Doyle623

I currently have 25.5 torsion bars with Bilstein HDs on the rear and Koni M474s on the front. I was considering moving to 200# progressive springs on the front to improve the ride harshness. Does anyone have experience going from stock to progressive springs, that could give a before and after account of ride comfort on the street?

Paulyy

No experience on my car but it will help.. But the back?

MAGK944

I experimented with progressives at the front and didn't like them. The front of the car rolled excessively into corners at slow speeds even with a 968 M030 sway up front and the rear of the car kept wanting to push.

333pg333

What springs do you have in now? It's probably not the spring but the shock. People have different opinions on what is a harsh ride but I had 600/700 springs with all rubber bushings replaced with metal and ran on 30 aspect DOT tyres on my previous car and it was fine on the street. It's often all about the brand of shock and it's valving.

Paulyy

I was going to say go get KW v1 as it still has the high and low speed valving. But they don't offer it for our cars.

Doyle623

I bought my M474 front shocks second hand and looked to be in excellent shape and if I recall (going by the painted dots on the spring) that they were soft (in the 140-160 range). Maybe the valving was altered by previous owner or maybe they just need replaced. Also my bilstein rear shocks are oil filled. Would I see a better ride with koni gas shocks in the rear? The car seems pretty harsh on bridge joints, seams, etc.

mikey_audiogeek

Harshness is often a "secondary ride" issue.

Secondary ride refers to all the other compliant interfaces between road and driver, and additional mass/spring resonances.

Think about the following:
Tires
Control arm bushings/springplate bushings
Shock end bushings
Swaybar bushings
Strut mounts
Torsion carrier bushings
Driver's seat squab
Engine/transmission mounts
Beer gut...

Cheers,
Mike

Paulyy

But you do drive a sports car..
It's no bmw 5 series comfort car.

mikey_audiogeek

http://www.diracdelta.co.uk/science/...de/source.html
http://support.prosig.com/2012/08/15...econdary-ride/


Cheers,
Mike

lee101315

Thats a bit of a stretch for a street car isnt it? You're a lot tougher than I am... Here in the northern NJ NYC area the roads are atrocious. I had to get another car to drive every day because 550 f/r springs and all monoball bushings on my autoX car were killing me.

I agree about the valving, matching the strut to the spring makes a world of difference.

Dave W.

How far are the front Koni's sadjusted? The range of adjustment is very broad, they might simply be set too stiff.

Doyle623

The rims that I added definitely added to the harshness and the tires are getting older (harder). I have the fronts adjusted all the way to the right, which I believe is the softest setting.

333pg333

Sure, if you hit holes with most suspension it will feel harsh. But on only what I'd term as ok roads my setup was fine. Again, it's subjective. I guess I loved how it handled so much I might have ignored the downside. But did go in other cars with half that spring and they were twice as harsh.

thingo

I'm with Patrick, a decent shock like a kw is way more comfortable than those old koni's, and the car handles a lot better as well.