PorscheDavid

Most of us by the time we got around to changing our springs/shocks had totally shot suspensions to start with. ANYTHING is an improvement in the handling after changing out old tired dampers...sometimes remarkably so. My C4S does not get tracked, so I went for the ROW springs and Bilstein HD shocks. I find the set up perfect in terms of ride height (RS spec) and the handling is flat and phenomenal...corner balancing afterwards is a must. I think most guys with the PSS9s don't do a whole lot of adjusting...I know I don't on my PSS9 equipped M3.

DJF1

Since there seems to be a lot of confusion and personal opinions on harsness I believe we should let the data speak for themselves (in pounds) :

1. Standard suspension : 150-160 Front, 225-250Rear ( ROW VS US is ROW= Progressive springs, US= Linear springs)

2. ROW M030 suspension: 160 -165 Front, Rear 280- 285 ( Progressive Springs)

3. Pss-9 Suspension: 225-250(Tender Spring) Front , 400-650(tender spring) Rear

4. H&R coilover suspension: 295 Front, 360 Rear

5. Sport H&R Coilover suspension: 310-350 Front, 385- 435 Rear

6. Bilstein "Supercup" suspension ( linear springs) : 350Front - 500Rear

Sways: ( From VIKEN's earlier post)

Carrera / Carrera 4:

USA Front: 20 mm
USA Rear: 17 mm
ROW Front: 21 mm
ROW Rear: 18 mm

USA M030 Front: 22 mm
USA M030 Rear: 20 mm
ROW M030 Front: 22 mm
ROW M030 Rear: 20 mm

Carrera S / Carrera 4S:

USA Front: 20 mm
USA Rear: 17 mm
ROW Front: 20 mm
ROW Rear: 18 mm

USA M030 Front: 22 mm
USA M030 Rear: 18 mm
ROW M030 Front: 22 mm
ROW M030 Rear: 20 mm

Turbo:

USA Front: 22 mm
USA Rear: 19 mm
ROW Front: 22 mm
ROW Rear: 21 mm

So I think its pretty clear of the choices available out there ...

OldGuy

I adjust my Pss9's. 3/4 for street 1/1 for track. Then I keep em there for a couple drives
and then put them back to street.

GratefulJED

I would hold out for No. 6, get Bilstein to revalve if they are used, and pair with the RS sways, RS front wheel carrier and tie rods, then rock on..

paradisenb

Danny: Great info. I will have to dijest that a bit to try to understand it. Thanks, a lot.

OG: I don't get the reset after a few drives? After you leave the track? How harsh do they feel to you?

ppressle

I have to agree with OG. My pss9s are still on stiff from the last track event. 3 months ago? Does this mean that I lam lazy or just like the firm ride? Probably both.

abar

Thanks for the list. Any figures for M033? Also ROW standard suspension is much lower than standard US. By how much, and how much lower M030 / M033 are would be useful, if availble!

Thanks, Al.

DJF1

I'll have to dig and find info on this. The only thing I know is that the US standard suspension is an inch higher than ROW and uses linear springs instead of the progressive used on ROW.

I'm glad I could help.

paradisenb

Danny. While your at it could you tell us something about 'linear' and 'progressive' springs. What it means, how they work differently?
Thanks

fbfisher

Sorry for the bad link above. It's www.schatzmotorsport.com

Abar, ride height is one issue, a "floaty" feeling on high speed sweepers is quite another. The M030 suspension keeps the car firmly planted with no float and no body roll, in a way that the stock suspension can't.

Mark in Baltimore

Progressive springs require more force as the spring is compressed through its range, while linears require the same force for every inch of compression. A linear spring that needs 600 lbs of compression the first inch will require another 600 lbs the second inch, 600 lbs the third inch, etc. A progressive spring needs 600 lbs the first inch, 650 the second, 700 the third, etc. In other words, it takes an increasing amount of force to compress a progressive spring through its travel. Since a progressive spring is initially softer in the beginning of its travel, decent ride qualities can be retained while still keeping the car from bottoming out under heavy compression.

Midnight Rider

Randy/paradise_ I live in buckhead and hit the mtns every weekend. I have h&r coilovers. Welcome to test em. Did I see you heading south on 400 (a bit south of the end of 400) around 3:30 today??

DJF1

The linear are just that an equal spaced spring that loads under cornering in a linear fashion till max compression.

The Progressive is wound up tighter at the top and the spacing opens up so effectively when the car corners the spring loads stiffer initially and then compresses more "progressively" till the max compression.

The pic below ( from the H&R site) demostrates to the left the progressive and to the right the linear. While I'm not an expert in this subject and people here are more educated than I am, this is the way the simple way I can explain it.
Hope it makes sense!!!

EDIT: Mark just explained it much better than me. Man you are quick!

paradisenb

blickie: Thanks I would like to see what the H&Rs are like.
I was out today, but I went north on PIB up to the lake. I have never seen another GR 993 w/Aero in Atlanta. Guess there at least one. Apparently it was running around Mid-town yesterday. Sadly I had no play time and Friday traffic sucks.

paradisenb

Would it be safe to assume a progressive spring improves handling a lot? Sound like the best of both worlds. Smooth yet firm when needed for cornering. Any big compromises in handling. I guess adjustable sways are not absolutely necessary to acheive VERY good handling, right?