Well i cant say what a ERST should get but i know that a standard rover tomcat, that has 197bhp standard gets 14.9 @ 94mph.

My car has 243bhp and from a 2.6 60ft time i managed a 14.508 @ 99.98mph. This was on a very very hot day.

Depending on your gear changes etc anything from 14.1 to 14.8 sounds right for a 200bhp RST.