Are sway bars worth it?

[wparsons]

Originally Posted by venturaII

Or if all you're looking to do is reduce lean a bit, and you're otherwise fine with the existing spring rates and balance, buy a set of bars that increase the diameter uniformly and call it a day.

I wouldn't do that, I'd look for a set that increase the front and rear roll stiffness by the same amount.


1mm more on an 18mm bar is going to be different than 1mm more on 14mm bar.

[wparsons]

Originally Posted by venturaII

I don't think he's disputing the obvious fact that sway bars tie both sides together to a certain degree, as they do with the factory setup. It's that going to a moderately larger bar doesn't immediately turn the suspension into a beam axle. Yes, some movement gets transmitted to the opposite side, but then again, that's how they're supposed to work in the first place.

I don't think he got that at all, and that's what I was pointing out. End links or attached directly to the strut, the only independent movement is through the sway bar twisting. We definitely agree on that, I was clarifying for the other guy.

[Ultramaroon]

Originally Posted by wparsons

I wouldn't do that, I'd look for a set that increase the front and rear roll stiffness by the same amount.


1mm more on an 18mm bar is going to be different than 1mm more on 14mm bar.

Even if the effective spring rate ratio between front and rear sway is maintained, the real-world results are still unpredictable. That's one of the things I learned studying this stuff formally. Do all the math to get ballpark but, even with today's numerical methods, that's all it'll be, ballpark.


Of course, for most of us, myself included, ballpark is all that matters.

[nikitopo]

I wouldn't remove the swaybars from a suspension that was designed to work with them. The only application I can think of it would be off-roading usage, but this is not very relevant to our platform.

[Tokay444]

Originally Posted by nikitopo

I wouldn't remove the swaybars from a suspension that was designed to work with them. The only application I can think of it would be off-roading usage, but this is not very relevant to our platform.

A lot of fast FWD racers remove the rear sway, setup an extremely stiff front bar, and just drag a limp ass around.

[venturaII]

Originally Posted by wparsons

I wouldn't do that, I'd look for a set that increase the front and rear roll stiffness by the same amount.


1mm more on an 18mm bar is going to be different than 1mm more on 14mm bar.

That's just basic math, but considering no one sells sway bars in tenth of a millimeter increments, the point I was trying to make was to buy a set that are as closely matched to the f/r ratio as the stock ones are, assuming no change in balance is wanted. No set will maintain the exact same rate ratio, simply due to how diameter increase changes torsional resistance exponentially, and that available sizes are not granular enough. But, they're close enough, generally, so that an even increase doesn't alter the balance much. Eventually the math would work in favor of an uneven increase, but I think that'd be a pretty sizable change at that point.

Also keep in mind that even though the rate rises exponentially, it's still a relatively small fraction of the total roll resistance at that wheel. As mentioned before, it's generally a tuning device if your existing setup is close to what you like.

[venturaII]

Originally Posted by Tokay444

A lot of fast FWD racers remove the rear sway, setup an extremely stiff front bar, and just drag a limp ass around.

Again, platform dependent. There was a popular suspension outfit at one point who had a very fast kit for A1 chassis VWs which did away with the front swaybar completely, and used a gigantic Carrera bar in the rear... The cars were undeniably quick, so the setup worked; it was just quite unconventional compared to the majority of other kits at the time.

[Racecomp Engineering]

The difference in effective wheel rate you get from going 1 mm stiffer in front vs 1 mm in the rear is a good point many often miss.

But what I think @Ultramaroon was getting at was...even if you increase front and rear wheel rates by exactly the same 10%, you could still be changing the handling balance of the car.

- Andrew

[NoHaveMSG]

Originally Posted by Tokay444

A lot of fast FWD racers remove the rear sway, setup an extremely stiff front bar, and just drag a limp ass around.

I have always seen the opposite on FWD cars to try to get the car to pivot more around the front.

[Tokay444]

Originally Posted by NoHaveMSG

I have always seen the opposite on FWD cars to try to get the car to pivot more around the front.

I have seen this, but not always. Nothing is ever absolutes. The theory is, you don't want wheels you aren't putting any power to, doing the any oversteering.

[NoHaveMSG]

Originally Posted by Tokay444

I have seen this, but not always. Nothing is ever absolutes. The theory is, you don't want wheels you aren't putting any power to, doing the any oversteering.

That is the opposite of what I have heard on FWD. They are trying to eliminate push so you have to take grip from the rear to get the car to pivot. If you watch some exterior video a lot of the times they will lift the inner rear tire from the front being so soft and the rear being so much stiffer (in respect to roll balance) . This is really obvious on even stock performance trim cars like the Fiesta ST.

[RayRay88]

Originally Posted by NoHaveMSG

That is the opposite of what I have heard on FWD. They are trying to eliminate push so you have to take grip from the rear to get the car to pivot. If you watch some exterior video a lot of the times they will lift the inner rear tire from the front being so soft and the rear being so much stiffer (in respect to roll balance) . This is really obvious on even stock performance trim cars like the Fiesta ST.

Agree, having owned an EK in the past. Honda Tech's race forum is riddled with large rear hollow bars and over sprung rear rates.
Not uncommon to see 12K front and 18K rear.
Recently the front biased stagger is becoming the norm. A lot of Japanese tuners use this to get the car to rotate better to great effect.

[Tokay444]

Originally Posted by NoHaveMSG

That is the opposite of what I have heard on FWD. They are trying to eliminate push so you have to take grip from the rear to get the car to pivot. If you watch some exterior video a lot of the times they will lift the inner rear tire from the front being so soft and the rear being so much stiffer (in respect to roll balance) . This is really obvious on even stock performance trim cars like the Fiesta ST.

Like I said, nothing is absolute. I've seen devastatingly fast FWD cars with no rear bars at all.

[NoHaveMSG]

Originally Posted by Tokay444

Like I said, nothing is absolute. I've seen devastatingly fast FWD cars with no rear bars at all.

Yeah I have no doubt. Sway bar is not the whole story. I know there is a CRX over here that does hill climbs and pretty much runs no rear suspension. I know a bunch of drift guys out here run stupid stiff setups with no bars at all, but drifting so I am pretty sure that with my 6k/6k rates that my sways are not a huge part of my setup, just that them being adjustable allows me to change the behavior of the car a bit.