Challenger extended ride plate

[Aquaman1]

I have been exploring several options to eliminate the porpoising on my 2004 challenger 2000. I looked into Place Diverter trim tab. Bolt on power trim tabs, but with the transum design that is not an option. I saw igneous extended his ride plate by adding a piece on stainless steel. I used his idea but made it look factory. I bought a piece of alimunim the same thickness as the stock ride plate. Had it cut to 13"x9". Then took the alimunim to a sheet metal shop and had him duplicate the stock one. It came out about 5" longer then the stock ride plate.

 

[Aquaman1]

More pictures

 

[Dr Honda]

looks good.

Should have have him make a few more.

What did he charge? And why did you put in extra holes at the end?

 

[Aquaman1]

I would have thought that from the time I took the ride plate off bought the aluminum, had it made, and reinstalled the new part was less than 3 hours. The guy in the picture replicated the plate in about 25 minutes. He charged me $50. The best thing was he did it right then and I was able the watch him. As for the extra holes, they were a mistake.

 

[Dr Honda]

Aluminum may flex under load.

I don't have a bouncing issue... but on hot days, everyone wants to sit in the back, (under the top) and because of that... I have to give it a lot of throttle to get on plane. An extended plate may help.

If the guy will make it out of stainless... that would be sweet !!


Maybe I'll machine one, to add to the rigidity. I think I have some 10" x 0.5 stock in my shop.

 

[jaimecbr900]

I would so pay someone to just ship me a bolt on/plug and play piece like that.

 

[Aquaman1]

Let me do some testing first. I am going to run this aluminum plate first. I have some stainless steel plates already cut. I might have to change the length with the SS. Hopefully I will be able the run the boat soon. I will keep this post up to date. Once I get this plate perfected, I may make a few if there is an interest in them, but first lets make sure it works.

 

[AirSniper]

With the place diverter tab, Place added a 90 degree bend in the trailing edge of the tab for rigidity (about 1/2 inch high) - early models did not have that. This may be the root cause of the pull to the left (I need 90 degrees of right steering wheel to maintain course) due to swirl of output.

The material is 0.090 stainless & the tab sees 289 lbs of force @ 30 mph @ 10 degrees of deflection (515 lbs @ 40 mph @ 10 degrees) --> with 100 square inch surface.

hopefully this helps in making the better mousetrap.

 

[Aquaman1]

Wow, air sniper that is great. The numbers will help tremendously. Thanks a lot. Right now it is made from aluminum but I have some SS. If the weather is good tomorrow is will test it out. Keep you posted.

 

[SLOWBRAH]

How did this do???

 

[Aquaman1]

Well finally got the boat yesterday. The winds were light and the sea's were calm. This ride plate worked better than I could have dreamed of. The boat got up on plane quicker. I ran the boat at varying speeds with absolute no Porpoising. I could not believe it. The speed range where porpoising was the worse around 4000 rpm's there was none. We cruised slow 20 mph to wide open 52 mph ( I estimate I lost about 2 mph with the longer plate) with no bounce. We were able to pull a wakeboarder at 18 to 20 mph with no difficulties. It was great!!

The tracking of the boat also improved. Before the boat would pull to the right. I would have to counter steer to the left quite a bit. Now with the new plate the steering wheel is straight with very little counter steer to the left. I think by lowering the right side of the plate, will get rid of all the pull to the right. This ride plate is the solution to the porpoising problem this boat had.

 

[Aquaman1]

We went back out today. I lowered the port side ride plate one turn out. This adjustment straightened out the tracking. The boat is a pleasure to drive. It tracks straight now.

 

[biffdotorg]

Along with all the others. GREAT WORK!! Put me on the list for one if you think you can produce a few. I have no issues with paying a fair price and a premium for all your efforts of course.

No hurry here in MN, as mine was winterized this week.

Again, thank you for the research!

 

[Aquaman1]

Biffdotorg, I will get a cost of the ride plate when I can.
I was thinking of making one out of Stainless steel, but I think the aluminum is better for several reasons.
As airsnipper stated there is more pressure on the plate as speed increases. Here is what I think is happening to the plate. Let me back up. I am able to flex the ride plate up about a 1/4 inch by pushing up on it with my hands. Lets just say the ride plate is set at a 10 degree angle. When starting out the 10 degree is great for getting up on a plane quickly. As the speed increases to around 30 to 40 mph, this is where the porpoising was the worse, the plate will flex, to 9 degrees under the increase pressure of the water. Now at top speed around 50 mph, the ride plate is at 8 degrees, which will let the bow rise and let the hull get more out of the water. This will miminise the speed loss. If it was stainless steel plate is still at 10 degrees.
Also cost, alimunim is half the cost of stainless steel.
Safety, if you hit something with the aluminum it will bend, like my old ride plate. The stainless might not bend and as easy and transfer the force to the jet drive.
I am by no way a engineer, just a guy with an idea.

 

[SLOWBRAH]

Heck YEA!! Sign me up too... However, I must ask... you state that your challenger runs 50+? What challenger model is it? have you got the chance to test with several ppl in the boat? This is when mine is the worse.


I've got an 05' Challenger 180 SC/IC... and I've only managed 46mph via gps with just myself in the boat. I'd like to say I can crack 50 with at least two ppl in the boat.

 

[biffdotorg]

Sorry Slowbrah, This is the Mercury forum. This ride plate would not be compatible with your Rotax powered SeaDoo. The Merc Sportjet pump is quite different. Although somone may have created a solution for the Rotax version, you may find that in the 4-stroke forum.

Also keep in mind, that many of us with the Mercs have cracked 50 on GPS, this plate is not made to give it more speed. I think most of us expect to lose a couple on the top end to gain ride quality.

 

[SLOWBRAH]

"Insert foot into mouth"... my fault. I found this thread while attempting to find a solution for my boat. Back to the drawing board!

 

[biffdotorg]

Don't be too deflated. I frequent the other forums as well. I have seen guys adding Trim Tabs to their transom for this same purpose. There are both fixed and adjustable versions that can accomplish ths same effect.

Good luck!

 

[Aquaman1]

Heck YEA!! Sign me up too... However, I must ask... you state that your challenger runs 50+? What challenger model is it? have you got the chance to test with several ppl in the boat? This is when mine is the worse.


I've got an 05' Challenger 180 SC/IC... and I've only managed 46mph via gps with just myself in the boat. I'd like to say I can crack 50 with at least two ppl in the boat.

Hi have a 2004 Challenger 2000. I have had it up to 54 miles an hour. I was the only one in the boat with no equipment on the boat with a light chop

 

[jaimecbr900]

As I said in the beginning, count me in on this. I will buy a plug and play version of this in a heart beat. Was out on the lake all day yesterday. Boat ran like a champ, except the occasional and very annoying porpoising. If you don't want to make a whole bunch, I'll be happy to be the guinea pig here in GA. :thumbsup:

 

[jaimecbr900]

Question:

I'm personally not that concerned about losing a couple mph on the top end to in return lose my porpoising, BUT......can that possibly be resolved and have the best of both worlds by changing the prop???? I know that I did that to my old XP, but I did it in conjuction with intake grate, ride plate, sponsons, and prop so obviously it made a difference. I'm thinking that maybe with the combo of both the custom ride plate and a more aggressive prop......???? Am I on the right path or off the beaten one?

 

[Coastiejoe]

Question:

I'm personally not that concerned about losing a couple mph on the top end to in return lose my porpoising, BUT......can that possibly be resolved and have the best of both worlds by changing the prop???? I know that I did that to my old XP, but I did it in conjuction with intake grate, ride plate, sponsons, and prop so obviously it made a difference. I'm thinking that maybe with the combo of both the custom ride plate and a more aggressive prop......???? Am I on the right path or off the beaten one?

You can gain on the top end but will lose on the bottom end unless you modify the engine somehow. Intake, injectors, SC'er, ect ect.

The Skat impellers see to give better out of the hole and retain top end due to their design.

 

[SeptemberC]

Oh and just curious.... Did you lose any reverse maneuverability?


Sent from my iPhone using Tapatalk

 

[Aquaman1]

I have put my boat away in storage for the winner. Although there's not much of a winter down here in Florida we choose not to boat when it is cold windy and the water is rougher. I will build some of these plates in the spring. I am still debating whether to build them out of stainless or aluminum. The one that's on my boat is made out of aluminum but after hitting the bottom a few times while it's anchored it has already bent a little bit. the performance is still the same I just don't know if it's a good thing if it's aluminum: If you get something the aluminum Wilband not sure if you get something with the stainless if it would do more damage other places. Still have to do more research but I will definitely keep you guys posted on when I decide to build these. These ride plates will only work on the Sea-Doo jet boats that have the Mercury M2 jet drive.

 

[biffdotorg]

I think if you build a stainless one for your boat, I would be fine with aluminum. We have cobra-jet fins on our pump, so it will hit the bottom before this ride plate would hit.

In fact, we will many times back our boat into the sandbar and let the cobra-jet fins sink into the sand. Probably not too good on the pump, but we don't set them in solid, But they have bumped the bottom enough to see the steering wheel move. We like to have the tower speakers pointed at the sandbar when playing.