at the risk of preaching to the wise, I've been trying to balance the handling on my JCW for two years (last year with Hoosiers in ASP and this year with Falkens in STX)

1. H&R coil overs and rear sway - full stiff
> still understeers, but much more grip and better perormance
2. Webb camber plates (-1.5 last year, and -2.2 this year)
> still understeers, but better turn in and overall grip
3. finally, in desperation, 40 lbs front and 30 lbs rear (I had previously gone UP on the rear tire pressures with no apparent effect, as high as 40 psi cold)
> rotates in slaloms nicely, but breaks away unless I am smooth - not progressive and really not too confidence inspiring, but better than before
4. and now at last, put in the adjustable lower rear control arms and take some of the excessive -2 or more camber out of the rear axle that occured due to stock geometry coupled with lower ride height - going to -1.0 degrees

That 4th step will occur Jul 3 and won't be tested in competition for a while after that - my hope is that it will be the final piece of the puzzle.

but the sway bar alone made less difference for me that tire pressures...

 

yeh, when you're running coilovers with high spring and damp rates,
you won't notice as much from swaybars opposed to someone running
stock or lowering springs + aftermarket swaybars.

 

with the PSS9s I felt the front sway bar was critical to keeping it flat...... Waylen drove my car at the Dragon and promptly made the addition

 

Subtle changes can make a big difference.

Progressive rate springs do not act like linear rate springs; A swaybar should be more noticable when paired with progressive rate springs...and a front bar will in general add to understeer and reduce traction to the inside front wheel. your PSS9 settings will also affect how noticable a swaybar is or is not.

Standing the rear wheels upright will absolutely remove understeer.

But as Kenchan wrote, heavy linear rate spring and dampers perform a bulk of of the work and the swaybar should be used as a fine tuning component.

In the end the total package matters most...set-up too

 

First, I am not an expert but from experience when I had the H sport springs and the Konis the car was stiff and flat and depending on the setting of the rear bar under and over could be adjusted...the ride ws beating me to death... I wantd something with more finesse..... I went to the PSS9s and the ride was much improved but the body rolled too much for my tatse and I just could not get used to it..... I added the front bar set the rear PSS9s at 5 and the fronts at either 3-4 with the rear bar in the middle and the front soft and the car is pretty neutral with a hint of understeer....which is what I wanted (the car came around at a bad time and I did not want that for the street) I can force under and over depending on throttle....which for my skill level suits me.... again, Waylen drove my car at the Dragon and made the change to his race car..... I just experimented and came up with a decent combo for an amateur driver

 

yeh, i should have referred to like the N1 level coilovers.

 

SpiderX,

I'm not an expert either - and I'm not picking on you. A swaybar works as the chassis rolls. When the body rolls, one end of the swaybar twists up and the other down. If there is no roll, there is no twist. some spring and dampers allow more intial roll rate - the car will intitially lean quicker. All else equal, a given swaybar bar will feel more noticable when used with progressive rate springs when compared with a stiff linear rate spring; the roll rate is intitially slower with a linear rate spring.

Cornering flat isn't on its own a handling attribute, but balance is and that's why I responded by writing a front bar will add more understeer and lift the inside front wheel...this is in general a fact...on its own it is fact.

But, how it all works really depends upon the rest of the package. I would have purchased the PSS9s if I intended to keep my car on the road. I prefer the consistency of a linear rate spring on the track. My Webb bar is set to nearly the softest setting and along with my Megans and the stock front bar I get all the rotation and grip I need. Others question that setting, why not more? It's the package, but certain truths cannot be changed; big front bars add to the understeer side of the equation...which is an attribute on the street.

This doesn't mean your set-up is wrong. My intention was to clarify, not to poke fun at your set-up.

 

Maybe I'm thick skinned but I didn't take it negative.... I was just relaying how my car behaves and how it is set up.... all I know is with my car set up the way it is it is flatter than it was before I installed the front bar and I like it...exactly what's rolling and twisting I don't even pretend to know (I will learn though) I have in my hands Fred Puhn's "How to make you car handle" Watt's "Secrets of Solo Racing" and Ross Bently's "Speed Secrets" my hobby is stamping out ignorance......starting with my own. Hopefully somewhere in these three books I'll get a start.

 

Noooo! Don't ever be happy. That leads to complacency and a slow, dreary death.

I assume you're dealing with the inherent understeer:
a) Are you still using the stock front sway bar? If not, your new one may be too aggressive.
b) have you dialed in enough negative camber on the front?
c) you may have to adjust your cornering technique to get a more neutral steering characteristic out of a street car that has to be suspension compliant enough to accommodate the occassional right seat companion. As you're entering the turn under power and you start to lose traction in front, lift on the throttle just enough to shift the weight to gain sufficient traction in front and lose enough in the rear to get the tail around for a neutral drift. Get back on the throttle hard (but smoothly) to maintain both front and rear traction at the limits. Using this technique you will find that relatively minor swaybar adjustments will make a big difference. This technique probably won't apply to slalom courses (never done that type of racing) but can take big bites out of high speed road course laptimes.

 

Yep, if cornering is on the bumpstops, a swaybar can do nothing, since then the "spring rate" is already really, really high.

Even when there is roll, a swaybar mostly affects steady-state cornering, while shocks control transients. So if you have a really big bar in back with floppy shocks back there and stiff ones in front, you can get push going into the corner and oversteer coming out of the same corner!