can someone explain the diff between coilover and adjustable shocks or whatever the hell else goes on in suspension. This is a major weak area of car knowledge for me.

I will eventually want to drop my car about 0.50 - 0.75 of an inch, any suggestions on the proper method.

 

coilovers=the spring and shocks as one unit and have the ability to change ride height by adjusting a screw located on the bottom of the spring

adjustible shock= are shocks that can be adjusted for ride quality

and for the drop your not going very low
and the only spring that i know of that will drop that little are the espelir springs they have a drop of 10mm in the front and 10mm on the rear

 

Spring with drops front/ rear
Z H-Tech .8/.7
G H-Tech .6/.3
Swift .9/.6
Tanabe NF 210 1/.6

The spring that seems to be the most popular is the Tein Z H-Tech because of the small drop most can get away without using camber kits and spring rates are slightly higher than the OEM coupe sports suspension.

I just bought the Swift spring but have yet to install them. The spring rates are less than OEM non sport suspension is the reason I choose them. Ride quality was my first priority but when I was younger I would have choosen the H-Tech because back then ride quality wasn't an issue. Even though the spring rates are less, I suspect the ride to be not any softer but hopefully OEM ride quality. Remembering any time you lower your car you install shorter springs therefore reducing a little spring travel which will equate to a firmer ride.

The only recommendation I would say is that make sure whatever spring you choose, the spring rates are higher in the rear. The G's already understeer and by putting a stiffer spring in the front that would only make the problem worse.

I then would install the Tokico D-Spec adjustable shock. The overall setup would cost you less than coilovers with the lack of height adjustability. I haven't looked at coilovers to closely but the Tein Basic would be the closest in cost (I'm not real sure if there are other choices in this price range) although they are adjustable they are sprung pretty stiff.

 

Props to figuring out the idea of softer springs that are tied into a really good shock upgrade like the D-specs. Thankfully the springs don't drop too much, you kind do need oem or higher spring level's to keep you off the bump stops though.

However, the assumption that going with softer rear springs is a guranteed way to add understeer is not the case. Having had a setup whereby I made Koni shocks into coilovers, I had the ablity to run many different spring rate combo's. Which I did. I ran the following.

448/342, 448/375, 448/427, 314/427, 560/448, 375/375, 358/375, and I'm sure I'm forgetting a couple. As rear spring rates go up, you drive down the car's ablitly to power out of the hole. Meaning that the throttle get's much more sensitive and time is lost because of having to wait as corning loads ease before the throttle can be rolled into. Their is a very good thread on my350Z.com that talk's about the reason's behind the Truechoice Koni coilover setup that talks about the Unitech race teams reasoning behind going with a 500/425 setup vs say 560/672.

 

My statement I made about spring rates and understeer were in general terms and not in absolutes. When I was younger I to used track my car and now that I'm older OEM handling is fine because I'm never going to push my G to the limit. As we both know many factor enter into handling, spring rates, shocks, sway bars, tires, air pressure, down force, balance, etc.

Again, I'm talking in general terms, if you want to set your car up the safest way for handling you would want slight understeer although the faster way around a track is to have some oversteer. On the G, basically it's a front mid engine design which by design probably produces some of the understeer.

I like the fact the G understeers because for most ppl it's the safest if they get too aggressive. Generally speaking most ppl are not going to track their cars so even OEM handling is going to be sufficent but for the others who would like to improve the handling I still would like to see a higher spring rate in the rear. Another reason I say this is the transition between braking and acceleration. During hard braking you avoid nose diving and under hard acceleration you avoid squatting. IMO, all my statements are based on general terms although this would be how I would prefer to setup my G.

I have not tested so I can't dispute your theory on real proper spring rate ratios between the front and rear on the G. Anyway, I know that we both love cars and it's fun discussing anything about our passion.

 

Sorry should have picked my words better. Text books, which includes some wonderfull self help books set the pace to totally agree with your thoughts. However, those same books tell our to prove that they say by seting the car up that way then actually testing them and having the willingness to make changes, even if that mean's changes in the direction that is opposite to what is usually sound tuning theory. You mention all the right elements that are envolved in the mix, their is a additional element that does effect this platform and that is excessive bushing flex.

Infiniti may want to hem as all in as a owners group that wants nothing to do with performance and being all for luxary, nothing could be further from what I'm interested most in.

 

I am by no means an expert but just speaking from personal experiences. FritzMan states that a stiffer front allows you a more aggressive turn-in and more steering respsonse. I would agree and disagree. A stiffer front is going to put more pressure on the tires to hold traction and a more aggressive turn-in would hold true until the tires loses traction. The question is will the front lose traction before or after the rears? Suspension is a puzzle you change 1 piece it effects another, so springs are only 1 piece of the puzzle. Steering response certainly can be effected by springs but equally important are tires and air pressure. He also states that bumps would upset traction because the rears are sprung too stiff. Again yes and no. What is your purpose? If you are going to set your car up for handling some of that is going to happen although I agree that the rear spring rates maybe too high. You take any race car they race on a relatively smooth surfaces. His agrument about a softer spring rate in the rear also improves corner exit traction. I would say again yes and no. Exit traction can't solely be based on softer rear spring rates, again there are tires, air pressure, rear sway bars to consider. One big element we haven't talked about is the driver. Each driver likes to setup his car that benefits the way he likes to drive. One thing I will totally agree with is he says that softer rear springs improves street ride.

I own older Porsche 911SC and driving that car fast is completely different than the G. One thing I always keep in mind when driving that car fast into a corner is slow in fast out. The engine is hung back outside the rear axle so if you take a corner too hot or brake near the apex of the turn you'll do a 360 in a flat second. Weight bias is toward the rear hence tremendous oversteer.

I guess, I agree with you in someways and disagree in others.