No more guessing, thanks to member T_K who send me the springs to test. We now know the spring rates for the Nismo Z.

Nismo Z (2007-2008) linear front progressive rear
Spring rates 492/336-672

Some interesting facts about the numbers.

Nissan said, the rates were 35% stiffer. Both the front and rear math out to be 57% stiffer vs 04.5+ oem.

Wheel rates: The amount of spring that actually makes it to the wheel to perform work. Spring rate is listed first, then the wheel rate is shown.

2004.5-2008
Front 314= 149
Rear 427= 180

Nismo Z
Front 492= 233
Rear 672= 283

^If you math out the front to rear rate bias, the two setup's have the same rate spread percentage front to rear, about a 22% bias to the rear. Which is not a tuning method I agree with once we start talking about rates that are higher then the oem baseline.

Nissan Motorsports T2 springs
Spring rates 616/672

Wheel rates
616= 292
672= 283

^Notice the rear rate is the same as the peak rate on the Nismo Z.

 

^ Cool. Thanks for doing the work. Have you had a chance to drive a Nismo Z yet? You think the 35% stiffer is based on a 03 Track model?

 

i thought that the newer z(hr) had higher springrates ~ closer to 35% of the nismo.

 

Thanks. Not sure what all the technical stuff means but interesting read.

 

the HR doesnt get new spring rates.

Its the 04.5 and up that have the revised spring rate iirc

 

Very nice!! i'm happy I'm going with HKS Hyper Max 3 Sport with 12K rates..

The non sport would have been to soft.

 

Stiffer doesn't mean faster or better.

Terry

 

having a nismo and having upgraded to the hypermax 3 sport, please let me disagree (in regards to the HM 3 sport)
than I can agree on the statement by itself.

it's curious the hypermax 3 sport rates...

F 616
R 672

 

Not to speak for him, but weren't all 03-04.5 at the same spring rate (which wasn't as stiff as 04.5+)? In that case, the difference would be even greater.

 

Thanks for the numbers.

All in all the Nismo really doesn't give a much stiffer ride compared to a regular Z IMO. I guess this may be contributed to the progressive rear, improved shocks and added dampers.

 

I understand that, I want to be able to take my car to the track and drive it on the street.

non sport HM3 is only 500 and I want to keep the rear at 600 or more.

 

HM3S are going to be decent on the street if you keep the shock adjustment "reasonable"... (I'm 8 click from full stiff front and 10 from full stiff rear)

on the track they are quite good (for the price).

 

Agreed. The ride is lots better than my 03 Track 350Z from the factory.

 

Damn, really? I have the Hipermax 3 Sports and at 15 rear/15 fronts, they are pretty bumpy to me. It must be because I STILL haven't adjusted the rear shock lengths after I dropped it via the spring assembly

Now that I think of it, the ride was much better before I dropped it. And considering that the fronts are shock-body adjustable, it must be because of the rears.

Did you adjust the shock lengths of the rears? I tried it once, couldn't break the collars on the shock free (they were very tight, and the swiveling shock doesn't help), and gave up. Been lazy every since

 

is the ride height of the nismos the same as 350z's?

--nevermind same height just found out

 

S...what are some replacements that will give the same spring setting...or even more stiffer?

 

^^^

Would also like to know which springs might be comparable to the stock ones so that I can lower the car, but not wear out the shocks.