I need some input

[spooled240]

Here's the deal, I have a base model s14 (no rear sway bar) with stock suspension except for lowering springs(about OEM stiffness) and solid poly TC rod bushings. Whenever I go drifting or grip driving I have some pretty bad body roll and it's getting pretty annoying so eventually I want some coilovers but I can't spend 1200 on the one's I really want. So I was wondering if a fat front and rear sway bar would suffice for now and fix my body roll in hard cornering and drifting. I was looking at the one's on ebay which are fat as hell compared to OEM. The front is 30mm and the rear is 28.25mm.

http://cgi.ebay.com/ebaymotors...71621

Any input and/or experience with this product would be greatly appreciated thanks

[simmode1]

I'm sure beefier sway bars will help. But they are really supposed to supplement the function of having a stiffer suspension, not do all the work.

I'd say get them, but there really isn't a substitute for having good damping and stiff springs at all four corners... GL!

[spooled240]

i was doing a little research and I found out a good combo was either stiff springs with moderate sway bars OR softer springs with fat sway bars. <I will have the second setup but looking on the bright side, cornering will improve drastically without sacrificing ride quality.

I think these bars will help A LOT. I will eventually upgrade to coilovers in the future but these will work for now I suppose. I just bought the ebay sway bars with some ebay thermoplastic endlinks, they should be better than the OEM's up front.

[crackler]

I don't run a rear bar. My front bar is a 1" 1/8"th tubular bar700/450 springs with Koni Yellow "race" shocks.

Sway bars are supposed to suplament roll resistance, not provide it. Be carefull running a rear bar that is to big. It wil reduce your rear tire grip. you might be happier if you get some stiffer springs for the rear and leave the bar off. A lot of people I know that run stiff springs in the rear, don't run rear bars. But if your rear springs are OEM stiffness, then you probably need a bar, until you get a proper suspension.

[spooled240]

yeah my springs are not much stiffer than stock I'd say. I have 245's out back and 225's in front so grip is really good, it's just the body roll that is killing me. I really think that the thick bars will work fine with my springs and my tires but we'll see.

[crackler]

If you stick a large rear bar on, it is goin to lift, or try to lift the inside rear tire, and when that happens you will actually reduce rear grip. You probably have really good rear grip because you don't have a rear bar. and the body roll is evident from the good grip. If the car wasn't hooking up good, you wouldn't get as much roll.

Bars are cheaper than Shocks and springs, but don't be surprised if you slap a large rear bar on, and aren't happy with the results.

BTW my comments about not running a rear bar, applies only to RWD cars.

I run a 205's all the way around.

[spooled240]

yeah I hear ya. I thought about that scenario where I would have less rear grip but what is the difference between having a large rear bar and having super stiff coilovers? It seems to me that coilovers would have the same affect.

I'm more of a drifter anyway so if the rear end wants to slide, I can make lemonade out of lemons lol.

[crackler]

No sway bars with high rate springs allow both rear tires to stay in contact with the pavement better. Since you A. have less body roll, and B. Each wheel is allowed to to move independently of each other, and maintain maximum grip longer.

Like I said sway bar, or anti-sway bars, are supposed to be used as a supplement to the springs.

There is also something about sway bars having a progressive spring rate, where coil springs on your dampers are typically straight rate. Not sure how this comes into play. But I am fairly sure it does.

And Drifters need rear grip just as much as us regular grip people do. Or at least that is how I understand it.

[spooled240]

I see your point, but sway bars will still allow each wheel to move independently by bending under stress, it is just limiting this movement.

I've heard of people removing rear bars for more grip on the track but that just doesn't seem right. From what I've always learned about sway bars, they are supposed to increase handling and cornering speed.

I understand how a giant sway bar can ruin handling because it makes an IRS setup into a live axle setup which is not optimum for track use..but with moderately softer springs, the sway bars will flex a little and the rear end won't be a solid one-peice unit. That's how I am thinking about it.

BTW, I'm pretty sure those bars are hollow so they are not as stiff as they seem.

[crackler]

yeah, I would call this limited movement.



They increase handling by altering (raising usually) roll resistance, at the price of over all available grip on one tire or the other. And this can help lower lap times. but if you adjust your spring rates, running no rear bar can help get a hard dig coming out of the corners, that if you where running a normal to large sway bar would not allow the same amount of bite . I know a lot of people who autox in stock classes use large sway bars in front, because they can't change spring rates, or rear bars. But you will often see them lifting the inside front tire. If the inside tire is being lifted off the ground, you have just lowered your available grip. Some times this is the lesser of two evils.

[spooled240]

I think coilovers would also result in the inside wheel lifting off the ground also because they don't exactly allow the wheels to "hang down." I've seen cars with coilovers drive onto a driveway or a little hill and one wheel lifts off the ground as if the wheels were permanently in a fixed position.

But my point is that even with stiffer springs fighting body roll, it seems like it would have the same affect-less grip when the inside wheel doesn't want to hang down.

hmmm, but maybe with the thick sway bars the outside wheel will "lift" the inside wheel in hard cornering like that beamer. Some race cars do go into a 2-3 wheel motion in extremely hard cornering and I don't know if that's right lol

[crackler]

What you are referring to is called droop. And you need some. Not having enough droop can be an issue as well.

[spooled240]

would you say that coilovers have more droop than sway bars in hard cornering? I think they would have about the same

[crackler]

Droop is how far your wheels travels from when it is squarly on the ground, to when it leaves terra firme, basically any ways.

If you have a stiff sway bar, it will limit the amount one wheel can move in relation to the other, The spring rate, as I understand it, just determins how much force it takes to compress the shock a given distance.

So I guess that sway bars allow less droop, becuase it ties the loaded wheel to the unloading wheel.

[spooled240]

yeah there are pro's and con's to different suspension components. But it's all about having it your setup dialed in, meaning the correct sway bar sizing, spring rates, etc..etc..

Hopefully these sway bars aren't too stiff but we'll see.

[Exar-Kun]

You guys are discussing a suprisingly complex suspension topic that I'll try and cover here tomorrow....

the short - cracker is completley correct in most things. Tuning through spring rate and length is the best way to acheive a balanced car. Sway bars are used as torsion bars to transfer load across the suspension - reducing overall grip by essentially taking any force trying to let the non-loaded wheel drop and transfering it over - more load on a loaded tire means less grip....this is how it reduces body roll and why, with race tires and compounds yo get the lifted wheel effect.

It's worth mentioning that you need to save your money and do a suspension right the first time. I understand const constraints, but stiffer sway bars on a stock suspension will actually reduce grip - but might make for a better feel because the car seems composed...and better slalom times since the tires get loaded/unloaded quicker (more on that later)...second point worth mentioning is how much cornering force are you planning on resisting in your setup? .8g, .9g? 1.2g? This is important to know as its directly affected by tire choice...and very important to picking the correct suspension settings...

-Chet

[spooled240]

My car is a daily driver but I do enjoy spirited driving on some back mountain roads and some drifting once in a while. I don't know how many g's I'm pulling but it can't be much more than .6 I'm guessing. I just want to fix my body roll in hard cornering and drifting..my car rocks back and forth in switchbacks, so I figured these swaybars would fix that.

So if I'm understanding this correctly, bodyroll isn't really the issue here it's the way the sway bar will eliminate drooping of the inside wheel and reduce grip?

Everytime I read about swaybars, they talk about eliminating bodyroll and increasing cornering speed, but these may not be related I'm guessing.

[crackler]

You guys are discussing a suprisingly complex suspension topic that I'll try and cover here tomorrow....

Cool.

I am always down to learn more. Especially suspension stuff. I am slowly starting to understand the basic's, and always try to keep an eye / ear out for new info.

[crackler]

So if I'm understanding this correctly, bodyroll isn't really the issue here it's the way the sway bar will eliminate drooping of the inside wheel and reduce grip?

It's not really droop, droop is more a measurement, than anything else. The sway bars try to keep the wheel's in a parallel plane to one another. So the more one side leans down, it is trying to raise the other side the same amount, to keep them Parallel. I don't believe it actually raises the one side in direct 1:1 relation to the lowering of the other side, but you get the idea. At least this is how I understand it, that and it is hard to explain without using my hands.

Everytime I read about swaybars, they talk about eliminating bodyroll and increasing cornering speed, but these may not be related I'm guessing.

They do reduce body roll, well, they actually increase roll resistance from side to side, but that is splitting hairs. They don't do anything for front to rear. IE: brake dive or squat under acceleration. But. . . less body roll usually means better, or more predictable, handling. And since sway bars do reduce body roll, they do some what increase handling. They just aren't as effective or as well suited to the task as springs are. There may also be a certain assumption that the sway bars are going on after the springs and shocks have been sorted out. It could also be marketing hype, or just plain misinformation / ignorance of how / what sway bars really do.

[spooled240]

I'm somewhat of a noob to suspension if you haven't already figured that out lol but I just use my common sense to try and figure things out.

I can understand a obnoxiously thick sway bar hurting the handling of the car by connecting the two sides together and wanting to lift the inside wheel in cornering. BUT having sway bars that flex and bend will still allow the wheels to move independently from each other-to an extent of course, while keeping the car flat in a turn.

[crackler]

I can understand a obnoxiously thick sway bar hurting the handling of the car by connecting the two sides together and wanting to lift the inside wheel in cornering. BUT having sway bars that flex and bend will still allow the wheels to move independently from each other-to an extent of course, while keeping the car flat in a turn.

Correct.

Here is a few links with dome good info.http://farnorthracing.com/autocross_sec ... /reference

And some info on brakes as well.http://www.stoptech.com/tech_i...shtml

[Exar-Kun]

it's easiest to think of a sway bar as Cracker described - something connecting the two suspension peices together across the frame.

"I don't believe it actually raises the one side in direct 1:1 relation to the lowering of the other side, but you get the idea. At least this is how I understand it, that and it is hard to explain without using my hands."

The ratio would depend on how stiff the sway bar is and how efficient the links are. Essentially the stiffer the sway bar and more efficient the links and bushings the more roll resistance you get and the closer the movement across the suspension arms gets. This is NOT a good thing in most cases...

This is also why you can get dramatic sway bar rate changes and roll resistance simply by changing the links from rubber to urethane to heim joints, etc....

Consider it this way - you have an IRS, something when developed revolutionized can handling because it allowed each wheel and tire to move freely(simplification) across the road surface ensuring more contact and thusly more grip. A sway bar takes this away essentially....just try tropping one side of your suspension out (like changing a coilover) without disconnecting the sway bar.....not gonna happen!

However, sway bars are excellent at eliminating body roll and allowing engineers to run softer spring and dampers - gaining back a bit of ride quality at the expense of tuning the suspeion more accurately for a specific purpose. The other big benefit of swaybars are how easy they are to adjust...changing the connecting point (and thusly the leverage) changes the stiffness of it and is MUCH easier than, say, changing a spring for a different rate....and then you might (depending on the length and rate change) have to change the damper valving too.....

Another thing to consider - the quicker loading and deloading occurs, the lower the grip and the harder it becomes to hold a car at it's limits. Also, the stiffer the suepsnion (sway bar or otherwise), the more body roll force gets transfered to the tires - more load, less grip. Think about an egg tipping one way or another, if it tip;s freely, no force is transfered, but if you put a little spring on one side to resist the tipping, force gets transferred over, loading the spring and the ground underneath it (in our case, a tire) with the roll force that if left alone wouldn't have transferred over.

Make sense? Probably not....but if you think about how much engineers on race teams spend maximizing track and ride height to eliminate this weight transfer (and adjusting roll centers as well) you start to see how important it is

I hope that helped more than confused!

It's also worth noting that if the swaybar is signifigantly stiffer than the springs...you'll end up with them doing all the work. ...and have a torsion beam style 'independent' suspension

In regards to a street setup as you describe - any idea how much stiffer the sway bars are and if the car currently under or oversteers? What tires are you running?

Regards,-Chet

[spooled240]

^ I think I get what you are saying with weight transfer, etc. In a corner body roll will transfer the weight of the car to the outside wheels but with sway bars and less body roll, will the weight tranfer be more evenly distributed to each side of the car?

I am imagining that the sway bar will apply upward force on one side of the car to fight the body roll affect and as a result keep some of the weight on the inside wheels thus maintaining grip and excessive weight transfer and body roll?

I am running Potenza re730 225/50/16 in front and 245/45/16 in back. The car grips really well surprisingly but the body roll is pretty bad. Sometimes the car understeers in a drift and I'll have to give it some gas to get the back end around.

the sways are 30mm in front and 28mm in back. They are tubular so they will flex like a smaller solid bar.

[Exar-Kun]

^ I think I get what you are saying with weight transfer, etc. In a corner body roll will transfer the weight of the car to the outside wheels but with sway bars and less body roll, will the weight tranfer be more evenly distributed to each side of the car?

Nope, the opposite. The force that would have rolled the body over, say 30 deg, will now (with swaybars) transfer to the suspension and leave you witha bodyroll of 15 degrees say - so 50% of force gets transfered, reducing grip potentially. This is a gross simplification...this effect works with springs too, FYI...sway bars also affect how quick the transfer occurs, quicker loading/deloading means less grip if the tire isn't built for it.

I am imagining that the sway bar will apply upward force on one side of the car to fight the body roll

Correct

...affect and as a result keep some of the weight on the inside wheels thus maintaining grip and excessive weight transfer and body roll?

Nope, it prevent the body roll by applying the (key) upward force on the inside suspension - reducing it's share of the load. If you want to reduce weight transfer look to the track and ride height of the car - those are the two biggest factors affecting it.

I am running Potenza re730 225/50/16 in front and 245/45/16 in back. The car grips really well surprisingly but the body roll is pretty bad. Sometimes the car understeers in a drift and I'll have to give it some gas to get the back end around.

Can you be more specific of how it would understeer mid-drift? lift-throttle, turn in, exit? Also, you should try out some more serious tires once your budget allows it to be really suprised at how much grip a S chassis can have...

]the sways are 30mm in front and 28mm in back. They are tubular so they will flex like a smaller solid bar.

...their rate change still depends on the material, endlink effectiveness and manufacturing...so you should ask the mfr the rate changes relative to the OE bar to get a decent idea....

Like any car mod, remebering that the car functions as a entire system is important - upgrading one area with dissregard to another will create problems..but sway bars can create a better feel so as long as you're happy with the effect - enjoy. Are they adjustable?

[spooled240]

no they are not adjustable. The understeer I was talking about wasn't in mid-drift(even tho i wrote that, sry lol), it is when I try and initiate the drift. Sometimes I will power over before the turn with the wheels turned and the car understeers and doesn't want to get sideways.

what tire sizes do you recommend for the future? I have 7.5's up front and 8.5's in back so I can put some wider tires on there

Hopefully these bars come in tomorrow, I will install them immediately and tell you guys how they are

[adrianfromthecastle]

I was looking at the one's on ebay which are fat as hell compared to OEM. The front is 30mm and the rear is 28.25mm.

http://cgi.ebay.com/ebaymotors...71621

Any input and/or experience with this product would be greatly appreciated thanks

zerothread?id=187320

[Exar-Kun]

If it's understeering you'd want to even up the tire sizes. You might also want to try flicking the car a bit, or running either lower or higher air pressures in the rear evrsus the front depending on the feel you want...

I'm a fan of 225/50/16 on S13's.

-Chet

[spooled240]

I got the bars on with thermoplastic endlink bushings and energy suspension poly bushings on the brackets. Cornering feels awesome! The car just feels way more responsive, because weight transfer and body roll is decreased. I am very happy with the handling of the car, however I would NOT recommend that ebay kit, as the brackets didn't work and customer support is very little/nonexistent...I don't know how good the ST set for $240 is but that's about how much I paid out the door with the the endlinks and the poly bushings/brackets teh eff bomb!!!1!!!eleven!! me..

BUT I'm very happy with the car's handling with these bars and the bushings. The car is way more responsive and stable in quick cornering.