newport996

Weight....Porsche is very specific about spring rates for their cars....maybe too specific...lol...but they will change a spring rate based on the weight and balance of a car.

Riad

Ah, that makes sense.

Rob in WA

No problem, here's another one. The suspension upgrade makes your car look darker too, it's further away from the sun.

10 GT3

My impression of the ROW M030 is different on the street and track. It is a good compromise. There are differences between coupes and cabs, 2WD and 4WD, and MY99-01 and MY02-04. I can only comment about a MY02-04 Coupe. The regular M030 (US, ROW std) has about the same ride quality as the US std suspension. It has a little less body roll, most likely due to the larger sway bars rather than the shorter springs and shocks. The balance is still very much on the understeering side. On my car, the ROW M030 lowered the front about 1" and the rear about 3/4". It takes a few weeks for the front to settle, but the rear settles almost immediately. Ride quality from the front is quite good as the ROW M030 is only slightly stiffer than stock. The US M030 and ROW M030 have the same spring rates, but the ROW M030 springs are shorter. The front shocks on US M030's are actually softer than US std. The ROW M030 front shocks are only slightly stiffer. The rear is another story. The rear is about a 25% stiffer with much more aggressive shock valving on the ROW M030. The US M030 is only stiffer on rebound over the US standard suspension. It is the stiffer rear that gives the ROW M030 a much more neutral feel. It also degrades the ride quality. You are still able to absorb big bumps nicely, but small bumps and transitions in pavement are far more noticeable.

Tire seem to be a big factor on the ride quality. Continentals, Bridgestones and older Michelins ride hard. Newer Michelins and Pirellis ride soft. A US std supension car on Continentals rides worse than a US M030 (ROW std) suspension on Pirellis. Driving my ROW M030 on Bridgestones is definitely stiff, but also very responsive. To compensate for some of the ride harshness and improve tire wear, I run only 36-38 lbs in the rear verus the rated 44 lbs. This keeps the centers from wearing out early. At the track on street tires, the car is well balanced and grippy until the temperatures rise. Then when the tires start going away, it slides contollably. On 235/40 and 295/30 Sport Cups it is perfectly neutral on the skidpad. With the extra grip, body roll becomes far more noticeable, in fact making the car feel soft at the track. The sway bars may still be a little too soft for track tires. Nevertheless, it is a good compromise for the money. I paid less than $1K for mine new out the door.

PSS9's don't include sway bars. They do offering adjustable shock valving to help get a balance for both the street and the track. The are ride height adjustable which is more important for corner weighting than anything else. Figure about $2500+ship for PSS9's and GT3 or H&R sway bars.

c4sdriver

I just installed H&R sport springs on my c4s coupe which originally came with the US M030 suspension (higher than euro). The car sits better on its wheels IMHO and the ride is less harsh (still has the M030 shocks which i think are the same as the euro).

10 GT3

US M030 (ROW standard) shocks are different in both travel and valving. The only parts in common between US M030 and ROW M030 are the sway bars and bushings.

Here is a link to an article that explains the differences between US std, US Sport (ROW std) and ROW M030:

http://www.pca.org/panorama/sample_article_3.html