Racing harnesses do not belong on stock Porsche seats.
Racing harnesses on race seats are good - IF -- and only if you also use a HANS type neck restraint - Ask Dale's widow and son.
If you take a car to the track that has standard 3 point belts and air bags this may/will/should protect you in a crash -- Yes, the race seat and harness and HANS may/will/should protect you better - but this will depend on the exact type of crash you have.
The track organizers are trying to help us be more safe on the track -- but lets face it -- the track is a very dangerous place. I know personally 3 drivers who have gone into the wall at 100MPH in DE/TT cars with full seats and harnesses and HANS -- they broke a rib and are very very sore afterward but no lasting results (hopefully)
or broken necks. My son now has a 911 track prepared car with cage, fire system, electrical shut off, Halo seat, 6 point harness, and fire suit, gloves and shoes --- all just for Time Trial. How safe can you be on the track---probability tells us the more you are exposed the higher the risk --- just like Craps, eh?
Flame suit on --- fire away
Take care,
Ed
PS: I have a MOMO seat and BK Rollbar available if you are interested...