what spring rates are people running ?


As most people already know, but the front end cannot be too stiff otherwise you will provoke understeer, but fitting stiffer springs in the rear will introduce a little bit of oversteer depending ln the spring stiffness which would be favoured by most people as it is easier to controll. On my d2s im looking to just replace the rears then see how that handles. Once i know i will guive some feedback.
 
Well I also use this 8-6 setup on track, with koni yellows on stiffest setup, and it's oversteered even with this setup. Not too much, but in such corners like a long left hairpin, I don't get enough power from the d15 to pull out the front end, so I have to do that in second gear, otherwise I would spun out if I take it with the same speed. I will have my rear arb installed on wednesday, will see what difference it makes. You know there's no rear arb on ek3.
 
if it was over steering whith no arb then it will cirtainly oversteer more with one. What tyres do you run ? Your shosks must be seriously stiff
 
Your wheel alignment has a pretty big role to play when it comes to handling , so if your car is ''understeery or oversteery :) '' make sure your alignment is suited to the spring rates as they are to the tyres.
 
KEVTI said:
if it was over steering whith no arb then it will cirtainly oversteer more with one. What tyres do you run ? Your shosks must be seriously stiff
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+1

If you're oversteering with no rear bar then you've got some other issue, alignment or RTA bushes perhaps.
 
well all the parts are on their way, just bought some r888's too. still to make a decision on the coilovers, trying to find someone within budget, that will supply custom spring rates, any reccomendations?
 
i hear along the grape vine that camtec are making coilovers now, ive also heard you can choose your spring rates.
defo budget price aswell.
might be worth firing nuno on here a pm.
 
natune said:
well all the parts are on their way, just bought some r888's too. still to make a decision on the coilovers, trying to find someone within budget, that will supply custom spring rates, any reccomendations?
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What is your budget ?

I seen those ''Camtec'' coilovers on some other thread , just look like the crappy Chinese gear with their sticker.. Unless that is proven wrong Id stay away.
 
Darragh_K said:
What is your budget ?

I seen those ''Camtec'' coilovers on some other thread , just look like the crappy Chinese gear with their sticker.. Unless that is proven wrong Id stay away.
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i believe they are made in china.
but meister r's are made in china or taiwan or some place not usually in the same sentance as quality but they are decent coilovers and people rate them.
 
i have messaged camtec already.

i would say my budget is up to and around £800ish, which i guess is the normal price for middle of the road coilovers. i dont want something pants just for the sake of having coilovers, but it also does not warrant me paying mega money for uber ones!
 
With an £800 budget I would be looking at a Koni/Bilstein damper and Ground Control coilover sleeve package.
 
kozy, what height drop do the spoon damper/spring combo roughly give?

is there anything like a rough linear equation to work out how stiff to go, depending on how low you go? if that makes sense?
 
Shocks were konis on stiffest. I don't know what RTA is, but I guess it is somekind of an arm :D tomorrow we will find out, I will have the arb installed. Wheels are alligned for normal, except the camber, that is set to a little bit negative. Tyres are hankook ventus rs2. I believe it will be perfect, anyway with softer shock settings, it was also a little oversteered, especially in long turns. But very handy.
edit: I see what RTA is, we call rta bushing "big bushing". Kinda weird in english, but that's how we use it in hungarian. But those are fresh bushings, no way they are tired.
 
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natune said:
kozy, what height drop do the spoon damper/spring combo roughly give?

is there anything like a rough linear equation to work out how stiff to go, depending on how low you go? if that makes sense?
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Spoons are not very low, but this is actually better for performance on the road.

You can work out required spring rate like that actually, but you need to have some idea of the amount of suspension travel you have currently.

If you say 6" compression travel as standard, and you standard spring rate is 250lbs/in, then it would take 1500lbs to bottom it out. If you wanted to lower 1", then you take that 1500lbs and divide it by 5 (6" - 1") to get 300lbs/in required spring rate. So a 2" drop would require 1500/(6-2) = 375lbs/in.
 
ok ive done some maths based on a few of the points you have made kozy, bare with me :p

im thining of lowering the car around 50/60mm, so im thinking a 6kg front spring rate, which is 3350lb plus 2000lb arb at the front.
then 6.6kg rear spring rate, which is 3700lb plus 4000lb arb at the rear.
this giving me 5350/7700, and a rsd of 40.99%?

how does that sound?
 
You've done something wrong converting kg/mm to lbs/in. Lbs/in should be 56x kg/mm, so 6kg should be 336lbs.

How have you come up with the front ARB rate? If that was from my post that was only approximate to give an example, and doesn't reflect the actual wheel rates as the ARBs operate on a different motion ratio to the springs.

I've realised what you've done with the spring rates now. The ones I quoted were in roll resistance per degree of roll, that's not a simple equation really. The standard EK9 does work out to roughly those numbers, but I had a large spreadsheet to calculate it all.

I've since then changed the spreadsheet as figuring out roll resistance in terms of lbs/in/degree was confusing, I now just add the wheel rate contributions from the spring and arb for both axles.

To get wheel rate you multiply the spring rate by the motion ratio squared, which in the case of an EK is around 0.7 front and rear. So your 250lbs would be 250*.7^2 = 123lbs.

The standard EK9 ARBs have wheel rates of roughly 170lbs/in up front and 280lbs/in in the rear.
So overall for the standard car, the front has 123+170=293lbs/in and the rear has 123+280=403lbs. Overall, that's 696lbs/in and a 42.09% front roll distribution.

Since you sound pretty interested in all this, fire me an email address over PM and I'll send you my spreadsheet. :)
 
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Loving this thread. Some useful knowledge being shared. Keep it coming
 
If you are trying to fine tune your suspension its best to change a small piece at a time, rebush/replace worn oe items, do a few events, pick some coilovers, do a few events, get some camber products, dial in a small amount, test it, dial in some more, test it, if you wish change your arb, test it and so on. If you fit it all at once the car will not match your driving level, you will not learn or get a proper feel for what does what.
If you are new to it all, trying to fine tune things when you dont even really know how you like it to be on the limit can be an effort, for most fancy calculations will just confuse. If you plan on doing trackdays, sprints etc then buy the kit to suit your budget, dont worry too much about the spring rates they come with if they wont give you custom ones - these can and probably will be changed later as you gain more experience - its a very cheap thing to do. If you need big rates later on, you will need new coilovers or get them re valved to suit anyway.
Others may run higher or different spring rates, it does not always mean it is better - the dampers/springs may be of poorer quality, the majority of cars are way over engineered to tackle a speed hump at the services anyway.
 
I run Bilsteins that have been revalved to my own spec and give amazing handling. A custom bilstein coilover kit can be made with springs for less than you think and will out perform any of the above mentioned. Pm for details
 
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