Yes. Do a search. You can't imagine how much I've learned SEARCHING first before carrying on a more advanced discussion on a subject. Remember. What you're interested in is most likely what we've all been interested in at some recent point in time. Same questions asked, same responses, then new questions on old topics that bring us all more insight!
With the minor drop and stiffening the Eibachs or H&Rs provide, you really don't need to upgrade the struts, anyway. It's only when you get into agressive changes to the suspension geometry/stiffness that replacing struts is recommneded b/c the imbalance between the springs and struts will wear out the stock ones much quicker.
Prodrive advertised an active suspension set-up a while back (do a search for it), but due to low demand has thus far elected not to produce it.
Well, according to his profile he doesn't explicity say he has the "sport" model that comes with the "sport-tuned" suspension. Infiniti claims that the sport version comes with stiffer struts/shocks and springs so dropping the car should be ok. If he has the supposedly softer non-sport suspension, would dropping the car still be ok? Who knows...
Then again, no one has been able to verify any differences in part numbers between the non-sport vs. sport struts/shocks so they might be the same firmness afterall. :roll:
Also, make sure that whoever does the springs also puts on the rear bump stop replacements that come with the Eibachs. If you leave the stock bump stops, you will be riding on them.
I finally had a chance to swap out the OE bump stops. I cut the ones from Eibach about 1/2". The ride has really smoothened out. My initial thoughts that the car felt like it was riding on its bump stops were confirmed, they did!
My only issue with the Eibachs is that the rear coils are progressively wound, and as such, there's actually coil bind when laden. What's the point of a progressive spring if it's so soft that the vehicle weight compresses the progressive section to the point of coil bind?? Seems pretty stupid to me.
i've had same issues with eibach...never bought them again. My 99 accord bottomed out like crazy when going down hills or steep declines and the ride was so bouncy. I swithced them out to neuspeed and the ride was like night and day!
I ran H&R on my TL-s with stock shocks and the ride was really nice. It stiffened out a bit but felt like my FX does now.
SO far Neuspeed and H&R springs have proven to be really good companies for springs from my previous usage.
Your experience with a '99 Accord appears to be a mismatch between OEM shocks/struts with the progressive Eibach Springs. It's hard to find out from Eibach what the "spring rates-kgs/mm, lbs/in" range are on each Eibach spring model but if you got any kind of pogo-affect, it's due to mismatched damping/rebound rates of the shocks/struts vs. the varying spring rate of the springs. The strut/shocks cannot do their proper job of controlling the dynamic movement of the wheels/tires/springs/suspension with the lowering and new springs, let alone the sprung weight of the vehicle. I owned a '98 Accord V-6 SE when they first came out with the new gen and remember that the suspension was soft and focused more on a smooth ride rather than handling. Bottoming out appears to be too little dampening and jumping back too quickly is too much rebound (you turn up rebound to get more resistance to this affect - eg adjustable coilovers) Also, "sag" which is where the vehicle and the variable spring sits during standstill contributes to bottoming out - meaning the struts/shocks are already compressed (being lowered ~1.5) limiting suspension travel (losing ~1.5" of travel) once the vehicle is driven. I've learned a lot about suspension set-up just from my track time and experience with Superbikes (2 modified Yamaha R1s) in the past.
On a highly-modified '87 Mustang GT (way back in college) I HAD to change the strut/shocks when I lowered it with Eibachs because of the same issues you had. It handled much worse than stock regardless of the lower CG. I installed Mustang-specific KYBs and they danced perfectly with the Eibachs! It was amazing in handling overall with that setup (over stock), much crisper and tighter handling. Night and Day changing the stock shocks/struts to match
For the FX45, the Eibach springs match very well to stock OEM strut/shocks although it could be improved by the aftermarket. You can only go with universal application strut/shocks (KYBs a good place to start) although experimenting in the dynamics of your suspension would be very expensive and not prove fruitful. An idea would be to find a modded SUV in the same class that uses Eibach springs and find out what struts/shocks complemented them. Most likely, the owners would just have Eibach-matched shocks/struts anyways. Another idea, look at applications for Eibachs on larger, heavier SUVs (Denali, Expedition, QX56 someday?) if you're going to track this thing or don't mind a firmer,stiffer ride. Just some thoughts...............
BTW, great site with links to anything you want to know about suspensions, including links to supplier/manufacturer websites: