Suspension Question

[Touge Kyousou]

http://www.mobilealloywheelrepairs.com.au/

OR

Goto local auto parts store, buy a can of spray paint gloss black. Shake can and spray into a small container, use a fine brush to collect some paint from container and then paint over rashed area on wheel.

The first option should have your wheel looking like new. Heard a few good things of those guys from other forum members who have used them.

[Frank350GT]

http://www.mobilealloywheelrepairs.com.au/

OR

Goto local auto parts store, buy a can of spray paint gloss black. Shake can and spray into a small container, use a fine brush to collect some paint from container and then paint over rashed area on wheel.

The first option should have your wheel looking like new. Heard a few good things of those guys from other forum members who have used them.

Hi Touge.

Appriciate for your post.

I will go for the second option as my wife also drive it, ( Which mean where will be more and more scratch infuture).

Thanks a lot.

Cheers

Frank

[Sydneykid]

In order to understand what a particular spring rate means to ride (what you feel) and handling (what the tyre feels) you need to know the movement raito and the leverage ratio of the spring to the wheel. In Z33, V35 and M35 they are both around 1.1 for the front and 2.0 for the rear.

This means a 12 kg/mm front spring rate = an effective rate of 10 kg/mm

And a 8 kg/mm rear spring rate = an effective rate of 2 kg/mm

As a rule of thumb, nice ride and good handling, requires an effective spring rate balance that is close to the weight distribution. So a weight distribition of 60% front and 40% rear should have corresponding spring rate spread. It's pretty obvious that 10 and 2 kg/mm are not really suitable effective spring rates for a car with 60/40 weight distribution. If 12 kg/mm (10 + 2 = 12) is a suitable total rate, then the distribution would be far superior at 7/5. (ie; 7 / 12 = 58%). The car would both handle and ride better with that combination. Generally speaking in a front engine, RWD car, I would specify slightly higher front spring bias, so around 7.5/4.5 (63/37) would be where I would start.

Dampers do not affect how the spring holds up the car's weight and how it absorbs impacts. Changing the damper rate makes no difference to how much the spring compresses under load. What damper rates can do is change the timing, more damping = a longer time for the load to take effect. That can be bump (compression) or rebound (extension). Simplistically, when a car hits a bump the spring compresses to abosorb that impact, a damper with a high bump (compression) rate will slow down how long the spring takes to absorb the bump. Too much bump damping means there isn't enough time for the spring to deflect, the bump is thus not absorbed and the impact is passed into the chassis and hence you. Conversely excessive rebound (extension) damping mean the recoil of spring after it absorbs the impact is delayed. In some cases that means the next bump is hit before the spring returns to it's full height and is therefore unable to absorb the next impact.

Cheers

Gary

[mosoto]

In Z33, V35 and M35 they are both around 1.1 for the front and 2.0 for the rear.

This means a 12 kg/mm front spring rate = an effective rate of 10 kg/mm

And a 8 kg/mm rear spring rate = an effective rate of 2 kg/mm

Not being a smartass just curious as to how that formula works?

If 12kg/mm X 1.1 = 10.9kg/mm then

8kg/mm X 2.0 does not = 2kg/mm

have I assumed that incorrectly?

[Sydneykid]

Not being a smartass just curious as to how that formula works?

If 12kg/mm X 1.1 = 10.9kg/mm then

8kg/mm X 2.0 does not = 2kg/mm

have I assumed that incorrectly?

There is a movement ratio and a leverage ratio to be considered, hence 8 / 2 (movement ratio) = 4 / 2 (leverage ratio) = 2

Cheers

Gary

[Frank350GT]

As a rule of thumb, nice ride and good handling, requires an effective spring rate balance that is close to the weight distribution. So a weight distribition of 60% front and 40% rear should have corresponding spring rate spread. It's pretty obvious that 10 and 2 kg/mm are not really suitable effective spring rates for a car with 60/40 weight distribution. If 12 kg/mm (10 + 2 = 12) is a suitable total rate, then the distribution would be far superior at 7/5. (ie; 7 / 12 = 58%). The car would both handle and ride better with that combination. Generally speaking in a front engine, RWD car, I would specify slightly higher front spring bias, so around 7.5/4.5 (63/37) would be where I would start.

Not being a smartass. But base on what my understand:

On the basis of movement ratio and a leverage ratio

8 / 2 (movement ratio) = 4 / 2 (leverage ratio) = 2

What I have currently

F 8kg/mm /1.1 (leverage ratio ) /1.1 (leverage ratio ) = 6.61 ( effective rate )

R 6kg/mm / 2 (leverage ratio ) /2 (leverage ratio ) = 1.5 (effective rate )

Total is 6.61+1.5 = 8.11

Weight distribution is : 81/19 F/R ????

Put on reverse:

If we start with Here:

Generally speaking in a front engine, RWD car, I would specify slightly higher front spring bias, so around 7.5/4.5 (63/37) would be where I would start.

It will end up with 9.07/ 18 F/R

I doubt any one will put 18 kg/mm spring on there V35.

Back to factory ( ref: http://g35driver.com/forums/brakes-suspens...w-updates.html)

F 314 = 259.5

R 342 = 85.5

259+85.5=345

Distrubution: 75/25 F/R

Totally confused

Frank

Edited July 8, 2009 by Frank350GT

[Sydneykid]

No problems Frank, questions are always welcome;

From the same web site;

Oem linear springs

G35 coupes 2005/2006 with oem 19's only

350Z 2004.5 to 2006 (revised suspension)

Front:314 Rear:427

314 = 260

427 = 107

260 + 107 = 367

70 + 30 = 100

Not bad (70/30) for a 350Z (2 seater) but a bit light on for rear spring rate in a 4 seater with a longer wheelbase.

I should mention that I haven't had a V35 on the corner weight scales, so the 60/40 was a guess based on 350Z's. All I was attemtping to point out was;

1. Comparing front and rear spring rates without knowing the movement and leverage ratios is a waste of time

2. The current aftermarket springs for V35's are not terribly suitable for V35's as they appear to have been designed for 350Z total weight and weight distribution. Understandable considering the comparative numbers of 350Z's and their sporting bias.

3. Nissan set up the V35 to understeer, hence the lower than ideal (for handling) standard rear spring and swaybar rates.

4. If you are interested in handling then the V35 rear spring and swaybar rates are more in need of upgrading than the front spring and swaybar rates.

#2 is the important one for this discussion.

Cheers

Gary