List of PSP motorcycle racing games?

[LunaMoo]

Moto GP, Ducati Challange and 3 different versions of SBK - Superbike World Championship('07, '08, '09) are the only games fitting your description on PSP, so if it's neither of them, your imagination made things up.
You can use sites like to easily find screenshots of most psp games, through worth remembering that PSP was a Visual Novel dominated platform, followed by RPG's, most other genres are poorly represented and often have worst versions of multiplatform games.