S4 Lowering Springs

[DavidT]

Been thinking about better suspension as I find the standard setup a bit 'floaty'

I can't convince myself that £ 1300 fitted for the H&R coilovers is money well spent as I would never adjust them once fitted.

Lowering springs seem like a good idea, ride height reduced by 20-30mm front and rear and increased spring rates.

Does anyone have experience of MTM (or any other) lowering springs ?


David

[jeffw]

Problem is that the reason that the car is floaty as you descibe it is down to the dampers and not the springs.

[DJG]

Interesting.

My car is floaty and underdamped particularly front to back (not sure I've explained it very well). On a particular urban roundabout near home this combines with a bumpy road and the damping of the seat to give a most unpleasant sensation which can almost make you feel seasick.

The car has just done 50K so maybe even new OEM shocks would improve things.

David

[jeffw]

I'm no suspension expert (Firewalls yes....suspension no) but I think that the standard S4 suffers from not enough high speed bump and rebound damping. I think that increasing the spring rate and lowering the car will not improve this.

I'm going to see Leda soon ( Leda Suspension) to see what they can recommend to try and improve the situation without turning the suspension rock hard.

[DavidT]

Do we not have anyone with experience of lowering springs then ? [img]images/graemlins/frown.gif[/img]

Jeff, how did you get on with Leda ? [img]images/graemlins/24430-audibash.gif[/img]

[Joshie]

Sorry David - didn't pick this thread up for some reason.

AmD fittend the H&R progressive springs to my S4 which lowered it about 30mm or so. Have a look at the photos in the gallery.

The progressive nature of the springs means that the ride is not as harsh as with the full H&R setup (so I was told by AmD) - handling is better than standard but probably not up to the full H&R setup but for £360 or so it does make the car look a little more attractive, IMO.

However, if you are going for the full H&R setup later you'll probably have to go for linear springs as the H&R coilovers (and someone will correct me if I'm wrong) are digressive.

If you want a technical explanation of the use of progressive vs linear springs I'll see if I can dig out the email from Stasis Engineering in the States.

[Dippy]

I have the H&Rs too, so I can't help on lowering springs. However I can't believe that simply lowering the S4 would really make it handle loads better. Surely both the springs need to be stiffer and the shocks more 'absorbent'?

However in regard to the H&R's, I too was sceptical about them considering the price, and originally I wanted to leave the suspension alone. However I now feel that they are amazing value for money. If I were short of funds for mods, I would actually get the H&Rs and a short-shifter before considering a remap!

[Joshie]

I agree Dave, not sure that the handling will be loads better with just the springs but I believe it was an improvement over standard which was a bonus because the reason I went for the springs in the first place was purely cosmetic.

I don't know how much better H&R setup is because I've never driven a car with this upgrade. Something I may decide to upgrade in the future.

Anyhow here is an excerpt of the email I received from my mate in Denver about progressive dampers versus linear dampers. Thanks to Stasis Engineering for explaing this topic to my friend.
-------------
"Progressive springs are a great idea when using a linear damper. Our entry level kit uses a similar system.

When we move to the more advanced digressive dampers we switch to linear springs. Lets see if I can summarize the effects in a couple of steps:

1. Driver inputs move the suspension a slower speeds (<5"/sec) that road inputs.
2. Freeway driving creates smaller movements to the suspension than back country driving.

So to achieve a nice ride and increased performance we can either.
1. Separate the suspensions response to different shaft speeds OR
2. Separate the suspensions response to different shaft stokes.

Here is the trade off
1. Use high dampening rates for low shaft speed motions while lower dampening at high shaft speed motions the allows the damper to absorb road irregularities. This gives us excellent driver response while keeping good ride quality. Use a linear spring for immediate response. The only downside is the high cost of building the digressive damper. (A little more expensive components, much lower volume as the damper response knee must be tuned per vehicle set up and spring rate)

2. Use a progressive spring to give soft response to small movements (such as freeway) while providing a firmer response once the suspension loaded. Use a standard (linear) damper. Disadvantage is that the transitional response to driver inputs will be dull as the first (perhaps 1") of suspension movement will be soft. Once loaded (sweeping turn) the suspension will harsher (linear damper and firm spring rate) and potentially have less grip (less road compliance). The big advantage is in the cost of the damper.


So it depends on the budget and your personal ride tolerance. Once the budget passes $1500 we will always run a linear spring and spend the money to build an advanced damper".
----------------------------

[RobK]

I had the H&Rs on my S4 and I thought they were excellent. The ride is actually better than standard in my opinion, damping is excellent and low body roll.

And they're Nogaro too!

[DavidT]

Thanks for the responses, the lowering springs are a cost effective upgrade then.

I've still never heard anything negative said about the H&R coilovers, amazing when you consider they are £ 1300 fitted.