I had a few questions regarding suspension if someone doesn't mind answering. I have a `07 G35 Sedan and was wondering if it's better to go with coilovers or air suspension; this is for long-term use. As of right now, only drop springs by H&R are available for the Sedan . So the question I have: what is the ride quality with the coilovers and the air suspension , and what are the pro/cons between the 2...Right now I'm leaning towards air suspension so I can automatically lower/raise, but the companies I've heard so far: Air Runner, Bold World, and Universal Air Suspension. Who here locally carries and installs 1 of these 3, and who here locally is running 1 of these 3. What are the qualities between the 3 (again long-term use). So far I've heard big raves about Air Runner...What a hard decision ...TIA for any help/response.

 

Sounds like you are more set on the coilovers the pros with the coilovers are as you mentioned adjustability and another pro is that there are no shocks involved. The softest setting on coilovers (at least with 03thru06 G35sedans) are still higher than the OEM spring rates so your ride will be more stiffer with the coilovers. That can be both a pro and a con depending on how much you prefer handling over ride quality. The coilovers will cost you more than spring and shocks.

H&R springs are progressive and your factory shocks are linear the difference between the two is that the progressive springs will send more shock to your shocks and other suspension parts where as the linear will absorb more of the shock (ex bottoming out) Spring/Shocks are cheaper than coilovers and if you are running the sport suspension your factory shocks can manage the H&R drop with no problems. I use to have Eibach which are progressive but switched to factory 350z spring in the front and G35 coupe springs in the rear they are linear and have the same spring rates as factory G35 sedan springs only difference is they are 1" shorter in the front and 1/2" shorter in the rear. I had them installed at Sonics took less than 1 hour.

Where to buy... I would say do some research and price them out yourself you will safe over buying them locally but if you rather get them through a shop Sonics does a lot of work on G35s and 350z.