well the optra/forenza wagon/sedan are the exactly the samer mechanically as the Optra5/Reno. i like the Reno but i love the Audi wagon look of the Forenza wagon.
"Formerly known as Jammit - JBO member since 1998" JBOM | CSS.net
This should answer all the question about the engines in the Optra / Reno
Optra Link to GM/Holden
As far as the aftermarket goes,
360 Dynamics already carries a line of product for these cars. And the equivalent of the j-body for these cars, would be the
Daewootech
From what I understand, you can think of the Optra engine as of the 2nd gen 2.0 Sunbird, with 16V head. As a matter of fact, the Optra engine (and older 2.0/2.2 daewoo models) make a bolt-on swap onto the Sunbird. There is a member on the board who swapped such engine into his turbo grand-am, and runs about 270hp with the Grand-Am turbo management
My 5 cents....