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Blaze
04-29-2004, 05:08 PM
Hi Again:

I have a few questions about sway bars. The questions are not who makes them, whos got them or what the best brand is.

I'm going to go shopping for a set of bars soon but before I do, I want to understand (more intimately) how they're designed and why they're created the way they are/were. I'd like to know what questions to ask manufacturers and what answers I should expect to have.

My thoughts are that most sway bars are designed in a similar fashion to the OEMs. But design-wise, what matters? Thickness to me means that they'll provide more resistance to body roll. But do all manufacturers run thicker bars to achieve this, or do some use other materials to make the bars. Once the bar is made, what makes them better then the one next to them? Do they use some type of chryo process?

Are some sway bars designed to work in a progressive fashion like springs or are they all linear by design?

Is resistance the most important thing with a bar? And if so, how much is too much? (how much is not enough for that matter) And how do you decide that number? Is it by the weight of the car, or the travel capacities of the suspension?

Thanks much,

Jason

Blak94GSX
04-29-2004, 05:34 PM
The primary purpose of an anti-roll bar is to trim the handling balance of the car. If the car is understeering, adding a stiffer rear bar reduces grip in the rear to reduce understeer. It is important to note that the stiffer rear sway bar does not add grip in the front, just reduces grip in the rear so the front to rear grip ratio is more front centric.

The primary criteria for choosing a sway bar should be track results and how it matches the rest of your suspension components. The bars are linear by definition, but are always slightly progressive due to the soft mounting and curvy design to clear stuff underneath the car. Basically it is linear... The stiffer the bar is, the more grip it takes away from that end of the car. So you choose the bar stiffness depending on how you want to change the balance of the car.

On an EVO, you don't need to change the front sway bar, as it is already a bit on the stiff side. Ideally you just go to a stiffer rear sway bar to reduce the EVO's tendency to understeer.

Lastly, the sway bar is just one part of the overall suspension package, so the bar you get depends on how the rest of the suspension is configured.

han74j
04-29-2004, 08:46 PM
i think blak94gsx explain it pretty good.

stock 23mm front, i think its like 21mm rear if im correct

cusco makes front 25, 23mm and rear 18, 23mm

Perrin makes rear 18, and 23 i think

Progress makes them too i think

eiboch also

from what i understand it is good to change the rear to a ticker one, 23mm adjustable is what most makes. from is already pretty good, and changing it ur self will take a very long time!! i got my like 2 month ago and still haven't put that bitch in yet!

leaveit2bevo
04-29-2004, 09:10 PM
If your going to get a sway bar go see john mueller at RRE he will set up peferct

ez76
04-29-2004, 09:16 PM
do people install thinner front bars?

put another way, why does the evo have a front bar at all, since the 60/40 weight distribution make it understeer so bad already?

leaveit2bevo
04-29-2004, 09:18 PM
it does have a front bar

ez76
04-29-2004, 09:30 PM
it does have a front bar

right. do people modify the front bar by putting a thinner one in place, to reduce understeer that way? or why not remove the bar completely, what's it doing for you?

han74j
04-29-2004, 10:10 PM
If your going to get a sway bar go see john mueller at RRE he will set up peferct

what does he do to the rear say bar??? i man the adjustable sway bars theres only 3 settings.... then there ares the energy bushings... other than those whatelse does he do to the back?

JanSolo
04-29-2004, 10:16 PM
Are the ends of the RRE sway bars welded?

han74j
04-29-2004, 10:22 PM
Are the ends of the RRE sway bars welded?

they make their own?? i thoguht they use perrin ones...

Blak94GSX
04-29-2004, 10:27 PM
do people install thinner front bars?

put another way, why does the evo have a front bar at all, since the 60/40 weight distribution make it understeer so bad already?

Here is info on the RRE bar:
http://www.roadraceengineering.com/evoswaybar.htm

Front bar helps to stabilize the car when sawing the wheel back and forth for the slalom tests. Much of the stuff on the EVO is designed around making it perform well in the usual magazine tests. Like the stock brake pads are best for a single 60-0 stop, but suck ass for 5 60-0 stops in a row. The stock tires are awesome for most magazine tests. The suspension is about as stiff as a stock suspension can be without losing points for comfort, and it is no coincidence that 2nd gear tops out just over 60MPH so you don't have to shift to 3rd.

I recommend keeping a front sway bar for all around feel. Disconnect the front bar (unbolt one of the endlinks) for low speed stuff like AutoX or a tight road course, and of course a stiffer rear bar helps balance things out.

With the EVO and most front engined AWDs for that matter, the front weight bias means the car understeers from the factory. This is desirable for the average stupid driver that panics and hits the brakes because they are going too fast for a turn or the car starts sliding. The goal for handling though is to first maximize front grip by keeping the front pretty softly sprung and not throwing on a stiffer front sway bar. Then after you've gotten the max out of the front, you take grip away from the rear until you get the handling balance where you want it.

ez76
04-29-2004, 10:43 PM
thanks man, great info

leaveit2bevo
04-30-2004, 10:43 AM
If your going to get a sway bar go see john mueller at RRE he will set up peferct

what does he do to the rear say bar??? i man the adjustable sway bars theres only 3 settings.... then there ares the energy bushings... other than those whatelse does he do to the back?

he also does an allignment which isnt the normal crappy one you get at a tire store.

han74j
04-30-2004, 01:22 PM
If your going to get a sway bar go see john mueller at RRE he will set up peferct

what does he do to the rear say bar??? i man the adjustable sway bars theres only 3 settings.... then there ares the energy bushings... other than those whatelse does he do to the back?

he also does an allignment which isnt the normal crappy one you get at a tire store.

icic