Wave Race64 works very well on Corn; Ridge Race 64 too, although with some major texture errors (but still playable, if you don't mind not to save the game...)
...the main problem is that Corn was an emulator made to run Mario64; a little after ContraSF (Corn author) made it, he entered in an internship or something, and then never got back (rumours says that happened because Corn v0.3 beta got leaked to the public)
If you're going to use Corn, give a look in its compatibility...
http://thecpy.emulation64.com/thelastresort/corn03.htm
Also, grab Version 0.2 and its update patches, 0.29 and 0.3, and the latest .ini files (by The Company or by Duncan)
http://thecpy.emulation64.com/thelastresort/Ultrhle.htm#Corn
You could also use UltraHLE 2064, they claim the reccomended processor is a PentiumII 450mhz, and has plug-in support...
http://www.ultrahle2064.com
But I still think you should keep you 1964,as it's the best n64 emulator still in development, with compatibility growing up, and I'm pretty sure there's still room for speed enhancements... I'm sure soon it'll be better than pj64 (1964 already is, in some games, v.g. Densha de Go! 64 - the only emulator that runs this game)