How Do I Tell What My Spring Rates Are?

[Sydneykid]

Hey, Can u please calculate my spring rates?

Figures as follows..

FRONT

155mm inner diameter

14mm wire diameter

3.8-3.9 coils

REAR

125 outer diameter

10.75 coils

13mm wire diameter

5 Sacraficial coils

Thanks Steve

Front = ~240 lbs/inch (4.3 kg/mm)

Rear = ~130 lbs/inch (2.3 kg/mm) on the soft rate and ~295 lbs/inch (5.3 kg/mm) on the high rate

cheers

[Simonster]

260 lbs /inch (4.6 kg/mm)

cheers

Thanks Gary,

I guessed they were around 5kg, just ordered some 4kg's.........this will suffice until your S13 Track kit comes out

Edited May 6, 2007 by Simonster

[Hotwire]

Hi Gary,

Can you tell me the rate of these coils (attached in pic)

Fronts are

98mm ID at the large end, 10mm dia coil

67mm ID at the small end, 14mm dia coil

9.25 turns

Rears are

102mm ID at the large end, 11mm dia coil

88mm ID at the small end, 13mm dia coil

10 turns

[Hotwire]

Hey Gary,

Would really appreciate some help with the above springs, cheers!

[Hotwire]

Edited May 21, 2007 by Hotwire

[sun33]

so wich spring rates are stefner guys[6,7,8]

i realy need to get hard ones at the rears..

cheers.

Edited May 24, 2007 by sun33

[GTRNUR]

Hi SK.

These are the coils i'm considering for my R33 GTR.

Fronts

Coil ID = 97/70 mm

Wire OD = 12.7 mm

# of Coils = 8.5 turns

Rears

Coil ID = 103/91 mm

Wire OD = 12.7 mm

# of Coils = 7.5 turns

Bilsteins coils.

Can you give me the rate in KG too please.

Edited May 28, 2007 by Vspec R33

[Sydneykid]

Hi Gary,

Can you tell me the rate of these coils (attached in pic)

Fronts are

98mm ID at the large end, 10mm dia coil

67mm ID at the small end, 14mm dia coil

9.25 turns

Rears are

102mm ID at the large end, 11mm dia coil

88mm ID at the small end, 13mm dia coil

10 turns

The front soft rate is around 185 lbs/inch (3.3 kg/mm) (they would never run at that rate, the top 4.5 coils would sit on each other and it would be at the high rate all the time)

The front high rate is 650 lbs/inch (12 kg/mm)

The rear soft rate is around 115 lbs/inch (2.0 kg/mm) (they would never run at that rate, the top 4.5 coils would sit on each other and it would be at the high rate all the time)

The rear high rate is 350 lbs/inch (6.3 kg/mm)

cheers

[Sydneykid]

Hi SK.

These are the coils i'm considering for my R33 GTR.

Fronts

Coil ID = 97/70 mm

Wire OD = 12.7 mm

# of Coils = 8.5 turns

Rears

Coil ID = 103/91 mm

Wire OD = 12.7 mm

# of Coils = 7.5 turns

Bilsteins coils.

Can you give me the rate in KG too please.

Front = 245 lbs/inch (4.4 kg/mm)

Rear = 195 lbs/inch (3.5 kg/mm)

cheers

[Hotwire]

The front soft rate is around 185 lbs/inch (3.3 kg/mm) (they would never run at that rate, the top 4.5 coils would sit on each other and it would be at the high rate all the time)

The front high rate is 650 lbs/inch (12 kg/mm)

The rear soft rate is around 115 lbs/inch (2.0 kg/mm) (they would never run at that rate, the top 4.5 coils would sit on each other and it would be at the high rate all the time)

The rear high rate is 350 lbs/inch (6.3 kg/mm)

cheers

Wow,

Well that's a bit higher than I was expecting for the fronts!

Got them in the car on the weekend with new KYB shocks, and it handles beautifuly. I would expect it to be harsh with this rate but its fantastic.. not sure why but feels really good.

oh well, can't complain lol

[Sydneykid]

Wow,

Well that's a bit higher than I was expecting for the fronts!

Got them in the car on the weekend with new KYB shocks, and it handles beautifuly. I would expect it to be harsh with this rate but its fantastic.. not sure why but feels really good.

oh well, can't complain lol

It is always a bit difficult to rate tapered wire coils, to be perfectly accurate you have to know the amount of taper over the full length of wire. Or test them on a spring rate tester. That's not very easy to DIY. The rates that are calculated are the lowest posssible (assuming maximum taper) and the highest possible (assuming the minimum taper).

cheers

[Hotwire]

Excellent, thanks for the help

[Scandrew]

Hi Gary,

A few 'on the car' measurements I managed to get. I find them a bit too harsh for Sydney streets.

Front:

Coil ID = 64 mm

Wire OD = 11 mm

# of Coils = 7 turns

Coil length = 180mm

Spring rate =

Rear:

Coil ID = 64 mm

Wire OD = 11 mm

# of Coils = 8 turns

Coil length = 200mm

Spring rate =

Rear springs:

Edited July 12, 2007 by Scandrew

[jimmmy]

Hey mate

I am not sure if this in your area of expertise but I am looking at grabbing a set of King Springs

The part number is KPS-101-X5K

As you probably know they go up by 25lb from 200lbs to about 1000lbs

Anyway. I want to run these in the front of a datto 1600 on r31 struts. The car will weigh approx 1000-1100kg with me in it.

What is a good spring rate for this car used on the street with KYB uprated shocks giving a firm yet comfortable ride? I think hub height to guard is about 330mm if that helps at all.

I have been told 200lbs is a good rate.

Any help would be most appreciated.

cheers

James

[Sydneykid]

Hi Gary,

A few 'on the car' measurements I managed to get. I find them a bit too harsh for Sydney streets.

Front:

Coil ID = 64 mm

Wire OD = 11 mm

# of Coils = 7 turns

Coil length = 180mm

Spring rate = 375 lbs/inch (6.7 kg/mm)

Rear:

Coil ID = 64 mm

Wire OD = 11 mm

# of Coils = 8 turns

Coil length = 200mm

Spring rate = 315 lbs/inch (5.5 kg/mm)

Rear springs:

[Sydneykid]

Hey mate

I am not sure if this in your area of expertise but I am looking at grabbing a set of King Springs

The part number is KPS-101-X5K

As you probably know they go up by 25lb from 200lbs to about 1000lbs

Anyway. I want to run these in the front of a datto 1600 on r31 struts. The car will weigh approx 1000-1100kg with me in it.

What is a good spring rate for this car used on the street with KYB uprated shocks giving a firm yet comfortable ride? I think hub height to guard is about 330mm if that helps at all.

I have been told 200lbs is a good rate.

Any help would be most appreciated.

cheers

James

Hi James, do you want a comment on Kings springs? If so, they are OK, nothing special. Or a recommended rate? If it's a recommended rate then I need to know a few things;

1. What tyres, normal road tyres, R type tyres or full slicks?

2. What stabiliser bar rates?

3. What do you mean by " KYB uprated shocks", are they 1600 shock "uprated"? Or are you considering them "uprated" because they are for a R31?

4. What alignment settings are you intending to run at 330 mm? ie; have you done anything about the camber change when you lower it, or the bump steer? Because if you haven't then you will need ot make the springs excessively harsh to avoid those problems.

Easy question, not so simple to answer correctly.

cheers

[Scandrew]

Gary,

Thanks for the calculations!

I've decided to go with your recommended street spring rates and ordered a set of King Spring coils 4kg/3.5kg to replace my current Zeal springs which I believe are 6kg/5kg according to their catalogue.

Going to install them today.

Hoping the ride is much more streetable afterwards.

Cheers,

Andrew

Edited July 14, 2007 by Scandrew

[bdz]

Hey mate new to SAU :lol: Just wondering do I have to take of my springs? If so, is it hard? Ta

[Sydneykid]

Hey mate new to SAU :lol: Just wondering do I have to take of my springs? If so, is it hard? Ta

Nope, check out page 1 of this thread, it tells you how to measure on the car.

cheers

[clkngezz]

does the spring rate have to suit the car for eg, i have a r33 gtst what is the rate on stock springs? what would i be looking to get if i were to get coilovers? would it be the same spring rate as stock? and does springrate stiffen/soften ur ride,