Dhadley, Walleyehed were you right after all?

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

Sincere question here, placing your tabs that far out......would it create drag or would it possibly create balance if your boat chine walk's I have recently put a new prop on a it lift's the boat up amazingly well .........so much so it does chine walk. Being a I/O there is little i can about engine height i can't help but wonder it the tab's would help that. I apolgize for jumping in like this..

I have absolutely no idea, it was the manufacturer that placed them there.

 

[Ron G]

Re: Dhadley, Walleyehed were you right after all?

TG i would think they would help alot for chine walking.but i dont know....
Hows your watr preassure at that hight?i dont know much about the runabout hulls but i would think the txp is the wrong prop for your hull after looking at the pics.the turbo1 maybe good but i lets see what Kenny And Dale thinks.

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

Ron,
The water pressure was about 20psi, at wot a bit above, no fluctuations. I'm really happy about that gauge, works great. I hope that a T1 or a lightning would do the job better at lower heights.

/Mattias

 

[Crownie2]

Re: Dhadley, Walleyehed were you right after all?

I am assumming you know this, but trimming that far out to create the roostertail shown in your picture is NOT how the boat should normally be run...

That high an angle is not efficient at all.

Bob

 

[Dhadley]

Re: Dhadley, Walleyehed were you right after all?

Exactly. The prop is trying to raise the stern more than the bow and you're trying to overcome that with too much positive trim trying to lift the bow.

This is a deep V hull with no pad or step so you're always going to have a lot of drag form a large wetted surface area.

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

Ok, so with this in mind, what would be the most logical choice, Turbo 1 or Lightning TXP? Btw, i sent you a PM, Dale.

/Mattias

 

[Dhadley]

Re: Dhadley, Walleyehed were you right after all?

To be honest, the TXP was not designed for the hull you're running. The TXP is doing what it's meant to do but your hull requires more bow lift. Your boat is a lot like my Hydrasports. Deep V, rides great but it'll never be the fastest 22' boat.

The Turbo I or II is a good prop but still won't have the bow lift that a Lightning has. Or a Fusion 4 either. It wasn't designed for that. But, a Lightning needs more X dimension that the standard Turbo. Since you have a jackplate I'd think the Lightning would be a good choice.

It'd be interesting to see why the guy who sold you a TXP recommended it rather than a Lightning.

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

Dale, are you talking about the "old Lightning" or the new Lightning ? The older one has pitches down only to 22" while the new version has down to 21". The guy who sold the TXP happens to have a Lightning 21". When i bought the Turbo prop back then it was more a choice between Turbo 1 and TXP, the Lightning was never mentioned. So if the new Lightning has more bow lift(=less trim) than the TXP, then it should work well with my rig, right?

/Mattias

 

[Dhadley]

Re: Dhadley, Walleyehed were you right after all?

The Lightning has been around a long time just like the Vector (14 1/2" diameter). The TXP is faily new, probably a couple years old. But yes, the Lightning is intended to produce more bow lift. The TXP's were designed specifically for certian boats. And those boats have built-in bow lift.

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

Hi Dale and other prop gurus!
Comparing Ballistic and Turbo props.
With top speed at 48.5knots/55.8mph at max 5400rpm(accordingly to Yamaha digital tach) with Ballistic, the prop slippage is very low even when adding an inch to pitch for cup, appr. 8%. I am thinking that the Ballistic was run with low engine height. Isn't that speed almost impossible to beat with a Turbo 21" if max rpm is only 100rpm higher?
Shouldn't i need to increase the pitch to 22" of, say, a Lightning to have at least a chance? With in mind that the engine runs a lot higher with a Turbo which decreases overall drag, this should reduce slip, allowing higher pitch, right?
Or am i thinking wrong?

/Mattias

 

[walleyehed]

Re: Dhadley, Walleyehed were you right after all?

Don't know how you're taking speed but the Tach or GPS is off...I suspect the tach....
I come up with 6.9% slip...quite frankley impossible with your hull, and I'm not convinced it will produce 8% with as much boat as you have in the water. The Lightning will lift the bow, decreasing the wetted surface, requiring less power, etc...
Remember 1 thing..if "that" boat was built for high-speeds, it would have a pad bottom, not just a straight V.

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

Hi Kenny, thanks for your reply.

Don't know how you're taking speed but the Tach or GPS is off...I suspect the tach....

The speed is taken with GPS. I don't know about the tach, it's a digital tach, shouldn't be too hard to make one accurate, at least not within +/-50rpm, which it should since the step is 100rpm, i swear i could put together one in a couple of days. If it is off more than that, then Yamaha inc. needs to take a serious look at their electronics department.

The Lightning will lift the bow, decreasing the wetted surface, requiring less power, etc...
Remember 1 thing..if "that" boat was built for high-speeds, it would have a pad bottom, not just a straight V.

Point taken. Every Yamarin(the make of my boat) comes with a Yamaha, they have that deal, and the Yamaha always comes with a Ballistic. They must have found that it works very well with the hull, has low slip etc. But they are most probably looking for overall performance, not just top end.
What i wonder is, in order to gain a little top speed, am i not forced to increase the pitch of a Turbo, if the Ballistic is as efficient as it looks?


/Mattias

 

[walleyehed]

Re: Dhadley, Walleyehed were you right after all?

I don't know if this will answer your question, but in my testing Data, I have ran 7 different Ballistics and low slip/high efficiency is not one of it's better traits...This prop is WELL known for high slip and venting.
The only Ballistic I have run that showed promise(besides one I had some work done on) was a 4-bld XL series.
As for gaining on top-end...with a bow-lifter, you're gonna end-up with less wetted surface equaling less drag requiring less HP. Net result should be an easy increase in speed. The pitch number itself doesn't tell us much about the "design" of that pitch.
As to whether or not we need to go up in pitch can only be answered by the results of a Lightning of simular pitch. It would be nice to have a chart that says.."This prop works best on this boat".
Very possible that a lightning could give enough lift to get beyond your RPM range, but depending on how much and where the engine is mounted at max efficiency will tell the story.

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

As for gaining on top-end...with a bow-lifter, you're gonna end-up with less wetted surface equaling less drag requiring less HP. Net result should be an easy increase in speed. The pitch number itself doesn't tell us much about the "design" of that pitch.

Yes i understand. And if slip is less i can gain more top end at less rpm, ok enough said about that.
I called the prop dealer yesterday he's gonna send me a Lightning 21", i hope it's here by next weekend so i can test it. He also said that next pitch is 23" which almost definitely is too much. What's left now is a lot of testing, which is perhaps the funniest part. I will, of course, let you know how it performs.

/Mattias

 

[Dhadley]

Re: Dhadley, Walleyehed were you right after all?

Lightnings come in 1" increments from 21 to 31. They can make bigger ones and there is a 19.

 

[walleyehed]

Re: Dhadley, Walleyehed were you right after all?

realmasa, sounds like your supplier is a bit behind in what's available....

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

realmasa, sounds like your supplier is a bit behind in what's available....

could be. i have now realized there are turbo resellers much closer, i couldn't just find them on the web. It would have been much easier if i knew that from the beginning, easier testing different models. Now i had to ship the TXP to Norway, and the Lightning from Norway to me.
Also, the guy in Norway is into boat racing with small models and are probably more familiar with cleavers etc. You can find it here, www.winrace.no
I hope i have the Lightning here by next weekend.

/Mattias

 

[Gammabusa]

Re: Dhadley, Walleyehed were you right after all?

Did you get that new propeller from Olle? tested it?

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

Hi, no i'm still waiting. It should arrive this week, i hope, it's getting cold outside. It's no Lightning speed on this delievery.
I'll let you know.

/Mattias