Hello all,

I have an Infiniti G35 Sedan that I'm looking at upgrading the suspension on (the rear shocks are shot, so now seems like a good time).

Everybody seems to be pushing coilover struts in the back instead of springs/shocks; some religiously so.

I'd to understand why...obviously Nissan/Infiniti could have put whatever they wanted in the car when they designed it. I can't believe cost is the reason; the difference for a major manufacturer I'm sure would be trivial. Since they have cars like BMW in their sights, performance seems a paramount concern for these cars. They must have had a reason for their implementation (which, by all accounts, is very good).

One vendor suggested that separating the two functions prevents the spring from impinging on the function of the shock (when the spring bows slightly under compression) and allows the camber to change dynamically as the suspension compresses. They also suggest that putting coilovers in may put stress in places not engineered to support it.
SPL Spring/shock vs Coilover

The best reason I can find for the coilovers is the ability to adjust ride height easily.

I'm a total novice here; any help in understanding this would be helpful.

pingwax

 

Alot of the reason people go with them is for adjustability

 

Cost is certainly the main reason why nearly no car comes with coilovers from the factory. Not to mention the fact that I am sure the engineers and marketers at Infiniti did not consider performance modifications as paramount reasons for recasting a car such as the G35 sedan as being the type of enthusiast car people would mod to that level (for example, they aren't common cars to find at a track day). No BMW comes with coilovers from the factory either.

That being said, you should read that SPL article more carefully. It is pointing out a very specific type of coilover design (a "true" rear coilover where the spring is mounted on the damper). The majority of coilovers on the market do not use this type of setup, and instead retain the standard type rear layout, where the damper and spring are kept separate from one another.

There are numerous advantages to coilovers. The ability to have control over ride height is one. Many also allow you to adjust dampening. Others let you adjust height independant of the stroke (travel) of the shock - so you can lower the car but keep the same amount of shock travel. Something no spring/strut combo will ever achieve. Yet another is having components that are matched and designed to work with one another as a unit, vs picking springs from one company and struts from another. Does this mean coilovers are the right choice for everyone? All depends on your needs, wants and budget