doninator 90mph - 105mph
11-27-2002 | 02:30 PM
#1
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From: riverton, ut, USA
doninator 90mph - 105mph
anyone experience chine walk at these speeds?
and, what model, size and pitch prop are you running?
have you done any bravo up-grades i.e. (nose cones, gearing, stronger internals, ext.)?
also, is the 1998 haul running surface different than the newer models? if so what?
and, what model, size and pitch prop are you running?
have you done any bravo up-grades i.e. (nose cones, gearing, stronger internals, ext.)?
also, is the 1998 haul running surface different than the newer models? if so what?
12-03-2002 | 06:15 PM
#3
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From: riverton, ut, USA
no rick,
i've been trying to get this damn engine project done for a full year now. thanks to the infamous BRUCE DUDLEY, all i have to show for it is a hole in my pocket where $20,000 use to be, no engines or anything. MAN i'm so pissed. he was going to build the engines, do all the rigging and then dial it in. but he's disappeared!
so now i'm way over budget, trying to learn all i can so i will know what to expect and do the majority of work my self. any info, ANY THING AT ALL, is greatly appreciated.
i will call this jim guy. but who is he? and what does he do?
thank you for the help.
i've been trying to get this damn engine project done for a full year now. thanks to the infamous BRUCE DUDLEY, all i have to show for it is a hole in my pocket where $20,000 use to be, no engines or anything. MAN i'm so pissed. he was going to build the engines, do all the rigging and then dial it in. but he's disappeared!
so now i'm way over budget, trying to learn all i can so i will know what to expect and do the majority of work my self. any info, ANY THING AT ALL, is greatly appreciated.
i will call this jim guy. but who is he? and what does he do?
thank you for the help.
Last edited by dean campbell; 12-03-2002 at 06:20 PM.
12-04-2002 | 08:16 AM
#4
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Ouch, another victim of the now infamous “Bruce”.
Sorry to hear about your luck (or lack of).
A good person to talk to about speeds in the 90’s to 100 would be Joe at the factory. He’s a busy man, and can tough to track down at times, but he seems to know the characteristics of this boat pretty damn well. I spoke with him at the owners Rally this past summer and he gave me a few ideas on what to do for added stability and / or speed.
The first thing I would personally check is the drive alignment. When I added external steering a few years back, I never really checked the drive alignment. At about 83 – 85 mph, I would get a very serious chine walk that couldn’t be driven out of. I eventually checked the drive alignment and realized that they were a good half inch of “heel – out” (toe in, or whatever people call it). I adjusted this to 0” and noticed the chine walk was gone, but there was just a touch of “wandering” above 80 mph. I then set the drives to 1/16th heel out and the wandering stopped without any chine walking.
I’ve spoken with many 30’ – 38’ twin engine boat owners about drive alignment and I always get really weird looks from most of them. Most people have never messed with them. This leads me to believe that my nose cones might be adding to my handling quirks. Granted, I’ve gotten all the bugs worked out, but it seemed like there was much more effort than most other people have done. I personally don’t think the nose cones did anything at all for hydrodynamic drag of the outdrive. The only reason I went with the cone, was for the low water pickup… which also sort of sucks. I’ve yet to (knock on wood) suck up any sand with the pick ups, but I’m also very anal and paranoid about shallow areas. If I could do it all over again, I would have kept the outdrive stock and went with a transom mount water pickup.
I’ve heard a few other options on “secrets” that might pick up a few mph. For example, Dave and Joe keep telling me to try spinning the props “inward” for a few more clicks. They also tell me to try this without anyone else in the boat, on a calm and empty lake (i.e. might be a little more of a handful to drive). I’ve also heard that little “convenience” items can start to add up and hurt power output. Stuff like: Silent Choice, Internally Baffled Exhaust Tips, Air Cleaners, Driving with the Hatch Fully closed, etc… I guess this is where the fun, and “art”, of driving these boats comes in, getting the last 5% out of them.
-Bayley
Sorry to hear about your luck (or lack of).
A good person to talk to about speeds in the 90’s to 100 would be Joe at the factory. He’s a busy man, and can tough to track down at times, but he seems to know the characteristics of this boat pretty damn well. I spoke with him at the owners Rally this past summer and he gave me a few ideas on what to do for added stability and / or speed.
The first thing I would personally check is the drive alignment. When I added external steering a few years back, I never really checked the drive alignment. At about 83 – 85 mph, I would get a very serious chine walk that couldn’t be driven out of. I eventually checked the drive alignment and realized that they were a good half inch of “heel – out” (toe in, or whatever people call it). I adjusted this to 0” and noticed the chine walk was gone, but there was just a touch of “wandering” above 80 mph. I then set the drives to 1/16th heel out and the wandering stopped without any chine walking.
I’ve spoken with many 30’ – 38’ twin engine boat owners about drive alignment and I always get really weird looks from most of them. Most people have never messed with them. This leads me to believe that my nose cones might be adding to my handling quirks. Granted, I’ve gotten all the bugs worked out, but it seemed like there was much more effort than most other people have done. I personally don’t think the nose cones did anything at all for hydrodynamic drag of the outdrive. The only reason I went with the cone, was for the low water pickup… which also sort of sucks. I’ve yet to (knock on wood) suck up any sand with the pick ups, but I’m also very anal and paranoid about shallow areas. If I could do it all over again, I would have kept the outdrive stock and went with a transom mount water pickup.
I’ve heard a few other options on “secrets” that might pick up a few mph. For example, Dave and Joe keep telling me to try spinning the props “inward” for a few more clicks. They also tell me to try this without anyone else in the boat, on a calm and empty lake (i.e. might be a little more of a handful to drive). I’ve also heard that little “convenience” items can start to add up and hurt power output. Stuff like: Silent Choice, Internally Baffled Exhaust Tips, Air Cleaners, Driving with the Hatch Fully closed, etc… I guess this is where the fun, and “art”, of driving these boats comes in, getting the last 5% out of them.
-Bayley
12-04-2002 | 12:38 PM
#5
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From: riverton, ut, USA
bayley
you're running 92 -93mph top end, correct?
1/16" heel out, and now you don't have any wondering or chine walk. that's good!
a while back i red here on oso (i tried to find the thread, but couldn't) that, in general, the drive alignment should be setup 1/16" heel in or out depending on wheather the props are spinning in or out. the theory was that no mater how new, good & tight the gimbals & other joints are, the metal will flex slightly under power especially as speeds increase due to the angling of the prop fin griping the water trying to walk sideways. but that doesn't really make sense in your case cause you had best results with 1/16" heel out and outward prop rotation.
sorry just thinking out loud, but did you ever try 1/16" heel in with your outward prop rotation?
what kind of nose cones are you running and how did you go about making sure they are perfectly aligned? i have never installed any, but plan on using some due to the possibility of prop blow out at those speeds. if you didn't have the cones wouldn't you be concerned with PBO?
one other thing where are you measuring the 1/16" diference from? i've looked at it before and couldn't really find good spots to measure from.
1/16" heel out, and now you don't have any wondering or chine walk. that's good!
a while back i red here on oso (i tried to find the thread, but couldn't) that, in general, the drive alignment should be setup 1/16" heel in or out depending on wheather the props are spinning in or out. the theory was that no mater how new, good & tight the gimbals & other joints are, the metal will flex slightly under power especially as speeds increase due to the angling of the prop fin griping the water trying to walk sideways. but that doesn't really make sense in your case cause you had best results with 1/16" heel out and outward prop rotation.
sorry just thinking out loud, but did you ever try 1/16" heel in with your outward prop rotation?
what kind of nose cones are you running and how did you go about making sure they are perfectly aligned? i have never installed any, but plan on using some due to the possibility of prop blow out at those speeds. if you didn't have the cones wouldn't you be concerned with PBO?
one other thing where are you measuring the 1/16" diference from? i've looked at it before and couldn't really find good spots to measure from.
Last edited by dean campbell; 12-04-2002 at 01:00 PM.
12-04-2002 | 01:20 PM
#6
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Good question on how to measure the difference.
On top the transom assembly, there is a little circle cast into the metal with a center line through it. I measure this distance between the two drives, then compare that to the distance between the hub centers. Most Bravo drive prop shafts have a small indent in the center of the shafts. It is a little crude, but I have had successful results doing it this way. I was thinking about trying 1/16th "heel in" and spinning the props inwards, but I haven't gotten around to that yet.
As for the nose cones, I simply had Bob's Marine down in Florida install them. They look straight and smooth, but he used some crappy flat paint on the lower units and it really looks like ****e! I guess that's a good reason to go with a -2" IMCO lower unit.
I was never really concerned about prop blowout. I was more concerned about the water availability with the stock lower units. I would be very surprised if a four bladed prop would blow out at speeds up to 105 mph on a stock lower unit. Of course, that's just speculation on my part.
93 mph? Sure, I'll take that!
I've actually seen 94 mph before... but that was on the old fashioned Dreamometer.
Best GPS speed so far has been 91.0001 mph.
-Bayley
On top the transom assembly, there is a little circle cast into the metal with a center line through it. I measure this distance between the two drives, then compare that to the distance between the hub centers. Most Bravo drive prop shafts have a small indent in the center of the shafts. It is a little crude, but I have had successful results doing it this way. I was thinking about trying 1/16th "heel in" and spinning the props inwards, but I haven't gotten around to that yet.
As for the nose cones, I simply had Bob's Marine down in Florida install them. They look straight and smooth, but he used some crappy flat paint on the lower units and it really looks like ****e! I guess that's a good reason to go with a -2" IMCO lower unit.
I was never really concerned about prop blowout. I was more concerned about the water availability with the stock lower units. I would be very surprised if a four bladed prop would blow out at speeds up to 105 mph on a stock lower unit. Of course, that's just speculation on my part.93 mph? Sure, I'll take that!
I've actually seen 94 mph before... but that was on the old fashioned Dreamometer.
Best GPS speed so far has been 91.0001 mph.-Bayley
12-06-2002 | 10:21 AM
#10
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Posts: n/a
After fooling around with a set of Spinelli's for so long with mediocre results, I Wanted something I know would work. The Bravo's might not be the fastest prop, but they do everything else as good, or even better than the rest.
At a poker run this past summer, I had a few people comment on how quickly I got on plane with the 32's (every bit as fast as the old 28's before the blower). It jumps right up and stays hooked up as the transom starts to lift. If I could got on plane in under 30 seconds with the Spinelli's... it was a good day.
Feel free to give me a call at the office if you wish: (313) 240 - 3841
-Bayley
At a poker run this past summer, I had a few people comment on how quickly I got on plane with the 32's (every bit as fast as the old 28's before the blower). It jumps right up and stays hooked up as the transom starts to lift. If I could got on plane in under 30 seconds with the Spinelli's... it was a good day.
Feel free to give me a call at the office if you wish: (313) 240 - 3841
-Bayley
