You can do the following:

[1] Quick Check: If the springs are any other color than black such as red, silver, green, etc...they are aftermarket.

[2] If they are Black springs: remove one wheel & see if there are any branding on any of the coils. Most aftermarket springs put their name on one of the coils.

[3] Find someone else who has a stock 350Z or go to the dealership & park next to it. You should be able to tell right away.

 

another way to tell is if u park the car on a sunny day, then walk across the street and take a pic from there. I recently took a pic of my car like that and realized that I need to lower it very soon!!!

 

+1 on 1 and 3...that's what I did.
I bought my car used as well and it looked low. I posted a thread with the same title over on motoring a while back.

Someone told me to turn the front wheel as far as it will go and then peek your head in there to look at the springs. I saw green springs with an Eibach logo. You can try that before jacking it up. If they are black with not logo..then you'll have to go through the trouble.

I also parked next to a stock 350Z...that was another telltale sign. So drive by a nissan dealership and park next to one and that will tell you as well.

 

looks lowered to me too.

 

Did you figure it out yet wether it's lowered or not?

 

It looks very close to stock..

 

IE:

I bought my 350Z used too. here's what it looks like right now... (All stock)

 

it is lowered on eibach springs! but its the black ones... anyone know which ones are these...

 

Black = Eibach Pro Kit
Purple = Eibach Sportline

 

then i have the prokit, i guess. i already checked it out on eibach's site that these are progressive design and such. not bad ride quality either.

 

Yeah the Pro-kits definitely road really well. Even better than my Tein Basics, though not as aggressive.

Had your car been equipped with the Sportlines there would have been no doubt. You would have been like,

"Daaaaamn...my car is looow"

 

are the sportlines really much lower? anyway how are the tein basics? i've been really thinking bout going that route and been researching bout it, how do they feel on the road? any creaking issues like the flexs? thanks for info in advance.

 

The Basics don't make any noise at all. Rolling at high speeds it feels nice and firm like the stock ride/ minus the constant bouncy feeling.

Cornering is where the coilovers shine due to the linear springs. It has little body roll like the Eibachs, but they transition with more precision and predictability.It is a VERY tight and confidence inducing feeling.
For example, when you come out of a corner and straighten back up the car will lean back gradually. On my eibachs it would feel a little more like a pendulum. It swings back a little then springs fast to adjust itself, and bounces a little.

The only "cons" of the basics (compared to the Eibachs) is that it's not as comfy or have a nice "cushion" feeling like the Eibachs. Every once and awhile I'll hit some imperfection on the road and you'll definitely feel it. The race car like feeling and height adjustability more than makes up for that.

Hope that gave you some insight.

 

yea that definitely gave me a thorough insight from an owner! damn you made me experience it just by the way you described it. it will definitely be my choice of coilovers after winter. i barely see any track time since there's basically none close to NYC so i dont think damping adjustability is a neccesity for a somewhat agressive street driver. thanks alot man much appreciated.