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hi,

I sometimes still feel an EX civic has flowing handling...maybe because it is light?

Can someone tell me what can I do to increase stability and handling?

what I know is front strut bar, front sway bar and rear sway bar...

what exactly sway bars do?

and how do I pick for good bars? I have seen many cheap strut bar on ebay, they are useless aren't they?


thanks

 
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i think the best thing you could do to upgrade the stock suspension is getting the rsx 19mm rear sway bar. this will stabalize the car alot more than stock and does not cost a whole bunch...under $100.00. read the suspension FAQ or search on the sway bar topic and you'll find alot of good info.

 
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Ah, from the knowledgable honda-tech.com:

in a nut shell,
depending on the thickness/size of the swaybar, it will adversely factor into how much that portion of the car "gives" prior to letting go.

a good example is arm wrestling.... lets say you arm wrestle a little peewee. you can easily win.....as you wrestle him, you slowly put his hand down to the table.

now lets say you wrestle someone 2 times stronger than you....as soon as the match starts, you can hold him in place....but then as soon as he gets pumped up, you get tired and he slams your fist into the table.

this example would imply to either a thicker bar in front , or in back.

Sway bars wont reduce "body roll" as you think it would.

instead they will probably cause you to really mess up your balance.

body roll is caused by the suspension accomodating stressful situations, and the piston gives in. to reduce this body roll, you can change the suspension to a shorter travelled shock with a higher spring rate.

this will cause your car not to induce as much body roll.

 
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Finally.

Anti-sway bars make a car lean less by tying the right and left sides of the car together. They basically allow a car with "soft" springs to have a nice ride when running straight but at the same time prevent excessive amounts of body lean when going around corners.

Ideally - you should not count on the anti-roll bars as much as the springs when designing a suspension. Choosing spring rates carefully can allow you to have great performance even WITHOUT anti-roll bars - or reduce the need for a thicker bar. The suspension setups provided by a manufacturer are always a compromise between ride comfort and performance. The more you swing towards the performance end of the scale - the more ride comfort degrades <---big generalization.

Generally heavier cars have bigger antiroll bars because they have bigger springs too. FWD/RWD/AWD and concomitant weight distribution of the engine and drivetrain will also affect the selection.


quote:
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My findings seem to indicate that sway bars have a much bigger effect on body roll than springs & shocks. Is this true?
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Sway bars affect the motion of the springs only. Spring rate and weight/height of the vehicle are the main factors in suspension dynamics.

 
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Oh, and strut bars only work if your car is lowered.

 
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thanks

performance trade with comfort ride...

what have lexus done on their car, how do they achieve performance and comfort all together?

I know lower the car would put center of gravity of the car closer to ground hence decrease effect of angular momentum (U1 engineering physics) however, shorter spring will be stiffer...so I affraide that since civic was never designed to be hard, an hard spring would lossen some mechanism in the car.

 
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Just so I dont have to repeat my self for the Umptenth time, just read this Suspension Tuning 101



SlammedBlueEM2 has some of it right, but there are some things that are just not practical for a street car to use. such as using the springs to adjust body roll ect... there would be a point where the springs would become to hard for comfortable street use as well as difficulty in adjusting the springs your self. Its just easier to get a set of sport springs with moderatly high spring rates, and tune the rest of the handling with the Anti-roll bars (this is especially easier with adjustible anti-roll bars).

there is a lot more to this, but its lunch time and I'm hungry.

 
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I wonder if anyone can provide the actaul data sheet of Lexus is300, subaru WRX or even cobra springs.

so at least we have actual numbers/coefficient to adjust to.

what kind of spring, bars with what data/coefficient will give best handling on civic?

 
Rep Power: 380

Ok, i've finished eating,

Strut bars and anti-rollbars/rollbars/anti-swaybars/swaybars do two completly different jobs.

Strut bars, also known as tie bars(when the car dosn't have struts) are a chassis reinforcment. Chassis reinforcements are very important to performance handling, the reason for this is that every time you hit bump, take a corner or other wise make your car move, the chassis flexes. Chassis flex is bad because the chassis acts basically like a very large undampered spring, where every time it flexes, it occilates. This can make the car difficult to tune, and if it is bad enough it can make it down right impossible to tune. As far as chassis reinforcements only working when the car is lowered is not correct, chassis flex happens just as much on a stock car as a lowered car you just dont feel it as much because of the compliance of the suspension. so reduce chassis flex as much as you can.


Anti-roll bars, These things do 2 major jobs. First the help the springs resist body roll. Body roll is bad because it alters the angle in which the tires interact with the ground(due to camber changer) thus altering the tires contact patch giving you less traction. Springs also do this job, but it is not practical on a street car to have springs with such a high spring rate as to completly remove body roll, as the ride of that car would be so rough that you would never want to drive it. (there are other reasons for not having an Extreamly High spring rate on a street car as well as on a race car) So with Anti-roll bars, you can have lower spring rates for a smooth ride and strong Anti-rollbars to lower the amount of Body roll durring cornering.

the second job an Anti-roll bar does and the more importiant is to Adjust the Roll Couple Distrobution of the car. Simply put, roll couple distribution is the amout of roll resistance at the front of the car relative to the amount at the rear. how this affects handling is rather complex, but basicaly the side of a car (Front or rear and side to side in some racing) with the higher relitive roll resistanc will have more weight placed on it durring a turn. On a front wheel drive car, more weight is placed on the front of the car then the back, 60,40 I believe is the weight distrobution for our cars. When we turn, most of that weight stays on the front tires, which easily over loads them and they skid, Understeer. By puting a larger REAR anit-roll bar, you force more of the weight to the back of the car durring a turn, allowing the front tires to grip better and lower the ammount of Understeer. Idealy when you tune your suspension you want nither Understeer or oversteer, what is called Nutural Steer(when both the front and rear tires "let go" at the same time) this is the point where your car is making its maximum traction with those tires, on that surface.

There is a bit more to it, but I have to get back to work now.

 
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This information would be worthless to us, as there is a difference between spring rate and wheel rate we would need to know the wheel rate. and you are also working against platform advantages/disadvantages as in FWD Vs RWD Vs AWD as well as where the engine is places as in Front mount or rear mount. the reason for this is that a FWD car will have harder springs in the back when compaired to a Rear wheel drive car with the engine mounted in the front, which in turn would be different to a Rear mounted rear wheel drive car.


Wheel rate is the Working Spring rate at the center line of the wheel. it is adjusted by the length of the control arm, and where the spring is attached to that control arm among other things. The wheel rate will ushuall be lower then the Spring rate, unless you have a Formula cars suspension.

 
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Like you said... it depends on the spring rate. I agree no one should have very high spring rates + shorter shock travel on the street unless you happen to track your car. But for good streetable handling, you can depend on springs more providing you choose the proper spring rate and not just throw on the stiffest spring on the market. Spring rate/ride comfort is a personal decision as some people do not mind a rough ride, but like you said, they're options whether you want to be practical or comfortable in your own way. It depends on how much one wants to sacrifice comfort for performance. But keep in mind I do agree that one shouldn't throw on the stiffest set of springs.

 
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most definitly, there are even times where a softer spring on a race car can be usefull, as not all race tracks are as smooth as we would like.

 
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Yeah, plus anti-roll bars can sometimes be bad for uneven surfaces. That's 'cause if one corner experiences a bump, it'll act as if there's a stiffer spring in there. Only when both front wheels or both back wheels experience a bump together will the anti-roll back not do anything.

I went on this one trip to the mountains with a bunch of other civics and TwilightX's DX with no front or rear sway bars and very soft spring rates did very well. That's 'cause it evened out all of the bumps. All of the other drivers were impressed.

 
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Get a tower bar

 
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ok, thanks,

will only one strut bar help if I keep the stock bars/springs?

if I want to keep the oem spring for comfort, will you think one extra strut bar will improve stability so that driving will be more safe on highway curve, highway lane change at 140km/h etc

I would prefer to do mod which improve comfort and safety and not lower/drop the car, since it is a more rational thing to do in a country with snow and uneven road....

 
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Of course it will, any thing you do to decrease the amout of chassis flex will improve stability. I would go with the front upper Strut tower bar first then go from there. Avoid Flat bars (DC) they arn't as rigid as a Tube type bar (Neuspeed, Spoon) also try to get one that has as few parts as possible, as in try to get one thats welded togeher (Neuspeed) rather then held together with bolts although some bars with bolts are very well made (SPOON). If you are looking for something to make the car more safe in a turn, a 19mm RSX rear anti-roll bar would be a nice addition for some one who isn't looking for all out performance. it will allow the car to turn better by lowering the amount of understeer. and its not strong enought to cause a loss of ride quality over bumps.