Best Top Speed Prop?

[croSSed]

Hi.
I have a 17' Cee Bee Avenger Mach II with an '87 Merc. XR2 150. Presently I'm running a small diameter 26P Mercury Laser II with a plastic hub ring around the prop to keep excess exhaust from venting over the blades. With that prop I'm getting 6200 rpm at just a shade under 70 mph. I do not have a LWP so I can only raise the engine so far. I have it as high on my jack plate as I dare right now before water pressure drops dangerously low. It also has the stock 2:1 ratio l/u that came on these motors. By just changing props, what prop do y'all think would give this thing the best top speed? Thanks.

TG

P.S.: Attached is a pic of the boat.

[Streamin101]

Try a 27 srx.

[croSSed]

Another question: What's the performance diff between a Mercury small ear chopper, and a big ear chopper? I don't need a great deal of bow lift... Boat is light and the bow lifts great now.

[whipper]

Another question: What's the performance diff between a Mercury small ear chopper, and a big ear chopper? I don't need a great deal of bow lift... Boat is light and the bow lifts great now.
You don't need a Big ear on there thats for sure. They are good load carry props but your better of with something like an ET if you get a LWP. I would seriously invest in that before i bought another prop.:thumbsup: You have a very sweet little package there I love how symmetrical she all looks with what you've done!:thumbsup: Send your gear case to Titus and get er done you wont regret it!! Whats the limiter on your motor at? My guess is with your 26 with some more hight you can see 80. Then when you can rise your motor up your options for props will greatly increase. The fast ones are made to run high. I would think you could turn a 27 better with more hight but with out LWP your 26 would be the most pitch for now that will give you decent performance all around. What other props have you tried you cant try to many. I really love the Hydromotive quad 4/ot on my vee hull with the 225PM. I run a 26 for hole shot and midrange but still yield decent top end up to 7200RPM. Another prop thats a dime a dozen you might want to try on there is a Trophy Plus. I would think a 24 would be a killer prop on your setup.:thumbsup: Not that you cant turn a 25 but the hole shot and midrange is were its at man! Trophy's like to be in the water a little more also than most performance props. So even with out LWP you can safely run these were there meant to be anyway. You'll still see 70 with it ill bet but your all round performance will jump up a notch. If you aren't getting LWP and want a prop just for the very fastest top end sacrificing hole shot and mid range drastically a 28 ET or Hydromotive Knob cut in a 28 also run as high as passable with out loosing water pressure will get her done. I'm thinking though you'll be going to fast and might take some getting used to or you might loose water pressure at those speeds? LWP first then you'll have no problems running that tall of prop in these styles nearer the surface. To run these bigger wheels its less stress on your motor if you can run them high. They both have lots of rake and a 150 on your 17fter can turn them much more efficiently higher up.

[croSSed]

I used to have an '87 I6 115 on this thing. With the 26P Laser II I was gps'ing it at 63 mph. Today I had this boat out running the same prop, but the 150, and this XR2 put the boat on a plane, with the motor all the way up on the jack plate, and 6 people in the boat, easily! If I tried the same thing with the 115, it might, barely get on a plane! This 2.0l motor is pretty awesome compared to the I6.

I could see 80, huh? She's quite a handful at 70! I recently installed a SeaStar Pro Hydraulic steering and that has helped tremendously in keeping her under control. Still, gets pretty loose at 70; I'm just now getting used to keeping her from chine walking. BTW, who is Titus? Thanks again!

TG

[whipper]

A handfull at 70.:thumbsup: Thats what I ment when I said that might be to fast and will take some getting used to. You have to learn how to conrol chine walk if are going to go over 70. My Allison is one of the hardest to learn how to drive over 70 but once you get used to it {Learn how} its realy no big deal. Like rideing a bike.:thumbsup: Theres lots of articals and threads on this in the search function. I would read as much as possable about how to steer her over 70 and you might pick up something that just clicks and bingo ya got it and always will after the first time. Every Vee hull chin Walks above 70 so if you want to go faster than 70 youll need this skill.:thumbsup:Titus is a custom gear case modifier. Arguably one of the best. When you run high speeds like that its something you want the best of. Your gear case can make or break your day or your life! So I would get the LWP done buy one of the experts like titus. Hears a link to some his work as you can see the work is impecable!! http://www.low-h2o.com/testimonial.htm To run the sweet props that are designed for speed like the ET its best to run them at the hights they are designed to run. The fast ones are semi surfaceing props. You will have a hard time running these the way there ment to with out LWP is all. If your happy with 70 then you dont need to do this. But if your like me you want to get more.:D I think your hull looks like a hull that can do 80 with a little set up work with your currant power. Id say all you need is to learn how to control the hull, get the gear case modified to allow a little higher engine hight and slap on a 27 or 28 ET prop and your doing 80. Ya know with the gear case done the feel will be lighter when your trying to counter steer for chine walk. I think its harder to control with the gear case deeper in my opinion. I run 1/4 below to even with my pad never ever lower. 90mph is very contolable. One thing you may or may not know about is balancing your hull? I for instance have a 40lb led shot bag in the starboard gunnel to off set my weight at the helm. I would suspect you would need to do the same. Its WAY easier to balance the hull chine walk less when your balanced and your being 17ft and light very notacable. When you sit at the helm. Look out at the bow and is she listing to your side?If so take some dumbell weights and put about 30lbs on the otherside near the back of the cockpit. Gunnels usually. Now sit back at the helm. Is she perfictly level yet? If not keep adding 5lbs at a time untill she looks level! It helps to have a friend looking from shore telling you if your level also from the sterm view. When you determine how much weight you need to flatten her out you can get some shot bags to stuff in there and leave forever. This is what all high performance Vee bottom guys do. It will greatly improve your handeling!! When I add a pasanger depending on there size I have a back up in the form of a battery booster and I move that to my side to cominsate. Makes life easyier. When you have more than one passange make sure the weight is evend out as best you can. You have a sweet package there and i think cabable and werthy of spending the little extra to get the most out of her.:thumbsup: You have the hydrolics the jack the sweet little 150 and a great looking hull. You have a real sleeper there with a little gearcase work and the right prop. I think you will surprise a lot of other boats if you get this done and learn how to handle her above 70. Loose means fast so be very carfull and always wear your saftey gear. Kill lanyard, great quality life vest ect.. Have fun P.S. Nice looking gear Cases in the link eh!! Call him up and tell him what you have and what your looking for and get a quote.:thumbsup: Later James

[David]

Chopper information

http://69.24.70.63/adamsdock/chopper.html

Small ear choppers have less lift, and are pretty fast props, at least for me. And they are a lot cheaper than an ET.

Does your boat have a pad? If not, 80 might not be possible.

[whipper]

I had a A5 before the fastest prop I ever had! I had it worked by DAH props in WI. The Cee Bee has a differant sorta pad like a hydrosteam if I recall. About 7 or 8 inches across. If you learned to drive her well over 70 is possable. They are a very fast hull!:thumbsup:You will need LWP for that though.

[croSSed]

I had a A5 before the fastest prop I ever had! I had it worked by DAH props in WI. The Cee Bee has a differant sorta pad like a hydrosteam if I recall. About 7 or 8 inches across. If you learned to drive her well over 70 is possable. They are a very fast hull!:thumbsup:You will need LWP for that though.

Yes, it does have a pad, of sorts. It doesn't extend down like most pad-v's; it's really just a flat place. I'd say in terms of performance capability, it's a step below a Hydrostream Vector. Thanks for the tips!

TG

[83PREDICTOR]

Just wanted to compare. I have a 17ft Checkmate with a XR2 150. I also run the 26P LaserII with a best top speed of 69.6mph gps. I do not have a lwp and run the p/s 2.5" below the pad.
Where did you get the plastic hub ring from. I have been looking for something like that to bring my rpms down. Have you run your boat with out the ring in?

[croSSed]

The plastic ring is a Mercury part. You should be able to order one from any Mercury parts dealer. I have not tried to run without the ring. I have the PVS holes plugged, and with the small diameter prop, and with the little amount of exhaust venting past the ring, the boat is very responsive at any speed. Comes out of the hole like a violated ape!

TG

[croSSed]

The plastic ring is a Mercury part. You should be able to order one from any Mercury parts dealer. I have not tried to run without the ring. I have the PVS holes plugged, and with the small diameter prop, and with the little amount of exhaust venting past the ring, the boat is very responsive at any speed. Comes out of the hole like a violated ape!

TG

[83PREDICTOR]

Do you have the part# by chance? How much it cost?
I think that you should pull out the vent hole plugs and try to get a few more rpms.

[croSSed]

Do you have the part# by chance? How much it cost?
I think that you should pull out the vent hole plugs and try to get a few more rpms.

Sorry, I don't know the part # nor how much it cost. If I remember correctly, it wasn't very expensive. If I pull the vent plugs out to get more rpm, isn't that rpm only a result of slippage? Therefore, a loss of top speed. I don't want more rpm anyway. Factory redline for this motor is 6000 and I'm already past that. The factory oil injection pump can't keep up if the motor is rev'd above that.

TG

[imq707s]

Try a 27 srx.

+1

I've tried probably at least 20+ different props trying to sqeeze every little last MPH out of my boat, and the best so far as been my trusy DAH worked 27 SRX. :thumbsup:

[olmo40]

I think part number is 82197a-1 ,However Eagle One supporting vendor on here sells them for about $25 or less ,My neighbour bought onefrom him and it is the goods .

[Oz Dude]

croSSed - I have an Australian Bullet 1750 (17.5ft) with a pad bottom so I'm in the same ballpark as you albeit on different teams. We run a 3L Merc on ours and with the motor 2" below the pad we generally see 5% slip on most our combinations. Based on the numbers you've given, you're getting approx 10% slip so there's room for improvement there on your current setup. We obviously have more torque avail but as you are at your RPM limit then it's now a case of seeing how you can improve your setup to bring that slip down.

When we run our small hub 24P Laser II for ski racing we don't use a prop seal ring or have the holes sealed and it doesn't change the top end we're seeing. If you're getting such a good hole shot, and you like the feel of the Laser II, maybe you could try a 28P and pull the seal ring out. You'll get a bit more slip out of the hole, so less torque strain on the motor, but at 70+ the water pressure around the gearcase should all but eliminate the exhaust from trailing over the blades.

As for different types of props, we have a 28P Trophy Plus which we've seen 90mph with on a bad day. The thing to remember with the Trphy Plus is that it's gonna carry the bow a LOT higher, especially on a little boat like yours or mine. If you try one, ease into it for a while and see how the boat reacts to it. On mine the difference between Laser II and Trophy Plus is night and day.

Based on your numbers, changing up to a 28P Laser II should see you around 74mph, and if you can get that slip down to 5%, then you'll be almost at 80. As others have noted however, you do need to learn to control chine walk before you push too hard or you're gonna end up taking a swim. Safety first - jacket and kill switch!

Let us know how you go :)

Oz

[croSSed]

croSSed - I have an Australian Bullet 1750 (17.5ft) with a pad bottom so I'm in the same ballpark as you albeit on different teams. We run a 3L Merc on ours and with the motor 2" below the pad we generally see 5% slip on most our combinations. Based on the numbers you've given, you're getting approx 10% slip so there's room for improvement there on your current setup. We obviously have more torque avail but as you are at your RPM limit then it's now a case of seeing how you can improve your setup to bring that slip down.

When we run our small hub 24P Laser II for ski racing we don't use a prop seal ring or have the holes sealed and it doesn't change the top end we're seeing. If you're getting such a good hole shot, and you like the feel of the Laser II, maybe you could try a 28P and pull the seal ring out. You'll get a bit more slip out of the hole, so less torque strain on the motor, but at 70+ the water pressure around the gearcase should all but eliminate the exhaust from trailing over the blades.

As for different types of props, we have a 28P Trophy Plus which we've seen 90mph with on a bad day. The thing to remember with the Trphy Plus is that it's gonna carry the bow a LOT higher, especially on a little boat like yours or mine. If you try one, ease into it for a while and see how the boat reacts to it. On mine the difference between Laser II and Trophy Plus is night and day.

Based on your numbers, changing up to a 28P Laser II should see you around 74mph, and if you can get that slip down to 5%, then you'll be almost at 80. As others have noted however, you do need to learn to control chine walk before you push too hard or you're gonna end up taking a swim. Safety first - jacket and kill switch!

Let us know how you go :)

Oz

Thanx, man. I really appreciate all the tips. I actually have some room to play with on my jackplate. I can raise the motor another couple of holes on the plate. That's the first thing I'm going to do, and then I'll take her out and see what happens. This doesn't cost any $$ either! I'll keep this thread alive with what I find out.

Peace to all.
TG

[Oz Dude]

croSSed - no worries :)

While you're playing with heights, also try taking that prop seal ring out. Run with it in and then with it out, on all of the same settings and see what, if any, difference it is making to your top end, mid range, and holeshot.

Oz

[croSSed]

croSSed - no worries :)

While you're playing with heights, also try taking that prop seal ring out. Run with it in and then with it out, on all of the same settings and see what, if any, difference it is making to your top end, mid range, and holeshot.

Oz

BTW, what HP you running? You have a pic of this rig?

TG

[Oz Dude]

Motor is a 3L Injected Merc 225 with upgraded computers and 4 throttle intake, so basically, a 250.

Motor weighs more than the boat when it's bare :)

Competing in 60mph class (notice how the boat isn't aired out properly - needs to go 70 to sit up higher - next season!)
http://img.photobucket.com/albums/v211/OzDude/Rage/2008BridgetoBridge01.jpg
http://img.photobucket.com/albums/v211/OzDude/Rage/2008BridgetoBridge07.jpg
http://img.photobucket.com/albums/v211/OzDude/Rage/2008BridgetoBridge04.jpg

A couple on the trailer:
http://img.photobucket.com/albums/v211/OzDude/Rage/DSCF3179.jpg
http://img.photobucket.com/albums/v211/OzDude/Rage/DSCF3177.jpg
http://img.photobucket.com/albums/v211/OzDude/Rage/DSCF3181.jpg

Dash Layout:
http://img.photobucket.com/albums/v211/OzDude/Rage/DSCF3182.jpg

Oz

[croSSed]

Wow! That's badass! You have a deeper V than I do. Here's the best pics I have of the back of my boat so you can see the hull shape.

TG

[Oz Dude]

Mine's definitely deeper :)

Yours should be relatively stable at speed I would think but it might also move around if you can't reel in the chine walking. That's gonna be your next learning curve. Once you can feel the weight of the boat shifting, you will counteract it without thinking. I can teach people to drive mine from the passenger seat just by getting them to copy my arm movements.

Oz

[whipper]

OZ you have your Foot on the left side? Thats the first time Ive seen that. You must be left footed.:thumbsup::D Sweet little rocket ya got there. Ive often thought my Allison GSE would make an excellent Ski race hull. I have the pylon and ski around 60 for kicks some times have since I was a kid. Ive never been over 70mph behind a boat though and on mine not sure how she would be above that pulling while balancing on the pad? She light on the pad. http://i63.photobucket.com/albums/h151/whipperr/pics020.jpg?t=1239779939

[Oz Dude]

whipper - I have no doubt the Allison would make a great ski race boat. It's amazing with the Bullet, you don't understand just how much technology is built into the hull until you start racing it. The balance of the boat at speed actually improves once you have the guys hanging off the back. The Allison looks relatively similar in principle of design so I would think you would experience the same thing.

You must've really been studying those pics to notice the throttle! Bullets have a footrest built into the floor where your right foot sits and that's where the trim buttons are located. If the boat was originally built as a center steerer, the foot rests can be on both sides so the driver could set up for left or right foot throttle.

I actually prefer it. Your right foot is pretty sensitive to touch cause it's the foot you use to drive a car which is perfect for a touch up or down on the trim. Your left foot on the other hand is smart enough to know how to keep a constant speed :)

I hope when you ski at 60mph you are using some decent equipment?? A fall even at that speed will clean your clock if you hit the water wrong. For 60mph class we use 100ft ropes (max permitted by the rulebook) and the guys are on 6-7ft double booted planks. They also "wrap up".

Like this:
http://img.photobucket.com/albums/v211/OzDude/Rage/2008BridgetoBridge08.jpg

Once we go up to 70mph the rope length is unlimited and we've found 180ft seems to be a nice balance. The guys are far enough back that there's actually a wash to ski inside (cause at 70mph there isn't anything at 100ft!) and they're pretty much out of most of the spray coming off the boat. It also makes it nicer to drive at that speed with a bit more flex in the rope.

I'm not sure what equipment you've used when running at 60 but try a bit longer rope and see how much nicer it is back there :thumbsup:

Oz :cheers:

[whipper]

TG your hull looks great at the transome for speed. If your up high there will be little hull in the water. The inside strakes are maybe a little low in relation to the pad. If you later on want more you can experament with adding more of a pad to ride on? You would bneed to be very carfull and test with cation if youve never added one before. Ive played with mine lots of the years. Its all about trail and error. They have to be perfict to work right. The nice thing about adding one if ya dont like it you just sand it down or off and try again.:thumbsup: Not rocket science. But can get danerouse at higher speeds if its not just so. You can tell before you get to top speed anyway the feel if its good or not. Just a thought. LWP.:D The cone makes a differance in the hydromatic flow to the prop. There is a speed were the design of the case will inharitly blow out at. With out modifacations to your case be very caustiouse above 75mph if you reach these speeds. The blunter the nose of the gear case the lower the speed were blow out will accure. Theres a whole lot to this and a good read if you find material about this information. If you have a buddy with say a bobs nose cone you could take a mold and work on yours and try to copy the shape. See how she goes and if need be your better of just buying a bobs to put on yours. Its not that expensive realy. I would make that a winter project though and send it away to have it done profetionaly. You would be with out your gearcase for a month or so and this isnt the time of year for that!:thumbsup:

[whipper]

OZ my buddy had a Maha[sp] long board ski real big bertha any way. Ive only done it a hand full of times. I never had the harness so was just hanging on and could only go for a short distance. It was behind a vee drive with a blower! Take your arms right off at the shoulder if he sneezed!:eek: I got lucky one time wearing my barfoot suit and just spun on my back for a mile! Could have been a lot worse. Thats the only time I crashed. I dont think I would try it again now though. Like you said I never had the proper equiptment on. I just kept giving the thumbs up untill i didnt dare let go to give it one more.:D Its very calm and quiet at those speeds. Just the wind and you. Glassy conditions always only for me. I respect those dudes the endurance they have is increadable and Nads to! Im sticking to piloting the boat for now on. I hurt my back last year jumping the wake and I cant help myself when i get back there so I better leave it to the young guys for now.

[Oz Dude]

That's why a lot of guys start wrapped up. They can then take a lot harder hit out of the hole and also much greater acceleration.

At least you know what it feels like to be out there at a reasonable speed. As you said, you can really appreciate the guys that go hard and fast. In Superclass here in Oz, they're now well over the 120mph mark on some of the straights...

Oz

[whipper]

That's why a lot of guys start wrapped up. They can then take a lot harder hit out of the hole and also much greater acceleration.

At least you know what it feels like to be out there at a reasonable speed. As you said, you can really appreciate the guys that go hard and fast. In Superclass here in Oz, they're now well over the 120mph mark on some of the straights...

Oz
:eek::eek::eek: Thats nuts!!!!:D:cheers:

[Oz Dude]

Welcome to EXTREME SKIING :)

Try these out for size:
Stinga Take off and Spin: http://www.youtube.com/watch?v=4vTogPJ6nGQ
Stinga Promo (not bad for a 20yo boat is it!): http://www.youtube.com/watch?v=7jdqvCJHNEA&feature=related
Stinga showing how much spray the skiers cop: http://www.youtube.com/watch?v=t1D2Jtt7BeE&feature=related
Crazy Horse from the Observers seat: http://www.youtube.com/watch?v=3FMLEu1q_Uk&feature=related
A couple of Hellbent at last years Southern 80:
http://www.youtube.com/watch?v=MRTKENmEbjw&feature=related
http://www.youtube.com/watch?v=yWl_HVmnJ-I
and finally, just after the start of the Hawkesbury Bridge to Bridge last year. It's a full on drag race to see who can get into the river proper 1st. After that, chances are there won't be any passing going on. 120? No problem, and not exactly glass flat water: http://www.youtube.com/watch?v=Pm6tSicuuhg&feature=related

THAT's nuts my friend :thumbsup:

Oz

[croSSed]

How would this prop work with my s/u, assuming I get a Titus nosecone/l.w.p.u?

http://cgi.ebay.com/ebaymotors/Mercury-racing-yamaha-chopper-propeller-prop-Spinelli_W0QQitemZ200333610989QQcmdZViewItemQQptZBoat_Parts_Accessories_Gear?hash=item200333610989&_trksid=p4506.c0.m245&_trkparms=72%3A1171|65%3A12|39%3A1|240%3A1318

TG

[croSSed]

I bought a 26P small ear chopper from someone here recently. I compared it side by side with my 26P small hub Laser II. There was no difference in top-speed performance. Both props - without lwpu - ran consistently between 68 to 69 mph. With the Laser II I managed one 70.0 mph for about 2 seconds. In a 17' pad v boat, that kind of speed is a RUSH! Fun stuff.

TG

[Oz Dude]

croSSed - I hear ya. Best we've run with our small hub Laser II 24P has been 82mph and that was while towing a skier. It always feels faster in little boats like ours! I drove a 21' boat a few weeks ago and 85mph felt like about 50 :)

Oz