Enough torque

[BirdFanatic]

Will my dune buggy have enough torque to go to the dunes at Pismo beach? It was estimated that without the torque converter and 24 inch tires it has roughly a 5.5 gear ratio with the current 31 hp motor . Frame weighs roughly 650 pounds with me in it .

 

[OzFab]

Without a torque converter, it'll have trouble moving downhill...

Even with a torque converter, 5.5 may be a little steep...

 

[BirdFanatic]

Without a torque converter, it'll have trouble moving downhill...

Even with a torque converter, 5.5 may be a little steep...

it has dual jackshaft's the torque converter goes to two jack shafts then goes into the tranny (Reverse neutral drive box )

 

[landuse]

I think I will have to go with Tony on this one.

it has dual jackshaft's the torque converter goes to two jack shafts then goes into the tranny (Reverse neutral drive box )

This isn't going to matter. What matters is the gear ratio

 

[BirdFanatic]

I think I will have to go with Tony on this one.



This isn't going to matter. What matters is the gear ratio

oh i thought a torque converter made the gear ratio 2 to 1 so i thought the final drive ratio was around 10 .Never knew that you learn new things every day

 

[landuse]

oh i thought a torque converter made the gear ratio 2 to 1 so i thought the final drive ratio was around 10 .Never knew that you learn new things every day

That will only happen if you have a 2:1 reduction gearbox

 

[BirdFanatic]

That will only happen if you have a 2:1 reduction gearbox

So how does a torque converter work converting speed to torque right ? less fast more torque

 

[landuse]

So how does a torque converter work converting speed to torque right ? less fast more torque

I don't have the time at the moment to explain how a TC works, but you should have a pretty good idea by now.

Google it and have a read

 

[OzFab]

Watch this...

https://www.youtube.com/watch?v=nVVFd-lIfGU

Take note of the position of the belt on the driver clutch (on the engine) at idle, then watch what happens when engine RPM increases...

Now watch it again but, this time, pay attention to the driven clutch...

Once you've done that, we'll talk more...

 

[BirdFanatic]

Watch this...

https://www.youtube.com/watch?v=nVVFd-lIfGU

Take note of the position of the belt on the driver clutch (on the engine) at idle, then watch what happens when engine RPM increases...

Now watch it again but, this time, pay attention to the driven clutch...

Once you've done that, we'll talk more...

ok so it changes like changing a sprocket does one side becomes bigger while one side becomes smaller and in the middle there almost both the same .

 

[afremont]

@Fabroman - Ultimately, what kind of ratios do you end up having. I know it depends somewhat upon belt width and condition some. In that example, it appears that it starts off somewhere around 3:1 and progresses to something around 1:1.5 or so. Does that sound about right. I never see any numbers stated anywhere. In that example, it didn't appear that the driven got expanded very much because the drive side already had the belt as far as it could take it. Was that example a little loose?

 

[OzFab]

ok so it changes like changing a sprocket does one side becomes bigger while one side becomes smaller and in the middle there almost both the same .

Something like that, pay attention the what I say below, see if it helps explain a little better...

@Fabroman - Ultimately, what kind of ratios do you end up having. I know it depends somewhat upon belt width and condition some. In that example, it appears that it starts off somewhere around 3:1 and progresses to something around 1:1.5 or so. Does that sound about right. I never see any numbers stated anywhere. In that example, it didn't appear that the driven got expanded very much because the drive side already had the belt as far as it could take it. Was that example a little loose?

First off, I have no hands on experience with torque converters so, the following is information collected from this forum as well as othere onling sources...

IIRC, the starting ratio is somewhere around 2.7:1-3.2:1, depending on the combination of clutches used (eg: driven clutches are available in different sizes)...

The top speed ratio of a TAV2 (all inclusive single unit) is 0.9:1 where other 2 piece units are usually 1:1

It's possible (but, not likely) that the belt on this unit is a tad big but, also remember, there's no load on it, the wheels are raised, the whole unit will act differently under load...

 

[BirdFanatic]

buggy is acting weird when i take the air filter off it goes way faster but you have to use the choke alot when i put the airfilter back on it starts without choke but bogs out and doesnt go very fast .I have pulled the carb open 4 times my brother has pulled it open 3 and we have pulled everything apart the butterflys and all and cleaned everything.But still same problem its driving me nuts.Does anyone have any clue as to what it could be

 

[machinist@large]

buggy is acting weird when i take the air filter off it goes way faster but you have to use the choke alot when i put the airfilter back on it starts without choke but bogs out and doesnt go very fast .I have pulled the carb open 4 times my brother has pulled it open 3 and we have pulled everything apart the butterflys and all and cleaned everything.But still same problem its driving me nuts.Does anyone have any clue as to what it could be

Based on this post, it sounds like its running rich. Have you done a plug read yet?

 

[Joe-405]

When you take a air filter off it runs leaner. With filter on a engine will run richer. Same goes for baffles in exhaust no baffle equals leaner and with baffles equals richer.


When you add more volume of air it will always run leaner.

 

[Poboy kartman]

.I have pulled the carb open 4 times my brother has pulled it open 3

Solution isn't coming to me.....but a possible cause is.....

 

[BirdFanatic]

How do i eliminate the problem and do it 50% 50% the plugs where good when we pulled them out ill pull them again and see .PLug is black like charcoal Im using a 6 psi (Electric fuel pump) the old fuel pump broke (Pulse pump) .My dad says its getting to much fuel when we pull of the air filter it gets all the air it needs so it runs like a bat outta he** . Put the filter back on and it gets to much he said change the fuel line down to micro from the gas tank to the fuel pump and then put a T on one end and a T on the other connect mirco line to both sides and make a system that keeps the pressure down . He said it is to much pressure and is siphoning fuel out of the bowl .

 

[machinist@large]

How do i eliminate the problem and do it 50% 50% the plugs where good when we pulled them out ill pull them again and see .PLug is black like charcoal Im using a 6 psi (Electric fuel pump) the old fuel pump broke (Pulse pump) .My dad says its getting to much fuel when we pull of the air filter it gets all the air it needs so it runs like a bat outta he** . Put the filter back on and it gets to much he said change the fuel line down to micro from the gas tank to the fuel pump and then put a T on one end and a T on the other connect mirco line to both sides and make a system that keeps the pressure down . He said it is to much pressure and is siphoning fuel out of the bowl .

In the previous post I said it sounded like it was running rich; if you added an electric fuel pump that forces that much pressure over atmospheric without making any changes to the engine?

Guess what, you get what you get. If you could please explain in detail why everything you did should have worked (but patently didn't) we might be able to help you sort it out.

And the above post doesn't count as an explanation, as its almost unreadable.

 

[BirdFanatic]

In the previous post I said it sounded like it was running rich; if you added an electric fuel pump that forces that much pressure over atmospheric without making any changes to the engine?

Guess what, you get what you get. If you could please explain in detail why everything you did should have worked (but patently didn't) we might be able to help you sort it out.

And the above post doesn't count as an explanation, as its almost unreadable.

Only thing i have done (Added a fuel pump ) looking for ways to keep the 30$ fuel pump and lower the pressure at the same time .

 

[machinist@large]

Only thing i have done (Added a fuel pump ) looking for ways to keep the 30$ fuel pump and lower the pressure at the same time .

You're not getting it. You have a problem, caused by whatever. Rather than actually trying to begin to understand the problem (the first step in trying to actually fix it), you've thrown who knows what by way of part's at it, all the while demanding help without giving anyone here any details on what you've been doing.

For the record, I'm a Machinist for a living. And I know for a fact that there's way more than one word in the dictionary between machinist and MINDREADER.

Feel free to actually make the count.