Hey guys I am thinking to swap my H TECHS for the ESPELIR GT springs cuz I like the idea of a higher spring rate, and i found this info in a different forum.
I would really appreciate some imput.

here it goes:

Where'd your idea of what the oem rates come from? Their on the low side, 4-5Kg of course equal's 224lbs-280lbs. The oem spring rates are in fact 314/342. When picking springs or coilovers for any FM platform vehicle, buyer beware, some products transfer a awefull lot of roll stiffness to the front.

The S-tune may have better valving in them, but you make a trade off with the progressive springs they use.

Oem spring rates
Front:314 Rear:342

Nismo S-tune (uses progressive springs, especially in rear)
448/504 F+43% R+48%
Transfers +5% roll stiffness to rear

Eibach's as noted (first number is the softer initial rate, followed by the higher final rate)
350Z 296/384 front 316/421 rear
G35c 229/337 front 274/463 rear
G35s 259/334 front 359/413 rear

RSR 350Z springs (just a wee bit progressive F&R, maybe one coil is progressive, but not actually looking at pics of the springs)
345/417 F+10% R+22%
Transfers +12% roll stiffness to rear

RSR G35 coupe springs (progressive front and rear)
315/315 F+0 R-8%
Transfers +8% roll stiffness to front

Hotchkis 350Z springs (linear springs)
340/330 F+8% R-3%
Transfers +12% roll stiffness to front

Tein S-tech 350z (fronts are progressive, rears are linear)
386/402 F+23% R+16%
Transfers +7% roll stiffness to front

Tein H-tech 350z (fronts are progressive, rears are linear)
358/375 F+14% R+11%
Transfers +3% roll stiffness to front

Tein H-tech G35 coupe & sedan(fronts are progressive, rears are linear)
324/260 F+ 5% R-22%
Transfers +27% roll stiffness to front

Tein S-tech G35 coupe & sedan (fronts are progressive, rears are linear)
358/274 R+14% R-18%
Transfers +32% roll stiffness to front

Tanabe GF210 Series 350Z
336/375 F+7% R+10%
Transfers +3% roll stiffness to rear

Tanabe NF210 Series 350Z
314/353 F+0 R+3%
Transfers +3% roll stiffness to rear

Tanabe NF210 Springs G35 COUPE
297/336 F-5% R-2%
Transfers +3% roll stiffness to front

Tanabe DF210 Springs G35 COUPE
308/353 F-2% R+3%
Transfers +5% roll stiffness to front

Tanabe NF210 Springs G35 SEDAN
297/269 F-5% R-21%
Transfers 17% roll stiffness to front

Tanabe DF210 Springs G35 SEDAN
286/280 F-9% R-18%
Transfers +9 roll stiffness to rear

Kg/mm springs 350Z
DR21 super sport 15mm drop
246/398 front 252/409 rear

Kg/mm springs 350Z
DRacing 30mm drop
252/454 front 252/482 rear

Espelir coupe springs (the U.S. importer recently changed specs, I do not believe the newly listed specs are correct, since the new one's are extreamly high. And when I called the company to ask if the springs are linear or progressive, they told me Linear, turn's out they were absolutley wrong, they are in fact progressive. I show the old specs for those reasons, take it with a grain of salt, same thing for the 350Z fitment)
409/460F F+30% R+37%
Transfers +7% roll stiffness to rear

Espelir 350Z springs
381/460 F+22% R+37%
Transfers +15% roll stiffness to rear


Tein Flex
672/672 F+114% R+98
Transfers +16% roll stiffness to front

Tein Flex JDM specs (can be special ordered est 6-8 weeks delivery)
560/560 F+78% R+64%
Transfers 14% roll stiffness to front

Tein Basic
504/504 F+61% R+43%
Transfers +18% roll stiffness to front

Tein CS (Monotube)
392/392 F+25% R15%
Transfers +10% roll stiffness to front


Posted by: jasonintoronto Aug 21 2004, 07:37 AM
wow - excellent information

Posted by: jkoc Aug 21 2004, 07:38 AM
outstanding info

Posted by: Gsedan35 Aug 21 2004, 02:45 PM
Your welcome, I somehow left off a whole page of specs, I ment to post the info below in my original reply.


Buddy Club Racing Spec coilover (Monotube)
748/280*
(very likely run's rear springs on the dampner body and not at the oem rear spring location)

Jic Flta-2 350Z fitment (Monotube)
560/672 F+78% R+98%
Transfers +20% roll stiffness to rear

Jic Flta-2 G35 coupe (Monotube)
560/560 F+78% R+64% $1750
Transfers 14% roll stiffness to front

Jic Flta-2 G35 sedan (Monotube)
504/392 F+61% R+15%
Transfers +46% roll stiffness to front

Cusco Zero 1&2
560/392 F+78% R+15%
Transfers +63% roll stiffness to front (no they do not run their rear springs on the dampner body, oem location, seen them on the car with my own eyes.)

HKS LS+ (rear springs are progressive)
496/440 +58%front +29%rear
transfers 29% roll stiffness to the front

HKS LS G35
448/336 43%front -1%
transfers 44% roll stiffness to the front

HKS LS 350z
448/448 43%front +31%
transfers 12% roll stiffness to the front

HKS II 504/504 +61%front +47%rear $1600
transfers 14% roll stiffness to the front

KW coilovers Variant's 1,2&3
Variant 3's are noteworthy as the only known coilover for these cars where the dampners are adjustable for compression and rebound independently. They also differ in using progressive springs front and rear
Front: 485lbs to 525Lbs Rear: 240Lbs to 548Lbs

D2 Racing Coilovers (Monotube)
840/728 F+168% R+113% (wee bit stiff eh, the recommended rate to)
Transfers 55% roll stiffness to front

 

Jesus, I believe GVice has the espelir springs and just had em installed. maybe hit up victor and see what he thinks about them??

 

Sorry dude..you got some bad info...I have the H Tech's

 

lol damn dude my bad!!

 

C' mon guys you can do better then that, need some advice!!!. Hey Devon got anything for me?

 

Jic Flta-2 350Z fitment (Monotube)
560/672 F+78% R+98%
Transfers +20% roll stiffness to rear