If you want to keep the adjustibility of the Konis, then you have many lowering options:
Linear Rate Springs
1. TEIN S-Tech: will drop the front 0.7" and the rear 1.0". Stiffer than stock, but within the safe range for the Konis.
2. Tanabe: will drop the front 1.3" and the rear 1.3". About the same stiffness as the Zanardi/Type-S OEM springs. Your Konis won't last long unless you re-valve them to match the rates. I suspect this would be a sweet lowered street/track setup w/o moving up to coilovers. I'm thinking about doing it myself...
Progressive Rate Springs
1. Eibach Pro-Kit: will drop the front 1.25" and the rear 1.25". Softer than stock at start, firmer at max. The Eibach/Koni setup is a very popular choice for NSX drivers. A LOT of people on Prime either have or have had this setup, including members with a lot of track time using it.
2. Dali: will drop the front 1.25" and the rear 1.25". The stiffest of the progressive springs, but still softer than stock at min. Many NSX owners use these with the Konis or Bilsteins as well.
3. RM Racing: will drop the front 1.5" and the rear 1.5". In between the Dali and Eibach in terms of firmness, but has the most drop. They are LOW (I have them with Konis, at least I think- see
http://www.nsxprime.com/forums/showthread.php?t=114542) and you will scrape a lot. Handling is very crisp and the rates feel just right. I want to try them on the track to decide whether to keep them or get the Tanabes. Scraping on everything (especially here in LI with our decrepit roads/1940's infrastructure) gets old...
RM's aren't sold anymore, but they appear in the marketplace every now and then.
4. Swift Sport: will drop the front 0.8" and the rear 0.6". They are the softest of the progressive rate lowring springs, but still firmer than stock at their max level.
Comptech also made lowering springs that I think had about a 1.0" drop and were slightly firmer than stock. Hope this helps.
