Dhadley, Walleyehed were you right after all?

[realmasa]

Hello,

A few months a ago i posted about my TXP. My engine is a Yamaha 200 HPDI, my boat is a Yamarin 6110. With the same adjustments the TXP(14x21) did 45knots at appr. 5100rpm while an original ballistic did 48.5knots at 5400rpm(i'm not completely sure about that latter rpm but it's close). So i bought and installed a manual jack plate, CMC ML-65. I kept the engine at the same height and did a test run with TXP and i reached 46knots at 5200rpm. The AV-plate is about 2cm above bottom. I readjusted engine height up 2.5cm - 1inch(totally 4.5cm above bottom), a new test run revealed no difference to my surprise, almost exactly the same 46knots - 5200rpm. This is with GPS and OEM tach. I also have a pressure gauge installed. How come that the engine can't turn the prop faster when one inch of the engine is out of the water?
When i run at WOT i can still trim the engine out of the scale of the OEM trim gauge, but the prop has started to throw some water up in the air and i wonder if raising the engine further would do any good.
This makes me wonder if the TXP is not suitable for my hull after all. Maybe the Turbo 1 would be a better choice or perhaps Mirage Plus or Laser II? Or would a pitch drop from 21 to 19-20 make any improvement?

Opinions, ideas greatly appreciated. If i have forgotten any details, let me know.

A picture of my boat: http://personal.inet.fi/surf/masa/myboat.jpg
and of the installed jack plate: http://personal.inet.fi/surf/masa/jackplate.jpg

/Mattias

 

[Crownie2]

Re: Dhadley, Walleyehed were you right after all?

Well you are correct - theoretically you should have gained some rpm's and some speed at the higher position. Maybe there were some other factors - wind, water and temp differences.

Perhaps the TXP needs more height to take advantage of it's design - I'd try higher.

It sounds like you achieved excellent results with the Ballistic. Was there something you didn't like about it or was it just the "need for speed" taking over?

Bob

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

Hi Bob,

the ballistic was destroyed when i hit a rock, so instead of buying the same i wanted to try something else. The conditions between the two test runs were the same, calm water, same temp etc. Also, the ballistic was very prone to ventilate at low engine height and low trim, but still performed very good in top end speed(obviously).

Yeah, i will do another test with increased engine height, but not yet, maybe in the weekend.

/Mattias

 

[Dhadley]

Re: Dhadley, Walleyehed were you right after all?

Remember, the TXP is made for very specific boats and has less bow lift than the Turbo Lightning. The TXP should be used on boats that have a lot of natural bow lift, like a Bullet, Allison, Hydrostream, Bumble Bee etc. Those boats have a pad and a step and naturally carry the bow with out a bow lifting prop. A TXP is designed to raise the stern slightly so it lifts the whole boat.

If your boat needs a lot of positive trim to get the bow lose then the Lightning or the Fusion 4 would be a better choice. The TXP will work and you might try going up some, as suggested. Since you're getting to the point that you're starting to show a rooster tail, that indicates the boat needs more bow lift. There will be a point that you need more height (X dimension) to gain rpm but you need less X dimension so the prop can lift the bow. Basically we're asking the prop to do something it's not designed to do.

Now, all that being said -- how many hours are on your motor?

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

Hi Dhadley, eninge hours are appr. 150h. I'm a bit disappointed that the Turbo reseller recommended me this prop after have giving him very detailed specs about boat and engine. I was originally asking the tech support at Precision Propeller for help but they redirected the request to Winrace Propeller A/s at www.winrace.no.
Ok, so you think a lightning would perform better than the Turbo 1? How about merc props? The boat weighs about 2700lbs with engine.

Anyone interested in a trade?

/Mattias

 

[Gammabusa]

Re: Dhadley, Walleyehed were you right after all?

Since you have a jack plate I would have tried to raise it until you loose water pressure, if you still dont get any more speed try another propeller, I have a Ballistic 21 and Raker 22 and 24, on my small 14 feet boat the ballistic is ****, it dont like lifting the engine and loose bite very early when trimming, I tried these three propellers on a Bayliner Mutiny 17 feet full of water with my Evinrude 140 V4(the boat came with the engine)and the ballistick was the best of them, it was mounted low with engine cavitation plate just abow bottom and I got it to 37 knots with the ballistic and only 33 and 30 with the Raker, these was to big for this setup but anyway the ballistic felt much better on this boat compared to the rakers, I weighted this boat/engine and it was exactly 1000 kilo(2210pound)....what I mean with this, well maybe ballistic is good propellers when boats dont have bow lift and mounted deep??

 

[walleyehed]

Re: Dhadley, Walleyehed were you right after all?

Don't remember for sure what either of us told you....?
I "can" say by looking at your boat design and the addition of a jackplate that you're going to get more lift in the area that might be pushing the bow back down slightly.
The trim sender is a variable that may cause incorrect readings on the gauge, and I think it would be best to trim by "feel" and RPM/Speed.
The TXP should stay hooked-up much higher than the Bullistic, but we also need to watch water pressure.
If I may ask...what did I or DH say originally? We need to know to figure out why we said what....does that make sense?

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

The TXP should stay hooked-up much higher than the Bullistic, but we also need to watch water pressure.
If I may ask...what did I or DH say originally? We need to know to figure out why we said what....does that make sense?

Yeah i forgot, here's the threads:
http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=40;gtid=1078825;gpid=1078832#gpid1078832
http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=40;gtid=1082557;gpid=1115117#gpid1115117
You suggested that the TXP was targeted for other hull designs, which seems to be correct. I should have chosed the T1 as i planned initially.. *sigh*

And yes, the TXP stays hooked-up much, much higher than the ballistic, the are not in the same league. My engine is pretty high now, and when on plane doing about 40knots, the TXP don't loose grip even if i trim out a lot. I have installed a Teleflex water pressure gauge that works very well, so i'm keeping an eye on the pressure.

BTW, there's a guy on ebay that has agreed to trade his 14x20 raker for my TXP, would this be the most stupid trade(for me) since Russia sold Alaska to the US? Don't know much about rakers. If i can't get the TXP to perfrom better at top end, do you have any suggested props that would the next logic prop? That would be a bow lifter, like T1, Mirage plus, Laser II, right?

Thank you guys,
Mattias

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

.what I mean with this, well maybe ballistic is good propellers when boats dont have bow lift and mounted deep??

Yeah, that has struck my mind too, my enigne -when fitted with a ballistic- was mounted low, AV-plate about 1cm above bottom. It vented easily when trimmed out and in sharp turns, but top end is still unbeaten, ok the TXP is only my third so there's a lot left to try...

 

[Gammabusa]

Re: Dhadley, Walleyehed were you right after all?

Hi again, my evinrude dealer here has sold two of these Nordkapp boats

http://www.nordkapp-boats.no/baat_noblesse.php

with 250 hp E-techs and they have a viper 21 inch one one of them, it goes 45-46 knots and the other one has a Raker 20 inch and same speed, they have no lift but I guess the hull is same type as your?

I think the Viper had som ventilating problems so they put on the Raker on the second boat so maybe the Raker is a good choise on your boat? just guessing....

These engines is now not mounted in same hight but I could speak with the dealer and find out what/why they did what they did?

Ronny

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

That would be kind of you Ronny. I have met a guy in another forum that offers me a Turbo 1 20P for the TXP, maybe that isn't a bad choice either. Given that both the ballistic and the TXP didn't reach 5500rpm, a one inch pitch decrease could be a good thing. Is it fair to say that if a TXP only reaches 5200rpm so would a T1 do too with the same pitch?

/Mattias

 

[Ron G]

Re: Dhadley, Walleyehed were you right after all?

No..... both props like to run at different hieghts or on my boat they did.have you tried raising it up first or even lowering it to see what happens you may want to play with it for a little bit before getting rid of the txp,its a shame you dont need a 25 turbo 2d

 

[Crownie2]

Re: Dhadley, Walleyehed were you right after all?

I was wondering - Yamaha has some pretty good props.

Are you in good enough with your dealer that he might let you try some?

Bob

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

No..... both props like to run at different hieghts or on my boat they did.have you tried raising it up first or even lowering it to see what happens you may want to play with it for a little bit before getting rid of the txp,its a shame you dont need a 25 turbo 2d

Yes, of course, i'm planning on a new test run tomorrow, if the weather allows. I'm gonna raise the engine 20mm and see how it works. I'm gonna keep raising until i can trim out so that the TXP lose its grip somewhere in the middle of the trim range, the only thing that happens now is that the engine noise is getting louder.

Bob, the local authorized Yamaha dealer is a pretty small shop, they only had a few ballistics. Of course they can get me one but they are expensive and i would like to trade my prop.

/Mattias

 

[Dhadley]

Re: Dhadley, Walleyehed were you right after all?

We're starting to compare apples to oranges. The TXP is not designed for the same thing as a Turbo I or II. Or a Raker. The T-Lightning might be compared to a Raker but that's not a fair comparison either (to the Raker).

Ronny has seen your style / type boat with a Viper and a Raker -- that tells us that that boat needs a bow lifting prop. The Turbo prop with the most bow lift is a Lightning or a Fusion 4. The TXP is an excellent prop when it's used on hulls it was designed for.

Ron G has done a lot of testing with a Turbo I (or II, can't remember) vs. the TXP and the results were fantasic but his boat (Bumble Bee) has a pad and a step and has natural bow lift. In his case the TXP was far better.

Rather than trade it off for something with less technology I'd try to go back to the Turbo dealer / distributor and see about trading for a Lightning or a Fusion.

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

Hi Dhadley, i understand what you are saying. A guy in Sweden offers me a Lightning 23", but i guess that would be way too hard to turn, another guy is offering me a Turbo 1 20" which probably would be a bit easy to turn(?).
With Lightning it still would be 21" pitch, with Fusion 4, 19" pitch?

Thank you all for helping me!

/Mattias

 

[Ron G]

Re: Dhadley, Walleyehed were you right after all?

Well said dale.i tested the turbo2 you dont need that one for your hull for sure.

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

Thanks for the advice Ron.
Dhadley, i have mailed the reseller that recommended the TXP in the first place, he will probably reply at monday. It will be interesting to hear what he has to say.

/Mattias

 

[realmasa]

Re: Dhadley, Walleyehed were you right after all?

I increased engine height with 20mm today and took a test run, which gave me 47.6knots@5500rpm, so now we're seeing some difference. I had about 15mm left on the jack plate, so i raised the engine max and took a second test run, this time i gained 100rpm to 5600rpm but i lost 1knot so i guess the previous setting is pretty much optimum for this prop on my boat.
At this height it gave an impressive rooster tail:

The reseller offered me to try a T1 14,25x21 which is probably what i will do.

And here's a pic showing the v-shaped hull:

/Mattias

 

[Tail_Gunner]

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 and 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..