Originally Posted by YoDog

You don't have to buy parts to change the timing. You have the option of expanding the range of timing with other sensor modules. there is a difference.
The other brands typically don't have as broad a timing range as the SP motors hence you are limited by what comes installed by design. Each module provides 10 degrees of adjustment and depending on which model you choose, it can be 0-10, 11-20, 21-30 and so on. With the 31-40 degree module, you are getting up in the range most motors can't accommodate. So in conclusion, if you know what timing range you intend to run, you may or may not need an additional module.