3DSimED is a Windows DirectX application allowing the creation and visualization of models from many racing sim formats.
Models
can be exported to Assetto Corsa, Automobilista,
rFactor 2 (and 1), GTR2, Race 07, GTL, N2003 and many other games.
Sim formats which
can be imported include F1 2017,Forza 7, Forza Apex, Forza Horizon 3, F1-2016,
rFactor2, Assetto Corsa, Grid AutoSport,F1-2010 to F1-2015, NFS Shift, DIRT, GRID, Race 07, GTR Evolution, STCC The Game, GTR2, rFactor, GTL, GTR, Papyrus Nascar 2003 & Grand Prix Legends (GPL), Formula 1 2002 (F1 2002).
Try with version 3.1
Mods & Tracks for GP4 - [www.mediafire.com]Keeping alive the GP4