neither boost or frequent racing of your car is really a good reason to run thick oil. the problem with thick oil is that people see high pressure and mistake it for better lubrication, its not alway the same. more flow= good more pressure = good, but if u have to sacrifice flow for pressure, then it is not.
sure some colleagues of mine run 20-50 in there drag cars, but they also run .004 clearance on the bearing surfaces and these are 1500 hp car that only need to survive a relativly short life. these are also aplications where your worried about the oil breaking down over a 1/4 mile span. theres such an incredible ammount of oil contamanation on these cars that they start with 10 quarts of oil and you drain 14 quarts out of the pan at the end of a race... apples and oranges