How Do I Tell What My Spring Rates Are?

[Sydneykid]

could be worse.... have you seen the sort of spring rates some of the japanese D1 drivers are using??

http://maxe.ausgamers.com/d1gp/imamura_.jpg

http://maxe.ausgamers.com/d1gp/maeda_.jpg

http://maxe.ausgamers.com/d1gp/suenaga_.jpg

18k / 16k.....     

anyway,  back on topic.

won't different materials have different densities?  If you are using the formula I think you're using,  you need to use a modulus of rigidity, which is different for different materials.

<{POST_SNAPBACK}>

All coil spring material (spring steel) is made to one of the 2 world wide standards, simplistically hot or cold winding. The end result (ie; the spring rate) is very similar once the finished product is normalised, tempered and or shot/peened. I have tested over a thousand coil springs in the course of business and the formula is very accurate. Most certainly accurate enough for this purpose.

As for the spring rates used in Japan, the Japanese have no real history of stabiliser bar upgrades. Not to the extent that we do with the KMac and Selbys history. Plus they seem to have no grasp of the art of shock absorber tuning like the Eurpopeans have. Add that to their bolt on mentality (good mechanics charge like brain surgeons) and it easy to understand why they rely excessively on spring rates to achieve what could be much better achieved usng other more sophisticated methods.

Since they all do it, they have no basis of comparison to realise that what they are doing is technically deficient. If drifting ever matures to the world stage they will quickly find that simplistically locking the suspension with rediculously high spring rates isn't a winning formula.

That said, they do a pretty god job with what they have. there is some skill that's for sure.

cheers

[neil_se]

My rates don't really surprise me, although the balance does. I'd guessed 10/8 or 12/10 but 14/8 is a fairly different rates front to rear. Might have to double check my coil numbers before the wheels go back on.

Do you think this might be part of my traction problem? :D

[Sydneykid]

My rates don't really surprise me, although the balance does. I'd guessed 10/8 or 12/10 but 14/8 is a fairly different rates front to rear. Might have to double check my coil numbers before the wheels go back on.

Do you think this might be part of my traction problem?  :D

<{POST_SNAPBACK}>

You don't really expect to have TRACTION with those spring rates. The tyres will be leaping from each small bump to the next small bump. Because the spring rate is so hard, the tyres will have to flex themselves in an attempt to absord the impact energy. This dramatically deminishes their ability to follow the road surface. The chassis will recoil off the spring rates so much it will flex substantially as well. The shocks will have to have serious rebound damping to control the spring rate. Consequently as the chassis flexes, the shocks will tend to lift the wheels off the ground.

cheers

[MerlinTheHapyPig]

All coil spring material (spring steel) is made to one of the 2 world wide standards, simplistically hot or cold winding.  The end result (ie; the spring rate) is very similar once the finished product is normalised, tempered and or shot/peened.  I have tested over a thousand coil springs in the course of business and the formula is very accurate.  Most certainly accurate enough for this purpose.

As for the spring rates used in Japan, the Japanese have no real history of stabiliser bar upgrades.  Not to the extent that we do with the KMac and Selbys history.  Plus they seem to have no grasp of the art of shock absorber tuning like the Eurpopeans have.  Add that to their bolt on mentality (good mechanics charge like brain surgeons) and it easy to understand why they rely excessively on spring rates to achieve what could be much better achieved usng other more sophisticated methods.

Since they all do it, they have no basis of comparison to realise that what they are doing is technically deficient.  If drifting ever matures to the world stage they will quickly find that simplistically locking the suspension with rediculously high spring rates isn't a winning formula.

That said, they do a pretty god job with what they have. there is some skill that's for sure.

cheers

<{POST_SNAPBACK}>

Cool, just asking.

Though, i might add, that a lot of suspension I have seen straight from japan, brands that spring to mind are Tien, hks, apexi n1 etc. tend to be the cheapo coilover of choice over there.

I think, partially, it depends on what you pay for. I've driven a car with 11k/9k spring rate - using proper race suspension, and compared to cheapo tien 8k/6k -- the ride was much more comfortable. So i think part of that was a better matched spring/shock - not to mention a better setup in general.

Anyway, I just purchased some european suspension for my skyline, so, we'll see how it goes. Quantum coilovers with 8k/8k springs

[neil_se]

You don't really expect to have TRACTION with those spring rates.  The tyres will be leaping from each small bump to the next small bump.  Because the spring rate is so hard, the tyres will have to flex themselves in an attempt to absord the impact energy.  This dramatically deminishes their ability to follow the road surface.  The chassis will recoil off the spring rates so much it will flex substantially as well.  The shocks will have to have serious rebound damping to control the spring rate.  Consequently as the chassis flexes, the shocks will tend to lift the wheels off the ground.

cheers

Thanks Gary, i spose that's why it was a drift car, not a drag car

[Sydneykid]

Thanks Gary, i spose that's why it was a drift car, not a drag car

<{POST_SNAPBACK}>

I would have thought that you would need SOME front traction :lol: :lol:

Cheers

[Dave R31]

Coil ID = 60mm

Wire OD = 10mm

# of Coils = 7 & 3/4 turns (6 full coils unground ??? )

Spring rate = ???

Thanks

[Sydneykid]

Coil ID = 60mm

Wire OD = 10mm

# of Coils = 7 & 3/4 turns (6 full coils unground ??? )

Spring rate = ???

Thanks

<{POST_SNAPBACK}>

275 lbs per inch

cheers

[NateR31]

75mm

7.5

12mm

and

75mm

7.5

11mm

[Sydneykid]

75mm

7.5

12mm

and

75mm

7.5

11mm

<{POST_SNAPBACK}>

75/7.5/12 = 310 lbs per inch

75/7.5/11 = 225 lbs per inch

cheers

[hrd-hr30]

garbage in garbage out is right.

you should only be concerned with the number of "free coils" in the loaded assembly. your results are skewed softer than the actual rate.

and your simplistic results are merely an average rate for the coil. no consideration given to variably wound coils.

[Sydneykid]

garbage in garbage out is right.

you should only be concerned with the number of "free coils" in the loaded assembly. your results are skewed softer than the actual rate.

and your simplistic results are merely an average rate for the coil. no consideration given to variably wound coils.

<{POST_SNAPBACK}>

I knwo the amount of free coil in a Skyline spring and allow for it.

I know the amount of free coil in a race coil and allow for it.

If you give me the spacing between the variable rate coils I can work out the various rates.

If you give me the taper on the wire I can work out the variable rate there as well.

Any time you want to check out the calculated rates for accuracy, just let me know, I have a spring rate tester.

cheers

Edited November 30, 2005 by Sydneykid

[hrd-hr30]

but you didn't ask for any of that extra info, so if someone had a variable rate coli, you and your calculations would have a bloody clue.

Then post up the numbers in this thread for Sydneykid to work out the spring rate like this;

Coil ID = 88/79 mm

Wire OD = 12 mm

# of Coils = 9.125 turns

my comments stand.

I knwo the amount of free coil in a Skyline spring and allow for it.

I know the amount of free coil in a race coil and allow for it.

so you claim every spring made for skylines anywhere in the world will have the same amount of dead coil? and that somehow you magically know how many free coils each of these springs will have when installed just from that info you asked for? :lol: shit, you are good!

[Sydneykid]

but you didn't ask for any of that extra info, so if someone had a variable rate coli, you and your calculations would have a bloody clue.

my comments stand.

so you claim every spring made for skylines anywhere in the world will have the same amount of dead coil? and that somehow you magically know how many free coils each of these springs will have when installed just from that info you asked for?  :lol:  shit, you are good!

<{POST_SNAPBACK}>

The spring seats, top and bottom, determine the amount of dead coil.

I know the effect of the standard spring seats (for R32/33/34 models of Skylines).

Therefore I know the number of dead coils.

Race coils always have the same configuration, ground flat both ends, to keep the coils at 90 degrees to the seats.

Therefore I know the number of dead coils.

Anyime you want to test it out, the offer stands.

cheers

[Beer Baron]

but you didn't ask for any of that extra info, so if someone had a variable rate coli, you and your calculations would have a bloody clue.

my comments stand.

so you claim every spring made for skylines anywhere in the world will have the same amount of dead coil? and that somehow you magically know how many free coils each of these springs will have when installed just from that info you asked for?  :lol:  shit, you are good!

<{POST_SNAPBACK}>

c'mon mate, give it a rest. no-one says you have to agree with everything gary says, but don't please just go seeking out all his posts to start an argument. I think some healthy disagreement is good, but this spring measuring thing is a tad petty don't you think?

[hrd-hr30]

you say petty, I say completely relevant. people should know that they are getting an approximated and average rate for their coil, based on a number of assumptions SK is making (and not telling them about) rather than the actual rate of the coil. (linear race coils excepted)

[Beer Baron]

fair enough. i don't think people need them pinpointed down the the lb/inch though. I doubt i could tell the difference between a 300lb spring and a 305lb spring for instance. but that wasn't really my point, i was just saying everything doesn't have to be about you vs gary. perhaps it was just the way you made your point that made it seem to me like you are seeking out garys posts for a chance of an argument. if i'm wrong then i applogise, but sometimes the written word can be misinterpreted.

[Sydneykid]

you say petty, I say completely relevant. people should know that they are getting an approximated and average rate for their coil, based on a number of assumptions SK is making (and not telling them about) rather than the actual rate of the coil. (linear race coils excepted)

<{POST_SNAPBACK}>

You should read back over my posts in this thread, #27 for a start.

There has only been one guy so far asking for progressive rate calculations which I did for him.

Because he was the only one, I haven't bothered to post up how to measure progressive rate springs so I can work out the rates.

If more people would like me to work out the rates of their progresive rate springs please let me know and I will post up the how to guide for the measurements.

If you don't like my calculations, perhaps you would like to take over this thread and do the calculations yourself for the guys. I have no problem with that, I have plenty of things to do.

cheers

Edited November 30, 2005 by Sydneykid

[momo]

Hello please help!

id: 70mm

od: 14mm

turns: 8.4

I got these as in japan at the moment, this is the front spring, didnt get a brand

but now a little suspcious that the bottom of the shock was cut and a new mount welded on. the holes to bolt to the suspension are not exactly inline with the shaft by sight maybe 2-3mm out, thought this might put stress on the shaft and/or oil seals, what do you think? they look new and are suposed to be new accept the weld and bottom mount which looks doggy. Other thing is the rear is 10 times ajustable and the front is 16 !?

they were advertised as 10. Weird i think.

any coment apreciated.

Ps I think most people can apreciate there is always a factor of error but close enough dont you think, or is everyone a F1 driver?

[CEF11E]

SK would you mind doing my springs,

Front:

Coil OD = 145 mm top

Coil OD = 186 MM Bottom

Wire OD = 14 mm

# of Coils = 4.5 turns

Rear:

Coil OD = 145 mm

Wire OD = 15 mm

# of Coils = 6.125 turns

Thankyou for your help