Adjusting Rear Swaybar For Less Oversteer?

[V28VX37]

Hi all,

I'm sure this is answered somewhere on SAU but couldn't find it on quick search...

I've got aftermarket ARC swaybars on my R34 and the rear bar is adjustable, with three settings. Right now I've got it in the middle setting and would like a bit less oversteer to help avoid the rear stepping out.

Which direction do I go with the swaybar links, towards the end of the bar (rear of car) or the middle of the bar (front of car)?

Thanks guys!

[Ben C34]

Away from the bar, towards's back of car will make it softer.

[kingtube69]

I believe the closer it is to the bar the stiffer so looking at that photo the hole on the right.

[XKLABA]

The hole closest to the end of the bar

It's leverage over pivot point v bar strenght

So the futher you are from the pivot point ( where bar is bolted to subframe ) the more leverage you have to twist the bar making it softer

[Ben C34]

I agree

[KiwiRS4T]

Yep you want to take some tension off so hole furthest from the bar is the one.

[Ben C34]

No way.....

[V28VX37]

Thanks guys, so most votes are to move links towards the end of the bar

I just watched the Whiteline video below, here's what it says

• Longer lever = softer, similar to a smaller diameter bar
  
• Shorter lever = stiffer, similar to a larger diameter bar
  

Tim Skelton's lists the following for oversteer corrections: 'Soften rear sway bar.'

http://www.timskelton.com/lightning/race_prep/suspension/corrections.htm

So yeah, last hole in the bar it is.

Whiteline adjustable sway bars explained:

Watch from 1m30: https://www.youtube.com/watch?v=0ISNWRMB6c4#t=1m30

Edited March 22, 2015 by V28VX37

[warps]

Yes. More importantly it sounds like you now understand why.

[Duncan]

Now we've got the which way under control you need to look at which end.

You need to stiffen up the end opposite to where you have the problem. so for less oversteer you make the front bar stiffer.

[V28VX37]

Now we've got the which way under control you need to look at which end.

You need to stiffen up the end opposite to where you have the problem. so for less oversteer you make the front bar stiffer.

Interesting point, the way I read Skelton's list is that you could either 'stiffen front sway bar' or 'soften rear sway bar' to correct oversteer?

Either way I only have adjustable rear bar so will try that first.

[GTSBoy]

Interesting point, the way I read Skelton's list is that you could either 'stiffen front sway bar' or 'soften rear sway bar' to correct oversteer?

Either way I only have adjustable rear bar so will try that first.

True. It's actually a philosophical point, choosing whether to add stiffness at one end or remove it from the other. What matters is what are your other driving factors beyond the oversteer problem? If you cannot afford to allow more body roll into the cornering, then you can't afford to back off the rear bar - so you add stiffness at the front. If you have plenty of roll resistance and could potentially do with a little more total grip as well as better front-rear balance, then you can reduce stiffness. And that equation is not always true for all corners on a given track, not always true for a whole given track, and certainly not always true for a variety of different tracks.

[kingtube69]

Lol i completely read this wrong.

[Dose Pipe Sutututu]

is your car oversteering with some power down OR as you turn in hard and coasting?

The factory VLSD is rubbish and often single spins so as you enter a corner (on a track that is) and apply some moderate power down the rear end ends up kicking out thus delivering some sideways action.

I found the best mod I did was install a proper mechanical LSD, there's some understeer on power now however so much more controllable compared to before.

[V28VX37]

is your car oversteering with some power down OR as you turn in hard and coasting?

The factory VLSD is rubbish and often single spins so as you enter a corner (on a track that is) and apply some moderate power down the rear end ends up kicking out thus delivering some sideways action.

I found the best mod I did was install a proper mechanical LSD, there's some understeer on power now however so much more controllable compared to before.

Well the back story is that I spun out twice on a recent Sandown track day, both times at turn 1 after overcooking the entry. Essentially: 200 km/h down the front straight > insufficient braking > start turning regardless > end up arse first in the litter halfway through the corner, on the right hand side. So a spinout with no power applied. It's 99% my s__t driving but it did make me wonder if I could have a bit more of a 'safety net' by adjusting the sways..?

The things I could look at improving next are 1. my driving, 2. semi slicks and 3. a proper mechanical diff. And I reckon spending on 2 and 3 is just trying to buy myself out of 1

[blind_elk]

Don't expect any size sway bar would have stopped that happening.

Get the "red mist" under control first, then get the car under control.

[Skepticism]

Well the back story is that I spun out twice on a recent Sandown track day, both times at turn 1 after overcooking the entry. Essentially: 200 km/h down the front straight > insufficient braking > start turning regardless > end up arse first in the litter halfway through the corner, on the right hand side. So a spinout with no power applied. It's 99% my s__t driving but it did make me wonder if I could have a bit more of a 'safety net' by adjusting the sways..?

The things I could look at improving next are 1. my driving, 2. semi slicks and 3. a proper mechanical diff. And I reckon spending on 2 and 3 is just trying to buy myself out of 1

Lol, that sounds fun

Agree with softer rear sway. Also if you're not running some toe in at the rear that could be an issue, toe-in will help keep things planted.

Changing to mech diff would be the go as well. Particularly if your own VLSD is buggered and doesn't lock any more , a 1.5 way will lock more on decel and reduce oversteer

Beyond that I'm pretty sure damping is the next port of call. At least if textbooks and iRacing's physics are accurate, haha :S... Basically if corner exit oversteer isn't a bigger issue, add more front damping. More stable on entry, the cost is less stable on exit. If you're oversteering in both entry and exit then gotta do something else. http://www.ozebiz.com.au/racetech/theory/shocktune1.html

Edited April 20, 2015 by Skepticism