Sway Bars

[maddowse]

hi iv been doing some searching but cant find much on here as everyone just talks about installing coil-overs !!

I'm looking at white line sway bars for my r34gtt before i install coil-overs. but what i want to know what thickness should i be looking at and also on ebay (were there selling white line sway bars) it has a guide and it says for rwd cars only install front sway bar ??

is this right or would i still get better handling by installing one in the rear ?

or is there a good reason why they say only on the front , just doing my home work before i blow UN needed money

thanks for your time

[itsme]

Hey bud I really hope somebody gives a good answer to this question. I posted a similar question not long ago and didn't really get any responses. I also own an R34 GTT Sedan and would like to do some work on the handling. I've got BC Racing Coilovers and have been told they are ok but the spring rates are a little soft so I still get body-roll. I've been looking for a while at getting adjustable whiteline swaybars.

If anybody at all can answer Mad's question please also add whether it is best to buy the adjustable swaybars (and any part numbers if you know them) and also whether it is something that can just be installed at home or if its best left to a suspension workshop to install and adjust. I've been told Mad that if you get the part number(s) you can order them through Repco, don't know if this is the best way to do it though in terms of price etc.

Cheers,

Steve

[ClutchBurndout-:(]

to answer mads question

you should really only upgrade the front sway bar because sway bars will lift the inside wheels or the "unloaded side" on a corner, and as we all know, the back of the car is the end that always loses traction first, so upgrading the rear sway bar will only make this worse. thats for rwd cars.

for fwd cars the front wheels are doing all the work that the rear wheels on a rwd car do, so its best to keep the front wheels down buy using the rear of the cars suspension to keep the car flat.

[maddowse]

thanks for the reply itsme i was also thinking of getting the bc racing coilovers after the sway bars !! you say the springs are a little soft ?? cant that be adjusted (damper) or is that a totaly different thing ?, funny the reviews i have read on them are that the springrates are too stiff but maybe with the weight of the sedan you need them to be stiffer . did you get them adjusted by a suspention workshop or installed your self ?

[maddowse]

to answer mads question

you should really only upgrade the front sway bar because sway bars will lift the inside wheels or the "unloaded side" on a corner, and as we all know, the back of the car is the end that always loses traction first, so upgrading the rear sway bar will only make this worse.

ok i understand thanks for the quick reply !! , does the thickness change much ?? is thicker better or is it dependant on what the cars going to be used for ? my car will be 90% street with a small chance of track days (dont have much time off these days )

[ClutchBurndout-:(]

ok i understand thanks for the quick reply !! , does the thickness change much ?? is thicker better or is it dependant on what the cars going to be used for ? my car will be 90% street with a small chance of track days (dont have much time off these days )

it dosent matter what your doing with it, you would compensate for the worst case scenario, because you can have the thickest sway bars on front AND back and it wont affect your every day driving, because sway bars only come into use on cornering, it wont give you a stiffer ride.

in most cases a thicker sway bar means stiffer, so by upgrading a sway bar it just means putting a thicker one in (correct me if im wrong)

i believe with the bc coilovers you can ask for different spring rates??? maybe your ones just has a softer spring rate, i dont see why you cant go to a suspension joint and ask for stiffer springs to suit your coils.

everyone talks about coils to solve body roll because to an extent a sway bar can help, but the term "more=better" dosent work in this situation, more (stiffer sway bars) will help till you find traction issues, with coils, they work individually and when cornering, one side of coils wont raise the other side, therefor not giving you traction issues.

i have tiens in my car and they are super stiff, and i have little body roll.

[itsme]

Clutch cheers for the info mate, I was looking to upgrade both but I may do the front first and see how she feels then I suppose I could get the back one at a later stage and if it really makes things worse due to lift I could always take it back off i guess. Would it be then safe to say that front and rear heavy sway bars are ideal for a GTR (being 4wd) or have I got this wrong? (suspension baffles me)

Mad, don't get me wrong I love the BC Racing coilovers I paid $1250 for the BR ones (not the REAL budget ones) and they were a great improvement over my previous crappy suspension (some no-brander from Japan). They have adjustable 32 point damper settings which I've been told is a little excessive and uneccesary. Admittedly I installed these myself which only took a few hours and I'm no mechanic just like to give things a shot. I haven't had them adjusted by a workshop but I'm tossing up whether to get the swaybar(s) and get it all looked at and adjusted at once rather than going back and forth. My car is a daily driver in Perth and our roads and carparks are absolutely horrible so I do have the dampening setting closer to soft than hard but I've been told this mainly affects how much you feel bumps, my concern is more so with the bodyroll i get on corners which is why i was looking at swaybar(s).

Sorry for the essay just really chasing an answer as well mate, hopefully we get more good feedback like Clutchs.

Cheers

[ClutchBurndout-:(]

Clutch cheers for the info mate, I was looking to upgrade both but I may do the front first and see how she feels then I suppose I could get the back one at a later stage and if it really makes things worse due to lift I could always take it back off i guess. Would it be then safe to say that front and rear heavy sway bars are ideal for a GTR (being 4wd) or have I got this wrong? (suspension baffles me)

i wouldnt bother with your rear sway bar, sway bars main purpose is to help with over steer and under steer rather than body roll. invest in stiffer coils if your keen on track work, you wont look back, but say goodbye to comfy daily driving

correct me if im wrong but you would treat a gtr the same as a fwd car.

also remember that, the downfall of stiffer coils is they become less grippier in the wet, because to keep good traction in the wet the suspension needs to allow the tire to monouver the bumps on the road to get maximum grip. so all in all, you cant have your cake and eat it to.

have you thought about strut braces?

[itsme]

hrrm.. thanks heaps again Clutch, unfortunately I don't want to sacrifice any more comfort mainly due to the amount I drive and the roads and carparks I go down.

I may get a front sway bar and then post the results in here as to what I find, its not thousands of dollars and worst case scenario I'll be paying for an expensive lesson if it doesnt feel good I'll take it off and know better for future.

My car is shocking with grip already (mainly due to sh*tty compliance tires) so that may not be the best option for me (i'll get some nankangs or something when these go bald)

Strut braces as in front strut bar? I have the stock adjustable front strut brace/bar and have read across many articles that rear strut bars are useless in R34 gtt's due to the suspension set-up. I think I read something from Sydneykid explaining it in depth.

Ultimately I'm looking to reduce body roll, and as noob as this might sound I also have this thing that when I stop my car and pull up the handbrake the car rocks back and forth a bit not sure if its normal but it feels like the whole chassis is rocking on the suspension or something..

[ClutchBurndout-:(]

hrrm.. thanks heaps again Clutch, unfortunately I don't want to sacrifice any more comfort mainly due to the amount I drive and the roads and carparks I go down.

I may get a front sway bar and then post the results in here as to what I find, its not thousands of dollars and worst case scenario I'll be paying for an expensive lesson if it doesnt feel good I'll take it off and know better for future.

My car is shocking with grip already (mainly due to sh*tty compliance tires) so that may not be the best option for me (i'll get some nankangs or something when these go bald)

yea lol, i have 255s on the back and they are still shocking in the wet, but the turbo dosent help...

Strut braces as in front strut bar? I have the stock adjustable front strut brace/bar and have read across many articles that rear strut bars are useless in R34 gtt's due to the suspension set-up. I think I read something from Sydneykid explaining it in depth.

i didnt know gtt came stock with a strut brace? im talking about the brace in your engine bay from strut to strut, this helps a bit with cornering.

yes rear strut braces are useless unless your doing heavy track work, even then you might only have a tiny bit of difference.

Ultimately I'm looking to reduce body roll, and as noob as this might sound I also have this thing that when I stop my car and pull up the handbrake the car rocks back and forth a bit not sure if its normal but it feels like the whole chassis is rocking on the suspension or something..

pull up the handbrake? when stationary? sometimes the car might lower in the back when putting the handbrake on, not sure what this means though, but ive never heard of the car "rolling back and forward" when putting the handbrake on when stationary, or do you mean using the handbrake to come to a stop?

[itsme]

Yeh the R34GTT comes stock with a front adjustable strut brace which goes from top of one strut to the other, it's a bit ugly looking but it's steel and apparently can be better than some of the aftermarket ones because although they look good the majority are aluminium which meanst they are lighter but generally not as strong.

If i'm say... rolling into my driveway at a slow speed and pull the handbrake before the car is completely stationary it kind-of 'rocks' a bit.. hrrm.. I'm thinking after reading all this I might be best taking my car to a suspension place and getting them to have a look at everything and make adjustments/suggestions as this stuff is way out of my 'forum-knowledge field'.

haha

[ClutchBurndout-:(]

Yeh the R34GTT comes stock with a front adjustable strut brace which goes from top of one strut to the other, it's a bit ugly looking but it's steel and apparently can be better than some of the aftermarket ones because although they look good the majority are aluminium which meanst they are lighter but generally not as strong.

If i'm say... rolling into my driveway at a slow speed and pull the handbrake before the car is completely stationary it kind-of 'rocks' a bit.. hrrm.. I'm thinking after reading all this I might be best taking my car to a suspension place and getting them to have a look at everything and make adjustments/suggestions as this stuff is way out of my 'forum-knowledge field'.

haha

yea not sure about the handbrake one, could be completely normal i dunno

yea take it to a suspension place, but good luck finding a joint that wont say, "you need everything, $4k"

[itsme]

Hrrm.. seems odd is all I'd just like the car to feel a little stiffer all round..

Yeah I don't like my chances in this regard, I looked around for months before going with the BC racing option and installing myself for that reason exactly. Even places I was recommended to go to pretty much disregarded the use of coilovers and told me to get good suspension i'd be looking upward of $4k.. I'm not by any means a cheapo and have tried to keep my car with the best parts my wallet will allow but there was no way I could dish out $4k on suspension. I suppose all I can do is keep looking for a good suspension place and hope they're honest =/

[ClutchBurndout-:(]

Hrrm.. seems odd is all I'd just like the car to feel a little stiffer all round..

Yeah I don't like my chances in this regard, I looked around for months before going with the BC racing option and installing myself for that reason exactly. Even places I was recommended to go to pretty much disregarded the use of coilovers and told me to get good suspension i'd be looking upward of $4k.. I'm not by any means a cheapo and have tried to keep my car with the best parts my wallet will allow but there was no way I could dish out $4k on suspension. I suppose all I can do is keep looking for a good suspension place and hope they're honest =/

lol $4k on suspension

if you want just a bit stiffer, ask a suspension join for some stiffer springs, should be fine.

other than that, i think if you lower non-damper adjustable coils they stiffen up as the shock gets less room to move? im not 100% sure on this, how low is your car?

[blind_elk]

i wouldnt bother with your rear sway bar, sway bars main purpose is to help with over steer and under steer rather than body roll.

Sway bars control body roll. By controlling body roll, they control weight transfer. Controlling weight transfer controls under / over steer.

As a rule of thumb, in a RWD setup, increasing the front sway bar will INCREASE the UNDERSTEER characteristics of the suspension. Increasing the rear sway bar will INCREASE the OVERSTEER characteristics. The lifting of the inside wheel in hard cornering is more dependent on where the weight is as you turn in. If the weight is forward, ie still under brakes, then you are almost assured of lifting the inside rear driving wheel.

Putting too heavy a spring in the rear will begin to introduce traction problems - you can't transfer weight to get the power to the ground. Putting heavier springs in the front will induce understeer. So you might get the body roll you desire, but you will likely have massive understeer or traction problems.

As with everything to do with car performance, it's all a tradeoff between competing effects. But fitting an upgraded sway bar will be the best value to enhancing the handling performance of the car.

Edited September 10, 2010 by blind_elk

[itsme]

Haha yeh i know.. I mean handling is important and shouldnt be neglected but GIVE ME MORE POWER ROAR!! haha

cheers mate i'll give that a crack..

um.. i wouldnt say too low.. low enough that it looks nice but still rides good.. funny thing is i just installed the suspension and it seemed to already be at a good height so i didnt adjust the height at all only played with the dampeners..

[ClutchBurndout-:(]

Haha yeh i know.. I mean handling is important and shouldnt be neglected but GIVE ME MORE POWER ROAR!! haha

cheers mate i'll give that a crack..

um.. i wouldnt say too low.. low enough that it looks nice but still rides good.. funny thing is i just installed the suspension and it seemed to already be at a good height so i didnt adjust the height at all only played with the dampeners..

if you have damper adjustable springs then why not play with them? should reduce some body roll, but like i said earlier, you can have your cake and eat it to, thankfuly the buety of adjusting dampers on your suspension is you can change it back after your "spirited cornering session"

[blind_elk]

if you have damper adjustable springs then why not play with them?

It's the shock absorbers that are adjustable, not the springs. All the shock absorber does is control the movement of the spring, in both bump (compression) and rebound (extension). And the spring basically supports the weight of the car.

[maddowse]

thanks for the help guys so if i get the 27mm front white line swaybar that will be all good ??

http://cgi.ebay.com.au/Nissan-Skyline-R34-...=item2c56ddd439

[nato_wp]

I have never met 'Clutch' before, and I have no idea what he does for a living, however... I did a search on his suspension related posts. 70% are in this specific thread. The other 30% are asking why his coilover is leaking. He doesn't really seem to me like a credible suspension expert.

I am not claiming that I am a suspension expert, however, I have researched a fair bit on the subject, as it is a personal interest of mine. I am a heavy vehicle mechanic for a living.

A swaybar connects one side of the suspension to the other. This means that one side cannot compress without also partly compressing the other. Which, in effect, means that when the Mass of a cornering vehicle pushes down on the outside suspension, it has to also push down on the inside, meaning the vehicle stays flat through the corner, thus, the vehicle has less body roll.

A spring is designed to separate the chassis and body of the vehicle from the changing road surfaces, ie; allow the wheel to move up and down over bumps to maintain tyre/road contact without the passengers bouncing around everywhere. The shock absorber slows this bouncing of the spring by essentially forcing it to move at the same rate as a volume of oil passing through an orifice.

A swaybar is specifically designed to reduce body roll. A spring is specifically designed to keep tyres in contact with the road while allowing a smooth ride in the cabin.

Maddowse: You should go and have a look at the suggestions by Sydneykid. He has a lot of experience in setting up skyline suspension, and I believe he would agree with me in saying that unless it is for a specific situation, you should aim for a well-balanced suspension setup, by upgrading both front and rear swaybars by equal percentage. Keep in mind that tyres are the most important part of your suspension setup, and bad tyres will always result in terrible handling, no matter how good the rest of your components are.