I would like for some one to explain to me why a G35 owner will prefer to buy a 350Z OEM spring unrevised instead of a revised spring. I assume that the revise spring would be better than the unrevise since it has a higher rate in the rear, therefore is stiffer, stronger and will put less stress in the factory shock.

The reason why I am asking is because I am selling revise 04 350Z springs and a guy that owns a G35c called me and told me that the unrevise spring is better for a G35 since the revise spring will bust the factory shock.

To me that doesn't make any sense as I would think it if anything it should be the other way arround the higher the rate the better it is for the shock.


I am no expert on the subject so please any input will help me understand if I am right or wrong.


Specs:

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

Oem springs 350Z 2004.5/2005 (found 04 car's that have the revised susp.)
Front:314 Rear:427

 

There are two components to the operation of a shock absorber and spring. Those components are "compression" and "rebound". The shock absorbers are "valved" to respond to both of these components, so what you have to look at is what a change in spring rate does to each.

When you hit a bump, two factors determine how much the suspension will travel (and conversely, how much of the bump is transferred to the frame of the car. The spring is going to compress at the rate determined by a)the tire traveling over the bump, and b)the valving of the shock. The stiffer the spring, the less the bump is absorbed by the valving in the shock. This "compression stroke" supports your understanding that a stiffer spring is better for the shock. But you have to look at the "rebound stroke" as well.

Once it's time for the suspension to return to its normal geometry, the spring and the valving of the shock again work together. The stiffer the spring, the more strain is placed on the valving because the spring is more aggressively trying to extend the shock to get the tire back on the road.

I'm not sure how the valves in the shocks of the G35 are set (if they are different compression and rebound settings), but it's possible that the stiffness of the "revised" springs exceeds the prescribed rebound rate of the shock, and could therefore cause problems.

Hope that helps.

 

Thanks alot for your help!!!

 

I own an 05 G35 and I have heard that the 350Z springs are stiffer (better for corners, not ride quality, hence the above mention valve spring rate comparison). I personally dont need them because my 05G had the sports suspenion with the 19 inchers. I believe that the G35 sport suspension has the rates equal to the touring Z... may a bit more?? , if that guy has a touring version G, then he is riding on Sharman style springs (super-soft)....lol Consider the functions of the cars...G's are for lux and Z's are for sport/track. So even a touring Z sring rates would exceed the G sport package rates....A google search could confim or correct me...lol My 2.5 cents brother.

 

Thanks for the info, very helpful.