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[gcarter]

Greg, there's very little drag in a transom pickup. In fact, I'd say there's no measurable drag under 100 MPh. At that point, a different type is generally used. Virtually all race boats use them.
But there can be HUGE gains in a good nose cone. Look at the performance difference between an old Volvo drive VS a King Cobra, or other good high performance drive.
Another, almost unrelated, analogy are the bulbs on the bows of large cargo ships. Absolutely huge amounts of money is spent on refining and tank testing various bulbs in the design stage because as much as 15% reduction in operating expense can be achieved.

[Conquistador_del_mar]

The TRS drive is a solid gear outdrive capable of holding up to relatively huge HP and torque loads so that might be a reason Warlock used that drive system in 1989 when the relatively new Bravo was not as robust and somewhat unproven. A customer might have actually wanted the proven TRS? In the 80s when I was installing lots of nose cones for customers, the rule of thumb was to put them on if the boat would do 65mph+. Since then I have since read that they only really come into play at 80mph+. Like George said, the newer Bravos are better designed housings than the older ones so they probably don't need nose cones for the length vs diameter parameter at high speeds like the older ones.
George, what is the theory of those bulbs on ships?

[gcarter]

Bill, back in the early '70's when I was working for a Naval Architect in Houston, so little was understood about them, only that they seemed to make the water react like the ship was 10-15% longer than it was........at displacement speeds, the longer ship can be more easily driven than a shorter ship. So if you had a 400' ship, but it performed like it was 500' long, it was cheaper to operate. Take those savings, multiply them by 12 months a year, and over a life of 20 years, you can see the motivations for them.
Back to the '70's, bulbs were round, not very long, and hemispherical on the front. The height was from the keel upward to just below the light water line, or so.
Today, bulb design has seemingly taken on a life of its own. They seem to be much longer than they were when I was involved. Also many seem to have flat upper surfaces and are placed just below the water line. If you get an opportunity to see some newer versions (newer cruise ship models are always on the cruise ship somewhere) it's obvious a lot of time and effort is invested in the shape of them.
I suspect more can be gained from good bulb design than almost anything else that can be done.

[Conquistador_del_mar]

Bill, back in the early '70's when I was working for a Naval Architect in Houston, so little was understood about them, only that they seemed to make the water react like the ship was 10-15% longer than it was........at displacement speeds, the longer ship can be more easily driven than a shorter ship. So if you had a 400' ship, but it performed like it was 500' long, it was cheaper to operate. Take those savings, multiply them by 12 months a year, and over a life of 20 years, you can see the motivations for them.
Back to the '70's, bulbs were round, not very long, and hemispherical on the front. The height was from the keel upward to just below the light water line, or so.
Today, bulb design has seemingly taken on a life of its own. They seem to be much longer than they were when I was involved. Also many seem to have flat upper surfaces and are placed just below the water line. If you get an opportunity to see some newer versions (newer cruise ship models are always on the cruise ship somewhere) it's obvious a lot of time and effort is invested in the shape of them.
I suspect more can be gained from good bulb design than almost anything else that can be done.

They are certainly an interesting modification! Thanks for taking the time to reply.