I'll be installing a bravo xz outdrive on my 25' sxt warlock cat. would a nosecone be recc or just install it without ? I have all winter to do the work. If yes, what brand cone ??

The question is HOW FAST do you currently run? Back when my 272 Baja only ran around 90 mph when I bolted my spare drive on without a nosecone it would slow down a solid 4mph or so, I use a well blended in hydromotive nose cone fwiw, Smitty

the guy that sold me the boat had a 572 w/ blower and the outdrive had a nosecone on it, he claimed that the boat ran 118 mph on gps speedometer. I'm installing a 565 w/ a blower, est about 850 hp. and a bravo zx drive w/ water pick-up in the nose. just wondering if I should do a cone over the winter.

For me it was the other way around (gained 5mph with a std lower over Imco lower) with my 28 Pantera that also ran around 90mph

I had the same experience too (sorta)-boat ran 99.5 mph with my current motor in it with very well blended hydro nose cone on a stock length merc lower casting , lost 5-6 mph with a Imco shorty (saw 95 once but usually 94 or so) , put a 1 inch spacer on, was still 5 mph slower, put a 2inch spacer on, was slower yet, put original housing on with nose cone and immediately had my speed back, sold that imco garbage. Never tried a merc lower without a nose cone at these higher yet speeds as it went slower when it was in the 80's with a non-nose coned drive, Smitty

The kinda speed your running I wouldn't even think of NOT running a nose cone, fill it and blend it though , I spent about 10 hours grinding, filling and sanding (with a D/A) on my fastest lower, Smitty

do they make a nose cone that works with the existing holes that are in the nose now, or do I need the cone that has a hose on the top of it ?

Hydromotive, does not like any holes in front of the cone. You can drill the side water ports, if your X isnt too high and cover the low water pickup. Most my experience has been with V bottoms and Hydromotive cone works the best. Not sure about a cat though. I have dimensions for drilling the side ports if you want them.

Dick

just curious...at what speed nose cones start to make a difference?
im runnin 77-78 with an XR....

I was told not to use a Nose Cone until the props blow out, I am running 81 mph at 4800 in a twin application. Curious again now lmao...