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Prefered car motor drive ratio!

Prefered car motor drive ratio

  • 1.7to1

    Votes: 0 0.0%
  • 2to1

    Votes: 0 0.0%
  • 2.38to1

    Votes: 0 0.0%
  • 2.68to1

    Votes: 0 0.0%

  • Total voters
    0
  • Poll closed .

Waterthunder

Well-known member
OK this is for ALL the car motor guy's what ratio do you prefer. Or would like to have as an option in a belt drive!

1.7to1
2to1
2.38to1
2.68to1
 
I have run more car motors than aircraft motors. I chose the 2.68 because of your explanations and reasoning behind why you like them and how they are used. I have run a lot of DD Buicks and a whole ship load of BBC with CH3 belt drives on them. Even the big belt drive boats always left me feeling like WOW these things can run some dry ground, they are fast and powerful, but I know theres more to be tapped from them just by refining the ratios and RPM and not much else.

So, were I building a car motor boat right now, and if I had the cash to do it, I would look for a 2.68 ratio redrive.

Scotty
 
I've used a 2.68 for eight years on a few boats, learned a long time ago what a good ratio it is. Heck I can remember some guys used to hide the numbers on their box so ya couldn't see the gear ratio, it was a big secret back then.
 
if it were not for torque roll and cage limitation i would opt for more reduction beyond 2.68 and swing the largest prop i can althiugh i too agree with with dave here that there is a point of diminishing returns ( i even use a 3.75 ratio). anyways, i am on waterthunder's 2.68 campaign. i think at the moment and until proven inefficient, it is the best ratio especially with not much of a power beast engines.
 
I chose the 2.38,the 2.68 didn`t work with the blades I have,by that i mean that my buick makes it`s power below 5000 and by the time I got enough pitch in the blades to keep it there I was just slapping air.BUT,I do believe the 2.68 will work best hands down with the superwide blades.
 
I've been running a K-way (think it's 2.08:1) for ??? now. Back then, that was the highest ratio there was. Worked great with the 80" 6-blade warp drive I'm currently running. I've always liked twisting up a small block to get the most out of it. But, It seems like these newer props work more efficiently at a lower rpm. I think if was to repower a new boat and go with a different prop set-up, I would lean towards the 2.6:1 ratio.
 
i would have liked to know what people actually run than what they think they would like to run, i doubt if any one here had a 69 ss camaro 427 hipo with a muncie rock crusher 4 speed would drive down the freeway in second gear, my prop is designed to make max thrust at around 2250 my engine makes max tq at 4800 it makes max hp at 5200 , 5200 devided by 2. 30 equals 2260.86 if igo to a 268 only two things well happen my prop rpms are gowing down a lot or my rpms are going out of my target range, now im left with one option go to the superwide senich design prop because they " claim " the same push at 1800rpms witch puts me right back where i was , i have not seen any bonified test on this sight that makes me belive that the 268 will out perform any thing else its all smoke and mirrors an if it was true you woundnt need waterthunder hp, i know as an ee racer and a airboater im not gonna pigion hole myself into any popular opinion i find it very limiting, because every body tha reading tis thread there is more than one way to skin a cat, and if ya dont think so you aint been around long enough i fogot to say my prop is pitched to the point if you twisted it any more pitch it would not be in its design parameters
 
well, i got a 238:1 on my GTO and she is pretty heavy but I am very happy with all around performance. I think the 268:1 might be better om with the new super wide blades. What do you think Thunder?
 
WELL HERE MY DEAL ! HAD A 238 WITH 2.3 80 INCH THREE BLADE AT 25 PITCH WITH A MILD 500 TURN 4800 RPMS DID REAL GOOD ! GOT SOME 80 INCH THREE BLADE SUPERWIDES WITH THE 238 KILL MY MOTOR BACK TO 4100 AT PITCH TWO BUT BLEW PRETTY HARD AT THE SLOWER PROP SPEED ! WENT TO 2.68 BOX WENT BACK TO 4200 AT THREE PITCH ! SUPERWIDES BLOWS SO MUCH DIFFERENT THAN THE 2.3 BLADES !THEY COME IN STRONGER FASTER THAN THE 2.3 !I RUN ABOUT 4600 AT 2 1/2 GIVE OR TAKE !SORT LIKE A BAD DIRT BIKE !ITS JUST THERE !WHEN YOU NEED IT ! ! :shock: IT S A BLADE BOX COMBO WITH ME !THREE THINGS THAT ARE A PLUS ! MORE PROP LIFE !LESS STRAIN ON ENGINE . AND THE HUSH DEAL !
 
Fatboy just made the point that's often overlooked here in my opinion ....... hush. If you've got the cage for the big blades then that means you won't have to turn em as fast to do the same work you're doing right now. That means less tip speed, which equals Quiet.

I want a Lightning belt for my boat because I like belt drives (quieter, dampen harmonics, reliable) because I can drop a lot of weight over what I'm running now, and pick up some reduction which will let me go to a bigger blade that will still fit my cage, but let me turn it slower.
More snap and push, no major re-rig, and quieter too. Works for me !

olf
 
I think you should match your motor and gear box, you can get the end result with a few combinations considering HP prop size and what you want to do. How does a WW maximus compare with thrust to a SW? I can see the benefit of less noise at lower RPM and I think that is good for those who complain about it, and I guess you can pitch the prop to give you the RPM's to match your engine's maximum tourqe output when using the 2:68 with a SW. I want maximum push for running dry, not to just go fast. The simple equation would be max torque of motor 5200 rpm than go 2:38 to run WW designed to spin 2200. But, if I can get more push with the SW and 2:68 and set pitch to achieve maximum tourqe from motor, then I would go that route.
I think the combos both can achieve each props max RPM but the question is
how fast can you get the prop to max RPM. If 2 boats side by side are running a 2:68 and a SW it comes down to who can get it to max faster, one prop pushes no harder than another if they are the same. Anyway thats my 2 cent worth and when someone finds out which prop actually gives the most thrust let me know, that way I can decide :D
 
It ALL comes down to prop choice and torque curve....Simple....Oh yeah, and that means if you chose the right prop for your boat. If brand "Y" prop makes x amount of push at 2600 and brand "Z" makes equal amount of push at 1900 I kinda "think" that would effect ratio choice. Now if brand "F" engine makes x amount of torque at 4800 and brand "W" engine makes x amount at 5600 I would think that plays a part as well........Or am I the only one not seeing the forest for the trees?

Felber
 
Felber, you are a complicated man. Let's just hang some kind of a prop on the bit*h and just go for a ride ....... :lol:
The beer is on me.

olf
 
felber i know exactly what your saying you can achive the same thrust several differant ways the main thing that changes is the sound
 
I'm running the 2.37 to 1 and am pretty happy with it , I've never run a boat with a 2.68 but have driven a couple of the 2.12 to 1. Hopeing some day to try a 2.68 but at what they cost and my bad habit of BLOWING UP motors, I'm stuck with what I got.
NOW IFIN SOMEONE WOULD OF TOLD ME THE SOUND DIFFERENCE BETWEEN THE NEW WIDER GEARED BOX'S I WOULD OF SPENT THE EXTRA MONEY ON THAT ONE, but no had to save that $700 and now I just live with the RATTLE BOX FROM HELL.
 
Thunder,I agree totally,Like I said the 2.68 would work best hands down with the super wides. NOW,if the wife lets me get the R,or the S blades,and I can find another 2.68 I`ll be good ta go :D What I`m trying to say is the 2.68 would be the best ratio for the bigger blades. And if ww would make em he would sell the sh@t out of em.
By the way,witch blades would work best for me,in your opinion,with the 2.38 narrow gear hard drive rotator,S or R?
 
well I know from videos my brother took of me running my boat I have very little to no prop noise all you can hear it the sweet sound of that WaterThunder LS2 pumping out lots of HP and the new super wide gear box is quit as well no more clanking and banging
 
Duece

Thunder and I tried the 2 blade set up on my boat and we came up with the same thing it did not cruse well the three blade set up made a big difference
 
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