For boosted class, I suggest to go with torque based motors. They are a lot better to get them running fast and relatively warm. As for timing, you have to first check what's the internal timing that comes with the motor. You wont be using much "endbell timing" due to the fact that the ESC will do it for you. The general rule is not to exceed past 60 degrees of total timing since the ESC will not perform above that (it will be useless). Having said this, you will want to focus the total timing on Boost since you spend the most time accelerating from turn to turn. Note: The Boost is also applied during the straights (as many people think otherwise) Now, the trick is to know how and when to engage the boost timing in order to maintain a great deal of acceleration while maintaining the motor running efficiently (cool) and avoid wheel spin. For example if your motor has 21 degrees of internal timing (SP MMM) you have 43 degrees of timing left to play. In our track we race 10.5T Boosted Class on an asphalt track that measures aprox. 150' x 90'. Usually, we race 46 degrees of boost timing (21 degrees internal on motor and 25 degrees additional timing on the ESC) with a boost timing acceleration (ACC) of 400-450 (the lower the number, the the more punchier the motor gets and also less efficient or hot). Since we have a long straightaway we program some turbo timing to get the car rolling at until 3/4 of the straight. We program 12 degrees of Turbo with a slope of 12 degrees per 0.1sec (Turbo slope refers to the turbo timing increase rate. The higher the number the faster turbo increases along with quicker acceleration and higher motor temperature). As you can see, we have used 58 degrees of total timing (motor internal timming, ESC boost and turbo timing)..
There is no universal setup for boosting since there are many variables you need to consider for example track size, track configuration, motor class, motor power delivery (more torque delivery or more peak power-RPM) etc. As an overall rule, always gear your car for a higher FDR since with boosting, you are basically doubling your motor power and RPM range (and making it less efficient) and try using batteries with a high C rating since the ESC will be drawing a lot of juice from the lipo at a very fast rate.
In setting the car, please start with the boost parameters. Race around your track and start making adjustments. Add boost and race the car for a couple of laps. Then, measure your motor temperature and continue on adding until your car is running faster. After that, adjust the boost timing ACC to better suite your acceleration needs for your specific track. ALWAYS check your motor temp. As a rule of thumb, the temp should not exceed 180.00 (yeap, in boosting class these temps are not uncommon, I race mine at 190..I want to win!!!
Once you've got the Boosting down, then you can continue on setting the turbo. Remember, the turbo thing is better suit for a track with a long straightaways or a lot of flowing high speed turns. You can always set it up in shorter tracks once you have more experience working with it.
Good luck and happy racing!