Spring Modification

[A80Avant]

the reason im not going for the S2avant HRs which would be the next solution,is the fact that they come lower than what im happy with even if im ok with the stiffness.So im looking for something in between before i head off for the coilover setup.

I reckon i like the looks of my car as it is as well,and a 15mm drop will be better of course,and add something to the handling,while a 30mm drop on a fresh set of shocks looks superb,after a while it seems too low for me.

[stiglet]

If you lower the car without stiffening the springs there is a good chance you will end up with worse handling. It will definately roll A LOT more.

[A80Avant]

why is that? i thought that the center of gravity being lower would make the car more difficult to roll.Can you explain please?

[stiglet]

Centre of gravity height above ground decides weight transfer, however the body roll is decided by the height of CofG above the roll centre. When you lower the car, the roll centre is lowered much more than the CofG, so you are increasing the distance between the two, which increases the roll couple. More body roll means more adverse camber, which will give less grip.

It's to do with suspension geometry. When the car is lowered it just messes up things. It's ok if the springs are stiff, but otherwise....

This is why lowering springs should always be much stiffer, and why cutting your springs is a bad idea (i realise you aren't cutting your springs, thats just an example).

[A80Avant]

ok i see your point.So i guess the amount of lowering has to do with the amount of increased stifness then,right?

Ill try to keep that into the equation.I believe that HR S2 springs which are not as stiff as the HR RS2 springs, and lower the car by 30mm should still be stiffer than any spring that would lower the car half the amount.I understand that the amount of lowering may not be proportional to the stifness,but at least it will be less.Ill see what the guys in the shop advise me as they seem to be doing this for a long time and they should advise me accordingly

thanks for the info!!

Vasilis

[stiglet]

Yes, basically, the lower you go the stiffer you should go. And the relationship isn't proportinal either, unfortunately. Which does complicate things. It is possible to overdo it in my opinion too, but i guess other peoples opinion from experience would be best on that point.

I would say that even if your aim is to keep the comfort with improved handling, stiffer springs would still be better as too much body roll is unpleasant!

It may be worth your while checking in on my thread about the extended ball joints which should increase the height of the roll centre on lowered cars

[A80Avant]

Good news,
in their latest responce they can measure the spring rate and also make the springs stiffer as well.Im going to have the OEM springs rated and keep the number,and then make the new ones...!

[A80Avant]

After a few emails i managed to make a package to post out to them.
I was asked if possible to measure the springs when the car is on the ground,as well as when they are in the assembly,but since i didnt have the facilities to do so,i only measured the spring length when the car is jacked up,as well as the springs themselves when off and free.

Lengths are: for free springs : FRONT: 310mm
REAR : 320mm
jacked up : FRONT: 280mm
: REAR : 280mm

If there is anyone with an AVANT RS2/S2 who has OEM springs and can measure the spring length when the car is stationary on a flat level,that would be much appreciated.

I will be sending the package to them on Monday probably and hopefully they will be able to make the change to a 15mm drop,as well as increase stiffness.Also there is a possibility to make them progressive as well.We'll see...

[A80Avant]

Got a figure for OEM AUDI S2/RS2 avant spring rates.

fronts are 210lb/in and rear around 300lb/in

i was told that mine are going to be lowered by 15mm and not tampered with stiffeness.Trying to figure out through emails if that means that the lowering is so little that there is no need for increased stiffness or there is any other reason for it...

[S2central.net]

'kin brilliant - just read this whole thread and was gonna ask the question about OEM spring rates.

The thread on KW coilovers found a spec quoting those springs as 70N/mm which equates to 400lb/inch - quite a hike on factory but not as brutal as I had always been led to believe.

WHats the rating on the H&R springs then ?

Dont wanna hijack this thread - but the info / comparison would be relevant... Now off to check some part numbers !

[S2central.net]

@Vasilis - does your car have air con ?

What paint marks are on your springs please ?

[lind4hl]

i have (had) and i think mine had yellow stamp,

[S2central.net]

That doesn't sound right - not for factory springs anyway... I'll create a new thread on the subject with reference info.

[A80Avant]

the springs were off an S2 avant,which are original OEM,and same as RS2 ones.Dont really remember the labels.I think there was a yellow and a blue but cannot be sure.Once i get them back they will be red anyway.Im sure they are OEM S2/RS2 springs,as they were excactly as the ones i have on the car now,which are bought 2 years ago from audi.

I havent had any HR springs to send them for measure,but if someone has,they can do that

[S2central.net]

The paint marks are important - can you PLEASE check them ?

Then we can start properly with this thread - http://www.s2forum.com/forum/showthr...790#post362790