With soft springs you're going to need to run more negative camber while on R-comps.

Some people run -2f, -3r. It really does depend on your spring and shock combination.

If you're going for more than -1.5-1.8 in the front (depending on the condition of your bushings), you'll need something like the SPC adjustable ball joint or the J's racing roll center joint.

The rears can generally get -2.8-3.3 stock.

We've tried -2.5f / -3.5r and -2.5f / -2.0r. But on much stiffer springs. This year we're going for -2.7f and -2.5 rear.

 

Agree with the above advice. Need to balance the non-staggered tires, bigger front bar is the cheapest way. RA1's like a lot of negative camber, and suspension alignment is cheap.

The best thing to reduce lap time is going to be a datalogger. Unless you are already within 1 second of the fastest S2000 on RA1 class tires, knowing where you're slow and working on the driving is where the time is found. I like to buy parts and tweak the car as much as anyone, but to get fast the first thing to do is make the car safe and reliable, then work on driver skill and lastly buying parts. Actually having a datalogger will let you evaluate any mods to see if they are really working for you.