postwarart

Hi everyone! I try to do as much reading as I possibly can before posting, so please excuse me if I missed something obvious. Or, if this has already been explained before, please direct me to the correct thread so I can continue reading.
I have a 2007 suspension, bone stock except for 1 sway bar swap(OEM). Given that the car is now over 10 years old (and 80k miles), I figure the shocks are due for a refresh. I ordered all 4 from a dealership.
BUT! I acquired a 2003 suspension a while back, so I have those set of springs. I have some questions about potential suspension mix n' matching, and some advice. For background, I do NOT daily my car, I use summer tires, and usually take it out mostly for sunny/cool days and autocross.
I have been reading up the mini dissertation from twohoos here:Characterization of OE Suspension Springs
The important information is here:Summary of spring rate findings:
Front Rear Front Rear
Model Year Spring Spring Sway Bar Sway Bar
--------------+------------------+--------------------
2000-2001 219 291 393 427
2002-2003 246 309 300 396
2006-2007 262 269 300 311

Note: All figures are in lb/in. Divide by 56 to get kg/mm.
My questions are thus:
1. I'm going to start taking the extra suspension apart, and I'm sure I'll find out as I go along, but... does anyone know if there are any suspension components that are NOT interchangeable (i.e. will not fit together)?
2. Is the large difference in oversteer/neutral handling from 01 - 07 primarily from the difference in spring rates? I see a difference of 72 lb/in. for the MY01 and 63 lb/in for the MY03, but only a difference of SEVEN for the MY07. I know that the difference between f/r sway bars aren't the same, and they aren't linear, so I'm not sure which had a stronger effect.
2. How different are the shock dampening rates (if any) between model years? This I could not find.
3. Since I primarily take the S out for fun, I was thinking about this setup:

Shocks: OEM all around Brand new MY07
Front Springs: Stock MY07 (262 lb/in.)
Rear Springs: Stock MY03 (309 lb/in)
Swaybars: Stock MY07 (or with the rear MY01)
As I understand it, this should make the car prone to oversteer, but I'm not quite sure how much of a difference (cue someone saying "It's about the WHEEL RATE"). Could I get some advice? Am I compromising something here other than making the car more tail happy?

4. Is there anything else I missed? Something that the more experienced will see immediately and say "Stop what you're doing, boy, before you kill yourself." I'm more than happy to keep it stock 07 completely, but I figured since I had these parts at my disposal, it may be fun to begin to mess around with suspension setup.

Thank you in advance!




PS. I included the 2000-2001 information because I got the sway bar from that MY. I BELIEVE it was the rear, but it was 2 years ago, so I can't remember (I have the stock one, though, so it would be easy to return to it).

B serious

The fastest stock S2000 has slightly stiffer front springs, and stiffer front bar.

twohoos

Everything will fit as you've planned it. You can also use the 269lb rear springs on your front shocks if you want the extra 7lbs. You *might* notice a fraction of an inch higher ride height at the rear with the MY03 springs on MY07 dampers. For bars, I'd keep the AP2 rear and look for an MY01 or CR front.

The biggest factors in AP1 vs AP2 handling were tires (size/compound/tread) and rear roll geometry (new rear subframe). The spring/swaybar changes were mostly tweaks to get better ride refinement with minimal handling impact. The '08-'09 went back to a little stiffer, more AP1-like ride.

postwarart

... The legend! Thank you.

B Serious, I'm assuming you mean in autocross? While the idea of being the fastest does seem appealing, it's not the primary reason for owning the car. I'm still learning how to handle it as it is, so I don't know if something like this would earn me seconds around the course... yet.

Either way, do you have anything to back this up? Not that I don't believe you, but I would like to do some reading on it if you have anything.

B serious

I was alluding to the fact that the fastest stock S2000 is the CR. Which is a fact...

What's the goal of your setup? I thought the point of it was to be faster during autocrossing. Or is this for ride quality?

postwarart

D'oh! How did I not see that? Thank you.

The goal is to experiment a little, without leading to disastrous results. I keep hearing that suspension tuning is a "dark art," and it is kind of intimidating, because I'm still not sure how I should change my suspension due to my driving habits. Or if my driving habits are good enough to warrant a change in suspension at all.

I do NOT want to sacrifice ride quality, but I do want to *improve* the handling for twisties/autocross. As far as I understanding, the 07 has the softest suspension, but the most neutral as well? I'd like to get a bit of both worlds - stiffen up the shocks, while introducing mild oversteer.

B serious

Well...try different stuff and see what shakes out.

People have different preferences...and it seems like you just want to learn. Experimenting won't hurt anything.

Its not really a dark art when the parts have already been developed, and you're mix/matching. Its all very simple and shouldn't intimidate anyone.

Shock tuning is different for all years, I'm sure. So you will likely have shocks with the most agressive compression valving and least agressive rebound valving since your shocks correspond to an 07.

I wonder if Honda sells shocks separately and if they are different part numbers per year.

Basically....stiff rear springs/roll resistance = over steer.

Stiff front springs/roll resistance = under steer.

Car Analogy

You are a perfect candidate for tbe suspension modeling spreadsheet I built. It lets you experiment on paper with mix and match different springs and swaybars, and see the effect on front vs rear bias, and lets you compare it to the stock bias for any year S.

It has formulas that use the motion ratios of shocks and swaybars.

It calculates wheel rate and combined bias of springs and bars. It will also give you the natural frequency of any setup you're modeling.

I already did what twohoos is suggesting here. I'm running rear '02 springs in the front, and '04 rear springs in the rear on my '06. I'm also running '01 swaybars. All planned out for those specific components based on spreadsheet.

It is indeed .25" higher in front now from running rear springs in front, as hoos speculated. Not ideal, and something I plan to address.

Anyway, I prefer this more livley rearward bias as my car is for fun, not for fastest way round a track. That and I despise understeer.

Send me your email address and I'll send you the spreadsheet.

It is of course just a tool. Nothing replaces actual experimentation and driving a given setup. But this can really help focus things and give real perspective, vs throwing darts at a board and hoping you hit something good.

hai1206vn

If you want the fastest combo possible, pick up the CR springs AND shocks, no question. It's a very fun ride and is only slightly stiffer on the street. Price is basically the same as other OEM combos.

If you're trying to stay in stock class at autocross, you can't do any spring change.

I feel that the 02-03 springs and sway bars give the most neutral ride. Put that on any AP2, which has better geometry, and you should get a neutral and predictable car.