[ccweems]

In the US we don't get the i30CW (MD?) so I can't come close to answering this question.  Trying to improve a torsion beam suspension without ruining the ride is near impossible.  The multi-link is another story.  There is a lot of room around the existing suspension on my i30 (GD chassis, Elantra GT in US) so I'm hoping Hyundai used much of the same pressing for both cars.  Don't expect it to be a bolt on but with a little welding, possible.  Would want it to yield a "stock" suspension in that it could use the same springs, shocks and sway bars as the i30CW.

You seem like clever lads, I wouldn't be surprised that someone hasn't already done it.

[Dazzler]

Welcome cc 

Most of our members would be too nervous to do that for fear of voiding their warranty.

Feedback on here is that there is not a huge amount of difference in ride and handling between the two variants. You might get a better result by trying to replicate the suspension tune of the new Aussie only GD "SR" model.

https://www.i30ownersclub.com/forum/index.php?topic=24138.0

https://www.i30ownersclub.com/forum/index.php?topic=24322.0

 

[agentr31]

i can show you a link to where a bloke changed the solid rear axle (borg warner M78) to an R32 GTR independant rear suspension, and while its not the hardest thing to do, it will take time LOTS of time.

http://forum.r31skylineclub.com/index.php?topic=43889.0

read this then ask your self if it is worth it.

[Doggie 1]

Welcome to the forum.
Not worth the effort IMO as the ride/handling with the torsion beam is fine.

[snakoil]

the i30cwFD was sold in the US as the Elantra touring from 2009 to 2012
this might be your closest match
Honestly I would not waste my time in doing this sort of swap as with the power the ElantraGt has you won't see huge improvements with a better rear suspension.
If you really can't live with the suspension setup in your ElantraGT I suggest you change it for something else like a 2014 Mazda3 with the 2.5 skyactive or new VW Golf
These options will cost you less than trying to do it and should yield better results