Are you asking why the tires won't smoke?

1) Fairly low ratio in rear axle
2) Your buddy is powerbraking. One does that to get max torque on launch (best launch) and minimize wheel spin. If you want to do a smokey burnout best just to punch it, no brake from idle.
3) Probably have way less horsepower/torque than you think unless whole engine is optimized (dyno tuned/jetted) and you have great flowing heads.

Open diff should allow you easy burnouts regardless if you just punch it from idle (one wheel only). For fastest launch higher rear ratio and Sure Grip mandatory