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W. Tripp

Gearcases

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Dreamer, The sportmaster is far better than the CLE in stock form, but can be made to work better.

If you need help let me know, I have been doing the above noted mods for years....... they work.... and there is free speed and handling.

RT

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My understanding is the short cut allison skeg is worse. You need all the skeg depth for an STV.

Since you can't weld onto skegs you can't lengthen it.

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Mr. Trip: I have a 2 hole c.l.e. . I have cut the skeg down to 200 h.p. size. I didnt shorten it , just "narrowed" it. What else should I do to it ?

Many Thanks!! RudeRiot

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Since this information was posted earlier in the year, I have had a lot of phone calls and e-mails from guys wanting to make a few mods to their gearcases. Several have contacted me with updates with results.

I would like to get them to post their mods and results here when they get a chance.

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Wow, what great info, thanks Wayne!!! Glad this came back to the top since I am a new member and had not seen it before.

Anyone have an opinion on adding a bob's cone to a 2 hole cle- good idea or a waste of money on a 96' euro w/ 2.5 200?

thanks,

fish

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I just thought you would like an update.

Just for the sake of comparison, I ran a noseconed XR case on my DR-20. The case had very straight sides and only 2 water inlets on the cone.

Then worked the tip of the cone, the water inlets, the skeg, and sharpened the trailing edge of the blowout ring. In the 1/4 mile, I picked up 1.4 mph and the boat handled much better, and planed off even quicker.

I will be doing the same thing with a coned Torquemaster on my STV. I will then compare it to a coned and worked Sportmaster. The stock Sportmaster is not worth comparing.

Watch for another update soon.

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Wayne,

What are your latest feelings on the DRX? Will it want the same basics as the DR-20 or is it so far, a different animal. Also did you get yours yet? Ours is a couple after yours so I'm just curious.

Randy

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Wayne,

What gearcase did you run on your old red Euro? If I remember right that boat ran 130mph! I have a 2001 Euro and the best speed so far is 110 with a GPI 2.5 and stock Sportmaster, but before I try to gain speed I need to resolve my blow out problem, or at least it feels like blow out. Every time I get off the gas the stern gets loose and the boat skids to the left. Even at slow speeds (60-70mph) it does this?? On my 110mph run about 3/4 of the way though the run I felt the bow drop so I gave it a tic of the trim, but it just felt loose so I trimed it back down so I know theres more top end there, but something is holding me back. It could be the prop and the SeaStar steering seems to have some play in it, or maybe its just me? I've only had the boat a week, but I do have 20 years experience in a 100+mph boat.

To make a good top end run I have to work my way past the midrange hop slowly, meaning a few hops then trim and work the wheel. Well I get beat all the time doing that!! sad.gif If I stab the gas, over trim a bit then set the boat it never takes a good set and almost always blows out at 90-100mph and turns right.

I'm running a 14 3/8X32p cleaver at 8400rpm@110mph NOT GOOD

What is happening???

Thanks,

Paul

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Sort of have the same problem. Ive got a 2004 river rocket that has been 110 with a 28 hoss triton at 8600 rpms. It has a stock 280 offshore race with the rev limiter raised. I had to shut it down, it was to squirrely. To get that speed my ass end feels loose and rocks back and forth like an allison. When I first set the boat up with a stock sportmaster and a yamaha drag copy(28p) ,3/4 above the pad. It would do this. Than I tried to modify the gearcase according to waynes mods. but not quite to the extent as wayne did. I tried it even with the pad and up to an 1" higher than the pad. It drove the same as being stock, it still felt loose and rocked back and forth like an allison. Height didnt seem to make a differance on the handling. The bottom has been blueprinted by Wally since new.

Even with three people in the boat it would still feel this way. I ran 101 with my two older nephews and it felt light and squirrelly in the back just like having one person in the boat. I thought the weight would have an effect on the handling but it didnt.

My new river rocket has a lip on the pad like an allison. I dont remember my 96 having this lip. May be a dumb question but do the STVs have a lip on the pad?

My 96 euro would never feel this way.The rear end would always feel planted. It had a stock 260 with a stock sportmaster 3/4" above the pad directly on the transom. It would always run 107 to 109 with a 26p drag copy. But this had to be on glass to do it.

I'm confused on the setup of this boat too. Or is it me or is this is how they run? Any suggestions would be helpful. Thanks Kurt

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When I ran 130+ in my Euro I used an XR case - the same case I used for racing it.

I am not a fan of the Sportmaster case for high speed use - especially on the STV's. The case has a LOT of tail lift and causes the problems you are having. The issue is the curve on the bottom front of the case between the water pick ups and the tip of the nose cone on the stock case.

I have talked several of the guys that drag race STV's into changing from their Sportmaster cases to coned Torquemaster cases. Each of then have said that the boat handled much better afterwards - even at the limited speeds they are getting at the end of the 1/4 mile (98-104 mph) in Lakeracer.

The Sportmaster case I modified (shown in this thread) had a LOT of work on it to reduce the tail lift issue. It is actually easier to modify the Torquemaster with a nose cone than to modify the stock sportmaster case. However, a nosecone on the Sportmaster would reduce this angle, and give you a better aspect ratio (width to length ratio) and SHOULD cure these issues with the Sportmaster.

I have several gearcases for my yellow River Rocket. I have a stock sportmaster (soon to be worked), a Torquemaster case that has been coned and worked, and a Steckbauer XR case that has been coned and worked extensively.

The Sportmaster will be coned and worked over shortly just to test against the other cases. I will let you know the outcome.

I have driven several STV's to speeds in the high 120's with stock Sportmaster cases. It can be done, but the handling is not great. I am hoping that by adding a nosecone to the Sportmaster case, many guys will not be forced to change gearcases, only modify the one they have in order to run at speed with improved handling. And it will not take the extensive mods that I put in this thread. We will see.

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Kurt,

The "lip" on the pad is wedge. At speed it helps to force the bow of the boat down and lift the boat from the water. It does add tail lift to the hull and makes the boat feel "loose" and FAST. It is added when the hull is blueprinted.

When you are running the boat at speed with only you in the boat, does the bow start to "roll over" and suddenly accelerate much better?

Modifying the wedge for your set up has potential speed and acceleration gains, but it must be modified correctly or you can really screw up the handling. Contact me for more info on this. I have changed mine slightly and change the amount of wedge on my DR-20 regularly for best performance. I have learned the right way and the wrong way to do this.

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Eurotrash, I am having GPI go through my Titus Coned gearcase and will have RP ship it to you to try. If its better, we'll go from there. The odd thing is, JLR never experienced those handling traits and your running the same heights and gearcase. My Euro was looser letting off with the sportmaster than the Titus or CLE case I have. Come to New Ulm this weekend and you can run the CLE...

Try getting as much play out of the steering as possible. I'm guessing here but but if there is air in the hydraullic steering, when you let off and the torque on the motor increases, maybe the motor is moving before the steering grabs it? Just a thought.

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Pro Comp,

You have brought up a really good point about the hydraulic steering. It NEEDS to be bled and the fluid flushed and replaced every so often. The results of doing this may surprise you.

Also, a heavier weight fluid can help to make the hydraulic steering feel better with less leaking passed the valving. Any local hydraulic shop will have a good range of fluid weights. Just make sure it is compatable with the seals in the steering.

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Wayne, I'm not sure if I would call it roll over on my boat. At speed it drives "normal" like my euro until the boat just pops up. The rear stays in one place but the whole boat rocks a little from side to side and REALLY STARTS TO FLY and SPEEDS PICK UP INSTANTLY. It feels like the boat sits high out of the water. Its controllable and not scarey but I usually shut her down at 110 or so. I'm just not use to this sensation. I'm playin it safe till I know the boat. I'll give you a pm on what to do with the bottom wedge. Thanks again Kurt

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Our River Rocket ran best in my opinion with the coned stock V6 case, however the Sportmaster i had modified by JC Propellers handles just fine on our STV, the boat just sits locked in and as stable as can be at 120+

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All the comments above reflect the reason I went through the gearcase mods we've been doing in the first place. The sportmaster CAN go fast, I just don't like it. The faster you go the worse it gets.

Randy

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All the comments above reflect the reason I went through the gearcase mods we've been doing in the first place. The sportmaster CAN go fast, I just don't like it. The faster you go the worse it gets.

Randy

I can't go fast enough to convince you all that RP's Sporty mod work, but I can FEEL it. It works. None of this up and down left and right tail butt feeling. Perhaps this means more on my pad V, but I think yunz that are running right are pretty much running like we do. Only with wings.

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My Practical Thinking smile.gif

Good readingTHANKS guys

For all practical purposes of STV boating, I think the SM gear case is the best. Yes there are gearcase mods out there that will give you a more luxo/cadillac feel but I dont think they are best gearcase for overall STV performance.

Throw in some other benefits like large volume passages, HD bearing carrier, big skeg with cup, easy inspection area access and again my practical thinking likes this case. Its bullet proof.

When I first got my SM, I thought wow what have a done, I cant figure this thing out, and why did I get rid of my luxo gearcase? That thing was so easy to drive etc etc,

However once I learned the characteristics of the SM, I found another 4-5mph on a 100mph STV

What does the SM like? For the most part it likes neutral to slightly negative trim (about -1/2°). Why? Cause that the way Mercury designed them for their offshore , skater type applications.

What does the STV like? .less then 2° angle of attack in to the wind (angle measured from water surface to hull surface.

Put those two things together (SM and STV hull) and I think you have a good fit. It is very simple if you keep those things in mind about how to fly the boat and how to fly the case.

Yes the case can hunt (bow steer like a V bottom boat with no lift) around and provide no lift to the hull at lower speedsget rid of the positive trim and put some power to the hull and it will work and lift better for you. The case likes height too, so make sure your not running the case with p/s c/l below the hull bottom.

Are there exceptions to the use of the SM? Yes of course, you have read many of them: Here is another thought:

If your STV is not capable of more then 95mphsay 200 or less HPthen the luxo case will work just fine and might be a cost effective way to have a mod done on a stock gearcase. For the most part, at 95 mph or less the STV is still driving like a V Bottom (bow lifting) and will not benefit from the SM case and its tail lifting characteristics. If you have tapped into the 95mph + phenomenon, youll know what we mean here, where you experience the nose sort of drop. In theory, the tail is lifting (not bow dropping) and compliment that with a tail lifting gearcase and once again you have a good fit for a fast and safe boat

Of course another exception is for those involved in ETs and stretching that last MPH out of your rig. So unduly respect for you guys

I still find that the luxo cases tend to emphasize bow lift and not stern lift and can keep most STV drivers happy with the luxo feel. Randy you can educate me on the Titus case hear about the lifting characteristics

Furthermore, I dont have any experience with driving an STV in excess of 105 mphso my experience is still with 100 mph boats and I still think this may still be the threshold for most STV owners with less then 260 hp or even the new owner that is trying to break 100mph

From what I understand the SM can still be effective at big numbers with some mods.

Dont get me wrong guys I do respect all of you, that have put in the time to refine and redefine the performance of OEM casesultimately we all benefit too from your experience so it is appreciated

Again my practical brainstill tells me that there are a number of STV owners that still need SEAT TIME, more then they need gearcase upgrades. Too many can make too many mods at once and just like finding the sweet spot engine height.the learning curve of the STV needs to also be incremental.

Once gain it does not go much further then refining your existing setup , with the fundamental elements and finding a good prop first.

Now,

ask Roark Summerford what his favorite gearcase isand he will say, the CLEgood point and well taken here tooafter all that is what the STV hull was designed aroundyet another story. smile.gif

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What I found out that made the most difference in the handling of the stv is the wedge on the pad. My euro didnt have it that I remember or very little. Now with the blueprinted bottom and wedge put on my RR. Its night and day different in the handling. The new boat really flies high. It had nothing to do with the gearcase. I now found out that this is suppose to fly this way. More seat time with this bottom should bring in some good numbers even with a stock motor. It rides more like an allison and not an stv. Time will tell on this boat. Kurt

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I have run my Euro 2.5 drag with the an unmodified sportsmaster to 110 with one passanger. Smooth as silk. Prop was a SRX/DAH 27 pitch with some couping added. I have not had the opportunity to try to go faster.

I should add that my boat was setup by Rick from Trade Winds. I am running zero to 2 degrees trim. The boat catches enough air to fly at around 90 MPH. I have tried a friends 26 ET. The prop pull hard to 100 MPH. I did have the chance to turn it loose. Seem to be a great prop!

The guy who loaned me the 25 ET now has a RR set up by Randy at GPI. It has one of the last 2.5 drags with a Hoss Trition prop. The guy is not very happy with his boat. He said it felt light and squirrelly. I told him to try the ET first. Second try runing the prop deeper. cool.gif

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STVBobK,

If the guy you are refering to is Pete from MI, you need the whole story. He was the one bound and determined to have A) the lightest boat they could build, B: a stone stock sportmaster, C) a new drag engine which are ported very high from the last build, and D) hasn't done the things I told him would tame the boat down. During this whole process I tried to steer him in the right direction so far as weight, gearcase, etc. But he is the customer and had his own ideas on what he wanted. I warned of the consequences but what do I know. A superlight river rocket is WAY harder to take a set and run big numbers with than a std build boat. WAY HARDER. I own one, I should know. It takes some well placed ballast and some skill to fly the boat properly. If you don't feel comfortable then the boat will never run up to the big speeds as most of us will not push it. I told him to take his time but evidently it was expected to just hop in and go. I ran the boat quite easily to some nice numbers but I will say it is not near as stable as my boat. Couple of reasons: I have 30lbs of ballast ahead of my feet his boat didn't at the time and he has a stock sportmaster and I don't. He also has 2 more inches of set back than I do, this makes it more flighty. All of these items were gone over during the order process but I was met with resistance on them. A boat of that caliber is the sum of all it's parts...choices are important. Every customer over the last 4 years we have has followed my recommendations pretty much. I don't recommend something for the heck of it. It is rare that I have someone unhappy. I have had one customer who followed his own lead more than ours and the result is not good for anybody. The boat is not bad but without being balanced it can take your breath away if pushed beyond what it will let you get away with. 560lb boats do that. Mine was no different, but I worked with it and the rest is history.

Randy

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I agree with Randy that the lighter the boat, the more difficult it is to set up - balance is a much bigger issue. As the hull weight drops, the balance point with the same rigging moves backwards in the boat. Adding more set back just agrevates the situation.

Also, If you are not running at high speeds, the modifications to the gearcases will not be noticed. It is not until you are running over 115 that the surface of the gearcase becomes an issue. The faster you go, the more you will notice the way the mods to the case change the handling. If you are running under 100 mph, I seriously doubt that any of the work listed here will even be noticed on a standard weight STV.

It is no secret that I REALLY dislike the Sportmaster case in stock form on a high speed STV - it has too much tail lift in my opinion. Add a big pitch Cleaver prop and you will really notice the lift. That being said, I have driven a standard weight STV with a stock Drag engine and two adult males in the front seats (over 200 pounds each) to 127+ with a stock Sportmaster and a Cleaver prop. It can be done, but it is not nearly as enjoyable as when using a worked case, and the let out on the stock Sportmaster at these speeds is NOT fun.

Take all of this as you will. There are a LOT of guys that have spent a LOT of time to work out the best handling and accelerating set up for the STV hulls. As times change and power increases, the set up changes. You can learn from their hard work or not...Just like Randy's customer has chosen to do. But I doubt you will wind up happy with the boat if you don't head the advice of those who have tested, tested some more, and are still testing.

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biggrin.gif Excellent responses as usual Wayne & Randy;

dry.gif Some people still seem to insist, on learning the hard way.

They read a little, do a little and come to the rediculous conclusion, that they know it all and can now, go at it on their own!!

I've been reading on this site for just a short time, and all the information and advice out there, on STV's alone, seems to be endless. ohmy.gif

I for one, do appreciate all the advice and knowledge that alot of the guys on this site, through years of testing, have to offer to the rest of us. smile.gif

I don't even pretend .................... to know the half of it. blink.gif

All I know is ..................... look, listen and learn. Also, don't be too proud to ask for help, from those who have been there and done that. Over and over.

Thanks guys !!

Regards,

Bruce. smile.gif

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On the light boats, I am in total agreement with Randy and Wayne they are a different ball game. One that is just a lot more sencitive in all respects. Gearcase's become as important as prop design, as does the balance of the boat. There has been some great information on here about balance. I was frankly a little shocked that at the Rumble on the River a few weeks ago by how many people asked why I placed stuff in the boat where it was, it is about moving weight to different places in the boat. ( the battery is behind the driver, this was the most obvious ) there are weight plates on the front bulkhead also. This boat ( better known as the Barney boat ) is also an All Kevlar boat like Petes boat ( not K1200, which is what Waynes boat is, Barney is K900 ) and it is easily the best running STV I have ever seen. ( Those that saw it run at the Rumble can comment.... please ). But to make it get there took a bit of work and a lot of experiance with STV's and seat time to know what the boat is asking for. If you get into any of the boats that are in the upper echilon you better know what you are doing, or you are not going to like the results. Barney is easy, I am not sure if that is because the driver makes it easy, the boat or a combination. What I am getting at is what Randy said about getting into the boat and squeezing off some numbers with ease.... he made it easy, but for someone without the experince might not see 100.

As far as gearcases go, I am not as hard on the stock sportmaster as Wayne and Randy are, I can live with it. That means it works and most will find it sutable, frankly most are not going fast enough to have major problems, BUT that being said you will NOT find a stock sportmaster on my boat. And those that have run a good one will understand. And coned cases are even better.

RT

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