Performance Boats Forum banner

1 - 9 of 9 Posts

·
mo balls than $cents$
Joined
·
11,734 Posts
Discussion Starter · #1 · (Edited)
Was just curious if anyone with a std intake tunnel and at least a grand in hp made the switch from your basic droop to a place hph mini droop? What kinda nozzle angle do you run to race?thinkin about making the switch but wanted to hear some opinions on them first.i dont need alot of transom lift but wldnt mind alil from a mini droop.the tunnels i watch with the hph do well but of course most are low profile intake boats.how well do the hph work on standard berk intakes at 4*? I run a fixed race nozzle so adjusting nozzle angle is done with wedge :( any droop vs hph stories to share on a tunnel? Whats the pros and cons?

It would take 1* wedge just to get a .5 up nozzle angle on my deal using a hph since im fixed nozzle.wld leave hard but im uncertain if its gna loosen up the boat as a whole for a clean 1125ft pass.only time time i wish i had a pd is when jacking with nozzle angle.be nice to not have to touch wedges :( fixed adjustable is sweet.
 

·
Banned
Joined
·
67 Posts
The mni droops are typically run on a low pro deal on the boats I'm familiar with, Of course they aren't tunnels. Only time and testing can tell as all boats are different, these things weren't made in heaven.
 

·
northern member
Joined
·
602 Posts
I've have lost 3 or 4 mph with a pd , maybe it was just the boat ? . i wouldn't use one for anything but a ski-barge .
 

·
B1 Racing
Joined
·
6,523 Posts
You will usually be losing some performance by raising the the thrust line, really depends on how the boat has been working with a full droop. If you can keep it in the water and there are not problems with unloading or the thing is trying to blow over or crazy loose due to lift your probably better off with the full droop. The hph is more efficient from the standpoint of not bending the water as much but the gains/losses of the full droop will likely come out on top. I ran similar tests years ago on my 19' and the full droop with that intake was the best. Full droop with a low pro is not the way to go, been seeing a lot of that. Mini droops with lo pro intakes are a must 9 times out of 10.
 

·
B1 Racing
Joined
·
6,523 Posts
Haven't seen any losses with a PD vs berk R nozzle, people claim there is a difference but I have not found that to be true. Tested both and they run the same.
 

·
mo balls than $cents$
Joined
·
11,734 Posts
Discussion Starter · #7 ·
Guess ill stick with droop then thanx . dont wanna run a divertor on this boat.sure they make em ride nice in rough water but i shldnt be running this boat in that kinda water ;) my nozzle angle is just over 5* with a 1* wedge thats nuff to carry the nose like i want to.not like its hard to do in a 16ft tunnel that weighs nada.
 

·
Registered
Joined
·
6,583 Posts
as was stated, changing the bowl extension with either a droop or mini droop affect's thrust centerline. lowering thrust centerline will result in loosening the keel earlier in a run. raising thrust centerline will tighten the keel, to a higher speed.
with a fixed nozzle, whenever you shim to adjust for nozzle angle, you are raising or lowering thrust centerline. in other words, you're adjusting 2 important setup elements at the same time, and it would be difficult to tell exactly which one benefitted or hurt performance.
with a p/d, nozzle angle is maintained with physical stops. so if you wanted to try a lower or higher thrust centerline, you could do that while maintaining the exact same nozzle angle (stop adjustments).

I messed with this a lot on the old boat. changing thrust centerline could make a big change in et. 3 degrees of wedge pretty much equaled 3 tenths in et. but... while lowering thrust centerline 3 degrees could work bitchin at marble falls, there were a few other places where that would toss the boat clean out of the water. all you can do is test.

running a fixed nozzle limits your adjustability back there.
 

·
mo balls than $cents$
Joined
·
11,734 Posts
Discussion Starter · #9 ·
Sure , im aware of the disadvantages on a fixed r nozzle :( maybe this spring i can find a good used pd nozzle and just run it fixed adjustable..
 
1 - 9 of 9 Posts
Top