^
1st§: That is what I have been reading for days now. Everyone warns me that japanese suspension are very very stiff and hard. They all come with pillow-ball upper mounts which again increases stiffness (though Pillow-ball mounting rocks). In Luxemburg the roads are fairly good, but being a little country I often go abroad. But the question I keep asking myself is: are cuscos, or BClub really that hard on a soft setting?
Your question implies a fundamental misunderstanding of suspension tuning.
The damper adjuster adjusts the damping rate, not the spring rate. Stiff spring rates are stiff, that's just the way they are. Basically, for any given spring rate there is one damper tune that absorbs spring oscillation the way it's supposed to. You
can adjust the car's ride "quality" or the handling balance by adjusting the damper rates, but it's not the correct way to change those characteristics from an engineery point of view. The proper way to change a car's ride or handling balance would be to change spring rates and damper tunes togther, to make sure that the two things are compatible with one another.
When you get your coilovers you might be like me and spend weeks driving on all sorts of roads and all sorts of surfaces at various speeds to find damper settings that absorb bumps the best in most situations. Then you'll leave it there, because at that point you've found the sweet spot as far as those dampers are capable. Adjusting from that point to effect ride or handling balance might "work", but it's the
wrong way.
Infos (some are really hard to come by)
-Cuscos Zero 2 :
http://www.cusco.co.jp/en/catalog/sport.html
5 level stiffness adj.
Front 12kg/mm Rear 10Kg/mm
12k/10k spring rates are stiff, but considering the weight of the R33, they're not
too stiff. The heavier the car, the heavier springs it needs to hold it up. I lean a bit on the hardcore side of these issues, but I would be comfortable with those rates.
What I can tell you is that the Bilstein dampers will have a better tune, and the adjusters should be more effective. What I mean by "better" is that it will not only control body motion effectively but will also absorb high speed bumps a bit better than the Cusco dampers. Japanese damper tunes typically are quite stiff over quick bumps (typical bumpy roads, sadly) because, as I said before, such rough surfaces aren't really common in Japan where their coilovers are intended to be used. That contrasts the US especially, because our roads are freaking terrible.
But the Bilsteins will probably be more expensive also. And they're less adjustable and probably won't go very low. Speed Junkie's Miata is on Ohlins coils and at full low it's still only moderate, whereas the Cuscos will damn near be able to put your GT-R on the ground if you want it.
Honestly, I vote Cusco. You're as close to being German as you can get and yet you've gotten yourself a Japanese sports car. Embrace your inner Japanese motorsports enthusiast and get some Japanese parts. High-end Japanese products like Cusco are just as highly engineered and perfected as anything coming from Europe, though their philosophies may be slightly different.
EDIT: Ah, I see the Cuscos are more expensive than the PSS9s. After looking into it, Alex is right when he suggests that PSS9s are relatively entry-level coilovers. Hell, if you want progressive-rate springs just get some Eibach lowering springs for $250.
Cusco all the way. For only 300 more you get a fully adjustable
real coilover. Plus, the PSS9s use stock top mounts, which is lame. You can use aftermarket ones like you suggested but that costs even more money, probably pushing the total price over that of the Cusco pieces which are a bolt-on affair.
, so I get the most opinions.
)
)
