jaboyd

I recently purchased a stock 2007 S2000 w/Volks CE28n 17x7.5, 17x8.0 running 225x45 and 255x40 street tires. Car is great but it has more roll than I'm used to in a performance car. After reading several posts and seeing the suspension changes from year to year it looks like I could help the handling a little by just upgrading the front bar to either an 2008 frt bar (354 #/ft) or an Eibach (368 #/ft). I'm not trying to make a race car, just a little better in the twisties.

Question 1). Would simply upgrading the front bar help the handling?
2) Does the 2008's handle much better than the 2007 ( 2008 has slightly higher frt/rr spring rates and front sway bar, but rear bar is the same)?
3) Will going from a 300 #/ft front bar to either the 354 or 368 #/ft front bar induce a lot of push (street driven only on Bridgestone RE11A) using the stock rear bar on an 07?
4) The Eibach rear bar seems huge compared to stock and probably wouldn't match well with the oem spring/shock rates, IMO. Any thoughts would be appreciated.

Looking for some guidance to improve handling wo/compromising the balance and daily driver aspect of the car.

deepbluejh

I upgraded the front bar in my '07 to a CR bar and think it's a nice upgrade. You're not going to notice any increase in push until you are at the very limit of handling on the car. Any lesser handling maneuvers are still going to display less body roll and no adverse effects. If you wanted a bar to compliment the front CR bar, you could either get a rear CR bar, or an AP1 rear bar. These will help restore a more neutral handling balance at the limit and are both very affordable upgrades.

jaboyd

I'm a little concerned with going to the CR front setup bc of the possibility for understeer at the limit...as you noted. I'm thinking about putting in a 2008/9 frt sway bar which is 354 #/ft ...softer than the CR frt @ 392 #/ft. If I just change to the front bar I mentioned, my bars would be the same as the 2008/9 = 354 #/ft, 311 #/ft but my springs would remain the same ...which are approx 20 #/in softer than the 2008/9. That would give me a slightly softer " effective wheel rate " but stiffen up the front.

I'm thinking about trying this as step one, but if I feel I need more rear bar I'd consider the rear CR sway bar. The combination of the 2008/9 front bar and CR rear bar would give a very similar frt/rear bar ratio 354/362 vs stock 300/311.

SlowTeg

I have an '06 and changed to a 00/01/CR front bar, and an 02/03 rear bar. I swapped sway bars after installing KWV3's, but feel the sway bars did help a little. Overall the balance w/ the larger front bar and larger rear bar is perfect for a staggered setup, imo. The handling is very neutral.

jaboyd

It sounds like you swapped the sway bars after the KWs...correct? If I understand correctly you are running 00/01 front bar (393 #/ft) and 02/03 rear bar (396 #/ft), so you are running a square setup. Do you know what spring rates you have on the KWs? What tire sizes do you have on the car?

SlowTeg

Yes sway bars were after the coilvoers. They are the "standard" KWv3 rates, which I think are ~450lb in on all 4 corners. I'm running a staggered tire setup 225/255 Dunlop Z2's.

jaboyd

Ok that makes sense. Most likely the reason that you didn't feel as much difference when you added the sway bars is bc you had increased the spring rates approx 60%. The sway bar effectiveness is determined by several factors and deflection (distance) is one of the key elements. Since you have stiffer springs the car will have less sway bar deflection, so increasing your bar dia approx 30% means you've probably returned to nearly stock sway bar ratios with those spring/bars. I'm sure it has a much tighter feel with the upgraded springs, valving and sway bars.

I'm looking to keep the ride quality while improving (but not radically) the cornering and roll characteristics. I'm going to try the front 2008 bar first and will most likely do the CR rear bar. When combined with the stock springs (more deflection) I should gain effective wheel rates without sacrificing much ride quality while sustaining the overall suspension ratios.

tcjensen

Just do the Eibach adjustable front and rears. Bars definitely help on the stock suspension. The adjustability will help you tune it to what feels best. I'd start with stiff setting front and soft setting rear. But with your staggered setup, you could probably do stiff front and rear. Just run a 1/8 to 1/4 inch toe in on the rear, and maximize your negative camber all the way around.

jaboyd

Thx for the tips!

jaboyd

I decided to use an OEM sway bar and swapped out my 2007 frt bar (300 #/in) for a 2008 bar (354 #/in). this is just slightly softer than the Eibach frt bar soft setting. This has done a very nice job of eliminating the front mid-corner roll and flattening the handling. I'm running stock springs so the ride is still very compliant. Considering swapping out they rear bar (311 #/in) for a 2009 CR rear bar (362 #/in) to raise the overall wheel rates without overly stiffening the ride.