Reply With QuoteBo some hulls "like" droops and some dont respond what boat what jet how much HP etc Tom
Could someone shed some light on what I could expect from adding a droop snoot to my boat. Does it benefit me from the fact that it adds "just" more lift or is there something else I should be looking for as well? The boat right now is running around 75 without a droop snoot. And is there a particular one that's better than another?
thanks for any and all advice in advance.
Bo
Bo some hulls "like" droops and some dont respond what boat what jet how much HP etc Tom
The hull is a 18 ft Rogers. It has a 550 hp 468, with tunnel ram, with (2) 750 holley's, w/ a Berkely pump. I don't know what impellar is in the pump though. I understand the only way to know that is to tear in to the pump. I may not want to go that far, yet. I may have some shoe angle adjustments to make as well. Are there different types of droops and how would I know which one would be best for my boat? If I even need one.
Thanks for the info
Bo
The hull is a 18 ft Rogers. It has a 550 hp 468, with tunnel ram, with (2) 750 holley's, w/ a Berkely pump. I don't know what impellar is in the pump though. I understand the only way to know that is to tear in to the pump. I may not want to go that far, yet. I may have some shoe angle adjustments to make as well. Are there different types of droops and how would I know which one would be best for my boat? If I even need one.
Thanks for the info
Bo
last i read, your boat ran 62 at 5500??? has all that been corrected with the boat now back at 75??? what rpm???
generally, droops lower the thrust centerline to create more keel lift. yes, there are droops sold from different manufacturers, and each has their differences. generally, droops are manufactured with between 7-9 degrees of "up" angle (angle difference between the bowl flange and steering pin centerline). the change in nozzle angle can create issues all by itself.
the only way to really figure out which is best in your application is to test with it. adding a droop is a big change, and may require other changes to work well.
be careful buying used droops, as the steering socket may be worn out, or may not provide sufficient clearance for your nozzle. it's important that the o-ring is relatively snug within the socket so that water doesn't bypass the nozzle. this winter, we changed from a berk to an amt droop because the socket was worn out...
Thanks bp for the response. Yes all the other issues I had, have been taken care of. The problem I had before with the 62 mph was the back barrels of my carbs weren't coming in. It seemed to be a cam adjustment on the carburators. Now they're kicking in and the boat is running relatively well. It ran 71.1 on gps Sunday @ 5700 rpms but I figured if I hadn't had 400 or so lbs of people and roughly 22 gallons of gas and the baffles in the headers the boat would have hit 75 pretty easy. This friend of mine keeps telling me I need a droop. I need to know if it would help or hinder me before I go out and just get one. You could buy a lot of little toys for this thing if you wanted to but if it's not going to make a hill of beans about the way the boat runs I don't think I'll waste the time and money.
Bo
Good info BP ! , Bo your estimated HP vs speed vs WOT rpm is of some concern ,its probably very important to know what impeller you actually do have to proceed Tom
did you replace the tach? 5700 at 71 is just too high, regardless of how many people are in the boat. either the tach is off, or the pump is severely cavitating at top speed.
just for comparison sake, my boat runs 104-106 at around 6175. if i back off to 5500, it's running 90, with a b impeller. my boat is heavy - over 700lb bare hull.
the point is, if you run into a wall with respect to speed increase because you have a lot of weight (drag) in the boat, the engine should not continue to rise in rpm - it is like a water dyno, and if power applied cannot overcome the drag, the engine will not accelerate any further. you either have a tach issue, or your pump is in need of some attention.
it is not possible to say you will automatically see performance gains just by bolting on a droop. it may work perfectly just bolting it on, but lowering the thrust centerline might create a porpoise condition or other handling issues, which will then be addressed by other things. i've seen too many instances where people were told "just bolt this on and your boat will run faster", then it doesn't on the first try, so the person gives up and takes the part back off. very unusual for it to happen that way. a droop will work on your boat, but it will have to be tested and adjustments made based on the testing.
Bo,
I have the same bottom on my boat that you have. I put an Aggresser droop on it with a 2ยบ down wedge and it made a big difference in the overall performance of the boat. The boat handled better, the top end was better and it has a lot better ride in rough water.
Running 71.1 isn't too shabby with an extra 650lbs+ of weight! The rpms are a bit high though. Before the drooop went on, I gps'd the boat at 71.8 with me and 2 full tanks of gas. 10 minutes later, I gps'd the boat at 69.6 with a 145lb person in the passenger seat. The weight is making a big difference.
All this is great info. I know I have tach issues because last week this buddy of mine was riding in the boat kind of showing me how to control the gauges and pressures. He happened to look at the tach and said, the tach is way off. He hit the tach and it immediately went from 5400 rpm's down to 4400. So, I have been looking for another tach but I'm having a hard time finding one with a rev limiter on it. The one I have now has rev limiting and I would like to replacve it with another one like it, but, new.
Good info BP ! , Bo your estimated HP vs speed vs WOT rpm is of some concern ,its probably very important to know what impeller you actually do have to proceed Tom
What is WOT? Sorry I'm new at most of this lingo.
Bo
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