Lightened Flywheel - raised limiter RESULTS!!!

[Myron]

from my experiences, starting at 1/8 below to even is good and safe, I have found that most Allisons run the best at even to about 1/4 above, I have never tried 1'' or higher because I have never needed to, just remember no 2 props are the same and the same with gearcases, and the bottoms of the hulls for that matter. I have always driven by seat of the pants, that is how I was taught, to drive close to 100 or above you really need to understand what is going on beneath you, each little bump of the trim at those speeds has an effect. When an Allison is set up correctly, it will take a good set and run as smooth as silk. Just all be careful.

 

[froggy]

BadBait and Myron +1!!!!

Guidelines are just that and a starting point only. ABotes set up differently than BBotes and both are different from air entrapment botes. I usually start with the propshaft height at the split and then prepare to go either way. We don't run many through hubs at all or I'd have to start lower with them.

Through hubs generally generate a bunch of tail lift at speed. They are harder to holeshot when only limited HP is available. They seem to be a good place to go to on certain fast hulls that can use high speed tail lift with mid speed bow lift. Four blade versions of three blade props have more lift (either bow or stern depending on type of prop). They run more efficiently at the same height the three blade versions run at, but I've found one can go higher on the four blade because it will lift more than the three blade variant. Three blade props are GENERALLY faster than four blade props with the exception of the new, big displacement, high torque engines. A Four blade prop will generally carry more load than it's three blade variant. Cleavers have bunches of tail lift but they leave the bow alone so one has a tendency to overtrim with a V bottom Etc., etc., etc. There are endless permutations and no absolutes.

All I can say is each minute spent perfecting setup will result in hours of enjoyment when the "sweetspot (s)" is found.

froggy

 

[badbait]

Myron, when people talk about running an inch or more above the pad I think you will find that for different reasons they have modified the lip or the guy that had the boat before them changed the lip. When I'm going fishing and know I will be carrying a bigger load such as passengers. I run an inch above and when running top end numbers I start at an inch above and work up up to 1 3/8 for most round ear props. My horn goes off if I run the through hub Hydromotive any higher than an inch above. They lift more than any other prop I have. It would be a favorite if it wasn't so slow out of the hole.

 

[Myron]

I know what your saying, I just have never seen it necesary to run that high, I set up an SS2000 with a 280 that ran well into the teens and it was best at even. On my 2003 with my 280 I have ran 106 with the stock pad at 1/8 above. Just hope everyone is careful in there pursuit of speed, I myself really don't care for running top end anymore,unfortuately I have seen to bad things happen, even had a friend get killed years ago, not in an Allison, but it doesn't matter anything can break or go wrong.

 

[fishnfireman]

I know what your saying, I just have never seen it necesary to run that high, I.

Same here..But I run more load than most.

I broke 100 with my 2003/280 running an RE3--- just me and all my fishing gear....never raised it above pad !! and that was at 1300 ft elevation

 

[badbait]

I respect your thoughts and I'm not going to argue with anything you guys are saying. But I will give you my theory on this subject and that is you cannot compare the safety of two setups based on propshaft height alone. That would be like comparing apples and oranges. How do Bullets get away with running up to 2" above the pad 1.25 is very conservative on a Bullet. There is a very simple reason that I mentioned in the above post. It's called size of the lip.

 

[fishnfireman]

I will give you my theory on this subject and that is you cannot compare the safety of two setups based on propshaft height alone.
.

Well said !

 

[suicidealli]

JMO i have ran more props then most.... there is no dought you have to change setup to each prop............ the chopper is the scariest with the motor high............. IMO
if you are going to run them on the ragged edge..... i have made a couple of bat turns... not real bad ones. only in the 80's.... have been well over a 100.. the chopper has so much more bow lift than a et... the trim gauge will read lower, but the bow is higher from the prop lifting it..... becareful guys!!!!!!!!!!!

roy

 

[GFinch]

"the chopper has so much more bow lift than a et... the trim gauge will read lower, but the bow is higher from the prop lifting it..... becareful guys!!!!!!!!!!!"

Thats a real good tid bit of information! Thank you...

 

[chad202]

The lip modified may or may not be any faster but it definetly much safer.

 

[catfish123]

Chad..........is that because the altered, reduced lip height lifts the back of the boat less, so that blowout isn't as likely???

 

[chad202]

IMO, that is correct. It can happen even if you just running wot. Another factor is if you run boats long enough, there will come a time when you're making topend runs and for some reason or another, you'll have to get out the throttle faster than you normally do and we all know what happens next. With the lip gone, it's a non issue.

 

[catfish123]

Chad.......can you post or pm me your phone number.......I'd like to call you............thanks, Bob

 

[chad202]

you have PM.

 

[chad202]

It was good talking to ya Bob. Everything should be clear as mud now.lol

 

[catfish123]

Great talking to you too.........I really appreciate all the time you took trying to explain everything to the "old dummy"............LOL

 

[props4u2]

The lip modified may or may not be any faster but it definetly much safer.

Chad, I don't agree with you there. More depends on weight placement and set-up than lip or no lip. JMO


Lee

 

[chad202]

I hear ya Lee. That's just been my experience on my boat with moving my batteries and onboard charger everywhere in the rear deck. I don't know of many allisons that can pull the kill switch at 104 and not be looking the other way. I can. Every boat is different so as you know, test, test, test. JMO

 

[suicidealli]

i have heard with the lip is safer from blow out!!!!!!!!!!!!! the lip is forcing the bow of the boat down... keeping it form blowing out!!!!!!!!!!!! on the other hand with little lip or no lip you use less trim to achieve the same angle, because the lip is not fighting against your trim..... as far as bat turns i would think it is safer with out the lip.. when you chop the throtle and you have the lip it is going to force the bow down, and we know what happens next.... without the lip the bow is not going to be forced down.... "should" not bat turn as easy!!!!!!!!!!!!!!!
this is JMO.. i have the factory lip on mine still.. i know it fights me on triming the boat, and i could get an extra mph or two... i'm going to take a little off over the winter...

so what chad is saying is true about bat turns, and faster... IMO
boat without a lip at all. the boat will trim higher and could get you in more trouble..
not sure about safer when running on the big end.......
when you have extra trim available...... i'm going to use it!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
also you can run the motor a little higher, because the water coming off the pad is not being forced downward from the lip, which = more speed = more danger......

it is a fine line.......... i think the heavier bass rigs it has a little less impact.. the ss is more drastic, and drag even more so....


now i really have you guys thinking..LOL or confused!!!!!!!!!!!!!!!!

roy

 

[catfish123]

I'll be glad to add to the confusion........as far as the relationship of the top of the propeller blade to the top of the water it is running through. If the lip is on and the water is therefore being forced down and you have the propshaft even with the pad, the top of the blade is where it is in relationship to the top of the water it is going through. If the lip is removed and the water is therefore not being forced down and the propshaft now because of this can be run 1" higher, isn't the relationship to the top of the water and the top of the propeller blades still the same? I know what I mean, not sure anyone else will...........LOL.........and if all this is true, and I'm not saying that it is, how come guys with Bullets who run 1-2 inches above the pad crack more blades than we do on our Allisons if in fact the relationship of the top of the propeller blades to the top of the water is the same in both cases?

In addition, I think the lip is not "forcing the bow down, keeping it from blowing out", but it is forcing the back of the boat up, maybe encouraging blowout of the prop do to it being elevated higher.