PSS9 and PSS10 - spring rates & valving figures from Bilstein
 

I found a lot of misinformation on these coilvers, so after numerous calls to Bilstein, I finally got the correct figures from them for all the 996 AWD PSSx coilovers. Here they are:

PART NUMBERS:
PSS9:
C2 - F4-GM5-8846-H0
C4/(C4S) - F4-GM5-8848-H0
Turbo/(GT2) - F4-GM5-8877-H0
(Some builds will be H1)
PSS10:
Turbo/(GT2) - F4-GM5-D536-H0

SPRING RATES:
8848/8877/D536:
f: 260 lbs/in main, 145 lbs/in tender -- r :515 lbs/in main, 145 lbs/in tender
Initial combined rates w/o static sag:
f: 93 lbs/in -- r: 113 lbs/in
Final rates before main coils close:
f: 260 lbs/in -- r: 515 lbs/in

VALVING: (max force)
8848 (PSS9):
9 = soft/adjuster open, 1 == hard/adjuster closed
Rebound (in N):
f: 9=1465, 1=2050 -- r: 9=2150, 1=2820
Compression (in N):
f: 9=935, 1/1=1410 -- r: 9=1310, 1=1530

-- Max Spring Rates supported w/o revalving:
f: 350 lbs/in main -- r: 650 lbs/in main (6.3kg/mm -- 11.6kg/mm)

8877 (PSS9):
9 = soft/adjuster open, 1 == hard/adjuster closed
Rebound (in N):
f: 9=1700, 1=2775 -- r: 9=2270, 1=3060
Compression (in N):
f: 9=1050, 1=1695 -- r: 9=1420, 1=1800

-- Max Spring Rates supported w/o revalving:
f: 375 lbs/in main -- r: 700 lbs/in main (6.7kg/mm -- 12.5kg/mm)

D536 (PSS10):
1 = soft/adjuster open, 10 == hard/adjuster closed
Rebound (in N):
f: 1=1700, 10=2775 -- r: 1=2270, 10=3060
Compression (in N):
f: 1=1050, 10=1695 -- r: 1=1420, 10=1800

-- Max Spring Rates supported w/o revalving:
f: 375 lbs/in main -- r: 700 lbs/in main (6.7kg/mm -- 12.5kg/mm)

Bilstein will revalve each strut for $125.

It would be interesting to compare valving data and spring rates for other shock models too, if anyone has that data.

Instructions:
gm5-8848_C4 Manual
gm5-8877_Turbo Manual

Images:
1) (left) front turbo, (right) front C4
2) (left) rear turbo, (right) rear C4

I would just add that: pss10 the higher the adjustment number the "harder"
pss9 the higher the adjustment number the "softer"

Thanks, I updated the post to try and make that clearer, and added new spring rate data, from Bilstein, that's valving specific.

Thanks for getting the info but weren't all H0 kits replaced with H1 kits that had improved valving?

itacud, is there any possible way that i can obtain similar information for 997?

Curious: What are the stock 996tt spring rates?

That's funny. When I called Bilstein some months ago trying to get stiffer springs, they told me there weren't any. So I bought a set of Motons instead of trying to upgrade my PSS9's. Re-springing and re-valving the Bilsteins will be more cost effective for those who choose to do it.

Larry, the PSS's on my dd use standard sized springs. They can be had in any rate/length from many sources. I didn't know you could revalve the pss9s though.

FWIW, I have the PSS9 FVD version. It has stiffer and shorter springs...I know they also make a Euro version...

I wish they would have told me this. I could have saved some money doing this.

Oh larry I'm your huckleberry... We can just swap, really, no problemo... you know how well my car handles with the lowly PSS9 custom valve jobbers... hilarious

Mike

Thanks for this info!

Adding detail from inside the instruction manual that is not easily found by Googling:

996TT PSS9 Instructions note part numbers of individual items (which is what you'll see when you look at your parts and try to figure out if it's right or not):

Front:
E4-FD1-Y623A00 - Main Spring
E4-FD1-Z349A00 - Helper Spring
VM3-A012 - Shock Absorber (The full p/n on my rear shock says: F4-VM3-A012-H0 )

Rear:
E4-FD1-Y518A00 - Main Spring
E4-FD1-Y504A01 - Helper Spring
BM5-A013 - Shock Absorber (The full p/n on my rear shock says: F4-BM5-A013-H0 )

So it doesn't look like there is any difference between the off the shelf PSS9 Ann PSS10 except that you have 9 vs. 10 clicks of adjustment. The rates and valving are exactly identical. Whats weird is that the instructions specify slightly different ride heights for the 9s vs. the 10s.

As far set up with other systems, I have single adjustable Motons and I am running 550 front and 750 rear. From Moton. Set up works great.

Thanks this is great info.