds like your dealer is like all the others around here (not just nissan). All dealers are hiring cheap labor now as more and more techs leave the field for better/higher paying jobs, probably why your master tech is no longer at the dealer. Yes he is correct that you can do damage and bind the rack and pinion is misadjusted. A good general rule is to turn the rack one way or the other and then adjust the adjuster until it just touches and then back off 1/2 turn. This will ensure you have clearence and will not bind. It is not unusual for a rack to have more play in the center as that is where the rack stays 99% of its life so the west becomes uneven.

There is a chart for allowable steering wheel play based on wheel diameter but it is pretty loose in my opinion (somewhere around the 2inch mark) where I have never really seen a rack and pinion get that loose without some very serious knocking or worn parts. I think that chart is more for linkage and gear box steering.