I've been pulling together a list of springs/dampers that I've been interested in (no coilovers) for my suspension work and figured I'd post the summary of my research here as there isn't too much out there all in one spot for springs/dampers. Lots of good info on coilovers though, but they're out of my budget for the time being so didn't look at them. I'm going to assume whoever's reading this knows the difference between progressive and linear springs, ie:

--- From redlude97 ----

Both linear and progressive springs get stiffer the more you compress them, but a linear spring does it in a linear fashion because the springrate remains constant. A progressive spring a unevenly spaced coils, which have differing springrates, so the compression force exerted as the spring compresses changes in a nonlinear manner. As the lower springrate coils reach their maximum compression, the higher springrate coils begin to compress more or less, which alters the effective springrate and the force the springs can exert.

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The 2 most common dampers that I've seen (based on general observation) on the board are the Koni's and the Tokico D-Spec's (note: OEM & Nismo dampers are tokico rebranded, however, the Nismo are far superior to OEM and the D-Spec's fall in the middle; OEM > D-spec > Nismo).


----The following blatantly stolen from GSedan35----

Their are two different suspension's on the USDM 350Z. Nissan did a running change mid way into the 2004 model year. We refer to 03/04 car's that don't have the changes as "unrevised". And we refer to 04,5+ car's as having the "revised" suspension. The most significant change in the revision is what Nissan did to the tuning of the shocks. They reduced their compression dampning (stiffness on bump) and increased the rebound control (rate of return from bump) So, a 03/04 car will feel stiffer vs a 04.5 car, but the 04.5+ car will have little to none of the 03/04 car's famous bounce and porposing issues.

How Koni factor's into all this:
When Koni did their R&D work for the Z, they noticed all the compression dampning that the 03 car had and that it was lacking in rebound control. They made it a specific mission to have less compression dampning and to have more rebound control (also remember that Koni's dampning adjustability is for rebound only). So, a 03/04 car owner that switches to Koni's will have less stiffness from the shocks, but much better overall control via better valving. Vs 04.5+ car's, would not expect their to be a lot of differance stiffness wise, the Koni's will still deliver better valving.

On Tokico D-specs:
When the shocks first intro'd, I spoke with one of their techs. He explained that you could adjust the shocks to be softer then oem or to be slightly stiffer then oem. He was of course refering to car's with the original unrevised suspension. So when a 03 or 04 owner reports that at full stiff his D-specs are only slightly stiffer then oem, I totally understand.

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Below are the springs I've been pulling stats together for. Notated as:

Name (front rate/rear rate) front drop"/rear drop"

::Linear::

Stock Springs 2003-2004 models (314/342) 0"/0"

Stock Springs 2004.5+ models (314/427) 0"/0"

RS*R Ti2000 (345/417) .6"/.6"

Swift Springs (335/365) ~.6"/~.8"

Tokico's Springs (375/375) 1"/1" (Note: stiffest linear setup you can get outside of the Nismo T2 springs)

Hotchkis (340/330) .6"/.8"

Whiteline (365/445) 1"/1.2"

Nismo T2 (625/700) 1”/1” (Note: Tokico/Koni don't really support these well as the spring rates are too high)

::Progressive::

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

Nismo S-tune (twin tube construction, uses progressive springs)
350Z .8"/.8" drop
Spring rates 448 final/504 final

Tanabe GF210 Series 350Z progressive springs 1”/1.2” drop
Spring rates in LBS 336/375 (only peak rates are published, softer initial progressive rates unknown)
Stiffer then oem springs by F+7% R+10% (vs 03/04 unrevised suspension)

Tanabe NF210 Series 350Z progressive springs 1.2”/1.2” drop
Spring rates in LBS 314/353
Stiffer then oem springs by F+0 R+3% (vs 03/04 unrevised suspension)

As I was writing this I found a post by Gsedan35 which basically is what I was trying to pull together (you don't find what you were really looking for until the last post you read ... Damn you search feature!!!). I'll include here for completeness...

https://my350z.com/forum/showthread....ight=whiteline

*Any spring or coil over that has “stiffer then oem springs by” does not factor in the higher rear spring rates of 04.5+ oem

350Z’s

Tanabe GF210 Series 350Z progressive springs 1”/1.2” drop
Spring rates in LBS 336/375 (only peak rates are published, softer initial progressive rates unknown)
Stiffer then oem springs by F+7% R+10% (vs 03/04 unrevised suspension)


Tanabe NF210 Series 350Z progressive springs 1.2”/1.2” drop
Spring rates in LBS 314/353
Stiffer then oem springs by F+0 R+3% (vs 03/04 unrevised suspension)


Oem springs 350Z’s 2003/2004
Front:314 Rear:342


Oem springs 350Z 2004.5 to 2006
Front:314 Rear:427


Eibach 350Z progressive springs 1”/1” drop
Spring rates in LBS initial/final front 296/384 initial/final rear 316/421
F +22% R +23% (looking at peak rates only)


Eibach 350Z sportline progressive springs 1.2"/1.2" drop
Front: 239/400 Rear: 257/435


RSR 350Z linear springs .6”/.6” drop on 350Z
Spring rates in LBS 345/417
Stiffer then oem by F+10% R+22% (see note at very top)


Hotchkis 350Z Linear springs .6”/.8” drop
Spring rates in lbs 340/330
Stiffer or softer then oem springs by F+8% R-3% (see note at very top)


Tein S-tech 350z (fronts are progressive, rears are linear) .7”/.6” drop
Spring rates in lbs 386/402 (final rates only, softer initial front progressive rate unknown)
Stiffer then oem by F+23% R+16% (see note at very top)


Tein H-tech 350z linear springs .3”/.2” drop
Spring rates in LBS 358/375
Stiffer then oem springs by F+14% R+11% (see note at very top)


Tanabe GF210 Series 350Z progressive springs 1”/1.2” drop
Spring rates in LBS 336/375 (only peak rates are published, softer initial progressive rates unknown)
Stiffer then oem springs by F+7% R+10% (see note at very top)


Tanabe NF210 Series 350Z progressive springs 1.2”/1.2” drop
Spring rates in LBS 314/353
Stiffer then oem springs by F+0 R+3%


Swift 350Z linear springs .8”/.6” drop on 350Z
Spring rates in LBS 336/364


Nismo T2 350Z Linear springs 1”/1” drop on 350Z
DO NOT buy these springs!!!, insanely far too stiff for use with anything but revalved Koni shocks
Listed for information ONLY!
Spring rates in LBS 625/700


Vogtland 350z progressive springs 1”/1” drop on 350Z
Spring rates in LBS initial/final front 257/354 initial/final rear 285/422


Kg/mm springs 350Z
DR21 super sport 15mm drop
Spring rates in lbs initial/final front 246/398 initial/final rear 252/409


Kg/mm springs 350Z
DRacing 30mm drop
Spring rates in LBS initial/final front 252/454 initial/final rear 252/482 rear


Whiteline 350Z linear springs (control)
Front: Part # 73219,
Spring rate 365 LBS Drop: .8"-1" (will be higher on a G35)
Rear: Part # 73220
Spring rate 445LBS Drop: 1"-1.2" (will be higher on a G35)
(sold as 2 front springs and 2 rear springs)
www.whiteline.com.au/store/


Espelir 350Z progressive springs 10mm drop F&R
381/460 F+22% R+37%
New specs Macklin now shows as follows
386/515 F+22% R+50% (a lot of spring for oem shocks)
http://www.mackinindustries.com/md/e...coilsprings.pd


H&R sport springs 350Z (progressive springs* {I'd to like see a picture of the springs themselves)
1.3"/1" drop
no spring rate info H&R refuses to give it out, something that is critical to making a informed buying decision, buyer


Nismo S-tune (twin tube construction, uses progressive springs, especially in rear)
350Z/G35 Coupe
Spring rates 448/504
Stiffer then oem by F+43% R+48%

PS - If there is anything on here you don't see or want more info on, just search for something by GSedan35. I'm sure he's posted your answer somewhere.

 

Your definitions for linear and progressive springs could use a little clarification. Both linear and progressive springs get stiffer the more you compress them, but a linear spring does it in a linear fashion because the springrate remains constant. A progressive spring a unevenly spaced coils, which have differing springrates, so the compression force exerted as the spring compresses changes in a nonlinear manner. As the lower springrate coils reach their maximum compression, the higher springrate coils begin to compress more or less, which alters the effective springrate and the force the springs can exert.

 

Much better definition, edit. Thanks Redlude.

 

so what you guys are trying to say is linears are more predictable

by the way, why do you guys think that koni's and tokico's are the most used...or at least seen to be used on the site...

I myself am in constant search for the better spring as i can't find to justify coilovers...I know I'll never track...(maybe once...and even at that just to see what it's like) just want the aesthetic appearance more than track purpose...

thanks

 

Linear springs are definetly more predictable, and just about any true track setup uses linear springs, or very slightly progressive springs. They are also rougher overall for daily driving though, which alot of people are willing to deal with.

 

Great thread from about 1.5 yrs ago that discusses linear and progressive springs in some detail: https://my350z.com/forum/brakes-and-suspension/135564-linear-rate-vs-progressive-rate-springs.html

 

Now we just need to get some info down on the shocks and we'll have a nice chart going on.

 

so are the tanabes linear or progressive....i thought they were progressive but the info you posted says theyre both...unless tanabe sustec gf210 is different fro m the gf210 series...i thught they were the same

??

 

Insanely far too stiff? not even close... They're still too soft for me.

I've had the Nismo T2 springs with my OEM shocks, it was fine except for bouncing around over bumps and potholes and the fact that it has no preload so it rotates my springs every once a while over bumps.

I got my hand of TC Klines and finished installing the fronts today, going to work on the rears tomorrow. I did take it out for a drive, MUCH better than OEM shocks and still very tolerable for street. Separate compression and rebound adjustment is a bonus. Currently have the settings set to "Track/Autocross" recommended settings from TC Klines.

 

I had it pasted in the wrong section, fixed now.

 

oh okay thanks i was so lost when i saw that..

 

very nice write up man, i think i'ma go with the tokico's myself...

 

Good write up, how long were you saving all that info up? should help out. I'm doing eibach pk and koni sports, I think that'd be a nice combo.

 

G35sedan will be proud. TCKlines + T2 springs is an EXCELLENT autoX setup. For street use, I have tokicko spring/dampeners at 2 from full stiff on the front and 4 from full stiff in the rear. Still soft ride, slight understeer and very rpedictable. Much better than stock.

 

i love and hate this thread haha....i originally wanted gf210s not htinking about the progressive/linear aspect of them and when i read this i decided to research again and now i want to get a tokico setup since i plan to track some....but man from gf's to tokicos....thats like an extra 400bucks

great info though youve collected

 

i have the eibach pro kit, and its like my front right wheel is sinking under my fender (i have 20's)....however, my rears and my front right are not doing this....the difference isn't that noticeable and the ride feels "okay" but will shocks fix this? or is there something wrong with the spring?

 

No theT2 springs were not fine with oem shocks, way too much underdampning. You really should have known better then to run twice the spring rate. Even on oem springs they aren't the greatest shocks. I ran them for a week with 448lbs rates and they were patheticly inferior to Koni yellow's with the same spring. If your going to make real use of what you have now you've got to be a whole lot more honest with yourself. Everyone has to establish when they've reached the most productive spring rate level. What may be your ideal may be someone else's lower ET's because they can't keep the tires in contract with the pavement.

 

I'd be all over the TcKlines "IF" they had shortened bodies and piston rods. But, for just a little more I can get Truechoice Phase IV shocks with the same overall specs and they have the shortened bodies and piston rods that I have to have.

Glad to know you like the D-spec shock and spring combo. I was hoping running those springs with their shocks was the missing link. Those springs didn't work so well with Koni shocks as I've mentioned before.

 

Thanks for posting this. I have a question -- I have a 2003 350Z with the original unrevised suspension. Could I simply buy Nissan OEM shocks and springs from a revised edition (2004.5+) to get the suspension improvements? Or am I better off buying some aftermarket shocks? (I already have a set of hotchkis springs here, not yet installed).

 

Careful - this description makes it sound like these three completely different dampers are the same.