You're getting close, but not quite there yet.
Still sounds like a pitched up idle as a rev up sample.
You should get a throaty, heavy sound similar to what you'd get by revving a Detroit Diesel to.
Like this (0:40Sec) https://youtu.be/x_xiS_ANySI?t=35s
A perfect Idle sound sample (and loop!), although, overall, a sound mod of horrendous quality. You can't just pitch up the Idle throughout the rev range and call it a day. Spend a little extra time finding the perfect rev sample and then add it in.
Then i'll come back here and give you a review that you can learn with :D