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novaguy
06-02-2002, 12:05 AM
Just wondering what you guys thought about having a rudder. When I installed my Place Diverter, I did not install a rudder. I don't know what the difference would be if I had one because I added the Place Diverter as soon as I purchased my boat. My main concern is cruising through the channel at low speed in Havasu and docking. I am all over the place right now, while cruising at low speeds. I am getting a lot better in my docking skills. I called Jack at MPD (he did my jet) and he said the rudder would help me a lot while cruising at low speeds but do nothing for docking. I was just wondering what your guys experience was with having or not having a rudder.
http://free.***boat.net/gallery/Reader_Rides/Jet_Boats/1boat1.JPG

ultimate1
06-02-2002, 02:11 AM
I have to agree with Jack it helps at low to high speeds and dosen't do anything at slow speeds. p.s. nice ride

Moomawnster
06-02-2002, 03:54 AM
Once you get used to it you will be able to spin that sucker in place ! I have not had a rudder for years and can still out steer "most" boaters , but then "most boaters" don't load the boat till they get on the ramp or check to be sure it will start ! I leave them in the rooster! Skill is it's own reward ......

1HOTGMCJET
06-02-2002, 09:08 AM
I may be the exception, but I LIKE having the rudder - not only helps for the reasons mentioned, but the boat just feels more "stuck" when handling and turning at ALL speeds - had one on my JE pump stock, and am putting on the large Place rudder with my diverter - may cost a TINY amount of speed, but I just like the "hooked" feeling...again, I may be the exception....Good Luck! http://free.***boat.net/ubb/biggrin.gif

Hotcrusader76
06-02-2002, 10:12 AM
Well....I have to agree that you don't need that "rudder"....leave it for the V-drives....but on the other hand your boat is a larger type than most "jets". So it will take more skill to move that sled around compared to a smaller boat...like 18' or so. Give it some time...practice....and then you'll be a better driver than most out there! Learn your boat, how it handles, and know your throttle response cues.
Take it from me, I used to drive an 82' Navy Mark V Twin Jet drive...with a joy stick...5000HP. No bull shit either!...Just keep practicing!
BTW! Nice boat! How much HP so far?

novaguy
06-02-2002, 10:47 AM
Thanks for the response guys. HotCrusader, you are right, my boat is kind of bigger than most jets. As a matter of fact everyone always questions me as to how big it is. It is only 21', but it is a deep vee hull. unfortunately, It only has a stock (330HP) 454 Chevy. In the future, I plan on having Dave at DNE build me a motor. That guy is awesome with motors. He tuned mine up when I added an MSD ignition and Sea Demon Carb. The boat is truly turn key. I wish I knew how fast it goes, I would guess 55-60 tops. I spin 4400RPM at WOT with an "A" impellar.

mud duck
06-02-2002, 12:31 PM
I purchased a rudder, used it for about a month, and then removed it. I've gotten so I like the slide you get at high speed when you crank the wheel. Also, my trailer is so low that I was scraping it everywhere driving around town.
At slow speed you just have to be careful not to over steer. That is a easy mistake to get in to. Just be patient and boat will come around.

GOT WATER ??
06-02-2002, 02:40 PM
73 Spectra 20, 3000 lbs, no rudder, berk jc A impeller, 455 olds, 4400rpm, Place diverter, 50 mph gps.
[This message has been edited by GOT WATER ?? (edited June 02, 2002).]

apollo74
06-02-2002, 07:00 PM
i really like the rudder. i have run mine both ways and did the same thing when i put on the place diverter-left the rudder off.gps'd it and then installed the rudder and gps'd again, no change in speed and rpm.
given that and the improved low speed and no throttle steering is worth having it. the steering at all speeds is more responsive. i won't take it off again. just my .02

Hallett19
06-02-2002, 08:39 PM
I like the rudder too, I find myself turning the wheel left to right just to keep it going straight w/o the rudder just to keep it straight.

77charger
06-02-2002, 08:56 PM
I just installed aplace diverter recently opted for the larger rudder because my boat had a stability problem at speed (I also didnt have the skags on the pump) but after redoing my pump i had some welded on now the boat tracks straight and is stable turns right now!!havent tried with out the rudder yet but am curious to do so.I probly lose mph from the drag(lg rudder could probably steer the titantic)But it does really hang below the boat pretty good.

Moomawnster
06-03-2002, 02:52 AM
Don't get me wrong , I like the rudder too ,I just can't seem too keep one on the boat. Does anyone know how to get them cheap? I broke three and gave up $$$$$.

DirtyBob
06-03-2002, 05:47 AM
Hallett19,
I used to have the same problems at low speeds (I have a 20.5' mini-day cruiser). It was pretty bad, especially in the no-wake zones. But a buddy showed me that if you just keep it steady, the boat will work it out on it's own. Sure the bow will turn a little from side to side, but it ends up going straight.
Originally posted by Hallett19:
I like the rudder too, I find myself turning the wheel left to right just to keep it going straight w/o the rudder just to keep it straight.

GasTurbine
06-03-2002, 06:02 AM
Nobody has mentioned drag. A rudder can cost you 1-4 mph on top end. I see guys who get the rear-set pump, ride plate, diverter to squeeze every inch of top end out of their jet...then slap a rudder on it.
Ive driven both, and the advantages for having one...dont out-weigh the preformance issues...IMHO... http://free.***boat.net/ubb/smile.gif
Happy Boatin'!

Unchained
06-03-2002, 08:30 AM
I have a rudder on my 19' tunnel jet and would never run w/o one. It may cost 1 to 4 mph but the rudder on a v-drive must be far more drag than that because it is larger and has to compensate for the prop torque. Also the rudder/lower unit on an IO or a outboard must be a tremendous drag because they have the gears in them and are much larger. Point being the control you need is always going to cost some speed.
Mark

novaguy
06-03-2002, 10:41 AM
Thanks for the replies....here is a view of my boat without a rudder.
http://free.***boat.net/gallery/Reader_Rides/Jet_Boats/boat3.JPG

HBjet
06-03-2002, 01:24 PM
Originally posted by GasTurbine:
Nobody has mentioned drag. A rudder can cost you 1-4 mph on top end.
This is not true. A rudder will not cost you any noticable drag what so ever.
The rudder helps at slow speeds (idling) and mainly for turning, etc. I took mine off (19' jet) and the only difference is if you get on plain while in a turn, you just have to pay a little more attention to the boat so she doesn't get away from ya. At idle, I have no problem keeping her striaght, I don't have to steer left, then right, then left, etc. If you have to do that, then your either oversteering each time, or your hull isn't straight. I will never put another rudder on the boat, simply because I don't like the way they look.
HBjet

Hallett19
06-03-2002, 01:58 PM
Originally posted by HBjet:
This is not true. A rudder will not cost you any noticable drag what so ever.
The rudder helps at slow speeds (idling) and mainly for turning, etc. I took mine off (19' jet) and the only difference is if you get on plain while in a turn, you just have to pay a little more attention to the boat so she doesn't get away from ya. At idle, I have no problem keeping her striaght, I don't have to steer left, then right, then left, etc. If you have to do that, then your either oversteering each time, or your hull isn't straight. I will never put another rudder on the boat, simply because I don't like the way they look.
HBjet
Fashion before function !!! http://free.***boat.net/ubb/smile.gif

HBjet
06-03-2002, 02:04 PM
Originally posted by Hallett19:
Fashion before function !!! http://free.***boat.net/ubb/smile.gif
Function? I don't need to worry about that, I can control my boat just fine. So in my case, I choose to not install one because I don't like the looks of them....
As for the Fashion before Function, don't you always mention how your woman is a Playmate when you talk about her? http://free.***boat.net/ubb/smile.gif
Just giving you some shit!
HBjet

GasTurbine
06-04-2002, 04:31 AM
Originally posted by HBjet:
This is not true. A rudder will not cost you any noticable drag what so ever.
Wrong HB...I have proven it, and any heavily experienced jetter will say the same.
It depends on the size (make) that you put on, and the boat. For example, put a small one a jet that has a top end of 40...you will only lose about 1 mph. Now put a large one on a 120 mph ride, you will see an about 4 mph drop...just like we did on our own jet.
Take care.

HBjet
06-04-2002, 07:11 AM
GasTurbine, on this test, what where the water conditions? Did you test the 40mph boat with the rudder first, and then without? Also, on the 120mph boat, what were the conditions, and how did you conduct this test? If it was at a drag racing event, what was the reaction, ET, and MPH of both passes?
I'm not saying you didn't do these tests, but I am saying just be removing the rudder you are not going to notice a difference in MPH. Now, like you posted, if you add a Large rudder to your 120mph boat there was a 4mph drop in speed. One question, why would you have a Large rudder on a boat like that anyway?
I'm not trying to start anything with you, I just think your results have another variable in the equation which you didn't account for and I don't want everyone thinking there rudder creates so much drag to where they would notice a difference in top speed if it was removed.
HBjet

GasTurbine
06-05-2002, 03:45 AM
Originally posted by HBjet:
GasTurbine, on this test, what where the water conditions? Did you test the 40mph boat with the rudder first, and then without? Also, on the 120mph boat, what were the conditions, and how did you conduct this test? If it was at a drag racing event, what was the reaction, ET, and MPH of both passes?
I'm not saying you didn't do these tests, but I am saying just be removing the rudder you are not going to notice a difference in MPH. Now, like you posted, if you add a Large rudder to your 120mph boat there was a 4mph drop in speed. One question, why would you have a Large rudder on a boat like that anyway?
I'm not trying to start anything with you, I just think your results have another variable in the equation which you didn't account for and I don't want everyone thinking there rudder creates so much drag to where they would notice a difference in top speed if it was removed.
HBjet
Im not going to individualy list the hundreds of tests we have performed on jets boat from 1968.
And yes...top speed will be affected by the addition of a rudder. A GPS only confirms what we have known since the early 70s. We can put any size rudder we want, on any boat.
You dont want "everybody thinking"? Sorry if the truth hurts...but rudders do in fact create more drag, and affect top speed. How can you even argue it doesnt? Do you just think that you can stick anything into the water from your boat, and it wont slow it down? Tell us HB...if your sure a large rudder wont affect top end...where is the line drawn? Can I still go 150 if I leave my trailer attached to the bottom of the boat?

propless
06-05-2002, 02:53 PM
To your question, do you experience steering loss of control.
I have a 27' controlled by a jet, quite unusal I'm starting to gather. I also recently put on a PD and found the steering well, unique, fun, and sometimes scary as hell at slow speeds when docking with twenty boats all around you at the same time.
My original system had a small rudder that somewhat helped, so I elected to go to the large rudder offered by PD because of the size of my boat. I'm back to having "some" control over this aircraft carrier in the docks. Was it worth it, yes. Did I notice any loss of speed, not at my max speed of 50 or something.
I feel several folks hit this note in your post, it takes experience with your boat to "feel" your way and gain confidence with the steering (or lack there of) at slow speed. My wife and 13 year old boy still spell their name in the water attempting to go straight.
Hey, this is all a part of having a blast!

HBjet
06-05-2002, 03:13 PM
Originally posted by GasTurbine:
Sorry if the truth hurts...but rudders do in fact create more drag, and affect top speed. How can you even argue it doesnt? Do you just think that you can stick anything into the water from your boat, and it wont slow it down? Tell us HB...if your sure a large rudder wont affect top end...where is the line drawn? Can I still go 150 if I leave my trailer attached to the bottom of the boat?
I'm still wondering if your 40mph test was with the rudder on, and then off the boat. Seeing a 1 mph increase the second time around, also with less fuel on board....hmmm? was it really the rudder removed that gave that 1 mph increase?
Let me ask you this, can you feel a 1 mph increase by the seat of your pants?
I agree a rudder creates drag, but your not going to notice a difference. A trailer, yes. But something a half inch wide which is rounded in the front, come on!
So if your cruising at 30mph and you stick your hand in the water (finger deep), making a rudder, will your GPS show a decrease of 1mph? Will the boat start to turn left?
Do you think we should remove the fins from each side of the intake because we can get another 1-2 mph faster?
I understand you saw a difference, but what were the variables? Water conditions? Did you run a few tests with, and then with out, our just one weekend with, and then the next without? Different air temps will effect on your motors performance, maybe you went a little faster because of the temp outside?
Do you see what I'm getting at? I would like to know what type of boats you conducted these tests on, and water conditions? Thanks
HBjet
[This message has been edited by HBjet (edited June 05, 2002).]

ChetCapoli
06-05-2002, 06:48 PM
Originally posted by GasTurbine:
Im not going to individualy list the hundreds of tests we have performed on jets boat from 1968.
Sounds like the guy has done his homework here HB....why question it? Sorry if your man told you different but like you said "what works for one wont necessarily work for another"
Chet

HBjet
06-05-2002, 07:26 PM
Problem solved!
Here is a pic of GasTurbine's ride. Apparenty we are talking about 2 different types of Jet Boats.
http://home.columbus.rr.com/n8wct/mvc-915f.jpg
HBjet

GasTurbine
06-06-2002, 07:16 AM
[QUOTE]Originally posted by HBjet:
I'm still wondering if your 40mph test was with the rudder on, and then off the boat. Seeing a 1 mph increase the second time around, also with less fuel on board....hmmm? was it really the rudder removed that gave that 1 mph increase?[b]
Our sets started using our salom course. We would make a few passes each way with the rudder on...then off. We would average our times and log them. We would then do the same test...this time with the rudder off...then on.
We would do these "sets" over many days. After ample data was recorded, we would consider that "test" complete. We then would repeat these "tests" on different boats.
[b]Let me ask you this, can you feel a 1 mph increase by the seat of your pants? [b]
Yes...as a (retired) salom skier, I can.
[b]I agree a rudder creates drag, but your not going to [b]notice a difference.[b]
Thats were your wrong. You see HB...the coefficient of drag is not linear. For example, if the "dragging" object robbed speed of say .03% @ 40 mph...the drag would increase to 8% @ 120 mph.
[b] A trailer, yes. But something a half inch wide which is rounded in the front, come on![b]
My dog can tell the difference in 4 mph at top speed. http://free.***boat.net/ubb/smile.gif
[b]So if your cruising at 30mph and you stick your hand in the water (finger deep), making a rudder, will your GPS show a decrease of 1mph?[b]
Probably not at the GPSR level, but you have in fact slowed the vessle.
[b] Will the boat start to turn left?[b]
Depends on where you stuck your finger in at.
[b]Do you think we should remove the fins from each side of the intake because we can get another 1-2 mph faster?[b]
We did research in that area too. Those fins make the pump more eficient, thus canceling any drag issues. We did find however that "loader" scoops help the pump at low speeds, but effected top end drasticly.
[b]I understand you saw a difference, but what were the variables? Water conditions? Did you run a few tests with, and then with out, our just one weekend with, and then the next without? Different air temps will effect on your motors performance, maybe you went a little faster because of the temp outside?[b]
See above. The *only* varible was the rudder.
[b]Do you see what I'm getting at? I would like to know what type of boats you conducted these tests on, and water conditions? Thanks[b]
Do you see what Im getting at? Your across the board statment that no one would notice any performance changes by removing a rudder is wrong.
The boats? Sheesh...the first was a 1968 19' Rogers with a High-Power Hemi/GM 6-71 blower/Berk AA...the last is a 2001 22' Rogers with a GM 454/dual Whipple blower/Berk AA.
While these two happen to be similar, we have had/tested no less 12 in between.

GasTurbine
06-06-2002, 07:19 AM
Originally posted by HBjet:
Problem solved!
Here is a pic of GasTurbine's ride. Apparenty we are talking about 2 different types of Jet Boats.
HBjet
No sorry...Im talking about jet-drive boats...Berkeleys, Jacuzzis, etc.
In addition to the turbine boat, we currently have a Rogers 454/Berkeley and a Cheetah 460/Berkeley.
[This message has been edited by GasTurbine (edited June 06, 2002).]

Unchained
06-06-2002, 08:41 AM
[QUOTE]Originally posted by GasTurbine:
We did find however that "loader" scoops help the pump at low speeds, but effected top end drasticly.
Gas Turbine, I'm not here to argue as it seems like you have done a great deal of research, but explain your statement above. How did the loader scoop affect the top end drastically? In your testing was the loader a large drag because it scooped more water then the pump could use?
Mark

GasTurbine
06-06-2002, 11:52 AM
Originally posted by Unchained:
[QUOTE]Originally posted by GasTurbine:
We did find however that "loader" scoops help the pump at low speeds, but effected top end drasticly.
Gas Turbine, I'm not here to argue as it seems like you have done a great deal of research, but explain your statement above. How did the loader scoop affect the top end drastically? In your testing was the loader a large drag because it scooped more water then the pump could use?
Mark
It only came into play at speeds over 90 mph, so it wont concern most who arent into triple digits. Were not exactly sure why...we believe the scoop created a high-pressure "eddie" in front of it, and a partial vacuum behind it. This was enough to disrupt the intake "flow", if you will, towards the back of the grate.
In our Hemi, we noticed better mid range (30-90) performance/acceleration, and then it stated to slack off. Our top end was 122 without, and 116 with. And yes...testing was done in multiple, reversing passes...starting with, one day, and without on another.
So, to clarify my statement, I would recommend a loader to anybody not at triple digits. It seems the drag issue is moot, as the "loading" benifits (to performance) cancel the increased drag.
Did you know that even painting a hull can hurt top end as well?
Worm can #3 now open. http://free.***boat.net/ubb/smile.gif

ChetCapoli
06-06-2002, 06:22 PM
Originally posted by GasTurbine:
Did you know that even painting a hull can hurt top end as well?
Worm can #3 now open. http://free.***boat.net/ubb/smile.gif
I just finished painting the bottom of my boat and was going to wet sand the last 3 feet with 1000grit paper because i was told the same as you just mentioned. If it's too smooth it will "stick" just like a piece of glass does. What speeds have you lost if any because of this?
thanks in advance, chet
[This message has been edited by ChetCapoli (edited June 06, 2002).]

Lifeguard
06-06-2002, 09:56 PM
Hi, I have driven jets forever at least it seems that way. Those pesky rudders that are supposed to help with low speed handling, dont. Jets without the rudder generally pivot at a point amidships similar to a twin screw and will handle just as well. The rudder kills that by moving the pivot point and forcing the vessel to have a wider turning radius. I prefer to be able to turn in my own wake, pivot in a circle without changing position and being able to walk the vessel sideways, etc. If you are used to props and rudders it takes a while to get used to but with a little practice you will be amazed by what you can do without the limitations the rudder causes.
Originally posted by novaguy:
Just wondering what you guys thought about having a rudder. When I installed my Place Diverter, I did not install a rudder. I don't know what the difference would be if I had one because I added the Place Diverter as soon as I purchased my boat. My main concern is cruising through the channel at low speed in Havasu and docking. I am all over the place right now, while cruising at low speeds. I am getting a lot better in my docking skills. I called Jack at MPD (he did my jet) and he said the rudder would help me a lot while cruising at low speeds but do nothing for docking. I was just wondering what your guys experience was with having or not having a rudder.
http://free.***boat.net/gallery/Reader_Rides/Jet_Boats/1boat1.JPG

GasTurbine
06-07-2002, 03:51 AM
Originally posted by ChetCapoli:
I just finished painting the bottom of my boat and was going to wet sand the last 3 feet with 1000grit paper because i was told the same as you just mentioned. If it's too smooth it will "stick" just like a piece of glass does. What speeds have you lost if any because of this?
thanks in advance, chet
[This message has been edited by ChetCapoli (edited June 06, 2002).]
We actually did not do that testing, but it was a close friend ours, who shares the same...perfectionism?...as we do. He had a 19' 300hp/Jacuzzi...he stated he lost 3 mph after painting his hull.
I will say I have never heard of a hull being "too smooth". Glass "sticks" to the membrain of water because it is flat and smooth...boat hulls are not flat...seems to me that one would want the absolute smoothest (hull) surface you could get.

Hotcrusader76
06-07-2002, 05:41 PM
You said it HB...I concurr!
Originally posted by HBjet:
Problem solved!
Here is a pic of GasTurbine's ride. Apparenty we are talking about 2 different types of Jet Boats.
http://home.columbus.rr.com/n8wct/mvc-915f.jpg
HBjet