Suspension Issues...
 

I want to lower my Z using the eibach prokit but i'm concerned about the camber problem that comes after. I know that i'm going to need a camber kit to correct this problem. will i need kits for both front and rear applications? Will these camber kits return my alignment back to it's stock form after the drop has been done?Lastly, will i need any other parts to completely finish this part of my suspension upgrades?
I want to lower my Z but i want to make sure that i have everything that i possibly need to make this happen SAFELY!
F.Y.I. I own a 2003 Track Model 350Z with all the performance goodies but with a simple but functional base model interior.

front camber is not an issue from what i've seen and read

you can get rear camber arms for a nice price from kinetix

PM lsdunique for info/ordering

Thanx Mike for your quick response. So if i order me the Eibach Prokit i am going to need a camber kit for the rear only? While doing some research on different suspension kit, i've noticed that some coilover kits come with camber plates for the front and not the rear. I'm confused, if i was to order myself one of these coilover kit with a camber plate, would i still need to order a camber kit for the rear?I'm still trying to get a response to this question from TEIN and JIC, but i figure "It never hurts to ask". Hundreds of brain is better then one.lol. Thanx

camber plates cannot be used on this vehicle.

camber is adjusted via a camber arm on the rear and via the upper arm for the fronts.

I have Eibachs and havent had any tire related cambeer problems, and i actually think the car handles better with the added camber. No complaints here@!

Thanx Mike & Eric. I appreciate your oppinions and suggestions and will seriously take them into account when chosing a suspension kit for my car.

It handles better until you lose the rear end. Then it's harder to regain control (than stock).

with the Eibachs? i havent run into that yet!

After you install the Eibachs, be sure to have the car aligned to get the toe back in spec. When I put in my suspension, the camber turned out to be around -1.7 degrees at every corner (which is fine with me)...

You know why that is? It's why, I would never run progressive springs on a car I intend on pushing to the limit very offten. The reason is, with progressive springs being dual rate, with a soft inital spring rate and a firmer final rate you have to look at what that means to the suspension in terms of "at the limit handling". That softer initial compression of the springs allows the car to roll more to get to the firmer final spring rate. Then that roll (or momentum build) hits the firmer part spring final rate. This puts a heavier load on the outside than linear springs because the linear springs would not have allowed as much roll in the first place. Now lets look at what can happen as the car rolls on the softer inital spring rate then hits the firmer rate. Most progressive springs don't have "seamless" transitions in rate. They change rate in significant steps as active coils bottom on each other. A sudden change in spring rate, while at the traction limit, can result in a nasty slide. And lets not forget that while doing steady state cornering that half the car is working on the firmer final spring rate and the other side of the car is using a totally different softer spring rate. Now what happens if you encounter a bump in the corner? What happens to the spring rates? Since they differ, from one side to the other, the chassis rotates around the roll axis... and the vehicle attitude changes/rotates differently than when in steady state cornering, also not a good thing. With linear springs, non of this happens. No sudden rate changes, no difference in spring rates from one side to the other side of the car while cornering, its always the same. All this is what I mean when I say, progressie springs are a compromise on performance for the sake of ride comfort.

Progressive springs can be made to work in very limited conditions where the parameteres are well known, like a specific road course where telemetry is constantly giving feedback to help select the right rates.....and the designers are experts on vehicle dynamics. Which given some of the spring rates I've seen used, their not always paying the R&D guys to well or its someones best guess it seams.

Gcoupe35: Very helpful explanation!!
What are the sway bars doing under these same conditions? I would guess that they act in opposition to the spring and resist roll more...but then I'm just learning about these things.

Gcoupe35,

I guess that's all the more reason to wait on the Konis and keep the springs stock.

When you say Koni's, do you mean the koni struts? If so, would the koni struts make a big difference over the stock units? How about struts from bilstien? I want to lower my 350Z and do everything that needs to be done all at one time. I'm not going to be racing my Z (much) but i want to lower it. Mostly for looks but i want my Z to be functional also.(As well as safe). Everyones advice and inputs has givin me alot to consider and i've found this forum to be very informative( overly aggressive at times, but informative none the less). Thanx

Hey john,
Thanks for the 411. To my understanding i was told that i would need to let the springs settle for about three weeks but i'll be sure to take care of those issues as suggested. Thanx

Check out this thread. Carter Thompson is a National Champion AutoX driver.

https://my350z.com/forum/showthread....threadid=46715

The SA Koni Yellow Sport shocks will allow you to use the stock springs. They were designed to work with them. Carter is running custom DA Konis. The SA shocks should be out early next year per Gordon at Koni.