PORPOISING 232 Deckboat Somebody HELP?

[jvcoconut]

Hi,

I own a 2005 232 Sunesta 5.0 gxi with a duoprop outdrive and double bimini from bow to stern. I notice when I look at some (not all) deckboats cruising next to me at all speeds, they ride smooth and nice, NO SLAMMING, NO PORPOISING.

I have tried everything.....Full Boat, empty boat, no bimini, both biminis, ice chest, no ice chest...I cannot get it to stop porpoising (even on semi glassy water). I currently trim the outdrive to just before the first line on the trim gauge and have tried all other settings below that and it still wants to porpoise. The only way I get it to stop is to back the throttle off momentarily and re-engage the throttle, then it smooths out for a bit.

WHY CAN"T MY BOAT RIDE LIKE OTHER SIMILIAR DECKBOATS????? The hull is deep enough and the boat is heavy enough, it should cut through chop smoothly and not porpoise on jetski wakes....RIGHT? I talked to my service guy @ Sun Country Marine in Onatario Ca and he rifled off several questions to make sure I was doing everything correctly in the operation of my boat, which he confirmed I was. I asked about trim tabs. He has some customers that installed trim tabs and it took away all porpoising. He also said they don't sit on the boat all that great due to the large swim step, but they can be made to function properly.

I purchased the boat because Chapparal claims to have the "best hull design years running" I think it is a crock of sh*t. I am happy with the boat, except for the ride.

Are trim tabs my answer?
Anyone experience the same problems and fix it with trim tabs?
Which ones will fit under my huge swim step?

Any answers would be appreciated

 

[Thept]

Re: PORPOISING 232 Deckboat Somebody HELP?

Hi, did you ever get this figured out? I ask because I am looking at a sunesta deck boat or the bow rider....both Chaparral....and don't want the same problems. I have heard that the sunesta's will ride over the wave instead of chop through it but it can be awfully rough if you get a 3' swell or bigger. I don't want it to be slamming all the time

Thanks'

 

[sevierd]

Re: PORPOISING 232 Deckboat Somebody HELP?

Howdy,
I've got an 04' 232 and I don't have any problem with porpoising. Now I've got an SX drive instead of DP but I'm not sure if that could be related. One thing I have noticed is that the trim range is very small. There doesn't seem to be a huge difference between full down and being too high where it does start to porpoise (on a side note, just before it starts to porpoise I get a drop in mph so as I understand it, it's getting too high anyway). On my Faria analog trim guage when I'm running at WOT, I'll have it trimmed up maybe a quarter inch max (and that's probably overestimated) from full down. I put nauticus smart-tab trim tabs on it to help it get up on plane faster and ride a little better and it does make the boat get up and out faster but I haven't noticed a change in the trim range or way it will porpoise at higher speeds and too much up trim. Also, they were a breeze to install with no problems with the swim step. They do tend to put up some spray behind the boat though so you get some water in the face when tubing on a shorter line. All in all I've been very happy with the boat which FYI, I get about 45 mph at WOT on smooth water. Could get more with a different prop but I want the low end grunt more than the top end. I'd love to hear if you find a solution/fix to your problem.

 

[12vMan]

Re: PORPOISING 232 Deckboat Somebody HELP?

I own an '04 252. I'm new to the site, and don't know if you ever figured out the porpoising problem.

A planing boat that has excessive weight at the transom will tend to porpoise. Underway the excess transom weight makes the boat go down by the transom, but then forward speed overcomes the weight and the bow drops, most often slamming down. This condition repeats itself time and again. The boat is simply out of balance.

The cure is to remove weight from the transom. Shift any movable weight forward, especially passengers if sitting near the transom.

The porpoising may also be caused by a problem they had with their thumb trim switch. It would short inside and continue to trim up, which would cause the boat to eventually porpoise.

 

[suzhol76]

Re: PORPOISING 232 Deckboat Somebody HELP?

We had the same problem with our 87 Chaparral we bought a hydrafoil at Bass Pro shops for 50.00 it makes a huge difference in the driving and riding of our boat!

 

[kmhattrk]

Re: PORPOISING 232 Deckboat Somebody HELP?

I had similar problem on my 22' Mariah Deckboat. My solution was to add the SX series Smart Tabs. These have basically erradicated this problem even in very choppy or busy ICW conditions. Besides correcting this problem, they also kill slow speed wander and DO get me on plane quicker. It is a very good fix at not a whole lot of money.

 

[steddy]

Re: PORPOISING 232 Deckboat Somebody HELP?

I know this thread is getting a bit on the old side, but I thought I might bump it up. I have the same problem with the porpoising on my 178 XL BR Chappey 3.0 Merc I/O. I bought a Sting Ray Hydrofoil with the hopes of the porpoising ending. Not the case, but that sure did help with planing, throttle response, and handling. I find that by trimming down for just a second or two, while it shaves off a few MPH briefly, eliminates the porpoising immediately. After a few more seconds, I trim back out and continue on my way. I repeat these steps every 10-15 seconds as the boat repeats its porpoising cycle. Annoying, yes.

We just bought a 1991 Thompson 205 Carrara, with the 4.3 Merc I/O, and it does about the same thing. It has the cuddy opposed to the open bow, and weighs probably twice as much.It has some cheapie rigid mount fixed trim tabs on it, but I don't know if they really help. Again, I just repeat the process with the trim down then back up.

Neither boat will porpoise unless the trim is nearly all the way up. Also, the faster I go, the less they porpoise. At full throttle, neither one does it hardly at all, even trimmed all the way out in a mild chop.

 

[littlebookworm]

Re: PORPOISING 232 Deckboat Somebody HELP?

This problem has come up on the Chaparral Owners site. The solution seems to be the installation of trim tabs. The topic came up because one owner was told by his Chap dealer that the dealer would not install the tabs without a signed waiver of liability! Go the site and read the thread; it might help with your problem. We're buying a 2000 Signature 240 so I've been reading up on Chaps everywhere to see the good, bad, and ugly. So far, mostly good. Hy

 

[avimgod]

Re: PORPOISING 232 Deckboat Somebody HELP?

Porpoising is trim related, either your drive trim angle is wrong, or you CAN add trim tabs.

BUT be aware trim tabs will alter the entire handling of the boat, the powered tab vendors all have intelligent / auto-leveling options available (I just have the switches on the dash, but have thought about adding the smart controller just to make sea handling that much easier..)

Either trim down when the bounce starts (let the keel brake the waves ahead of the boat), get yourself a set of trim tabs, or live with the bounce!