200 MPH
You'll do over 200 no problem, just keep on trying different settings and props, there's lots of advise and knowledge on the subject, check out some of the other posts, have fun with your whiplash, its a kick in the pants at any speed but especially over 200.
150 MPH--------- Pucker Factor 50%
200 MPH--------- Pucker Factor 80%
225 MPH--------- Spinkter collapse