Burnout technique A999 trans

I have been racing 904s since 1993, with transbrakes...been starting burnout in 1st gear and shifting into 2nd gear before leaving water box. ..Never have had a problem...
After breaking a ring gear...8 3/4....I made about 5 more passes on that trans with a damaged sprag....after that it was making a lot of noise...since the 904 uses a bolt in spraq it was easy to fix the trans.