Sway Bar Recomendation

[float_6969]

...The whiteline ones are like 26mm front and 17mm rear or something retarded...

Whiteline = 27mm Front w/ 5 adjustments & 22mm Rear w/ 3 adjustments

...but also understand that the thickness of the bar is by far not the only thing that matters. the distance from the axis of torsion (the axis through which the bar brackets mount) to the axis of the endlinks and the length and direction of the endlinks matter just as much. i haven't looked at them, but it may very well be that the rear bar simply has a longer respective distance between the axes and/or longer endlinks...

This a VERY true statement, and I think there are 2 reasons why the diameter of the rear is smaller. First, as I said before, I think the rear of a 240 should be setup "looser" so that the tires will stay in contact w/the ground. That means softer springs and anyisway bars. Second, just from looking at it, the rear antisway bars looks (I have no proof) like the suspension has less abilty to put force on the bar in comparison to the front. That means that you don't need to run as large of a bar because the suspension can put as much force on it.

[InsanityInc]

The size of the end link doesn't matter because you're forgetting how a sway bar works in the first place. It transfers force from one side of the suspension to the other, therefore the force to be transfered has to work against the mechanical advantage of the endlink's geometry with the bar, so even if you have something working for the force on the other side, it's going to be exactly the same when it gets applied to the other side of the suspension. x*5/5 = x.

The point is, almost all aftermarket springs and antisway bars are set up for understeer, just like the stock pieces. It works fine if you have some ridiculous amount of torque, but it's going to make a stock (or near stock) powered 240 understeer a lot.

[95lstegman]

no, the endlink will matter. the stiffness of the bar isn't measured by how different it is from side to side; it's the same on both sides because otherwise it won't work and it will bind immediately. this is why companies sell adjustable end links. it's not as big an adjustment as the size of the bar or the multiple mounting points for the endlink on the bar, but it is a noticeable adjustment. it just makes the bar give a higher moment against movement by increasing the radius. M=r x F. increase r, increase M, as long as you don't go past the point where r is perpendicular to F. since in this case increasing r will also rotate r in relation to the bar.

oh, and BTW, where the sway bar end links mount on the control arm have a lot to do with it, too, now that i think about it. if the front bar is close to the pivot point of the lower control arm, and the rear bar is closer to the hub than the pivot point on the chassis, that will make the rear much much stiffer. in fact, if you could design your own control arm, or even simply weld a new mounting point onto your stock control arms, this would be a very easy way to get a lot more stiffness. be prepared to snap sway bars, though. i haven't analyzed the stresses and strains in the bar, so i wouldn't recommend doing this unless you want to break something.

maybe this would be a decent project to consume a few minutes later today. i'd need somebody to go make measurements for me b/c my car is still in the shop getting the drain plug obliterated on the transmission. also the material that the sway bar is made out of would be hard to find out, but requisite. post if you give a crap about it. i don't really b/c it's not something i would do to my car, but maybe somebody else cares enough, and it wouldn't take me long, so what the heck.

[float_6969]

The point is, almost all aftermarket springs and antisway bars are set up for understeer, just like the stock pieces. It works fine if you have some ridiculous amount of torque, but it's going to make a stock (or near stock) powered 240 understeer a lot.

Do you mean springs and bars in general? I don't think that they're "setup" for understeer. You have to tune the suspension of your car, just like you have to tune the motor. I've got a lot of stuff done to my CA. But if I don't program the standalone properly to make all of those parts work together, it doesn't matter how good they are, the motor will run like crap or grenade. Suspension is the same way. It could be that if you use the wrong parts, the car will understeer. But if the whole point of things like coilovers, adjustable struts, adjustable antiswaybars, ect, is that you can change their characteristics to get the car to behave in the manner that you want.

I just don't believe that most aftermarket stuff will make your car understeer, it's how you put all of that stuff together that makes the car behave, not the "stuff" itself.

[InsanityInc]

no, the endlink will matter. the stiffness of the bar isn't measured by how different it is from side to side; it's the same on both sides because otherwise it won't work and it will bind immediately. this is why companies sell adjustable end links. it's not as big an adjustment as the size of the bar or the multiple mounting points for the endlink on the bar, but it is a noticeable adjustment. it just makes the bar give a higher moment against movement by increasing the radius. M=r x F. increase r, increase M, as long as you don't go past the point where r is perpendicular to F. since in this case increasing r will also rotate r in relation to the bar.

You're not getting it. Any increase in radius on one side will be a decrease in radius when you apply to the other side. Mechanical advantage isn't free power.

Quote »oh, and BTW, where the sway bar end links mount on the control arm have a lot to do with it, too, now that i think about it. if the front bar is close to the pivot point of the lower control arm, and the rear bar is closer to the hub than the pivot point on the chassis, that will make the rear much much stiffer.[/quote] All that would do would be to preload the bar. Good luck getting it on the car, though. Let me draw a picture:



If the force going to the sway bar through the system from the tire to the link (P1) has a mechanical ADVANTAGE, then the symmetrical opposite side has a DISADVANTAGE when applying force from the link to the tire through P2. Just like if you have a gear system with a little gear a giant gear and a little gear. You can change the size of the middle gear to be as big or as small as you want and it won't change anything.

[InsanityInc]

Do you mean springs and bars in general? I don't think that they're "setup" for understeer. You have to tune the suspension of your car, just like you have to tune the motor. I've got a lot of stuff done to my CA. But if I don't program the standalone properly to make all of those parts work together, it doesn't matter how good they are, the motor will run like crap or grenade. Suspension is the same way. It could be that if you use the wrong parts, the car will understeer. But if the whole point of things like coilovers, adjustable struts, adjustable antiswaybars, ect, is that you can change their characteristics to get the car to behave in the manner that you want.

I just don't believe that most aftermarket stuff will make your car understeer, it's how you put all of that stuff together that makes the car behave, not the "stuff" itself.

So, you're meaning to tell me that 27/22 sway bars and say 8/6 springs are not going to make the car understeer? OOoookay.

[95lstegman]

it's not a matter of how long one side's radius it compared to the other. the simple fact that both are longer will result in more torsion of the bar. the bar is designed to resist torsion by having a high elastic modulus. so when torsion is applied through a longer arm, the sway bar does more work by twisting more, and when it twists, it stops transfer from side to side.

and yes, preloading the bar is the idea of lengthening the end link. that's why the adjustable ones have a threaded center; because it won't go on easily if it's hardly any longer. it gets installed at roughly stock length then it screws open or closed as desired. hint: lengthening the end link on BOTH SIDES by the same amount WILL increase the observed "stiffness" of the bar.

i think you're mistaking my comments. the manufacturer of the bar can't change the overall geometry of the bar. in principle, if you could, you could greatly vary the stiffness w/o changing bar diameter. this is what i'm saying. the front and rear don't have the same geometry, for obvious reasons, and i'm saying this is why aftermarket bars are larger in front. the geometry demands it in order to acheive neutral handling.

BTW, notice, on adjustable sway bars, most are adjusted by having multiple mounting holes on the ends. all you're doing by adjusting the bar is changing the radius from the axis of rotation to the axis on which force is applied. same thing i'm saying, where this radius is affected by length of bar on this axis, length of endlink, and in coordination on the left-to-right axis of the car the point on the control arm where the endlink mounts also affects the radius.

and no, perhaps 8/6 springs and 27/22mm bars won't understeer. it depends on the geometry. i'm not saying i've looked at the geometry to prove it won't understeer, i'm just saying those numbers are only a small part of equation to figure out if it will or not.

[float_6969]

I'm not saying that at all. I'm saying that you've got to tune your setup. 27/22's with 8/6's might make the car understeer. I think 8/6's are too stiff for the street as well. 7/5's are the limit for the street IMO, and still probabally too stiff. I intend on running more like a 6/4 or a 5/4. I DO plan on running a 27/22 whiteline sway bars, but I know from experience that I can play with the different settings on the bar and get the car pretty neutral.

Tires and tire pressures also play a big role in the handling of the vehicle as well.

The beauty of suspension is that there are soooo many variables. I think that's why it's one of my favorite aspects of building a car. Unfortunatly it can be expensive as well, as a lot of it is trial and error. And sometimes you have to go through 3/4 sets of springs before you find the right combination. The 240 that I'm building now is different from the other 2 that I've done and I already know that the spring rates that I've used in the past may not work exactly the same way. Heck, those whiteline antiswaybars that I like so much may not even work. But you do what you've go to to get the car to behave correctly. Luckily I've got some experience with it and I'm fairly confident that I'll get the right spring rates on the first or second set, which will save some money. I'm also fairly confident that the anitsway bars will do what I want, but I'm not so closeminded to accept that even they may not work and I'll have to try something different.

I'm all about math and physics, as I love them both. But building a car on paper only gets you so far. After that it's experience or trial and error.

That's what life as taught ME so far anyway. It could be different for you.

[95lstegman]

i'm not saying i like engineering more than cars; i don't. i'm just explaining to people that the diameter of the sway bar is only a tiny part of the process of designing a sway bar. just because the rear is thinner than the front doesn't mean crap.

oh, and if those whitelines don't perform like you want, i'll GLADLY take them off your hands .

BTW i, too, am an adjustment-happy person. alignment parts, tire pressures, adjustable dampers, and other such goodies grace my last project car (integra), which is now owned/operated by my fiancee. when she first started driving it she would keep coming to me with "hey, why does it do this?" and i would go and fix it .

[float_6969]

That post was supposed to come in before yours. I'm kind of on the same page as you are...

[95lstegman]

well i'm glad we're on the same page . . . seems like mister insanity there is still stuck somewhere back in our dust. he'll catch on, hopefully. as for me, my first suspension mod will probably be whiteline's sway bars, if i can get some good pics of how they fit. i'm worried about possible oil pan clearance in the future with a greddy pan and i'm worried about my S14 exhaust not clearing the rear one, so we'll see. but i fully intend to get those b/c they're a hell of a deal for the money and they're adjustable, which makes me giddy like a school boy .

[InsanityInc]

I'm just gonna say two things, because it's obvious that you don't believe in physics or something:

1) Yes, it applies torsion to the bar, but that applies torsion elsewhere. That place happens to be the other side of the suspension, where it applies it via the link.

2) the stock spring rates are 2/2 and the sways are 21mm/15mm if I recall, and the car comes from the factory set up to understeer. Even if you replace the rear with the HICAS bar it will still understeer. So, with 2/2 spring rates and 21/17 bars you understeer. What do you think is going to happen with 8/6 and 27/22? I think that's a no-brainer. And yeah, you can monkey with your tires to get it to handle how you want, but I prefer my suspension pieces to be set up a bit more correctly from the get go.

[95lstegman]

once again, i'm not saying that it won't understeer, i'm just saying this it's *POSSIBLE* that the differing geometries of the front and rear *COULD* cause a thinner rear bar to end up causing more stiffness than the thicker front bar. i haven't even looked at it, so i don't know if it would or not. i'm just saying that there is a lot more to a sway bar than its diameter. that's all i want you to realize.

and in any case, ideally, i like my street cars to exhibit ever so slight natural understeer. i like it for safety, and because if it's just ever so slight, it can be turned into large oversteer or large understeer with a variety of means, such as a fient, slight throttle inputs, slight braking inputs, etc. but this really isn't my point. my point is just that the thickness of the bar does have a big role in the stiffness of the bar, but geometry is just as important.

[nismofly]

straight out of the FAQ -

Note - Remember to consider the construction of the sway bar and the endlinks. A solid sway bar has more resistance than a hollow bar of the same diameter. Also the addition of solid or polyurethane endlinks will artificially raise the diameter of the bar in terms of effectiveness.

[float_6969]

2) the stock spring rates are 2/2 and the sways are 21mm/15mm if I recall, and the car comes from the factory set up to understeer. Even if you replace the rear with the HICAS bar it will still understeer. So, with 2/2 spring rates and 21/17 bars you understeer. What do you think is going to happen with 8/6 and 27/22? I think that's a no-brainer. And yeah, you can monkey with your tires to get it to handle how you want, but I prefer my suspension pieces to be set up a bit more correctly from the get go.

OK, but you're not comparing apples to apples here. First of all, the stock bars are hollow, the whiteline units are solid. Secondly, the fact that you changed the bars will alter everything else about the handling of the car. EX; stock springs w/aftermarket bars will change the handling of the car. POSSIBLY causing it not to understeer anymore with changes to the settings on the bars. The same applies with springs. You could use the stock bars and play with the springs and get the car not to understeer. I don't know about 8/6's with the 27/22's because I haven't tried that specific setup. I DO believe that if those 8/6's are on a good coilover and the 27/22's are adjustable, and possibly manipulating some other aspects of the suspension geometry such as camber, caster, toe, ect, that the car could be setup not to understeer. But Tires play a VERY LARGE role in the handling of a car. Even more so than suspension IMO.

When it comes down to it, unless someone tries this exact setup and lists all of the aspects of their suspension geometry, tires, and pressures, we CAN'T know if it will tend to understeer or not. Driving style can even play a large role in how one "percieves" the car to handle. You can MAKE any car understeer. You can also MAKE any car oversteer for that matter.

This is essentially an "opinion" post. And w/o hard evidence (ie exact #'s and some sort of evidence of understeer) nobody is right, and nobdy is wrong.

[95lstegman]

speaking of tires, this is why i REFUSE to be a zombie 240 owner and put wider tires in the rear than the front. i would rather have a slightly wider rim with the same size tire in the rear. i don't want more grip; i just want the transition from grip to slip to be more gradual. and the wider rim will look better. but putting extra-wide rear tires on will create more understeer. back when i was a FWD guy i always had wider tires in front than in the rear to reduce understeer.

[nismofly]

speaking of tires, this is why i REFUSE to be a zombie 240 owner and put wider tires in the rear than the front

if anyone complains about understeer while running stagger they are a worthy recipiant of a darwin award

also, tires are the most important part, anywhere...theyre what take everything youve done and connect it to the pavement

funny when people complain about handling when running crappy pep boys tires or something...if youre running 8/6 you need to be running tires sticky enough to use an 8/6 setup, otherwise its a waste

[95lstegman]

personally i like to run crappy tires for driving around town b/c i can screw around and put lots of miles on them and not spend more than $60/pair for used tires. then for competition of any kind i go for high performance used - Corzo Tire. they buy used tires in europe and bring them here, so we can have their fancy shmancy sweet rubber for little more than the price of a standard used tire. most of the time i get hella nice stuff from them like AA traction, A temp, 140 wear for like $25 for 14", $30 for 15" . . . haven't bought 16's yet (my 240 has 16's; my old car had 15's) but they have a lot of 15's in low-profile sizes, so that's a plus. 16's are usually cheaper b/c they're in lesser demand.

[InsanityInc]

OK, but you're not comparing apples to apples here. First of all, the stock bars are hollow, the whiteline units are solid.

If the two bars in the set are constructed the same way, then any differences in the diameter are still going to produce the same handling characteristics as the original material bars. The only way this would be at all relevant would be if you were using a hollow bar in front with a solid one in rear, or vise versa.

Quote »When it comes down to it, unless someone tries this exact setup and lists all of the aspects of their suspension geometry, tires, and pressures, we CAN'T know if it will tend to understeer or not.[/quote]All things being equal, if you throw those parts on your car, it will make your car understeer more than before it had them on. End of story.

Quote » Driving style can even play a large role in how one "percieves" the car to handle. You can MAKE any car understeer. You can also MAKE any car oversteer for that matter. [/quote]Yeah, sure I could roll down the road at 100mph and pull the e-brake to make a metro oversteer. However, I'm only actually concerned with how the car handles when driven properly. Talking about anything else is pointless. If I try and do a U-turn at 50mph in a corvette by spinning the steering wheel as fast as I can, I'm gonna understeer. Does it say anything relevant about the handling of the car? nope.

[95lstegman]

well, given your example, if you jerk the wheel hard, you're going to get understeer. the only way to avoid this is to have absolutely retarded rear spring rates and/or rear sway bar. have you put a pair of matched bars on your car? does it still understeer? there are too many variables in how stiff a sway bar is to calculate it here, unless somebody wants to do some measurements for me. hit me up at [email protected]. otherwise, try it and find out. i'd be willing to bet understeer is VERY minimal, although in 99% of car and driver combinations minimal understeer is a good thing. most people can't handle a car with heavy tendencies to oversteer, and even those that can aren't generally very fast that way. it's just annoying IMO. you have to REALLY know the car well to be fast with it set up for massive oversteer (not throttle oversteer; i mean natural oversteer).

[InsanityInc]

well, given your example, if you jerk the wheel hard, you're going to get understeer. the only way to avoid this is to have absolutely retarded rear spring rates and/or rear sway bar. have you put a pair of matched bars on your car? does it still understeer?

You do realize that was my point, right? Saying "understeer is caused by driving more than anything" is a non-sequitur.

[rbsileighty]

This thread really started to run away...

Quality = good ride... which is why my 9/7's ride just as well as some stock "sport suspension" setups... that and I have 15" wheels... so with a shorter stiffer sidewall I'd expect a bit harsher, but still a decent ride

Just run a hicas rear... factory dials in a bit of understear, but with decent supporting hardware (ie coilovers) it will handle great... well actually it does handle great...

[95lstegman]

You do realize that was my point, right? Saying "understeer is caused by driving more than anything" is a non-sequitur.

but you don't differentiate driver-induced understeer from natural understeer. unless you go out and buy a matched pair of bars and observe them exhibiting natural understeer more than a tiny tiny bit, i won't concede that aftermarket bars cause the car to understeer. a tiny bit of understeer doesn't count as understeer b/c it it 100% avoidable and also a good thing for inspiring a little confidence in the driver, and when the driver is confident in him/herself, he/she is always going to be faster.

[95_240]

My car is lowered with whiteline sways and both settings are as stiff as they go. I have 255 kdw's in the rear and 245s in the front and i only have oversteer not under.

[float_6969]

My car is lowered with whiteline sways and both settings are as stiff as they go. I have 255 kdw's in the rear and 245s in the front and i only have oversteer not under.

So now we have 2 people, (95_240, and myself) who have both PERSONALLY used whiteline bars (I've used them on 2 different cars) and never had problems with understeer?

You can look at #'s all day long, but real world proof is kinda hard to ignore...

[nismofly]

paper/numbers racing is the suck

thats like saying "i have X, Y, and Z parts, therefore i have 234.7 rwhp and 242 rwtq, and will run a 13.89 @ 101.3 1/4 mile"

[240sxjeff]

Hopefully I will have some time next week to install my whiteline sway, since I am finishing up finals this week, I will post up a review of it so you guys can add one more personal opinion on whiteline products (well at least swaybars)