Hi,

On an FF car (ITR, civic,etc.), what do you guys think of the effects of removing the (stock) front anti-roll bar on a relatively stiff coilover setup to help it rotate (get it to be more neutral), on a front stiff biased spring rate (14k F/10k R .. typical Japan coilover specs)

*For road course racing conditions - not autox.

As you go to relatively high spring rates, the effects of a mild stock bar with all the soft bushings and such becomes less and less effective ... is this a good assumption?

Anybody else tried this before? I had experience with this setup on an EF civic before (with a very small rear bar ~16 mm) and it worked quite well. Anybody with a relatively stock DC2/ITR tried this?

Benefits: less weight ... save $ .. wht else?

Problems: more body roll ... unpredictable handling? etc.?

Thanks,

 

Why not switch the Springs front to rear and leave the sway bars?

 

while my car is awd, it still handles similarly, and has a similar weight distribution to a FF car. And I do have a pretty stiff coilover setup.

At VIR-South last year the car was understeering horribly. I couldnt figure it out, I thought the camber plate slipped or something was off with the alignment (later proved to be false)
So I unbolted the front swaybar (which is a beefy 22mm peice), expecting wild oversteer. But the effect was minimal, I got a little more rotation but nothing drastic at all.

It was pretty embarrasing that my instructor's SS Neon rotated better than my car!

 

True, we can definitely do that, but we're just trying to explore some ideas here ... and if I can save some weight ... all the better w/o the front bar.

As you guys are probably aware, some of the best handling cars don't have anti-roll bars ... like the Lotus Elise series.

Trying to get some comments about this as I'm planning to try this out soon and wanna see if anyone has some big No-No's or warnings about doing this.

Thanks,

 

Lots of ITA CRXs remove the factory front bar. Some schools of thought say to run the least front bar you car (like HF stock) if you have the spring rates to go with it.

When I was a kid, my step-dad used to build and prep formula cars for people and so I used to sit up for hours handing tools and asking questions. His line of reasoning was that "sway bars are un-handlers" as they limit the motion and travel on that end of the car. His point was that the springs and shocks were control devices but not limiters like a sway bar. Better to use them first to enable the suspension but leave opportunity for motion before attaching the sway bar to be a limiter. Obviously on a street car where you want to save some ride quality, sway bars are very good as roll limiters while keeping the springs livable. If you went up higher with the rate as ride manners matter less, then you need less bar to limit the roll. Just one point of view but it has some very valid points.

 

I dont think taking the front antiroll bar will give u unpredictable handling. I would say its the opposite. Just like having a snap-oversteering rear end from using a thick rear antiroll bar, using a thick front bar would probably result in a similar manner--snap-understeering characteristics. The more roll stiffness u create from using thick bars, the more unpredictable and snappy the car becomes. But using a smaller diameter antiroll bar or not using one should make the car more predictable, allowing the driver to detect when the tires traction limits are about to be reached. Using thick bars create a handling characteristic that is less driver-friendly as traction limets are reached more instantaneously.

 

well.........there is more to it then that. ironically, if you increase your spring rates high enough that the swaybar has little effect, removing it has little effect too. it really comes down to being able to hit your roll resistance number without a spring rate that is undriveable. the lower the car, the higher your roll resistance needs to be. the more grip your tires generate, the higher your roll resistance needs to be. test it and see what works for you. my bet is you won't feel a change at all, other then the placebo effect, which may be enough to make you faster in and of itself.

nate

 

Is there a 'roundabout rate that the front swaybar adds to the spring rate?
As to which swaybar, that is up to you....I just want to see some numbers.

 

24mm front bar has a wheel rate of _about_ 60lbs/in. it isn't very easy to measure this bar because of all the bends.

21mm front bar has a wheel rate of _about_ 40lbs/in. again, very hard to measure so this number is only a rough idea.

the thing with swaybars is that they are connected to both tires. so if your car rolls enough to compress the outside front 1", the inside front would be in droop 1". so if you had a 24mm front bar, you've now transferred 120lbs off the inside front and put it on the outside front.

what i'm trying to say is that just because the bar is "rated" at 60lbs/in or whatever, you need to have an idea of your terminal roll angle to know how much spring rate would compensate for the absence of the bar. trial and error is the easiest way to figure it out for your particular app. but with some measuring you could figure it out on paper too.

nate

 

What is the use of having a front antiroll bar if its going to reduce traction for the inside tire by lifting the suspension and thereby reducing the traction limits for the outside tire from the extra load transferred?

 

transient response and reduction in roll. swaybars don't effect the suspension when a bump disrupts both tires, therefore straight line grip wouldn't be affected such as what would happen with say 1000lb front springs. the swaybars still come into effect as the car rolls, reducing roll and preventing decambering of the outside front. think of swaybars and springs as a system, with both parts having to balance each other. too much of one with too little of the other is rarely good.

nate