nosecones
 

Wondering what some of you think about the neccesity of using a nose cone on a bravo driven boat in the 100-105mph range. I have been told that the F class boats cannot run them in APBA. I guess some of them run near these speeds. If I still have my boat into next summer, I was thinking of shortening the drive. The question is, is there any reason not to test the boat without the nosecone first? Can a bravo driven boat lose control in this circumstance like I have heard outboards do? The reason I ask, is , a couple of individuals that have knowledge of boats in this speed range, expressed hesitation in installing a nosecone. I primarily want to know if this could cause an abrupt handling issue, if tried. A fellow at mercury racing once told me that the blowout speed of the late bravo was at least in the high 80s.

Thanks.

You will have better handling, less slip, and less chance of blowout when using nose cones. If you are trying shortened drives the Mercury sportmasters and the IMCO gearcases already have the nose of the drive shaped properly.

as long as its alinged up straight. thats the part that is crucial/ the Bravo drive at 80 mph is like running a torpedo through the water without the thrust,use a nosecone on this one!!! just my suggestion, compare it to a pencil running thru the water or a big cigar/ hu /Darin

OH !!!!!!!!!TEST WITH OUT, AND THEN TEST WITH ONE AND LET US KNOW THATS WHAT ITS ALL ABOUT./ p.s. need a test driver. ha

Yeah Brad Perry, please test without & with then let us know your results, that is what i'm planning on, but i won't be ready to test for a couple month yet. so if you beat me to it i will be really curious about your results.

Problem is that I installed a nosecone on a late model bravo while increasing power significantly. I wish I hadn't done it at the same time. I might install a new XR that I have and might even shorten the XR lower and don't want to make the same mistake again, unless it is common knowledge that a cone at those speeds is the only way to go. It is a couple of individual comments I got from a couple of guys that should know their stuff that got me debating this. I guess the writing might be on the wall, from the fact merc (bravo and speedmaster) and imco only come with a lengthened torpedo...

If your boat likes a lot of trim go with something that is more rounded than pointed. The pointed cones work well with relatively level drive angles, while the rounded type are better for boats that need trim to run good. I think the Hydromotive cones will be the best bet for your type of application. I remember when I got my SS drive from IMCO they offered it with and without a nose cone. Now they only offer it with a cone. They were thinking that since my boat was small and liked trim the non coned version may be better because of the trim angle. To bad we never tried it out. With the current drive the VETTE handles very well in the 95 MPH plus range on calm water of course. One interesting thing I noticed about my boat is as I increase speed the water pressure goes up. When I am fully trimmed out the water pressure actually drops about 5 PSI. If I tap the trim down 1 tap the pressure comes back up and If I over trim the pressure will drop 8 to 10 PSI. The pick up is below the bullet of the nose cone and as I trim the water is hitting the top of the cone and creating a void around the water pick up. I filed the hole a little larger and now it keeps good pressure in my operating range, but I can imagine if the bullet was rounded the boat may go faster. What do you guys think?

It depends on the boat. I know of a 26 eliminator tunnel that runs 117 and does not use a nose cone. The boat has a bmax drive with a mercury lower. I have been in this boat many times and not once has it ever felt like it was out of control, or blow out. It launches out of the hole and has extremly good mid range pull. As for the top end it does 117. I would try a nose cone it deffinatly wont hurt it.

Eliminator 26 horsepower?
 

Tom, what kind of horsepower does the Eliminator 26 have to reach 117?

Through the years their has been a lot of controversy of the effects of nose cones. A few months back I did a test with a set of Hydromotive nose cones. At the time the best top speed on gps with my 32 active was 94.7mph. I had installed the nose cones prior to my new combination so I wasn't sure if the cones really worked. As much as I hated the idea of removing them I had to know the affect they had on my performance.
After running the 94.7 I went home and beat the cones off, cleaned up the drives and went straight back to the water. Would you believe the boat would only run 90.5 and handled like sh---t!
The next day I called over to hydromotive and asked his opinion on gains and he said 3 to 4 mph at 90 and the faster you run the bigger the gains. Anything in the 75 to 80 mph range would not see much affect from the cones,maybe better handling and a 1mph gain.
The best thing about the cones is they install easy with epoxy and can be removed. Be careful when selecting a cone many longer edged cones look great but if overtrimmed will drag and cause poor handling and lose of speed. Even a boat that requires a lot of trim can use the hydromotive cone due to the design it will not become an anchor or hurt handling.
I have since found better props and brushed 100mph safely with the aid of the cones.
Sorry so long, I had such great success I felt they deserve a long post.

Mike

Thunder - How hard was it to knock the nosecones off your lower units?

Jeff

brauer

You install them with marine tex. Removal will sound scary, but its real easy. Go into your tool box and get a heavy hammer and hit the cone on each side a few times and it will break the marine tex. On install all you do is sand the paint back, so when removed all you have do is sand the marine tex off and repaint. I was able to knock the cones off, prep the drives and shoot them in awlgrip within an hour or so. Make sure to etch prime and repaint with awlgrip, its the only paint I've been able to keep on. Second choice would probably be quicksilver phantom black if a spray gun is unavailable.

The cones are really cheap(around a $100 or so). I really think anyone considering a nosecone should try the hydromotive nosecone. I am not affiliated in anyway with hydromotive, I've tried a few cones over the years without much success until now.

Gotta get, I'm getting ready to make my way over to the Miami show


Good luck,
Mike

Great story. I get a visual when you said, "when home and hammered them off" ! EEK!

This might be a dumb question, but here goes. I have the XZ drive with low water pick ups, does the nose cone affect the performance of the water pick ups?:rolleyes:

So what do you guys think one would see by putting nose cones on older bravo's '89s? I believe that the old bravos had a blunter nose. The boat only see's 64 mph now. Would this be a waist of time.

Russ

I'm not sure, but I don't think anybody offers a glue on cone with the low water pickup. I has to do with the water passage connecting between the cone and the drive.

I installed a Hydromotive cone 2 years ago. Unfortinatly, I also didn't have a before-after comparision. I can tell you that it's a real joy trying to blend the cone into the body of the drive. You have to sand a compound curve and it's hard to get the shape just right.

Russ-I believe the older bravos didn't have enough body length. The newer ones had a shape changed that corrected this. Hydromotive does have a cone to address this, but I really don't think you'd see a benefit.

My drives are off now for new paint, now would be the time. Would the cones help with highspeed stability? Is there any differance seen on water pressure. I mean by changing the flow of water around the drive will it change the flow at the water pickup?

Russ

Unless you were planning on going 20mph faster or wanted the look of the cone, I don't think it's a worth while investment.

Thanks Cord

Well that saves me a little money

Cord, I'm with ya on the compound curve. I think I gained 2 inches on my arms hand sanding that with 80 grit paper and a flexible file. I didn't expect that, but it looks better than almost every other cone I've seen.

Robbie racer
To answer your question the eliminator has a 600 cid merlin block with dart heads and 871 blowershop blower. its makes 890 hp on the dyno, real conservative for a motor with this many cubes. Ran last year put over 50 hrs on it and didnt break down once. Boat will run 100mph all day long with out breaking anything in the motor. As for the Bmax drive thats another story.

Thanks for the response Tom. That is very good performance for 890 hp. It took me 150 hp more than that to go 115. I have also had a few problems with my B-max drive. I broke the prop shaft once and hurt the lower gears another time. I haven't heard of any of the other drives that would do any better though. Thanks again, R/R

Eddie marine has the Hydromotives for just under $100. If they don't make them with low water pickups, what says you couldn't drill some of your own? Is it because water pressure entering the cone would create drag? Just a thought...

Eddie marine also has the EMI pointy cones for around $150 with low water pickups. Does anyone know if these are "glued" on or are they screw mounted?

One last question: I know it was alluded to lightly above, but at what speed would one reasonably expect to see a noticable gain in speed or planing ease, and how hard is the alignment during install? For $100-150 1 mph gain is much more economical than some other more expensive prop work...

Right On ObnoxiousThundr!!!
 

Greatly enjoyed your post! :D

Thanks KAMMA,

I did indeed purchase the blown 572s, I'll keep you posted as to the results. Should run over 100 easy.

Obnoxious :)

I'd say you're going to be around 104-107mph. What are you doing with you're 509's?

KAMMA,

They are 515s. Their at my buddies shop disassembled, I was in the process of freshing them up when I stumbled on the new monsters. Now I will be selling them as a package or piece by piece. I have all the accessories blowers (420 holley) etc. Do you know any one interested. A friend stepped up to buy the whole package disassembled but were off alittle on the price.

Obnoxious

Nose Cones or Not?
 

I have to agree with wette vette. When running in the low to mid 90's with my 280, last year, did not have any problems with the stock bravo. The newer style bravo's can easily run into the 100 mark without blowout on certain type hulls. My boat loved trim. One of my buddies has an identical one to mine, and has a nose cone and when he added it, could not tell enough difference to be worth the effort. I believe they are worth the difference if using the old style bravo's. The only thing about nose cones, I dont believe it hurts to have them, it just my not help under a 100.

I put one on my B-Max drive and it did pick up about 4 mph (121 mph) but now it cavitates the prop more getting my 25' cat on plane. Once the boat is on plane, all is okay. But now I can't get my 250 lb. buddy up on a single ski, where I was able to do that before the nose cone.

Robbie-----who's nose cone is it? (manufacturer)

I saw cones on Teague (Hydromotive I believe) and IMCO that are for low water pickup drives. Couldn't tell much fro the pix, but they were a separate part number that was specific to LWP cases.

Kamma, I'm not sure who the manufacturer of the nose cone is. I sent it down to Greg Shoemaker and he sent it over to WPM and they installed it on my lower drive unit. Then they sent it back to me. R/R

robbie racer,

I tried wpms cone with no success I had poor handling and a lose of speed when trimmed out. The cone I received had a long leading edge looked cool but didn't work for me.

Obnoxious, that is good to know. I would like to buy another lower unit that will fit my B-max drive with the Hydromotive nose cone installed to compare. That would also give me a spare lower unit in case I break it (again). Thanks again, R/R

Very good/useful info on this thread. Thanks

Yes, this is good info. I just called the Bravo Shop and they now sell a lower end unit with a nose cone already molded in. Has anyone used the B-max drive with their nose coned lower? If so, how do you like it? Thanks again, R/R

Someone's right about the 1 MPH gain.

I have a Baja 232 / 454 MPI running 67 on a bravo one.

If intalling a nose cone can gimme a 1 mph gain, it would be a good investment !

Anyone knows if it will change something ?

By the way, what do you think about the stearn-jack ?

what do you guys think about 75-80mph trs drive? nosecone or not. if so what results have you had and what brand.
Thanks,
Martin.

no body?

thanks for the input:rolleyes: :(
so no one runs nosecones on trs?