Dale Gribble

First off ,

Let me give credit to KPV on 6speedonline who i am copying this info from.

here is a very comprehensive pair of threads that discuss the effects of uberlowering using the PSS9 suspensions. i thought it might be worth posting here for those who were considering the move.



Thread 1

Thread 2

TT Surgeon

I would seriously advise anybody considering pss9's for hard track use to read this post and reconsider your options. After reading this and making my own inquiries, I would be nuts to go with anything other than factory peices. I know the majority of guys who have done this mod have done so for bling/looks and will never drive their cars hard enough to make a difference. Do you think most guys who do pss9's actually go thru what Ken did? I doubt it, nor did the 'tuners' who intalled them. Off my soapbox.

earlyapex

I've had PSS9's on my 40th, which improved it's overall handling on city streets and on the track. That was an interesting thread. Thanks for the information. I'm glad I have a mechanic that knows what he's doing.

Cupcar#12

my car is suffering from the same symptoms the KPV's is
PSS-9's with limited travel due to lowing (i bought it this way)
i will be raising the car soon to gain some more travel in the suspension and allow the shocks to work. Right now i will not planning on returning to the stock setup (sport suspension) but may depending on what class i will run it (auto-x. stock) or moving to the Moton CS shocks
either way the PSS-9 is eventually out.
i did post some issues i experianced durring the last skills days on another thread (no replies, interestingly enough)
Right now - i am in the camp that the PSS-9 solution is not the way to go if you are looking at streetable - track setup. otherwise stick with the stock stuff

sharkster

I know and talked to KPV a lot about this back in the day also because I did have this symptom too when I had PSS9s. As far as he was talking back then and as far as I know this was applicabable to the Turbo/C4S kits and not the narrowbody kits which are different. Lowering on a C2 doesn't seem to cause any "pogoing" due to riding on the bump stops since they seem to be lower down than on the Turbo kits.

As far as track kits go, do Motons or JRZs. For the street and occasional track stuff we do PSS9s for most folks and then for the more serious track guys/girls we use Motons and/or JRZs...

ca996

Got pss9's on my C2 and have had no problems.

sharkster

Exactly We've never had any issues with installs on a C2. Just the TT/C4s widebody cars.

TD in DC

I have PSS9s on my C2, and after I paid someone to completely "tune" the suspension, it handles outstandingly well. My instructors at DE and autox also commented on how well the car is handling. With respect to C2s, the only thing I think you need to do is have a professional who knows suspensions very well install and tune your suspension. I cannot imagine using stock parts.

Dale Gribble

^ god to hear the you narrow body folks havn't had problems.

how high to PSS9's look when they are are maximum ride height? i've heard that they are still at X73 (or X74, i don't know which is which anymore) or RoW M030 height, which isn't bad at all in either case.

Cupcar#12

Mine is actually much lower than RoW ride height currently - i just lost my laptops HD or i would post some pictures. so there is a limit to the amount you can lower a C2. i do not have issues with the rear stability- just reduced shock piston travel leading to a non-linear rebound of the wheels. this is really not evident in anything but very hard driving.
i am going to raise the ride height to near GT3 Mk1 specs as the first stage (+1-1.5 inches) which should allow the shocks to work as designed, as well as adding gt-3 sway bars F/R.
i am picking up where the PO left off in this dev cycle
not knocking PSS-9's they are good gear - just may not be right for me in my case

Dale Gribble

^ what about revalving and going for harder springs?

TT Surgeon

Somehow, I can't believe c2 narrowbodies are magically immune, while c4s/tt's are plagued. I would bet that a lot of the c2's with them have'nt been pushed 10/10 on the track, or are pure street cars. I think if you push them hard enough, gt2 style lowering will take it's toll on c2's as well. jmo

Cupcar#12

thought of re-valving and switching springs -
couple of issues with that though...I depends on the class i run in - if i go stock classes then it's just wasted $ b/c i will have to swap in the M030 shocks and springs.
if i run street prepared which i believe allows 2-way shocks, the Motons are the better setup.
i am going to try raising ride height first and adding the GT-3 sway bars before going any further.

C2's are not imune to this - it just depends on the ride height
for comparisions sake (auto X setup by a local shop here in town)
Total Weight 3278 (w/155 lbs driver)
Front
-1.6 -0.50 Camber
7.9 6.50 Caster
0.01 0.18 Toe

Front Cross
0.1 Camber
0.0 Caster
0.01 Total Toe
0.15 set back

Rear
-2.00 -2.00 Camber
0.11 0.10 Toe

Rear Cross
0.21 Total Toe
0.01 Thrust angle

I need to double check the ride height <edit> but it is lower than GT-3/2 ride height</edit>

sharkster

Actually they ARE different kits and the bump stops (which cause the problem on the Turbos) are not in the same "Zone" so to speak so you can lower the C2 far more without the problems associated with lowering on the Turbos. Riding on the bump stops, which is what a lot of lowered turbo PSS9 cars end up doing is what causes these problems... You don't ride on the bump stops on a lowered C2 996 with PSS9s and can lower further on those kits. Typically lowering more than 1.5 inches with PSS9s on the turbo and you're on the bump stops. Been there, done it and installed it too many times to know

TT Surgeon

Alex, to clarify, they are both prone to the problem but the C2 is markedly less due to different mounting positions relative to the bump stops.
Sounds reasonable.
Chris