Ride Plates

[Bob Hostetter]

Am I correct in assuming that ride plates for jets work the same way as cav plates on a v-drive? If so, why are they usually only under the bowl/nozzle and not all the way across the hull? Also why aren't they setup with an override pedal?
Thanks...........

[Squirtcha?]

This one's been discussed in pretty good detail here.
Rideplate discussion (http://www.***boat.com/forums/showthread.php?s=&threadid=49701&highlight=cavitation+plates)

[moneysucker]

No, they do not provide lift on the rear to bring down the attitude of the boat. A ride plate is extended area for the boat to ride on and should be set around 2 degrees up from the keel as a base line. Ideally the boat should be riding on the intake and the ride plate. I am sure that there will be more details to come.

[Bob Hostetter]

So, If I understand you right they act as a pad for the boat to run on. Probably in combination with the intake?
If you set the boat up free enough to get out of the water at top end speeds wouldn't a cav plate give you extra control in getting the hull on plane quicker, and control porpuising at lower speeds? You could also use the down pedal the same way as on a flat to set the boat at launch, then roll off the pedal lifting the cav plate and letting it set on the ride plate as speed increased?
I suppose you could do the same thing with a flexible ride plate that in its natural state was several degrees down but as speed increased it would be forced upward. You would have to fab up a mechincal stop to limit upward flex but you would lose the ability to override the plate forcing the nose down. Would probably be a real pain to dail in.........You would have to control the flex rate by material thickness but it could be done.
This is what happens when you take an early retirement and need a new toy to play with...........

[riverbound]

Doesn't a diverter do all the stuff you are trying to do?

[MudPumper]

Originally posted by Bob Hostetter
wouldn't a cav plate give you extra control in getting the hull on plane quicker, and control porpuising at lower speeds? You could also use the down pedal the same way as on a flat to set the boat at launch, then roll off the pedal lifting the cav plate and letting it set on the ride plate as speed increased?
We just use Diverters for all of that.;)

[Bob Hostetter]

I used to have a Eliminator 19' picklefork that I put a Divertor on and lost some speed as a result. The divertor, especially with a droop snout, is always dragging in the water causing fiction. It seems if you set the intake/pump/snout/nozzle/ride plate angle for best top end and used a cav plate setup with a down pedal you could have the best of both worlds. The cav plate would be pretty much out of the water when fully up at top speed eliminating the additional drag.
Plus I like the ability to instantly override with a pedal, must be from my old flatbottom days......
I am mostly concerned with 0-60mph times with a top speed in the 90's, but I want something that is very controllable.

[Squirtcha?]

There are some other innovators that post up here.................try it out and let us know how it works.

[BrendellaJet]

Perhaps the boat you had the droop and diverter on only needed the diverter? If you just put the diverter on it should not be dragging in the water and would be above the ride plate. Of course you could put the cav plates on, there have been a few online lately, but they are pricey to build. Id put a diverter on it and go play on the water...

[Beal Motorsports]

On our older texas tunnel we eliminated the droop and went with a rooster booster. Picked up several mph.
Same setup on our Placecraft, rooster booster, diverter. This was also how they ran it in top fuel. Plus withthe placecraft since the pump is set back so far, the rear of the boat has cavitation plates that are adjustable, just not from with in the boat. We talked to Ray Lumbert, owner of it when it was a fuel boat, and he said to check the plates. They were way out! We set the plates at 1/8" up at the rear of the plate from the bottom of the boat. Made a world of difference. Easier to carry the nose a bit higher.

[1Bahnerjet]

Originally posted by Bob Hostetter
Am I correct in assuming that ride plates for jets work the same way as cav plates on a v-drive? If so, why are they usually only under the bowl/nozzle and not all the way across the hull? Also why aren't they setup with an override pedal?
Thanks...........
just thought to add a pic. to hostetter's Question (mainly because the Boat looks Bitchin')
http://dragboats.com/images/classifieds/ads/large/2211_goins_mike.jpg

[pops1]

Originally posted by Beal Motorsports
On our older texas tunnel we eliminated the droop and went with a rooster booster. Picked up several mph.
Same setup on our Placecraft, rooster booster, diverter. This was also how they ran it in top fuel. Plus withthe placecraft since the pump is set back so far, the rear of the boat has cavitation plates that are adjustable, just not from with in the boat. We talked to Ray Lumbert, owner of it when it was a fuel boat, and he said to check the plates. They were way out! We set the plates at 1/8" up at the rear of the plate from the bottom of the boat. Made a world of difference. Easier to carry the nose a bit higher. I HAVE A PROBLEM WITH THAT ONE! i I don't think what you say is not what happened. A roost boost is a hard abrupt angle change causing water to crash into the walls in order to make the transistion change demanded by the 7 degree angle bend in a very very short distance. What I think maybe did happen is you were dragging the droop causing you the problem, and the outcome is the drag exceeded the harsh bend of the roost. Sorry to disagree. I do know it was pulled off the old going place's for a smoother transistion.

[Beal Motorsports]

On the texas tunnel it made a difference.........
NOT on the placecraft.
On the placecraft, we bought it with the booster already on it. and have not changed a thing except wedge it down a bit from losing the capsule weight.
The texas tunnel results shown on the time clocks made us gain 6-7 mph on the same tune at several race courses. But your right it could be from less drag.

[Bob Hostetter]

The boat in the picture was basicially what I was talking about. I wonder how he/she used the plates? My thinking is that you can use them to force the nose to roll over faster and get the hull to take a set quicker. I think your 0-60mph times are going to be quicker if you can get the boat to take a set quicker, get on plane faster and moving forward instead of upward.
Guess I am just going to have to do it myself and find out.....

[AZKC]

Lenco makes some electric(Servos) non hydraulics trim tabs. Ck them out on Overtons website:cool:

[Beal Motorsports]

Bob, just call the owner of the Ahhhsum Toy boat. It is posted on Dragboats.com maybe he can answer your questions?

[Bob Hostetter]

Thanks for all the input guys. Beal, good idea, I will see if I can send him an email. If he answers I will let you guys know what he said......

[Bense468]

The plates are to roll the boat over Bob. The pump on that boat is fixed (wedged) up with the plate to override. To be honest this is not needed with todays technology. Most jet boats 99% don't run a down pedel. This boat is a cole. I have seen a few others this way and most were cole's as well. Its more hardware in the way that is not really needed in a jet. Wouldn't want to get on the plates too hard in a tunnel would you?
So the question really is do you want to be different? It won't be something new because it has been done and for a long time (back in the jet circle days) but you would be different then most. Hope that helps
The real question is why is that blower sitting on an edelbrock tunnel ram?

[Bob Hostetter]

<<rolling the boat over>>
Thats what I thought they were for, and that was what I was thinking of using them for. Yea it seems like a lot of work but I still like the idea.
Tunnels like the Daytona (at least in the early 1980's) had a blow over problem and several guys were playing with wings on the nose to get control of it. I am wondering if the cav plates could be used the same way by slightly lifting the tail and blowing the air out and leveraging the bow down. You are right about being carefull about getting too hard on the down pedal but you can help control that by working with the different activator lever ratios and setting up a overtravel stop.
By having a way to roll the nose over with the cav plates you have the ability to set the ride plate up very loose for maxi speed on perfect water, and still have a usable setup for cruising and rough water. Oh course this is all based of my experience with flatbottoms, not jets. Like several people have mentioned most people are using a place divertor for the same thing but I don't care for the way they work or look. I do like the way cav plates look and work ( must be the flatty thing again) assuming I can get them to do what I want them to do.
I probably should just buy another flat bottom but my kids want something to run on the river with and I don't to be buying more props and prop shafts. Our Hallet cruiser v-drive is great but not over sandbars, and in shallow water.......lol. If I can figure out a way to setup a decent jet we would have the best of both worlds.
Last question, has anybody tried running a 2 speed with a jet? I have a left over shorty PG that I am not sure what to do with......

[cyclone]

although it looks to be a costly setup, i like the idea of having a down pedal. I dont think it would work out so well if you kept a diverter on the boat. Too many things operate at once.
One of the hardest things for me to overcome while driving is getting my boat to holeshot without having it bounce out of the hole.
I've tried launching with the diverter all the way down which does eliminate the bounce, but then the boat plows through the water, killing the holeshot.
I"ve tried launching with the diverter in the middle but then i have to gently roll the boat over, land it and the mash the gas.
In either instance, my 1/2 track times were not ideal.
I've found that it takes a lot of practice to be able to roll the boat over quickly, get it to set without bouncing and then take off but it does happen.
The smart guys with expendable amounts of cash rely on a launch controller to handle the engine RPM and a slick timer setup for the diverter. Takes some of the guesswork and human error out of it I guess.

[mach1alaska]

On the subject of cav plates on jet boats, my 18' kona has built in cav plates from the factory . They are flush with the bottom of the boat , the hardware in the back of the boat is still there(inside not outside the boat) but all the controlls have been removed. is anyone familiar with this setup And would it be worth designing and reinstalling controlls to use it?
my thought was to wedge my fixed race nozzle up and use the cav plates to controll launch and make it ski able when needed.
the boat has a 12JR pump w/ shoe , rideplate and droop snoot. or should I just leave them disconnected an buy a diverter.
I am concerned about loosing speed with a diverter because of the drag of the reverse passage (my current nozzle has reverse in the bucket rather than the nozzle )

[cyclone]

got any pics of the back of your boat, mach1?

[Wally_Gator]

My cousing used to run the drags in his tunnel jet.
Talking to him, he used ride plates mentioned earlier.
His jet was wedged to the tune where he could get the best speed. The plate on launch would be down to get up on plane a take a set and as he launched he would let off of the pedal until he was completely off of it.
He was chasing drag records in the late 80's and early 90's until his boat was stolen. Then he moved onto cars..

[mach1alaska]

lets try this

[mach1alaska]

or this

[mach1alaska]

.

[cyclone]

it's a shame the parts are missing. i'd love to hear how well it works.

[BrendellaJet]

Very interesting Mach1. How long have you had the boat? I wonder if it came stock like that? My Jet has the recesses for plates, but I figured it was because the bottom was from a hondo mold(or so I've deductively reasoned...)
http://www.***boat.com/image_center/data/520/212100_0600-med.JPG

[Bob Hostetter]

So it seems this idea has been around for a while, and has worked with at least some success. I guess I am not a complete idiot.........
I will have to try it, after all its just money, and thats what boats run on, right

[mach1alaska]

I have not had the boat too long but I bought it from a friend that owned it for about 15 years, they were disconnected when he bought the boat. I am quite sure they were installed at the factory, they are molded into the hull and sit flush.
they sit fairly far outboard so they would be most effective at lower speeds . being out of the area that should be in contact with the water at speed they might even help the hull trap air?? just a thought.

[Beal Motorsports]

Mine has the same plates on the rear of the placecraft. Besides the set back transom of my boat the pump is set back as additional 2" or so so it looks like the flange of the pump where it bolts to the intake sticks out past the back of the boat. Since there is no boat for the pump to ride on that far back the plates are needed.