i glitched the rai jin with speed boost then raced another rai jin on south bay up to the observatory. It doesn't actually make it faster it just increase's its acceleration it could have just been a bit of rubbish drivin by me but they started to keep up with each other on south mountain and that is uphill so i dont know wat is is like on a actual race unfortunately i cant test this on a race because the glitch dosen't transfer to racing