Measureing Spring Rates..whats yours?

[Gorilla]

hey guys, finally got my suspension sorted, the unfortunate things about these, they are not Damper adjustable, and the car is STIFF! The person i bought it fron say the rates are 6kg Front and 8kg Rear (Remember Mid Engine). To me this seems like a good compromise, but thats having heavier cars before (1400kg plus), but this car weighs a tad over 1000kg, and you can feel everything! I have a feeling the rates they gave me were wrong (as they imported teh car and sold the coilovers to me). How do you measure them and also what are you guys running? Especially the lighter guys, MX5, Civics etc

[Babalouie]

6/5 on the MX5, and on my AE86 I ran 5/3, so 6/8 is pretty stiff, maybe ok for a mid sized car like a Silvia or FC....

Could be that the dampers are shot? My MX5 rides fine, a little firm but can still pass for a factory setup.

[black200]

you have a daily driver, what are you complaining about

ask roadster what he has in his car haha

[Gorilla]

yeah, im just being a bith, it isnt that hard hehe.

[Mr-M00D]

On SAU sydneykid has a post in there that he get you to measure up your springs and he work it out for you,
its in the suspension section

[Roadster]

f/r 8/6 kg/mm here...

this is comfy compared to 14/10 i drove the other day..

[Gorilla]

On SAU sydneykid has a post in there that he get you to measure up your springs and he work it out for you,
its in the suspension section

Awesome! Thanks man.

[monkeymajik]

I had 7.1 and 5.8 on my ae86. Too hard for best grip i reckon. Really predictable when you want to slide it though. I've just softened it up a bit to 5.8 in the front 3.75 in the rear and it feels muchos better comfort and grip wise.

[CoffeeBoss]

12/10 here, and while it is excellent loaded up in corners, the bump handling is problematic. I have been unable to determine wether this is due to spring rates not maching my shocks (damper adjustable through 4 steps) or that the shocks need to be revalved to suit the springs. Everyone has an opinion on how suspension should be set up,but no one seems to be able to give a definitive answer.
I have been in cars with soft suspension that had way to much rebound, and i've been in cars with tight suspension and no travel that had really good, unfussy bump handling.
Still, with no damper adjust, i guess dropping to softer springs is all you need, Shane. In my humble experience, lighter cars are much more tolerant of softer spring rates, and it doesn't necessarily compromise the handling. Shorter springs on a standard IS200 is a compromise, but shorter springs on an MX5 can be a good improvement.

[proconcept]

12/10 here, and while it is excellent loaded up in corners, the bump handling is problematic. I have been unable to determine wether this is due to spring rates not maching my shocks (damper adjustable through 4 steps) or that the shocks need to be revalved to suit the springs. Everyone has an opinion on how suspension should be set up,but no one seems to be able to give a definitive answer.
I have been in cars with soft suspension that had way to much rebound, and i've been in cars with tight suspension and no travel that had really good, unfussy bump handling.
Still, with no damper adjust, i guess dropping to softer springs is all you need, Shane. In my humble experience, lighter cars are much more tolerant of softer spring rates, and it doesn't necessarily compromise the handling. Shorter springs on a standard IS200 is a compromise, but shorter springs on an MX5 can be a good improvement.

you said excellent on load but bump is a problem. do you realise you will never have a perfect setup if you are using for street. even in racing it is very much a compromise.

why can't your regular workshop tell you what is the definitive answer for a good setup or help you develop that good setup you are after? i'd say move on to someone who does really know, and there's nothing wrong with that. it's your car afterall.

you said you are unable to determine if it is your springs or your shocks. have you even tried different spring rates? or even revalved your shocks?

i have a problem with people on forums blurting out no-one knows the answer to this or that, but what steps have you really gone through to find out otherwise - afterall, that good setup you're after is all about personal preference.

you may well find later on that your current setup is a great compromise already.

[VTECMACHINE]

I'm using buddy Club racing spec dampers on my DC2 (weights 1002kg's atm) and apparently Spring rates are 16kg/mm front... and 12 kg/mm rear. Those specs seem a bit stiff tho. All in all... They are freaking hard... but it's awsome!

Can't you just get softer springs....

btw... you'll get used to them after a while... and you'll hate driving cars with soft sussy.

[xolent]

6.3f/4.7r; ae86.

i want to kill myself.

[Buddy]

11 front and 8 rear.. ae86

great for track.. need more bracing though,

very rough for street and street twisty rds..

but thats the fun of it

[CoffeeBoss]

Shane, apologies for the following thread hijacking!


you said excellent on load but bump is a problem. do you realise you will never have a perfect setup if you are using for street. even in racing it is very much a compromise.

Disagree, unless you are trying to say that i will never have a perfect setup for street AND circuit.
Everyone has a setup that works best for them. A good setup for me is one that has better bump handling then i have currently. Having gone through 4 completely different suspension setups on my car, i can definitely say this is the best on a smooth road by a long shot, but it just needs tweaking. Rather than continously throw money at the problem, i am looking for advice on what area i should focus on, and that will probably be springs. I already know that i should save up 8k or more for some top spec coilovers with remote reservoirs, as i have been in a few cars with such setups (Clio Sport, Altezza, R34 GTR) and the suspension setups in these cars were all exceptional. Sadly, i don't have that kind of budget so i shall have to tweak what i already have.


why can't your regular workshop tell you what is the definitive answer for a good setup or help you develop that good setup you are after? i'd say move on to someone who does really know, and there's nothing wrong with that. it's your car afterall.

They already have done, and they are more than happy for me to spend money on developing that setup! Nothing wrong with third, fourth and fifth party opinions though. I take all advice with varying quantities of salt grains, because naturally, everyones expectations and experiences are different.


you said you are unable to determine if it is your springs or your shocks. have you even tried different spring rates? or even revalved your shocks?

I have made no changes to my existing setup because i don't want to spend any further money on my suspension without being armed with better advice.


i have a problem with people on forums blurting out no-one knows the answer to this or that, but what steps have you really gone through to find out otherwise - afterall, that good setup you're after is all about personal preference.

Exactly, which is why i'm trying to find out advice/opinion from as many quarters as i can, rather then have someone critique me on my posts. My apologies, i should have made that more clear :D


you may well find later on that your current setup is a great compromise already.

That's still the cause of much debate, particularly following (yet another) recent car swapping exercise between myself and black200.

Would love to chat with you at the next JDM meet about all these topics and more, nothing like good informed (and misinformed) debate - hope we can both make it!

[proconcept]

i shall have to tweak what i already have.

I take all advice with varying quantities of salt grains, because naturally, everyones expectations and experiences are different.

I have made no changes to my existing setup because i don't want to spend any further money on my suspension without being armed with better advice.


you have already outlined the problem with bump handling with the current setup. if you have gone through 4 sets of factory set suspension. you seem to know what you want - or need to resolve - out of your suspension setup. you will need to spend money to tweak your setup, whether you like it or not.



Exactly, which is why i'm trying to find out advice/opinion from as many quarters as i can, rather then have someone critique me on my posts. My apologies, i should have made that more clear :D


if you will quantify advice given here with varying degrees grain of salt, then there is no point, because as you pointed out everyone has varying degrees of expectations and experiences. you already said you know what the problem is.



That's still the cause of much debate, particularly following (yet another) recent car swapping exercise between myself and black200.

Would love to chat with you at the next JDM meet about all these topics and more, nothing like good informed (and misinformed) debate - hope we can both make it!

considering that your suspension has been installed correctly and any pivot points associated with your steering linkages, has been seated correctly, after having been changed/moved/loosened up then tighted up again, then you need to measure the amount of bump steer in your current setup. it's quite involved, and will cost you $. most of it will be in labour. your suspension shop should be able help you on this.

based on the results that have been measured, you will need to change, adjust, shim or relocate the suspension bits and pieces to get the result you want, depending on what toe symptoms you get on compression and rebound - this is what causes unwanted "steer" bump steer.

if you are experienced enough to realise a top notch suspension setup with the other cars you have driven, then thats great, because many don't realise there is a cost for quality - especially with suspension. but do remember there is always a factor of bump steer in every car, even if it's an absolute minimal.

the only way to attain zero bump is complex, and is only for race cars. even on race cars it is a compromise, as you want to have certain amounts of bump in/out depending on the type of corners and surface and where the driver wants his stability during a corner phase. this is really in the realm of sports sedans, formula cars and the like. which is why you are wrong when you say it - a perfect setup - is achievable, because as i said, it is a compromise.

but if you wish to spend your money to get this perfect setup, then who am i to say you can't. you need to extrapolate lines from your tie-rods, upper ball joint, lower ball joint, upper a-arm pivot point, and the lower control arm pivot points. the centre line of the tie rod must cross with a factored intersection involving the upper a-arm, lower control arm and the pivot points of all of these. when this intersection does cross, essentially what you have is your tie rods are on the same arc as the travel in your suspension, i.e. zero bump.

but if the expert advice you have been previously given from your usual channels is, lower spring rates, revalve to suit, etc (which is why i asked you this in my previous post), then you know what is informed as to what is now misinformed.

i won't advise you what to do - as the first step. i think you can determine that for yourself once you have all the info you need to make your decision. i would suggest to work closely with your suspension shop. good luck with what you're trying to do.

that's all i'll say about this topic, apologies for the hijack.

[CoffeeBoss]

Josh,

Point taken, overkill perhaps. We're talking about an underpowered 4 door sedan here, not a race car! It appeared to me that i was being lumped into that whinging group of posters who expect to be given answers for nothing, and hence i got my back up a little.

Would like to PM you to discuss further, but 'you no accept the PM's....' ??

Ergo, a new thread http://forum.jdmstyletuning.com/showthread.php?p=26349

Meanwhile, Shane - any udpates?

[Cazal 856]

Incidently, spring rates on their own aren't an indication of how harsh ride quality may be. You also have to take into account where the springs mount to control arms, pivot points etc.

For each individual car you can compare spring rates, but once you changes the chassis, there's not much point in bickering over it.

Chris.

[proconcept]

that is what you want, right? to resolve it, and get that perfect setup? that is the length you have taken so far -4 different suspensions- to get that perfect setup. how is my explanation overkill? for christ sake you said you want a perfect setup.

obvious you have taken my last post as a very small grain of salt, because in your new thread you talk about changing springs or revalving to resolve your issue. where in my explanation to resolve your issue, did i talk about changing springs or revalving?

one reason why pm's are off, and this is exactly why.

[Gorilla]

no no, no hijack, continue!

Updates are...Coilovers sold for some TRD 4 Way adjustable shocks. Im not sure what springs to get yet, what rates, and I want the ride height to sit exactly how it is with teh coilovers.

[Justin Fox]

Matt. I am pretty sure that Josh at Proconcept knows a hell of a lot more about suspension set-up than many of us forumers.

He's invested in a hardcore suspension set-up in his workshop which might not reap him as much cash back as a dyno for example. I take it as a sign of real dedication.

The fact that Josh has taken the time out from running his workshop to post here in order to help you, and potentially the rest of JDMST, is fantastic in my books. We need more people like Josh on here, people who have real experience.

Take it from me, if you trust me that is, that you can definitely put a little more trust and faith (or grains of salt if you like), into Josh's opinions more so than mine!

[Justin Fox]

Also, will add my opinion and experiences.

I do agree that there is no perfect set-up and that some sort of compromise has to be reached.

Sydneykid on the SAU forums set up my GT-R when I 1st bought it with a Whiteline works set-up. FACT is that it was designed for Australian conditions (whatever that is!) but damn it was the hardest most crashiest ride I've ever felt. I complained about it out loud on the forums and Sydneykid questions whether it was installed correctly or not (installed by Powerplay Imports).

I took the car to Minto, to Whiteline themselves. The head designer there took the car for a spin and said nothing was wrong. Great car he said! Lots of power! LOL.

OK, so it wasn't the install. Whiteline would not give me my cash back no matter how hard I complained about how ridiculously crashy the ride was and worst of all it was stiff on street and too soft on track!!!

All in all it's each to their own. This whiteline kit is selling like hotcakes on the SAU forum and no one but me seems to be complaining about it.

[44 this year]

Also, will add my opinion and experiences.

I do agree that there is no perfect set-up and that some sort of compromise has to be reached.



whether or not that whiteline suspension is harsh or not on the street, least you realise a compromised has to be reached.

[Justin Fox]

Now now Mark, no need to be harsh on Matt for trying 4 different sets of suspension.

I say trial and error is an expensive exercise, but one that you definitely could learn a lot from. Trial and error with buying the wrong parts, as well as playing with what you have already got (I recently raised the GT-R by 20mm, damper was set the same but damn was the ride totally different!!! So much better at absorbing bumps but I couldn't handle how ugly it looked so down she went again lol).

Through my own personal experiences and my own personal preferences I definitely will never ever go for a lowering spring set-up, or a progressive rate lowering spring for looks, or an A) brand shock and B) brand spring set-up ever again. It's coilovers with adjustable damper and height for me from now on. 100%. I am sure Matt can try someone's Altezza with coilovers from the club as I am sure more than a few members would have coilovers, it's a sure way to save cash and gain experience that's for sure (ie: Matt, you've already driven Charlie's, try more different set-ups perhaps?).

[CoffeeBoss]

obvious you have taken my last post as a very small grain of salt, because in your new thread you talk about changing springs or revalving to resolve your issue. where in my explanation to resolve your issue, did i talk about changing springs or revalving?


Dude, please, enough with the agro already! I haven't been very clear here, speak to those who know me, i ramble. And don't take me so seriously - i've been on this setup for about 18 months? So it's not like it's a major issue or anything!

I have also done a bit of research and know well enough not to take your advice with a grain of salt. If you insist on assuming i'm some moron who has no idea what he's talking about, i can assure you, your absolutely right!

OK, will post on the other thread, which i have started to try and be more specific.

SHANE! Sounds like your getting the same gear i have, careful, bit can of worms there (see above!) :lol:

[CoffeeBoss]

Mark, Mark, Mark. If that is you posting, then i seriously don't understand you, man! But, the agro has some context now..sort of. *laughs*

44.... you know, i'm always telling people that modification is all about improvement vs. compromise. I guess i'm just searching for a better balance or more specifically, a better ride vs. handling compromise, which i am fairly certain i can acheive based on some of the other setups i have experienced.

Enough already - so, how 'bout them Knicks?

[nate]

n00bs! all of you!!!

Spring rates...

Uncorrected stress = (2.55 x spring load x mean diameter of coils) / wire diameter cubed

Deflection = (uncorrected stress x mean diameter of coils squared x number of effective coils in the spring x pie) / (shear modulus * wire diameter)

rate = (98.98 x 10^8 x wire diameter ^4) / (number of coils * mean diameter of coils^3)

Then you will need to apply that along withthe critical damping coefficients...
damping coefficient = 2 x square root (spring rate / sprung mass)

that should get you kids started :)
*waves to T2*

[VTECMACHINE]

whoa... crazyyy!

1+1= window :)

[nate]

cmon its pretty elementary! :P

nah, just playing with my new book, seems to be pretty thorough!