eddiebrock71

iTrader: (1)

I have a 2008 Z. I want to improve handling. I only want to run linear springs. I wanted a .75 inch drop, with some spring rates that were like 400/500, but the only thing out there are cobbs, and the rear is lowered more then the front, I like the rake. and also the front springs do not seat perfectly on the spring perches.
Who makes custom springs, can I get them from like Eibach or H&R, or somebody?
Or if I stay stock how would it be to go with H&r swaybars or cusco swaybars. Would the cuscos give oversteer, or neutral.

those are the only two sway sets i like so far, i do not want poly bushings, always had problems with them.

What are your thoughts.

Gsedan35

iTrader: (10)

I can make you the following setup, but you cannot have more then a .5" drop and it will not ride as well as other (coilover) choices. From experience, bail on using that much rear spring rate.

Koni shocks
Custom 6061 lower shock mounts $35 material + machine shop time
Tein tapered springs 448lbs in rate $160 (CANNOT be used without custom mount above and only with Koni or Bilstein shocks)
Revised oem rear springs (04.5-08) 427lbs in rate ($70)
Oem upper spring seats cut down .5"

If you must have a 500lbs rear spring and I really don't recommend it, go to ebay, search 350Z coilovers, look for the $160 coilover spring kits (add $40 shipping) and use only the rear springs and rear adjustable seats, throwing the other parts in the trash, spring rate is 500lbs.

You can read owner comments about the setup here, I sold the parts to him. It's a SPL camber arm install thread, but he does comment about the suspension I sold him.

https://my350z.com/forum/brakes-and-...pl-a-arms.html

huyrua

iTrader: (30)

Try swift springs. It's linear and give you the same drop you wanted.

eddiebrock71

iTrader: (1)

I was looking at those spring rates, I dont think they are too high. according to specs they are still softer then Nismo S-tune, NISMO Z, and Cusco.

I can use the NISMO s-tune shocks or NISMO Z shocks, or get some revalved Bilstein. The only reason I am hesitant on the NISMO s-tune is due to it being progressive springs.

As for the Swift springs, the rear rates are low. Right now on my 08 the rear springs are 427lbs. So without going through the expense I could just get the RSR down for .6 drop and get 345/417 spring rates. But I was looking at a closer to NISMO specs.

drifter5

Whiteline springs. 365/445 spring rates.
F/1"
R/1.2"

I know it might not be the drop that you are looking for, but these springs are the stiffest linear springs with the lowest drop.

PaulyG

In terms of an inexpensive upgrade that in fact improves the handling, I installed the Hotchkis sways on friday and took the car to Watkins Glen yesterday. The improvement was excellent. Ride height wont change of course but if its a handling improvement that you want with the stock springs I recommend it.

Gsedan35

iTrader: (10)

1. As I said, I dont' recommend that much rear spring rate, not on a 400 or 450 front rate. Cusco coilovers do not have a high rear rate bias, 560/392. As is the case in a lot of instances, I am speaking from the experince of having been their. I have run 448/500, it was not a pleasant or productive experiance vs 448/427 or 448/375 or 448/358 or 560/500 or 560/448 or 560/427 or 650/427. Have a lot more to say on this, I'll stop here.

2. You can't run the Ten tapered spring I mention on the front Nismo or S-tune shock nor can you find a spring with the rate you want in the aftermarket. Revalved Bilstein H.D.would be a better choice then the Koni's I mentioned if your after less of a compromise on ride comfort, provided your conversation with Bilstien on how you want them revalved is a very informed and CAREFULL conversation. The front springs on the Nismo Z are linear, rears are absolutely progressive. The front springs on the S-tune are progressive, but with only prehaps one coil to bind to effect rate change, the differance between min and max front spring rate is not enough to have negitive effects, which is why I don't harp on Kw's front spring choice but loathe their wide rate progressive rear spring choice.

3. Swift was non starter choice from the beginning. You can get what you want by simply buying a used Nismo Z suspenison and swap out the rear progressive springs for the Ebay kit I mentioned, though I'd switch to a 5.5" OD 9.5" tall Eibach ERS spring 425lbs in rate.

eddiebrock71

iTrader: (1)

I like the way my z sits stock, only other choice would be to do a moderate lowering of 1/2 inch. Maybe the swift sport springs, with Bilsteins revalved for them. And maybe the cusco or H&r sways.

eddiebrock71

iTrader: (1)

Why softer spring rates then front. doesnt the higher rear spring rates help reduce understeer.

Gsedan35

iTrader: (10)

Because you are better served by getting the car's front tires to perform getter levels of work. And the car's very weak oem VLSD. The other side of the coin is that these car's have a large amount of anti dive and anti squat geometry designed into them that effects the cause and effect surrounding basic tuning logic. This is why Ohlins, Cusco, and Unitech Racing (the Grand Am race car team that did the R&D for the Truechoice coilover system) all went with a lower rear rate bias. Find the first thread that brings up the truechoice coilover and read the first few pages. Your of course absolutely free to do what you want, but having run so many rate combo's. I totally agree with the three product examples above and why.