G35Sedan thanks for your post:

"KW coilovers Variant's 1,2&3
twintube construction,
V1=non adjustable dampning,
V2=adjustable damping,
V3=separate adjustability for compression damping AND rebound damping and is the only product of it’s kind at this time.
Spring rates Front 485lbs to 525Lbs Rear: 240Lbs to 548Lbs (progressive springs)
Notes: High progressive rear spring rate spread can be fixed easily with Eibach ESS springs in place of the KW rear springs, cheap fix at only $100 for a pair."

-------------------------------------------------------


Guessing from the spring rates, it looks like the car would understeer alot from the kw v3's springs, did anyone have that problem?

I'm wondering if anyone with the kw v3 has swapped out the rear springs for the Eibach ESS to get rid of the large spread in spring rate. How does it drive? Does it noticably change the balance to oversteer or understeer?

 

I am really confused with all these numbers. Can someone please tell me if i can put Eibach pro-kit springs on my 03 G35 coupe?? Thanks
The reason why i am asking is because i already have the springs from my previous G. thanks again

 

May want to add this info to the first post?

COBB Tuning 350Z (03-07) lowering springs (appear to be linear), $250
Front lowers 3/4-in. at 15% stiffer rate (does not state which year spring)
Rear lowers 15/16-in. at 15% stiffer rate (does not state which year spring)

They also have a 350Z (03-07) front and rear sway bar package (bushings require grease):
Front Bar Rates $205
Position 1 = 25% Stiffer over stock
Position 2 = 50% Stiffer over stock
Position 3 = 85% Stiffer over stock
Position 4 = 135% Stiffer over stock

Rear Bar Rates $160
Position 1 = 85% Stiffer over stock
Position 2 = 130% Stiffer over stock
Position 3 = 190% Stiffer over stock

All available as a staged package for $575.

 

Any idea on what the spring rates are for the 07+ G35 Sedan Sport Model?

 

VERY NOOB QUESTION WHAT THE HECK DOES THE NUMBER IMPLY

EX:

Eibach 350Z sportline progressive springs 1.2"/1.2" drop G35 drops will be higher
F: 239/400 R: 257/435


SO THE LOWER THE NUMBER MEANS THE MORE SOFTER THE RIDE IS AND THE HIGHER THE NUMBER MEANS THE STIFFER IT IS WHAT DOES ALL THIS MEANS SO IF ITS HIGHER WE CAN TURN BETTER AND THE LOWER THE NUMBER WE CAN;T TURN BETTER BUT HAS BETTER SOFTER RIDE? CAN ANYONE GIVE ME ANY INSIGHT THANK YOU

 

With what you posted specifically is a progressive spring rate. Lowering a car is small part of how it will handle, lower too much and you may do more damage then good to the handling aspects of the car.

I'll explain the rates and what I mean by progressive rates. OEM springs are linear rate, meaning the listed spring rate is constant throughout the compression and rebound of the spring. With progressive, the coil is wound tighter at one point than it is at the rest, it becomes progressively stiffer as the spring is compressed.

So with that example, the Initial rate of the front is 239. this is for softer initial feel and typically felt during slow turns or driving. The final rate of 400 is what is used during higher speed compression where you will want a stiffer rate because there are higher forces being applied to the suspension at higher speeds. Same for the rear obviously

Progressive springs will give the car a somewhat bouncy ride and a snappy feel in the corners, or at least thats what my interpretation of it was on my 240SX with Eibach sportlines.

Linear rates will give you a more consistant transition through the turns and an always stiff feeling if the rate is high enough. If you like the turn in of the OEM setup you may want to seek out a linear spring with higher spring rates.

 

damn thanks for the answer that really clears a lot of question on top of my head. So if i understand this if i'm looking for springs that want a good drop and good comfort ride i would choose a spring that is linear correct agains thanks for al the info

 

another new C/O system:

Endura Tech Coilover package, ETC-NZ3500
10k front and 10k rear, $2211.00
The Endura-Tech Nissan 350Z coilovers feature a twin tube gas damper for steady handling, durability and excellent ride quality. They are a 10-way rebound adjustable gas shock for your driving demands and comfort level.

 

this might clear up some info about the cobb suspension...

yes the sways are made by hotchkis, supposedly the exact same as their newest versions (welded collars). however I have seen some discrepencies from post saying the sway bar rates a smidgen different...I chalk that up to margin of error as they're within a few %'tage of each other.

and as for the springs and the questions regarding which Z-gen the springs were designed for, it was developed from a newer Z, so it should be 15% stiffer f/r compared to the revised suspension on the Z.

I found this from my350z:

"the Hotchkis and Cobb sways are the same thing

the Cobb springs are stiffer than Hotchkis, since Hotchkis was designed around pre 04.5 cars and Cobb was designed on a later model (which have different struts)"


UPDATE 09-02-08
just received mine today, did some quick spring calcs for the info below, please note, the measurements do not take into account the material type, so these are rough estimates at best, make the same measurements with OEM springs for a comparison:

Front
wire diameter = .55-in
mean coil diameter = 3.95-in
free coils = 5
Using this it measures 436-lbs/in

Rear
wire diameter = .60-in
mean coil diameter = 4.465-in
free coils = 4
Using this it measures 535-lbs/in

Update 02-2009

thanks to some fact finding from some my350z members the newest spring rates for the Cobb spring rates are as follows,
Front 345 Rear 438

 

Hi, while were on the subject of Hotchkis springs, Ive checked out their site and X checked twice and they quote! 350z and 03 g35 coupe have the same part Nos and the same drop specs and spring rates, cant work that one out! confused, as I can pickup a new set at a good price, Im only after a modrate drop. Can anyone HELP with correct specs or check their web site and confirm maybe. Thanks for any Info guys Regards G.T.

 

Major updates to the first 3 pages.

 

I shouldnt have any issue running these from a 350z on my 04 coupe right?
what exactly does it mean that the free length is different? when the spring is not compressed it is longer than a g35 spring would be?
thanks

 

It should mean that on the G35 coupe application that the rear springs are slightly longer to give that car rear drop range is more in line with it's higher overall oem ride height vs the 350Z.

IMO however, pick a different coilover product. Contact Adam at z1auto.com and tell him what you want out of your suspension and your budget, he is a sponcer on my350, here's a pm link http://my350z.com/forum/private.php?do=newpm&u=11322

 

I actually already bought a set for 850.00 shipped! and after looking at the specs it looks like the 350z is 200mm spring and the g35 is 220 and 230

 

I'd hope it wouldn't be too late to cancel or return, but,....sigh.

Having a longer spring in the front doesn't make as much sense since doesn't that setup have full height adjustablity? If thats not the case, then that would make sense.