porpoising and chine walking.....what cause's it??
The following 2 users liked this post by vdrsnk04:
Smarty (08-14-2024), tommymonza (08-15-2024)
08-15-2024, 02:40 PM
#32
Registered
This is just my observed opinion, and it is probably not worth a ****, but here it is!
In order to get a better ride, some hulls carry the point of the keel all of the way to the transom. This gives a better/dryer ride with the designed power, as most of the bottom of the transom is in contact with the water giving side to side stability. Ricky Bobby replaces the 400 hp stock power with 750 HP and things change. With trim, the increased lift brings more of the boat out of the water and no longer is the bottom of the transom there for balance. The boat is now attempting to balance on the keel and if you do not have the experience to handle it, it can become a handful fast. Smaller boats magnify the results. Go to YouTube and check out the Crocket Rocket at the Shootout a few years back. Tyler is a bad ass with huge balls to match and he almost lost it, even with his level of experience.
Basically, every hull has its design limits to where adding more HP gets to be dangerous.
In order to get a better ride, some hulls carry the point of the keel all of the way to the transom. This gives a better/dryer ride with the designed power, as most of the bottom of the transom is in contact with the water giving side to side stability. Ricky Bobby replaces the 400 hp stock power with 750 HP and things change. With trim, the increased lift brings more of the boat out of the water and no longer is the bottom of the transom there for balance. The boat is now attempting to balance on the keel and if you do not have the experience to handle it, it can become a handful fast. Smaller boats magnify the results. Go to YouTube and check out the Crocket Rocket at the Shootout a few years back. Tyler is a bad ass with huge balls to match and he almost lost it, even with his level of experience.
Basically, every hull has its design limits to where adding more HP gets to be dangerous.
The following 3 users liked this post by 36Tango:
08-31-2024, 10:26 AM
#33
Registered
>
This topic will be ongoing forever. As mentioned above, all of us that "Ricky Bobby" the power in our boats may end up with one or both of these problems where it never showed up before. I started a couple threads about chine walk myself. New members bring up the same old topics. I noticed this season that my boat seems to have less or at least more controllable chine walk running 28" B-1's. I ran a set of 26's last season and the chine walk was much more noticeable. I don't see how spinning larger wheels slower has anything to do with chine walk but maybe? I'm also about 2-3 mph slower with the 28's and maybe that's the point where it gets serious with my boat? I asked about the lower strakes that on some boats go all the way back to the transom like on the Saber and on my Enticer they stop about 12' from the transom. Seems to me that these would help keep any boat more stable however I guess they also may add lift and that could make it worse? Like most everyone on here I wanted to go faster so for my rebuild I replaced the cast iron stuff with aluminum heads, intake and exhaust. Took a little over 200bs off the engines. I also now have 2 smaller batteries (one on each side) where I used to have 4. Two of which were physically larger which I located together on the port side that fed the stereo. These changes didn't stop my chine walk but I think help as far as controlling it once it gets started. Less weight, less influence. My boat has turned down chines like built in trim tabs. It's been mentioned that these can cause chine walk. I don't see how but maybe? I would think turned down chines might have more influence with porpoising. I can see that they would work for you by helping to get on plane but once on plane they would work against you trying to keep the bow down while you're trimming up possibly introducing the porpoise affect? I don't see them introducing chine walk any more than a boat without this "feature".
In the end there's a reason boats come with a given power. My boat still puts a smile on my face and I haven't been passed by a jet ski since the new power but still, after it all, I would have been better off leaving it stock.
This topic will be ongoing forever. As mentioned above, all of us that "Ricky Bobby" the power in our boats may end up with one or both of these problems where it never showed up before. I started a couple threads about chine walk myself. New members bring up the same old topics. I noticed this season that my boat seems to have less or at least more controllable chine walk running 28" B-1's. I ran a set of 26's last season and the chine walk was much more noticeable. I don't see how spinning larger wheels slower has anything to do with chine walk but maybe? I'm also about 2-3 mph slower with the 28's and maybe that's the point where it gets serious with my boat? I asked about the lower strakes that on some boats go all the way back to the transom like on the Saber and on my Enticer they stop about 12' from the transom. Seems to me that these would help keep any boat more stable however I guess they also may add lift and that could make it worse? Like most everyone on here I wanted to go faster so for my rebuild I replaced the cast iron stuff with aluminum heads, intake and exhaust. Took a little over 200bs off the engines. I also now have 2 smaller batteries (one on each side) where I used to have 4. Two of which were physically larger which I located together on the port side that fed the stereo. These changes didn't stop my chine walk but I think help as far as controlling it once it gets started. Less weight, less influence. My boat has turned down chines like built in trim tabs. It's been mentioned that these can cause chine walk. I don't see how but maybe? I would think turned down chines might have more influence with porpoising. I can see that they would work for you by helping to get on plane but once on plane they would work against you trying to keep the bow down while you're trimming up possibly introducing the porpoise affect? I don't see them introducing chine walk any more than a boat without this "feature".
In the end there's a reason boats come with a given power. My boat still puts a smile on my face and I haven't been passed by a jet ski since the new power but still, after it all, I would have been better off leaving it stock.
