stascom

The rear Eibach springs don't work with those links. Need 2.5" springs. Should I piece the shocks and springs separately or just get the kit and an extra set of rear springs that match Eibach? What would be a good match?

Thank you!

MicVelo

Check with SPL on this. I seem to recall reading something on their site about spring recommendations or calculating what you may need for your application, be it street, track, auto-x, etc.

As a suggestion, the other thing you can do after you determine what type of springs are needed for the rear-mid-link, get a matched set F&R (example, a 2.5" Swift in the spring rate needed for the rear and another pair of mated Swifts for the front.)

Then.... Buy the B12 for the shocks alone - still cheaper than a la carte - then sell the ProKit spring set complete. No one wants half a spring set. And, this helps to offset the cost of the springs you NEED to work with the mid-link.

Frostydc4

iTrader: (3)

I'm pretty sure Eibach will sell you a 2.5" ID spring in any spring rate and length you want.

MicVelo

stascom

went ahead and ordered the B12 kit.
Now, finding specs on the Eibach springs is a chore.
Best I could do was find this list:

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Oem spring rates 2003-2004 350z unrevised suspension
314/342

Oem spring rates 2004.5-2008 revised suspension
314/427

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

All other known 350Z aftermarket springs

RSR 350Z linear springs .6”/.6”
Spring rates in LBS 345/417

Hotchkis 350Z Linear springs .6”/.8”
Spring rates in lbs 340/330

Tein S-tech 350Z springs .7“.6“ (fronts are slightly progressive, rears are linear)
Spring rates in LBS 386/402 (estimated front intial rate is 327lbs)

Tein H-tech 350z linear springs .3”/.2”
Spring rates in LBS 358/375

Progress Technology progressive springs 1.0”/1.0”
Spring rates in LBS 425/385 (final rates only, softer intial front progressive rate unknown)

Tokico D-spec shock & spring package
350Z - DSK512 - 375f/375r - Linear Springs 1"/1.5"

Tanabe GF210 Series 350Z progressive springs 1”/1.2”
Spring rates in LBS 336/375 (only peak rates are published, softer initial progressive rates unknown) Not much stiffer vs oem, IMO Eibach prokit is a better choice because of that springs higher spring rates which should help keep you off the bumpstops more often.

Tanabe NF210 Series 350Z progressive springs 1.2”/1.2” higher
Spring rates in LBS 314/353
Little to no increase in spring rate over oem, little to nothing added to keep you off the bumpstops

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

Swift 350Z Spec-R progressive springs 1.2”/1”
Spring rates in LBS intial/final Front: 291/392 Rear: 280/448

Nismo T2 350Z Linear springs 1”/1”

Spring rates in LBS 690/690
Way too much spring for oem shocks or Tokico D-specs, HP, GR2 or Bilstein Sport(unless revalved). Koni sports are debateable.

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

DR21 super sport 15mm drop
Spring rates in lbs initial/final front 246/398 initial/final rear 252/409
Very wide spreads between the softer initial rates and firmer peak rates.

Kg/mm DRacing progressive springs 1.2”/1.2”
Spring rates in LBS initial/final front 252/454 initial/final rear 252/482 rear
Very wide spreads between the softer initial rates and firmer peak rates.

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

Espelir 350Z progressive springs 10mm drop F&R
386/515 (softer initial progressive rates are unknown) {most often seen being resold by track guys that thought they were onto sonething based on the numbers}

H&R sport progressive springs 350Z 1.3”/1” drop
Spring rates in LBS 370/400 (peak rates only, softer initial rates are unknown)
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So Eibach Pros are progressive in front and rear. No idea how long they are. And I'm not sure how close I have to be to that rear spec to not screw up the dynamic with the fronts. I see some other sets (Tein, for ex.) have progressive front and linear rear. Maybe get a set of linears that are closer to the final rating of the Eibach rears?