Zanardi springs picture request

[goldNSX]

Maybe I just too lazy to search the hole board but I'd like to see some pics of NSX's with Zanardi springs and Bilsteins (upper or lower perch) or Koni installed with an emphasis on the distance between the tire and the fender.
Background: I'm going to cut perches on the Bilsteins to match the ride height to the Eibachs and like to know where the perches have to be cut.

Thanks in advance,
Thomas

 

[stephenti]

The Zanardi spring rates are linear... as ghetto as it sounds, you're almost better off simply cutting the springs themselves. Either way, you are losing damper travel, but no more than if you used Eibach springs.

Stephen
1stephen1.com

 

[goldNSX]

Hi Stephen,

I would never cut a spring as the springs characteristics are changed. It's like drilling a fifth hole in a 4-hole wheel as I've seen on prime: unsafe an crazy.

The Zanardi spring rates are linear... as ghetto as it sounds, you're almost better off simply cutting the springs themselves. Either way, you are losing damper travel, but no more than if you used Eibach springs.

Stephen
1stephen1.com

 

[stephenti]

Not true... what is unsafe about cutting a LINEAR SPRING RATE to slightly shorten length?

As I've previously mentioned, it is a "ghetto" mod... but, a shortened linear rate spring is no different than if the spring was drawn shorter... rates do not change. Put a Zarnadi spring vs. a .75"-cut Zarnadi spring on a damper dyno, and you will still get linear readings with a very slight increase in rate across the board.

If it is a progressive spring, then you get into all kinds of problems because you can land anywhere along the rate curve.

I have never cut springs for my own use. But the question posed offered the alternative of cutting the spring perch on the damper. Well, I assure you, cutting and rewelding the spring perch is not favorable to cutting the springs on a linear spring rate spring. Why? 1st, in either case, you are not increasing the damper travel, so there is not advantage one way or another. 2nd, cutting and re-welding on a damper body is not good due to heating and cooling of weld spots on the damper body... and unless you are very assued of your welding skills, I'd soon trust the factory welds over home-brew.

Again, the proper way would be the buy a spring that is already at the right height. But, cutting a LINEAR RATE SPRING to gain a small drop does not pose any issues, and I would certainly suggest that over cutting and re-welding spring perches...

Stephen
1stephen1.com

 

[goldNSX]

True or not true I'm really indifferent about that! I described the way I will definitly go and I just like to see some close-up pics of Zanardi springs gaps if someone could supply them.

 

[stephenti]

Just trying to give you some advice, man. Here you go... Zanardi and Koni setup courtesy of Jadkar...

Stephen
1stephen1.com

 

[goldNSX]

Thanks again for the pics. The front needs to go down by another 2 cm/0.8 inch and the rear too to match the Eibach look. What I'm wondering about is the front/rear drop of the Zanardis. I thought the front is dropped a little bit more than the rear or has the rear been modified?

 

[Jin1976]

I think deflection of springs also depends on the number of coil it has. :smile:

 

[Hapa88]

Not true... what is unsafe about cutting a LINEAR SPRING RATE to slightly shorten length?

As I've previously mentioned, it is a "ghetto" mod... but, a shortened linear rate spring is no different than if the spring was drawn shorter... rates do not change. Put a Zarnadi spring vs. a .75"-cut Zarnadi spring on a damper dyno, and you will still get linear readings with a very slight increase in rate across the board.

If it is a progressive spring, then you get into all kinds of problems because you can land anywhere along the rate curve.

I have never cut springs for my own use. But the question posed offered the alternative of cutting the spring perch on the damper. Well, I assure you, cutting and rewelding the spring perch is not favorable to cutting the springs on a linear spring rate spring. Why? 1st, in either case, you are not increasing the damper travel, so there is not advantage one way or another. 2nd, cutting and re-welding on a damper body is not good due to heating and cooling of weld spots on the damper body... and unless you are very assued of your welding skills, I'd soon trust the factory welds over home-brew.

Again, the proper way would be the buy a spring that is already at the right height. But, cutting a LINEAR RATE SPRING to gain a small drop does not pose any issues, and I would certainly suggest that over cutting and re-welding spring perches...

Stephen
1stephen1.com

Cutting a Linear Rate Spring will increase its overall stiffness because of physics. The equation for the k constant of a spring is as follows:

k=(Gd^4)/(8nD^3)

where k=constant
G=modulus of rigidity of spring material
d=diameter of the wire
n=number of coils
D=mean coil diameter

therefore, by decreasing "n", with all other parameters being the same, the "k" constant will increase.

 

[goldNSX]

Thanks for the math, Adrian.
BTW, the Bilstein's are on their way to Bilstein Germany for revalving and the Zanardi springs come from SOS. I'll keep you informed.

 

[MJK]

These are Zanardi/Koni: