-
Bow Rise & Porpoising
Was suggested by other BBC members to place this post in this forum. 2011 Ranger Z118, 150 hp ProXS, 23P Tempest prop, two 8' power poles, NO JACK PLATE.Stingray Pro Hydrofoil (just installed with little to no improvement) Most responses so far are motor height as cause of issue. I have owned boat 14 months. No position change of motor on transom (mounting area) that I am aware of. Had port side power pole installed about one month ago. Have been instructed by Ranger dealer, where power pole was installed, that once motor is mounted by Ranger only way to adjust height is jack plate. Due in part because adjustment that is needed may only be 1/4" but mounting holes are about 1 ".
I was also considering Trim Tabs but given it's a Ranger and from watching other Ranger's obtain plane in 1/2 to 1/3 time I can and the porpoising. This boat was made to perform well. I have also consider moving trolling batteries to middle rod storage unit with rewire to trolling motor. Or adding weight to center Rod Storage area.
So I look to those who have experience in resolving these issues. This was a Retirement gift to myself, but if I have to keep spending $$$$ I will have to come back out of Retirement.
Trim Tabs, 4 blade prop w/ 25P, Jack Plate, Let me know what you all have found that works. 
Thanks for your help, FishinRay
-
Trim tabs aren't needed on a bass boat. A 4 bladed prop will definitely help you will gain hole shot. How are your poles mounted? Do you have a transducer mounted where it might drag? Sounds almost like they might be dragging. No need to move the batteries or add weight it will throw off the balance of the boat and the prefomance will suffer all around.
The cheapest route would be a Jackplate and a 4 blade prop. Prop will give you the best holeshot and Jackplate will let you fine tune your setup to get the prefomance you want.
I fought my setup on my previous Charger for years and just ran it the way it was. Everyone told me it had to 3-1/2" p2p to get the best from the hull. A guy on the Charger board told me to raise my motor so I went and ran it raising it 1/4" every run. At 2 3/4" p2p it became a new boat. Hole shot was amazing even loaded and gained a little speed on top end. After finding the correct height of the motor I did have to have the prop worked to lower the rpm's.
-
Jarhead, Sounds like you are experienced in this area. I have an extra prop, 4 blade 24P, but what I have read most Ranger owners are running 25P and I have Both Power Poles on transom mount brackets.
You mentioned "raking" so I assume you are referring to contacting water surface during travel. I will pay closer attention and see if you are correct. Your p2p I assume is distance from transom bottom to top cav plate outboard. thank you. Any other suggestion please send
-
P2p is the distance between the pad (low spot in the hull right in front of drain plug) to the center of the prop shaft.
So you need to know where the motor is to know how to correct it. Find the flatest spot you have, unhook the boat from the truck, use the trailer jack to raise or lower the front end of the boat till the pad is level, lower the motor till the cavitation plate is level, measure from the pad to the ground, measure from the center of the prop shaft to the ground, and the difference is the p2p distance.
Yes I was wondering how the poles are mounted to the boat? Most mount on the jackplate and I have heard of a few that by mounting position or design of the bracket would drag behind the boat during the hole shot.
Last edited by jarhead175; 08-09-2018 at 01:23 PM.
-
With no jackplate you have two ways to adjust the prefomance changing the prop, adding a hydrofoil, or both.
4 blade will make your holeshot quicker and better handling at low speeds. Hydrofoil will help your holeshot but does nothing once your up on plane because the hydrofoil is out of the water.
Keep in mind this time of year your holeshot is going to a second or two slower anyway because of the warm air. Warm air doesn't compress as much as cool or cold air does so the motor losses some HP.
Ideal holeshot should be 3-4 seconds with a tournament loaded boat and be turn roughly 4,000 rpm's right before the boat breaks over.
Question and I am not trying to offend. You said this was a retirement present to yourself. I am assuming you have driven other boats and know how to trim a boat?
Like motor needs to be all the way down before you give it gas and needs to be back down before you let off the gas. My Charger would porpoise below 30-35 mph if the motor was half way up or higher. I would have to trim down further or give it gas to stop it. Porpoise is caused by the prop trying to lift the hull but not having enough force to do so. So when it begins to porpoise you have to give it more rpm's/energy to lift correctly or trim it down setting the hull further down in the water eliminating the lift issue.
Last edited by jarhead175; 08-09-2018 at 01:18 PM.
-
I completely missed the part about you owning the boat 14 month's. So when did the issue start? After rereading I'm assuming after pole install.
-
You can't turn a 25" prop with a 150 and power poles so forget that. What are you current prop to pad measurements top speed and rpm's? An 8" jack plate would be the first thing I'd get, hydraulic if you can afford it. If you don't go with a plate set the motor in the second hole from the top mounting hole which should make your prop to pad measurement 4.25" under and that's where it should run without a plate. You may be mounted too high now and that will cause it too porpoise so you have to measure it. Have the prop worked if it will turn max rpm's now to keep it from dropping the bow.
-
Present hole position is 4th from top. Dealer confirmed with Ranger that is correct for factory placement but being that my boat now has 2 power poles which add 200 lbs. hanging off the back of transom that makes common sense. Cause & Effect! I will do some checking of #'s @ P2P. Tempest 23P is the correct 3 blade prop per dealer also.
-
I'm sure the motor is set right, and a 23p 3 blade prop is right for a light load it would probably run great. Install dual power poles with a pump, Add a full tank of fuel, fill the livewells full, put all you gear in there, and add a driver/passenger it will be a dog.
What I would do if it was mine....either call Mark and do what he says or find a local prop guy that will meet you at the lake with a couple of 4 blades to try. I found a local prip guy and ended up buying two props one for pulling tubes/watersking and one for everyday use. My tube prop was a 24p Trophy + amazing hole shot but too many rpm's never found out how fast it would run hit the Rev limiter at 64mph. Everyday prop was a 25p Trophy + light and dry would run 67@5900 rpm's loaded dropped down to 65.
If your going to leave the motor without a jackplate than prop will be the only adjustment you have left.
Take it out fully loaded, trim it all the way down, time the holeshot and keep track of the rpm's during the holeshot. When it's up keep it hammered at keep track of WOT speed and rpm's. Without those numbers we are all guessing.
-
If you go back to the top of the setup page and look at the first sticky at the top that's the info needed. And if you really want it setup right pm the man that posted that sticky. Pat has forgotten more about bass boats then 99% of us will ever know.
-
http://www.bbcboards.net/showthread.php?t=62660 This thread will show you how to measure prop to pad
-
Got it the other day after reading some other posts. But Thank you . I am going to keep working at it. Have it printed out and checking this weekend.
-
Remember what ever you measure from ground, floor, parking lot has to be level then level pad of boat.
-
Member
23p tempest prop is normal for a 150, too big to swing for a 150 with all the xtra added on weight
Reply With Quote