We all know the Eibach Pros made my 14k mile suspension simply squishy. It may do wonders for cars with 40-80k miles but my handling fell off. Is there a linear spring that's considerably better than a 2005 or maybe even a moderately priced combo or coil over. 1500 is too much. 1300 is maybe. I know I'm re- addressing an issue but I never found the tried and true solution.

 

First off, you do realize that the Prokit is pretty close to stock 05 spring ratings....only progressive:

oem baseline

2003/2004
314/342

2004.5/2007
314/427


Eibach 350Z progressive springs 1”/1”
Spring rates in LBS initial/final front 296/384 initial/final rear 316/421

I know your car has only 14K miles...are you the original owner? Reason I ask.. worn shocks may not be holding up to new Prokit. I assume you went and got alignment and still have the problem? There's NO WAY a switch from stock to Prokit would cause your problem..unless alignment is off or you have blown shocks. Get new OEM shocks or better yet D spec shocks and then see
how Prokit performs.
Stiffer Springs aren't going to solve your *problem*...stiffer is NOT always better. It all about balance. In fact, I have Nismo S tune set up with 505lb progressive rear springs and I'm going to switch to those Prokits on the rear. want to sell me yours? I'll take em! Pm me and we can arrange it.
BTW...Whiteline has one the stiffest linear shocks. I think they're on back order now, but you an place an order. Do a search for Whiteline Dealers. I still think you may need new shocks to go with it.
If you want a nice coil over kit..Eibach ProStreet ( same as KWv1) can be had for around $920 here:

http://www.wickedcarparts.com/2008-n...coil-over-kit/

Again...if it's not the alignment, then replace the shocks first. The springs are fine!

 

Ok Ronn, you make tons of sense & your info is invaluable. Answer this. Stock springs & shocks were AWESOME. After I put the 9.5 & 11 rear wheels it was a beast. I do have the shocks under maybe an inch of load but survey says that makes them work better. SO why was I great before? 350Z tech forums go over this issue. Lot's of chatter about how a suspension needs travel to work. We are what, 4.5 off the ground stock? I'm thinking maybe Koni Sports "yellows" and maybe just cutting a coil off the stiffer stock set. I actually liked the stock ride height though, IDK. There was also talk about shifting the CG & now the front is being asked to take more of the load. I got lots of pillar roll and it rises instead of squats at WOT. Lowing an aggressive sports car doesn't mean it's going to handle better. I've ran H&R, Sportlines on my F-body & they were great. I guess if my shocks were bad, why were things so great with stock springs? My car did require new front pads and my hatch struts fail, but doesn't everyone's? My car looks and even smells new. Not a chip, ding. The OEM Bridgestones were maybe half worn except for the one wheel spinner when I changed to the 19X11's, as I have an open diff. You are correct, I bought the 6 speed at 12690 miles. The car fax only had oil changes. The guy was averaging 17mpg which is better than me in town. I can get in the 20's on the freeway. I'll let the springs go if Eibach doesn't work with me. No real evidence of shocks gone. They don't have to visibly leak (which they aren't) but everyone's gone over them. I'll know next week.

 

You haven't yet confirmed that car was aligned...was it? I read your other thread and you said *alignment was good*. I REPEAT>>>

DID YOU GET IT RE ALIGNED???

When I first switched out my shocks/springs and tested the car it was SCARRY and *floated* as you described. Got car aligned (rear toe was off) and it was a different car! If you haven't already done so..DO IT!

 

If I do that with no change then I'll have to do it again. Most tracked cars tow the rear in any way to keep the *** end from getting out of control. My car tracks fine. Have you seen that show where they race the Solstices for a contract with Pontiac? Their pro crew chief tells them that. You really think an alignment is going to fix body roll linear & lateral & bounce? Portland Speed Industries does not. They want 2 hours to do my Z absolutely correctly. They charge 100 an hr. What would you do? I'f there is little change from stock to Pro's spring rate, I'll go back to beast mode with an inch more forgiving clearance. I initially bought the springs to close the gap I thought the 19's would create. They actually filled the wheel wells. I had already ordered them and wasn't going to get what I thought would be a better ride. The dealer the car was bought from inspected everything. Good. I don't like people touching my car. I'll get it aligned after the coil overs go in or after the Eibach's come out. If Eibach doesn't take them back, I'll sell them to one of the two people who asked for them. I've been offered 150. Thanks for the help Ronn. I'm not disregarding you. You're info has been valuable.

Lincoln

 

If you have an NTB in your area get the alignment with a warranty. They offer 2 yr, 3 yr, and maybe even longer. You can get an alignment free every time you change or alter a component. The alignment shouldn't affect how "bouncy" or "soft" the car feels, but it will definitely affect how sloppy it feels overall.

 

tockico d spec shocks/springs are the way to go. linear springs and nice shocks, good drop too after you cut the rear spring mount

 

Stance GR+ are only 1000. Problem solved. I've ran the Eibach's for a week or around 100 miles. I will run Eibach's coil over kit if they take my springs back & cut me a break for all this trouble. It does say "improved handling" on the box. For a no mileage car like mine this became not the case. I personally feel it disrupted the geometry and gave no room for the suspension to work or travel. When I put the 19X9.5 19X11 wheels with Hankook Ventus V12's, the car became an animal. Handling and stability increased 100000 million percent. When the springs went on. It was worse than when I had stock 17's. I know my car & I push it. Root cause analysis, process of elimination but it's the single factor. This is why I always only change one thing at a time. If I did two, where would I look. The stock springs are firmer than the Eibach's and are linear. You don't want you car giving and then halfway through the turn say, "hey, let's tighten up". Kinetic energy is already set in motion. I didn't do my homework & paid the price. I am gambling 400 on alignments if it's the case. Dealer, PSI & I don't think it's the issue. The car really didn't noticeably lower. Barely. It just got soft.

 

Ok..so you didn't get the car aligned? They will first check your current set up for any out of spec #s. You don't even have those do you?..how do you know your current set up is within spec? The install may have thown it off.
This would be the first thing I would do.... having ruled out any install errors.

I have Nismo S tune and the shocks are progressive.
The Eibach rates are Stiffer than stock up front and pretty much equal in back. However, they lower the car as well and so the car should handle BETTER than stock..providing you're in alignment and have good shocks.
BTW, I'm going to be putting those exact Eibachs on the REAR with my S tune set up. S tune rears are too stiff at 504lbs.

 

I've been driving on Eibach Pro-Kit springs for a few years now with several other components changing over time. The only time it ever felt wrong was with poor alignment. If that isn't the case with yours, then something else is wrong. I truly don't believe it's the springs.

 

But its a no mileage car... duh.

 

 

I took it to the dealer it was purchased from and had them go over the install. Every nut bolt etc. I paid for an hour of labor & a test drive. The tech said everything was perfect. I verified the orientation of the springs through the wheels & paid to have it all checked out by Nissan. The say the car drives fine but I have a "section" where I push my car. First turn & I just backed out. I'm bouncing & bottoming out everywhere. The front wants to immediately push. Hey, like I said, everyone is stumped. If it is "shocks" & I buy the coil overs & sell the Eibachs it's six one half dozen. It's worse with the Eibach's period. One way or another, I'm going to have to fix it. I'm doing what the Eibach tech says. BTW, yes, Nissan checked the alignment.

 

I have a whole damn shelf full of linear springs...

You can get any rate/length you want if you call eibach or hyperco. That said, you get some sleeves for a set of koni yellows (fronts) and some adjustable perches for the rear....you can run an off the shelf 7 or 8" spring.....which are available in spring rates from 100-2500lb (or more).

 

ARK drop springs are linear

 

One more *detail*..maybe I missed this, but did you verify the part # on the kit...6364.140?




Free springs are rear..6364.002
Installed springs are FRONT..6364.001


I'll just say this one more time ...alignment will cost you around $60-$85. You could have done that FIRST..before all this stuff with the dealer. They would let you know if anything looked *off* as well. It's still something you can do relatively cheaply and may very well solve your problem. Seems like you're set on a new set up though...so good luck.

 

Oh yes, all verified before I put it on & after. Too much ambiguity. I ordered a set of Stance GR+'s Coilover's.
Or as Stance says "now called super sports". Done with the guessing. I know my car will handle better this way.

 

I would have gone back to stock

 

Ok.... Let us know how it turns out.
Are you getting True Style coils on the rear or OEM like these:

 

Really?