I would suggest getting a datalog in 3rd gear, and one WOT for atleast 1-3 as that will tell you more info. Make sure to log your OAR, KR, speed, load, spark, A/F parameters (bank 1 or 2), and fuel pressure parameters.
Also if trying to brake boost launch, the car will get mad if held too long, as it has a safety feature for this. it will be less mad at you if the traction control is all the way off, but still angry at you.
My car used to spin like mad on launches, and still does occasionally, but my tune has been smoothed out a little as far as bringing in full boost, so that I can hook and then go all out.