hopefully these races are on a track
But that being said, the 335i with SSTT is sitting at a 131 lb disadvantage stock for stock (with slightly better aerodynamics on the 3 vs 1...but that wont come into play off the line much)..add an extra 170lb person (this is assuming the 1ers passengers weigh the same as yours per person)...and you are racing a 135 who has ~300lb advantage over you...
Even the 35whp the SSTT gives you (also assuming you had given that thing time to adapt...as it takes a day or so..youll notice the difference), cannot overcome a 300 lb weight advantage.
The fact that you stayed within a car length is showing you the extra power you do have, since the jump is variable, that car length is negligible, essentially, youre dead even, but he has a 300lb advantage. There is your power