Nose Cones
 

Anyone here use a nose cone? I found two different styles, the Hydro and the one that looks like a Imco. Anyone seen any gains in the mid 70's on a Vbottom single with a propshaft 5" deep. Right now my slip numbers are good 9.8% at WOT. Prop only blows out on tight turns or getting on plane if hitting it to hard. Just looking for 1 or 2 MPH (one would be fine), the manufactures claim 2-6 MPH.
Another thing its a 1994 Bravo drive.

We put them on our trs on the race boat and noticed a 2 mph gain and made the boat handle alot better. We used to hydro motive ones, Worked well.

I think nose cones work great. They increase the efficency of the outdrive going thru the water. This typically reduces your prop slip numbers because the prop is now getting more.. and cleaner water. Because of the reduced prop slip... and thus more efficient prop, sometimes a prop change is in order to get the fullest benefits.

Chris

Put a set of Bob's on my old Fountian ( 1990 38' Fever) B 1's ,just fo the heck of it. Did not notice much on the top end, (only a low 70 mph boat) but the handling improved a bunch and my slip calculations improved from 18% to about 13 - 14%. Engine rpm also dropped about 200 rpm (decrease in prop slip). Would not recommend the cones from Bob's, fit and finish $ucked. Took alot of work to make them fit and look good. Have a spare drive that I installed a Warlock cone on, it was a nice piece, fit great and did not take alot of blending to make a great install. Have used the Hydro's on a previous boats, also nice cones to work with.

Thanks, thats good to know.

Did you see any speed gains? Which type did you use?

Thanks, I have not heard of the "Bobs" brand. So increased handling, lower slip numbers, no speed increace?

Well it is hard to call. Rpms lowered and speed stayed the same. So call it a speed increase, no , but the prop just became more efficiant. Need a couple more hundred horse to real see the gain (on my application). The B-1 is good effciance wise, they say to 90 mph. The increase in handling was the most noticable on my boat. Also was able to trim out a bit more. But no on the speed gain. Did do some prop swapping and speed wise a 1 or 2 mph differance (3 blade mirage virse 4 blade B1's). Bob's Machine, you can look them up on the internet, they make all kinds of speed stuff. Every boat is differant (drive height, boat bottom. pad or notch transom) so all you can do is give a shot. As everyone say's more horsepower is the true way to more speed. Pete

Anyone else?

Bob's used to be great. too bad their quality control has headed south. I had them do a lower unit on my boat about 15 years ago. worked great. I have a 26' baja and have an imco shorty lower. Didn't pick up speed but get the same speed with less trim -which was a plus for me. The difference has more to do with the shorty rather than the more hydrodynamic nose.

Most say that you won't gain speed unless you are already at 80 or more.