[Dazzler]

Great find Trev... (I always wondered too) 

Sounds like they had an oportunity to touch everything. What they ended up with in Oz is not too bad for a tall car but I wonder what the others get feels like. I wouldn't have wanted anything "softer".

According to a post above the rear sway-bar for the Oz car is 14mm. Anyone from another country care to climb under and measure theirs?

[Lorian]

My stock rear sway/anti-roll bar is 17mm. Its only identifying mark appears to be "25ti"
  

[Surferdude]

Yeah. Mine's only 14mm, too.
I guess if they've stiffened up springs and shockies, they figured thinner was OK.
There is no doubt my car has a nice stiff, positive feel about the suspension and steering.
More on this later. I'm due for a 6 month update on my thoughts.

Interesting that the UK model ended up with a stiffer anti-roll bar... presumably they also have softer springs.

This quote,
..This involved refining i30's European settings to accommodate our multi-patched, lumpier, bumpier local roads...
suggests to me that the Oz suspension tune was probably much less concerned with outright cornering ability and more with general stability things, like bump-steer. I find it tracks pretty straight and is not put off by pot-holes, tram lines etc. I'm less happy with road corrugations where it performs very poorly in my opinion, crashing and dancing all over the place.

Also interesting to see that the rear anti-roll bar is the same for the heavier diesel as for the petrol engine and I really wonder why they bothered to go from 17mm to 14mm for the rear anti-roll bar. The difference must have surely been minimal and considering that some here now want to increase it beyond 17mm, possibly might have been better left anyway?

[Surferdude]

Actually, mine handles the rough stuff very well.
Had it up in the edges of the Kenilworth State Forest a while back and it seemed preety tame and controllable on the ruts, potholes and corrugations.

Actually, mine handles the rough stuff very well.
Had it up in the edges of the Kenilworth State Forest a while back and it seemed preety tame and controllable on the ruts, potholes and corrugations.

Yeah, I wondered when I wrote that whether I might have been alone. I am waiting for my service guy to come up with a plan to sort a rack (and column) rattle which probably infuences my feeling of poor handling over corrugations. That and the lower profile tyres on the slx pumped to 38psi.

Also, I suspect you were going a lot faster than me which sometimes helps.

[Surferdude]

Actually, mine handles the rough stuff very well.
Had it up in the edges of the Kenilworth State Forest a while back and it seemed preety tame and controllable on the ruts, potholes and corrugations.

Yeah, I wondered when I wrote that whether I might have been alone. I am waiting for my service guy to come up with a plan to sort a rack (and column) rattle which probably infuences my feeling of poor handling over corrugations. That and the lower profile tyres on the slx pumped to 38psi.

Also, I suspect you were going a lot faster than me which sometimes helps.

No to the last bit. i had my wife on board and she gets a bit freaky. I WAS hurrying though.
I run at least 36 so there shouldn't be too much difference there but certainly the lower profile tyres would make a big difference and may well be where your issue lies.

[bobbyd]

Well i got the bar from signature and fitted it up- it corners beautifully now !! gone is the tendency to fall into corners when there is a dip or bump mid corner.  Its positive and predictable, under steer is gone, the limiting factor now is tyre traction as it can really be thrown around with confidence. Ended up getting 20mm bar and side by side compared to the standard bar makes you wonder why the bothered with 14mm ?  Doesn't feel any harsher ride.

Only issue i had was i ended up grinding down the ends of the bar as they were a tad longer owing to the larger diameter bar being crimped to make the eyelets- the eyelets where actually bigger in outside diameter if that makes sense- oversized compared to the standard and made it tight to get in without removing the springs, few mm ground down was perfect and still meatier eyelets compared to standard. Other than that it was a perfect match up, really happy, excellent investment.

Next stage for me is to get standard spring reset to a lower ride height, dont want to go any stiffer with springs. Quoted $80 per pair to get done, will take them out next week.

Well i got the bar from signature and fitted it up- it corners beautifully now !! gone is the tendency to fall into corners when there is a dip or bump mid corner.  Its positive and predictable, under steer is gone, the limiting factor now is tyre traction as it can really be thrown around with confidence. Ended up getting 20mm bar and side by side compared to the standard bar makes you wonder why the bothered with 14mm ?  Doesn't feel any harsher ride.

I've been waiting in quiet anticipation of good news from you. I'm really too old and stiff to work under cars now... but I could make an exception here. Nice report.

Be sure to give any update as you live with it longer.

[stkman]

Well i got the bar from signature and fitted it up- it corners beautifully now !! gone is the tendency to fall into corners when there is a dip or bump mid corner.  Its positive and predictable, under steer is gone, the limiting factor now is tyre traction as it can really be thrown around with confidence. Ended up getting 20mm bar and side by side compared to the standard bar makes you wonder why the bothered with 14mm ?  Doesn't feel any harsher ride.

Have been meaning to upgrade the rear bar after upgrading both front and rear bars, springs and dampers on my last car. Robdridan's feedback about a 20mm rear bar has kicked me into action and today I removed the standard rear bar and will take it in tomorrow so it can be duplicated in 20mm.

Can confirm my standard rear bar is 14mm and the front is 23mm. Would be interested to know what diameter the front bar is on UK/European models as Australia and NZ definitely have a downgraded bar. Driving without the 14mm rear bar doesn't feel a lot different. A little more understeer but not by much. I suspect most of the rear stiffness comes from firmer springs (as compared to UK/Europe).

The new bar will be black but new bushes will be red (will get some Nolathane bushes as they are easy to get here). Will need new mounting brackets as well as the standard ones have an odd shape to locate the Hyundai bushes. Will probably get new links with longer thread as the new bar will have thicker eyes.

Will take photos and post when completed.

Andrew

[bobbyd]

Now having lived with the new rear bar for a coupler weeks i also had my springs reset a little lower.  I am so happy with this combo, handles brilliantly and no bad manners that i have previously experienced with getting lowered "heavy duty" or stiffer springs.  With the 18 inch wheels it gives plenty of road feedback but not too harsh, its so positive around all corners- mild to tight.  Highly recommend this upgrade combination for anyone who wants their i30 to handle well.  I'm still keen to find anyone who does a bigger front bar but having looked underneath the car well now, i suspect getting the front bar out is a major job ??

[stkman]

having looked underneath the car well now, i suspect getting the front bar out is a major job ??

Hi Robdririden,

I replaced the front bar on my last car (Toyota) with a larger one (went from 17mm to 25mm) and it looked about as tricky to get out. Paid the local workshop to do it and watched. They dropped the rear of the suspension 'subframe' and slid the bar out backwards, slid the new one in and bolted it all back together. Took less than 1/2 and hour. i30 looks very similar. I measured the front Hyundai bar at 23mm.

Andrew

[stkman]

Hi All,

Finally got all the bits and pieces together to instal a larger rear swaybar and spent the morning in the sun doing just that. Took photos along the way ...

Comparison of the original 14mm bar and the new 20mm bar. Was made by a local spring manufacturer. This is the third bar they have done for me and I have been happy with their work on all of them.



Used Nolathane bushes and clamps.



I liked the way the Hyundai bar has fittings to stop lateral movement. A suspension guy I went to to get the parts to fit the bar from suggested rubber hose and hose clamps but I found a "lateral movement lock kit" by Whiteline.



The ends of the new bar are a lot sturdier looking ...



so I got some universal swar bar links and cut them to length to suit. They look a bit more substantial.



Fitting the bar took a bit of doing. The old bar came out easily but the new one is thicker and with the more substantial ends, wouldn't slide in place easily. I ended up removing one shock to allow the spring coils to open up so I could slip the bar in between the coils and I dropped the lower suspension arm on the other side so I could pull the bar past the coil. Maybe easier to pay a workshop to do it!

Got it in though.



So the question is, how does it change the feel of the car. Actually, around town and driving gently on the motorway, there isn't an amazing amount of difference to me. Steering feels a bit sharper ("turn in" is better) but no really dramatic difference.

However, once you push it a little into corners, it will put a real smile on your face. Windy uphill for the last km or so to my house and was susbstantially quicker around corners with much less understeer. The car felt very neutral. Feels when it finally slides, it will be all four wheels at once. It really is a great improvement. It doesn't seem at all harsher to me.

I used to have 35psi air pressure in the front and 32psi in the back ... to me, it felt it steered better than 32 psi all round. Have gone back to 32psi all round and I like it.

Andrew

[Paolo5]

WoW!!! Looks like the people who made your new bar did a fabulous job. And you did too! Well done!!

Cheers,
Paolo5

[agentr31]

mate that is awesome!! got a link to the place that made the sway bar? and mabey how much it cost you! im quite interested in doing some suspention modifications to my car!

[Dazzler]

Great Photo Guide Stkman. From what I've read I might need to do a similar mod if I upgrade to an i45 ...

Great Photo Guide Stkman. From what I've read I might need to do a similar mod if I upgrade to an i45 ...

From what I've read you might need to do more than that... however, I also read that Hy are looking at making some changes themselves after the motoring press universally caned it.

By the time you get one it might already be fixed.

Although if they Australianise it in the same way they did the i30 there still may be room for improvement as has been documented here.

It truly baffles me that the strong inherent understeer from FWD cars is not more seriously considered something to be minimised to improve the balance and handling as a safety factor. While it might be better to go off front first instead of backwards, forgetting ESP and its influence on this, I would always prefer to have some steering response if I've overdone it.

It could be that it's easier for the ESP to correct an incipient front-end slide than a rear-end slide. And even if this is true, why start with such strong understeer if you don't have to? When push comes to shove a FWD will understeer anyway. With the advent of stability control will the conventional wisdom, that understeer is the safer setup, be questioned as unnecessary?

While there would obviously be differing opinions on which might be the preferred balance I am of the opinion that it really doesn't matter which is the final tendency (about the time ESP comes to your rescue - whether you need it or not) but that the general balance up to that point be near to neutral for an enjoyable and safe drive.

Those here that have changed the balance to more neutral report a much nicer drive... and I'm assuming they are not talking about anything more than normal driving.

[Dazzler]

Great Photo Guide Stkman. From what I've read I might need to do a similar mod if I upgrade to an i45 ...

From what I've read you might need to do more than that... however, I also read that Hy are looking at making some changes themselves after the motoring press universally caned it.

By the time you get one it might already be fixed.

That's interesting .. I might just hold off until they do... Have you got a link to where Hy say they are looking at changes..

[stkman]

The correction for understeer is to apply the brakes which ESP can do quite easily and very well. With oversteer, braking would just make the situation worse ... in an oversteering situation, it is best to keep the power on (or even increase it) so that the car pulls itself out of the oversteering situation. I don't think I would like ESP to increase the throttle input and release the brakes for me!

I intend to try the i3o with the 20mm rear bar in the wet in an empty carpark at some stage to see if I can induce oversteer. In the dry it's very balanced with no hint of oversteer.

Andrew

[jason117]

Here ya go Dazzler.

http://www.carpoint.com.au/news/2010/medium-passenger/hyundai/i45/hyundai-i45-set-for-chassis-tweaks-20080

[agentr31]

understeer is the enemy... in a fwd you should aim for pretty neutral handling

you really dont want oversteer in a car with no weight on the rear axle... it just turns out badly

[Dazzler]

Here ya go Dazzler.

http://www.carpoint.com.au/news/2010/medium-passenger/hyundai/i45/hyundai-i45-set-for-chassis-tweaks-20080

Thanks Jason (and Pip) guess I will be waiting until they sort it out...  

Sounds like I might be best to wait until the new year and see if a Diesel arrives and also check out the 2011 Kia Magentis 

understeer is the enemy... in a fwd you should aim for pretty neutral handling

you really dont want oversteer in a car with no weight on the rear axle... it just turns out badly

Agreed, but as I said (and I don't direct this to you Agent) a FWD will always understeer in the end because the weight and the drive (and the steering) are all at the same end.

I drove a lot of (panel van) Holdens from the 60s, 70s, (and yes, it was in the 60s and 70s) and it was interesting to take a corner "too fast" to say the least. Lose the back and it was often terminal. I understand... I rolled one three times... I counted them as I went around. You guys are so lucky to have me here.

What I was trying to say was that extremes of balance (and I really meant strong understeer) are really unnecessary, particularly when ESP will ultimately correct your mistakes to some extent, because it detracts from the driving experience for normal drivers and normal driving.

I look forward to more feedback from those whom have taken the step of fitting rear anti-roll bars.

Here ya go Dazzler.

http://www.carpoint.com.au/news/2010/medium-passenger/hyundai/i45/hyundai-i45-set-for-chassis-tweaks-20080

Thanks for that link, I was hard pressed to come up for one as my quote was from a throw-away line from a newspaper.

[stkman]

Saw this article about rear sway bars ... may be of some interest!

http://autospeed.com/cms/A_2359/article.html?popularArticle

Andrew

[agentr31]

Agreed, but as I said (and I don't direct this to you Agent) a FWD will always understeer in the end because the weight and the drive (and the steering) are all at the same end.

yep, this man speaks the truth!!!!!!

i have once encountered oversteer in a FWD, i took a rather large round-a-bout wayyyy to fast in the maxima (70kph) and the arse came out, i wasnt expecting it to do that and man did i panic, its not like a RWD where you can dial in some opposite lock, put the power on and drive out of it in a rather calm manner, it was just a pig to control and very nearly ended in tears...

[Surferdude]

Oversteer + front wheel drive is exciting isn't it?
It's OK if you expect it. Some opposite lock and either keep the power on or gently lift off (any sudden movement is deadly). A FWd's inherent stabilty will generally kick in as you wash off speed.
Of course, if you don't expect it - disaster with a capital "D".
The early model Subarus had a narrower rear track than the front, so oversteer, especially on gravel was a regular occurrence and certainly helped you get through corners.
In my rally days I used to switch around between a Renault 12, a Datsun 1600 and a Subaru.
Interesting (and exciting) times.

[agentr31]

gentle brakes, VDC and opposite lock saved the day for me... i hate the fact that a computer aided me, but i think with out it i would have most ceartinly spun out

[jason117]

I've had an upgraded (18mm) rear sway bar fitted to the i30 for a couple of months now and around the streets it doesnt feel a lot different, just a crisper turn in at moderate speeds. Where I'd hoped to find the greatest improvement was on the track and I wasnt disappointed. My lap times at Eastern Creek dropped by over 2.5 seconds per lap  and the car's terminal understeer has been tempered but not removed altogether. I think for the track a slightly larger again bar would be of benefit but as the car is only going to be tracked sparingly I wont change it again. The car is totally stock apart from the bar change.