Complex sentence: During the 1930s, Eduardo worked with his brother Jorge at the "Irmãos Ferreirinha" shop, where together they transformed Ford Vehicles into race cars, which became popular with Portuguese racers.
Split into simpler sentences: During the 1930s, Eduardo worked with his brother Jorge at the "Irmãos Ferreirinha" shop. Together they transformed Ford Vehicles into race cars, which became popular with Portuguese racers.