I have also been doing some research into the suspension of the Optra/Optra5/Reno/Forenza/Lacetti/Nubira versus the Leganza suspension.
The purpose of this is to convert the 4 X 4.5" pattern to a 5 X 4.5" pattern ( mainly for Kinkyllama who needs wider tires/rims )
I took indepth measurements and the front knuckle of the Forenza and Leganza seem to be identical.... so it's just a matter of swaping over the knuckle/hub/disks from a Leganza to a Forenza.
The rear is a little tricky.... they both use the exact same style suspension with a trailing arm and two latteral links and the knuckle from the Leganza does have the correct pattern to fit the Forenza strut.
But.... the lenghth of the bars are different.... so I'm going to cut and thread the bars (one lefthand thread one right hand thread) and install an adjustment nut (just like a tie rod)
This will allow the Forenza bars to match up with the leganza knuckle/hub/disk assembly and it will give the added benifit of making the suspension completely adjustable for Camber, Castor and Toe in/out.
Once I have a set of prototypes and have tested them on my own car I will probably turn the manufacturing over to Kenny (audacityracing) since this is his specialty.
So that's the good news..... anyone with a Lacetti based vehicle will be able to switch bolt patterns and get an adjustable rear suspension
Here is a couple of pics showing the suspension and where the three bars would need to be cut and threaded......