Liao

Hi,
I've been taking my AP2 to every auto-x event in the past year and have been slowly tweaking the car to my liking for these events. I'm not competitive (Just curently attending practice events), looking for more seat time and learning the car in a HPDE setting. I'm looking for some opinions on my current set up and potential insight on tweaking alignment, as I'm not 100% certain with behavioral changes that come with changing camber/toe/caster settings.
Here is my current set up:
07 AP2
00-01 AP1 FSB// 06+ AP2 RSB
Mugen NZ1 coils (7kg F / 11kg R)
Volk CE28 17x7.5 F / 17x8.5 R
Falken Azenis RT615K+ 235/40 // 255/40

Alignment:
Front:
-1.5 Camber
6.0 Caster
0 Toe
Rear:
-2.5 Camber
1/8" Total toe in

I'm looking to stick with a staggered set up for the time being. Car came with the Mugen coils, so I've been building the handling around that. The car used to be extremely tail happy until I got the AP1 FSB installed to combat the higher rear spring rate from the coils; car seems to handle pretty well now, but I can't say that I know for sure what a 'neutral' set up feels like. I plan to get another alignment soon and would like to see if there is benefit from changing my current set up.
I.E. If the car still tends to oversteer more than my liking, would increasing rear neg camber help?
Looking to hear your opinions and learn a little bit more about cause/effect of alignment settings.

Fokker

You'll want at least another degree negative camber in the front for Autox; Autox's tend to be technical, rapid transitions that will push you onto the outside shoulder if you don't have enough camber. You can confirm by temperature probe and chalking the outside shoulders to see how much of the shoulder (or sidewall) you are putting down to the surface. You should have a greater available camber adjustment up front if you've dropped below the stock height with the Mugen setup (stock height maxes out between -1.7-2.0 up front). The rear should be fine, though you'll probably want to confirm through temp and chalk checks (personally, I run a couple points more negative camber in the rear).

Less rear stabilizer bar would also help the back end stay planted, though the spring balance runs contrary to what most would be running in an autox (norm is stiffer front, softer rear). If the spring lengths are the same (looks it in pictures) and the valving can handle it, you might consider swapping springs front to back. A cheap solution for helping to tame the rear is a NC Miata FSB mounted in the back, if you feel like experimenting.

Liao

Thanks for the insight.

I'll try adding more camber in the front for sure. Any specific reason why you have more neg. camber in the back than the front, vs. other people who usually have it the other way around? Did you come to that conclusion via chalking/tire probing alone, as to how much functional camber you needed in front vs. rear?
I have been told that my current spring rates aren't ideal for auto-x before, so I will definitely look into swapping the springs for a new experience. I haven't driven any other S2000 before (never had a chance to test the limits of the S2000 stock, either) so it'd be nice to feel out the other set ups and really find out what I like.

However, since I'm planning to stay staggered, and if I swap the springs around, wouldn't that induce a lot of push?

Fokker

You're welcome. I run -3.0 in the front and -2.7 in the rear. I don't know that you would want that much negative up front with stock front wheels; the fronts even with a 10mm oversize will be an inch narrower than a square setup (255/40r17) and that will cut down on the amount of tire contacting the ground for acceleration. With the stock stagger, it would probably be pushier if you kept the AP1 FSB; you could try throwing the stock bar up front again with the spring swap. The spring balance would provide the same effect of cutting down the amount of tail happy while providing more overall grip up front in slower sections.

Experimentation is key to finding out what works best for your preferences/style and what provides the best performance. Just try not to change too much all at once. Since you already know what it feels like with the springs as is and a stock, late-model bar up front, the swap of FSB and springs wouldn't be too much to compare. Another useful tool to have for comparison review is video of your drives, preferably capturing yourself in the process (Modifry mount for the secret compartment).

DavidNJ

If you are building specifically for autocross, you will want to determine what class you want to be in. The Street classes put lots of limits: stock springs, stock rear bar, stock wheel size (offset can be increased by 7mm), no offset ball joints, no lowering, etc. The next class, Street Touring Roadster (STR) allows coil overs with any springs, any anti-roll bars, lowering, 17x9 wheels, 255mm wide tires (restricted explicitly), air intake, tuning, etc. Street requires OEM bushings; STR still has no steel bushings. In either class, having competitive tires is essential.

That said, if you could get it, -3.5° or more is probably ideal. However, legal in the street classes you will max out at -1.9° in the front. I have a frozen adjuster and could only get -1.7° in front. I run -1.5° om the rear. I have a Karcepts front bar (a clever, beautiful work of art). Some competitors have very expensive shocks...some over $4k/set. Tires combos are typically 225/255, 245/255, or 245/245 on the OEM rims or same size aftermarket rims. Tire Rack rims that fit the bill. STR has more extensive modifications and uses 255/255 tires. Offset ball joints give over -3° camber.

For the past year, the competitive tires have been the BFG Rival 1.5 (popular with front-runners because of BFG contingency program for winners) or the Bridgestone RE71r. Both are less than ideal but ok street tires. Dunlop has a new Direzza III for 2018, but so far no one knows if it will be competitive.

There is more info in the Racing and Competition forum.

Slowcrash_101

More neg camber in the rear lets you lean on the throttle more mid turn and coming out of corners, this car has a lot of caster baked into the suspension so you don't need a lot of static front camber as you gain camber as the suspension compresses, as well as when you turn the wheel due to the high caster angle.