124Spider

I use my S2000 for autocross, track days, and as a daily driver.

Following the advice in the autocross setup FAQ, I have ordered a Gendron sway bar (the middle thickness). As I await its arrival, I am curious about how best to use it.

As I understand it, the MY04 has less oversteer than previous models, and in fact can understeer more easily than the previous versions. I know that my car has understeered trying to get around turns on a track in suboptimal conditions, to the detriment of my front tires and my line.

How does one set the Gendron bar on a MY04 so that you control oversteer (presumably the purpose of it), but don't cause the car to badly understeer? Are there different settings one would use for the street, autocross and the track?

Thanks.

Nickfromny

I have an MY01. I use the solid Grendon bar at one off full stiff. When I used the stiffest setting the car would not roll at all and I could not get enough weight to the outside wheels and I would get lose and sometimes spin. Had my best results with bar set at one off full stiff. The FAQ says full stiff at Topeka which is concrete. I have not driven on concrete for auto-x or track yet and this is my experince on sealed and non sealed blacktop with A3S04's. I would understear only when I over cooked a corner but mostly pin turns and had to learn the threshold at each course usually by the 2nd or 3rd run. Pin turns cause everyone to understear IMHO, no matter what the set up.

kitwetzler

on my 04, I use a gendron bar 1 from full soft. Try that as a starting point, but I don't have a stock suspension, either.

PedalFaster

[quote name='124Spider' date='Feb 17 2005, 08:41 AM']As I understand it, the MY04 has less oversteer than previous models, and in fact can understeer more easily than the previous versions.

kitwetzler

The 04 cars are a lot more stable on the throttle, because they have so much less bumpsteer than the earlier cars, they can be run with less front bar because of that.

Ok, that said, I haven't autoX'd my car, but my 04 is a lot faster around the track than my 00 was...

PoweredByCamry

I have the hollow Gendron with the 0.25" thick wall (I think the same as what you have). I have run with and without the bar, on stock and R compound tires (Victoracers and A3S04s).

You need an alignment, the push on the '04 is all coming from the fact that the OEM front tires are ridiculously undersized for a 215 (contact patch probably smaller than most 195s), and with factory camber you are only using half of that.

You don't need to worry. The Gendron bar has a lot of adjustments, there are 6 holes total (though one is blocked by the shock). The 3 softer ones are pretty soft. With either stock bar or Gendron on one of the softer holes, you can achieve pretty good balance on OEM RE050s. But the car will always feel limited in steady state by the tiny front tires. Inside rear wheelspin is not an issue on street tires.

The stiffer settings will be more useful on R compound tires, or if you get a set of street tires with less rear bias. In my mind the car will always be faster with more front grip and then the bar to balance it out. The amount of bar you need and want is directly proportional to the amount of grip you have from tires *and* surface.

Peter

Nickfromny

Steve,
On full stiff I could not get the car loaded up the outside wheels. Car would not "roll" at all on blacktop. It would stay flat and then break lose suddenly with no body roll at all. At 1 off full stiff car would roll slightly and weight the outside wheels heavily, providing more grip and giving me more feedback pryor to break lose point.
Nick

glagola1

You nailed it there. The discussion of the bar needs to be prefaced with a tire size reference. If you are running stock tires, your car will understeer so much more that it will handicap your lap times.

Now if you have changed your tire stagger proportionally to the bar, things should be good.

The front sway bar became popular because of available R compound tire sizes and the fact that in Solo II stock class ruling, you are allowed to change the front swaybar. I think the car handles quite well in stock form (albiet almost too neutral) and I understand the MY04+ is slightly understeer biased from the factory. I would think in stock form the car would not benefit from the use of a front sway bar.

124Spider

So, do I understand correctly as follows:

As long as I am on stock tires, I should keep the bar at a setting which approximates the stock setup.

I have R tires--Michelin Pilot Sport Cup; not an aggressive R, but probably a good deal stickier than the stock RE050s, in 255/40-17 and 225/45-17. When I use these, I will be better off using the bar on a stiffer setting.

The correct setting will be a matter of feel.

For the track, as opposed to autocross, I may again have to put the bar on its softest setting.

PoweredByCamry

Sort of. You will want to go a bit stiffer with the PSCs, because you are not only adding more total grip but also changing the F/R tread width bias (maybe not nominally, but in reality yes) toward the front. You may not need the stiffest setting, I found I only needed anywhere from the 3rd of 6 to the 5th of 6 with Victoracers depending on the surface (dirty asphalt to grippy concrete).

As for stock tires, I would still start on the 2nd softest hole and see how it feels. The big factor is whether you have sufficient front camber. I think the bar will still help. My car on 12000 mile RE050s with the bar on 2nd soft is still overall very loose, it pushes in tight, slow corners and is quite loose in fast stuff. But I am running about -1.7 camber in front.

Personally, I would want to start stiffer on track. Cars tend to get looser at high speeds, mine certainly does. However, parking lots can be deceiving because the surface is often quite dirty so you have to experiment.

One thing about the Gendron- when you are on the 2 stiffest holes you need to keep an eye on your steering boots rubbing the arms. Make the endlinks as short as possible, and if you run like that on the street check your steering boots periodically.

Peter