You can hear the high RPM on throttle samples pitches fight each other a bit and the stability/blending of the samples overall might need another look over. And (IMO) the distant version of the rear on throttle sound comes on a bit to close and could be mixed for a little while longer to help them blend. BUT... what you have given us here is a very nice cohesive base for a more polished version down the road. That is to say this needs a little more work but IT IS WORTH it! :)