Hydromotive first run

[Jay Martin]

Jay,

Not sure how you are coming up with 5% slip. 6400*28*.5347*.0009469= 90.73mph with 0% slip.

90.37*.95= 86.1mph with 5% slip.

Again, not trying to argue with anyone, and I know slip numbers are a reference, but numbers don't lie.

It is IMPOSSIBLE for these boats to run at 0% slip.

Nothing at all against what you said, but some guys on here must have real special water that they boat in or some big advantage that no one else has, because the speeds mentioned with a certain pitch prop, rpm, and gear ratio are not even in the ballpark.

Check this out...Todd said "do not add 1 pitch for cup on his prop" I went back and re-calculated the 28 pitch, now I'm at 1%....:shock:....

 

[xb03fs]

all that really matters is that you like how they run...most modern props are variable pitch and throw in some cupping and blade shape and it is a bit of black magic. The stamped pitch can be no more than an average at best, if it runs well it runs well doens't matter what the pitch is

 

[catfish123]

I believe you may mean progressive pitch instead of variable pitch?

 

[TBuck2003]

Have seen a lot of OT's in the 3-5% range. Not a lot in the 1-3% range. Lets just be happy our boats run good!!!! Everyone have a cocktail and go play in the snow!!! Gotta go snowblow now. Have a good weekend fellas...


TBuck

 

[xb03fs]

I believe you may mean progressive pitch instead of variable pitch?

you are right progressive is what I meant

 

[xb03]

Have seen a lot of OT's in the 3-5% range. Not a lot in the 1-3% range. Lets just be happy our boats run good!!!! Everyone have a cocktail and go play in the snow!!!

So, your saying it's possible! :very happy

Anyone that feels like :furious needs to :relax: Winter is almost over lets be happy.

 

[whipper]

Prop slip is NOT by itself a variable. Prop slip is a result of all the influences of all the variables, therefore, it becomes a measurement of efficiency.

Whipper... with all do respect, I have never seen you disagree with anything posted in here whether it was based on facts or not.

Thats because I agree to disagree. Ok ya got me. Hows this. I dont agree with anyone its all a load of bull and if anyone thinks they can run 90 with a 26 pitch prop on an Allison with only 6750 rpm is a complete and utter liar!!:wink

I could disagree but i dont know? I never saw it and I cant call anyone out unless I saw it. So basically Im giving anyone the bennifit of the doubt because all things are possable. As you have said maybe the tachs out I dont know? So lets just say its as it is and time will tell all as it always does. I never want to start a pissing match as i dont do anger very well.unch So Ill always try and see the bright side and try and figure out as every one has been trying to do how its possable rather than hows its not. Oh thats also why I do these smily faces. They make me happy damit.:big grin

Hears a point. If some guy came on hear and said they ran 122 with a 29 pitch Mazco on an 02 standard layup tournament hull or 129mph today what would ya say? Both these have been documented and over 130mph for that matter. Theres no one else hardley even close to these numbers with the same prop and motor. So I always figure theres the exception to every rule.
A video with no breaks in the tape and GPS always in sight is the best way to prove it. So XB03 how about it. Borrow beg or steel a video camera and try to repete this and show us what ya got. Im sure everyone would love to see 88-90 with a 26 pitch prop on an 03. You have nothing to prove but it would be cool to watch a new vid anyway. There hasnt been to many latley to watch.

 

[xb03]

A video with no breaks in the tape and GPS always in sight is the best way to prove it. So XB03 how about it. Borrow beg or steel a video camera and try to repete this and show us what ya got. Im sure everyone would love to see 88-90 with a 26 pitch prop on an 03. You have nothing to prove but it would be cool to watch a new vid anyway. There hasnt been to many latley to watch.

No problem James about the video, I had a few from that day I need to look throught them. I was planning on getting yall a good one when the weather is nicer, and I'll be solo this time! Even when my buddy said I hit 92 "with current" I didn't believe him lol but two separate gps and their recalls don't lie.

 

[2003225X]

Once again fellas... No one is saying you are not telling the truth about the speed of the boat. That is not in debate here at all.

For you to run those speeds with a TRUE 26 pitch one of the following things needs to be false... A 6750 limiter, a much different great ratio than 1.87, or it is MORE than a 26 pitch.

Todd said he has seen them in the 3-5% slip area, so no he is not saying your speed is possible. For you to be running that speed with a true 26 pitch and 1.87 gear ratio you would have to be turning 7300+ rpms.

You would have to be running NEGATIVE slip to get that speed with the factors you mentioned which is not possible. Even with 1.75 gears it would be stretching it to get that.

I would try to get an accurate tach reading that you know for sure is right.

 

[Jay Martin]

I bet this is the longest thread on Allison Owners site has ever had...

Sorry!!! Had to change the subject...:beer:...:big grin:big grin.....

 

[2003225X]

Jay,

You are probably right! Probably would have only taken 4 pages if folks would know an Allison can't run negative slip!!!

 

[Jay Martin]

I look at slip numbers all the time and as for a bass boat or lets say a v-hull like the Allison there is no other boat that can match or beat it from what I've seen.
I can honestly say when I bought my Allison I removed the engine from my old boat and re-installed on the Ally, Fuel mileage increased from 3 mpg to 4 mpg and picked up 7 mph over the other hull..

 

[xb03]

1278 views, 92 replies in only seven days could be a record! :blah blah blah

 

[silverbullet02]

93

 

[2003225X]

I agree, Allisons are very efficient boats and run excellent.

They are addicting, there is no doubt. The problem is you always want to go faster and faster.

I would love to have a 280 on the back of mine... who knows maybe one day. :very happy

 

[Bobalouie]

Prop slip is NOT by itself a variable. Prop slip is a result of all the influences of all the variables, therefore, it becomes a measurement of efficiency.

Correct, Prop slip as calculated does account for all the variables and is a measurement of efficiency. However, the two words, Prop + Slip leads people to think they are measuring the efficiency of a propeller. That is not true. That is what I was wanting to clarify.

 

[catfish123]

Yep................we probably could have saved at least 5 pages of all this if Jay would have just understood that you don't add an inch of pitch for cup in a prop when the prop has no cup........... but finally Todd came in and got him straightened out---- Who knows, maybe the current where the guy runs is 10+ mph, he had a 15 mph tail wind, his gears are 1.75's instead of 1.86's, and his tach is off by 500-600 rpm's............that would just probably explain it all. We could have continued for awhile longer :beating dead horse or:argue but I think the best suggestion was to :relax: and hope for an early spring thaw. It's like some other things in life..........it's all good, some's just better than others!

 

[xb03]

If you have an xr-2002 same hp, lu, and prop @6500rpms, and a 21 xb same hp, lu, and prop @6500rpms. Do the boats run the exact same speed or is the xr faster?

 

[ROBERT CROSS]

"but I think the best suggestion was to and hope for an early spring thaw. It's like some other things in life..........it's all good, some's just better than others!
__________________
Rookie Pad Sander "

Well I'm ready....got my new 26 Q4 OT, Erie hasn't frozen over this year and Spring can't come soon enough. :at the bar

Bob

 

[Jay Martin]

Yep................we probably could have saved at least 5 pages of all this if Jay would have just understood that you don't add an inch of pitch for cup in a prop when the prop has no cup........... but finally Todd came in and got him straightened out---- Who knows, maybe the current where the guy runs is 10+ mph, he had a 15 mph tail wind, his gears are 1.75's instead of 1.86's, and his tach is off by 500-600 rpm's............that would just probably explain it all. We could have continued for awhile longer :beating dead horse or:argue but I think the best suggestion was to :relax: and hope for an early spring thaw. It's like some other things in life..........it's all good, some's just better than others!

I was hoping we was finished with this BUT, My Hydromotive O/T's do have trailing edge cup, Todd knows his prop better than anyone so I'm just taking him for his word.

For 17 years of myself being in the Propeller business I have always added 1 pitch for cup. Theres no misunderstanding of propellers on my part.