I just picked up a set of Eibach sway bars. After reading the forums, the general consensus is to just install the front Eibach bar and leave the rear stock. What are the advantages to just using the front bar vs the set? I really only use the car for autocross.

Here is my set up:

2000 AP1

Koni Yellow struts (Front turned to hard, rears 3/4 hard)
Swift Spec R springs
Hankook RS3 tires 225/255 set up

Thanks for the advice!

 

Keeping the OEM rear will keep some rear compliance.

Not many upgrade the rear. I've just gone back to OEM (stiffest one though)

 

well seeing you have an AP1 and autocross. seems like you have an STR classed car. im not sure how much prep you will get into. for example squared tires. if the eibach bar is stiffer than your stock ( which is already stiff ) it will induce oversteer. AP1's are already known for that. most guys in STR either leave the rear bar off or go with a miata front bar. ( theres a DIY ) but also depends on your driving preference. personally i would put just the front bar on first. see how that works out

 

Running both Eibachs on staggered tires is fairly neutral on track. Since the auto-x people tend to prefer much more understeer than track people, I'm guessing you'd prefer to leave off the rear bar and stick with stock.

To compare, the Eibach front bar at full stiff is just a tad stiffer than the CR front bar. The rear Eibach bar, even on full soft, is a lot stiffer than any of the stock bars, enough to lift wheels on driveways. I'd view the rear Eibach as a track band-aid for staggered tires and overkill for auto-x or track non-staggered setups.

 

Run both bars if staying staggered with moderate spring rates.

I have been running both with staggered tires for 2 years and have been very happy. The car is very neutral with slight understeer tendancy. Only recently after I installed SRC's on 16k springs did i find the rear bar just adds too much spring rate and has to go.

 

I ran both Eibach bars with Eibach springs on a staggered set up on my AP1 and it over steered like crazy during autocross runs. I ended up disconnecting the rear bar.

 

Wait ,I thought the CR and AP1 front bar were the same. The Eibach front bar is only a small amount stiffer than either of those on full stiff setting?

 

The bars changed through the years so there isn't such a thing as an AP1 bar.

https://www.s2ki.com/s2000/topic/960...way-bar-rates/

 

FWIW, I like the balance of my '08 with comptech front at second from stiffest (around 750 lbs and the Eibach non-adjustable rear (around 500 lbs). This is on stock suspension with square 17x9's and 255's. I feel it helps control the body roll of stock suspension and makes the car faster, but higher springs rates would be a better solution. Setup the car the way you like it. I don't like many people's overly pushy setups that require chucking the car to get it to rotate. Everyone has their preference.

 

Keep in mind that STR winners are running 800-900 lb springs, square setups, 2.5-3.0* negative camber, tons of caster, $3,000 + remote reservoir 2-way (or more) adjustable shocks, etc etc ... When you are working with such modest modifications, what you need may not look quite the same. For example, the koni's don't have much bump travel. You are likely running on the bumpstops out back, effectively multiplying your rear spring rate. Your car might handle better with more rear bar to help keep you off the stops. Counter-intuitive but possible. Look at GC's extended rear top hats for another possible solution. Lots to think about.