Front to rear gear ratios for pulling competition.

Supershafts said:
At the begining you should very well be able to plant and move since the weight is at the back, i would want to plant and get it moving as quickly as possible before relying on wheel speed




Actually that is done because you don't want drag, you want it to roll free or we can call it bind, so the outside tire goes around the long way and covers more ground so that stagger is done purposely to remove all possibility of drag, the axle is locked there is no diff, like a pt case, if one end is faster then the other but not covering the same ground differently it's drag or bind, don't want that in a turn it creates slow.
You also run a heavier spring on the inside to keep that tire planted and weight jack. I don't and have not seen any type of countering the effects of the sled and transfer the weight

Now since you aren't turning and the front of the truck isn't doing anything different than the back other than being unloaded i can't see how forcing a unequal transfer on the same frame is helping.

The way i see it, you want to definitely try and plant it off the start and get it moving without wheel spin when it's at it's lightest.


Also saying 4.11 and 4.10 is the same as 4.9 and 4.5 is way way off

A factory truck with 4.11 and 4.10 is due to which way the teeth are designed to be the quietest and packaging of it in that diff , but that .01 isn't ANYTHING like .5 to .9 but also you have never ever seen a factory truck come with 4.9 rear and 4.5 front or 4.5 rear and 4.9 front, that just won't work at all.

To show how bad bind is, take a pt case which most of us have and we have 4.1 to 4.1 and go in the street and just turn the wheel full lock, remove your foot from the brake and see what happens.
Do the same in dirt

Hit the gas in both cases on both surfaces, dirt is more forgiving, but the bind and power being used to overcome are still there.
So if you had a 35" tire at both ends and aired down to 10 lbs so you can increase your area, you then could rely on power and gearing to get you up to speed quickly while the weight is off.

So as you go down the track and the weight is added and the drag becomes harder, now the truck is having to overcome that and the odd gearing it has front to back as that pressure is increased, you don't feel it because the wheels have no traction, but there is a drag present.

The same way you have power being lost due to just a simple design, there is a power consumption there.
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Build a truck and prove everyone wrong.
 
I don't hardly ever jump in on these because I am a rookie in the truck pulling world. But sprint car racing I know a little more about. Disturbed is correct stagger is used to help turn a car better. It does decrease drag, if you choose to look at it that way. There is obviously such a thing as to much stagger, if it was just used to decrease drag, then you would want as much as you can get. Not always the case. And you don't ALWAYS run a stiffer spring on the left rear. Rebound is typically used to try to keep the weight on the left rear. Now on a winged sprint the will almost always run a stiffer on the LR, but that is do to the wing and body roll. Sorry for rambling.

Sent from my DROID RAZR HD using Tapatalk
 
I'm no expert but this fella sounds like an engineer and I've only known a few engineers with any real world useful knowledge
 
DISTURBED said:
We are discussing it. Your numbers have nothing to do with sled pulling. Nobody runs a huge tire out back and a small tire in the front and try and get a gear to make them equal. What we do though is run a faster gear in the front or bigger tire in the front and it works. I don't know what kind of back ground you have in motorsports but it does work and has been proven numerous times. They were doing this back in the 80's with cut tires and alky engines. This is nothing new.
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So what changed your mind and opinion Jeremy on this all since my "tube chassis build" post back in 2010. At the time you went into a big debate with me on why running 5:29's in my rear 106 and 5:13's in my D80 front was a terrible idea and would never work and would basically make the front end go into orbit? not to put you down, but it seems like everything you are stating now is exactly what I was trying to tell you 4 years ago!

Ryan
 
RyanB said:
So what changed your mind and opinion Jeremy on this all since my "tube chassis build" post back in 2010. At the time you went into a big debate with me on why running 5:29's in my rear 106 and 5:13's in my D80 front was a terrible idea and would never work and would basically make the front end go into orbit? not to put you down, but it seems like everything you are stating now is exactly what I was trying to tell you 4 years ago!

Ryan
Click to expand...

Nothing. That was a discussion about running a over drive with cepecks at 3% difference. Cepeck is a whole another animal vs a street tire. Stuff you can push and get away with on street tires don't always work on cuts. If you over drive the front to much with a cut tire it will chatter the front axle
 
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Now why would it chatter the front ?


So i watched bad habit have something break, something at the back broke ?
 
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DISTURBED said:
To your comment about turning the wheels and seeing what the truck does. The reason it binds is because the rear is try to go forward and the front is now not on the same plane and is not moving the same distance in the same direction. So the front travel is shorter then the rear. so it spins the rear tires


Oh and we make way more power then we can harness and this is done by people way smarter then you and your kindergarten theories!
Click to expand...

Now you see you're being like a little kid here, my kindergarten theories can build 3000hp, i can do many things that are far from kindergarten.

You know what my kindergarten mind has learned, discuss and don't act all it's this way and thats it.

If i had that in a pulling truck i'd be looking to see how to get it to counter the sled and plant the tires, not offset the gearing and create a obstacle for hp to be lost.

Now in a simple perfectly geared truck a simple turn of the steering axle on the same plane creates STOPPING forward motion, which maens you need to increase power to overcome that.
You truly believe that having even more offset front to rear wouldn't be causing power to be lost having to overcome a designed in bind.

How much weight are the front and rear axles seeing during the pull, is that even known ?

.
 
3000hp in what? Surely nothing on dirt.

I'm done discussing this with an idiot.
 
No not on dirt, but hp is hp, doesn't matter where its used, it's how it's used and where it's made to work.

awesome, always result to insults, just like kindergarten.
 
Supershafts said:
No not on dirt, but hp is hp, doesn't matter where its used, it's how it's used and where it's made to work.

awesome, always result to insults, just like kindergarten.
Click to expand...

The problem is you can't understand how it works and your number just dont allow it! Well guess where you can stick your numbers and your lack of experience on dirt.

How many 4wd drives have you ever built?

And what works on asphalt doesn't work on dirt! How many off road trucks have you ever seen on a slick?
 
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If all that power is kept in a RWD, pushing the front is a given and easy to comprehend!! LOL
 
Supershafts said:
If i had that in a pulling truck i'd be looking to see how to get it to counter the sled and plant the tires, not offset the gearing and create a obstacle for hp to be lost.

How much weight are the front and rear axles seeing during the pull, is that even known ?

.
Click to expand...
What everyone has been saying is that this has been done by many going back 30 years, and by more than a few points champions. I don't know how much truck pulling you have been around, but watch some other videos and just watch how the front of the truck lifts at it begins to move the sled. This results in a loss of traction in the front compared to the back. The SMFWDs in the video above are set up a lot different than street class trucks with factory suspension, watch a few videos of them. There are also so many different ideas and concepts to suspension, hitch, and weight design that it will boggle your mind if you really get into it. I have ran many a FBD playing with different designs.

You asked about the forces (weight) on the front versus rear, and yes there are those that have ran numbers to try and figure it out. They are the ones that try everything to get the maximum traction out of both rear ends. Do you also know that no one truck pulling runs the same air pressure front and back? This is also for the same reason as mismatched gears, to try to get as much traction in the front. When doing your calculations on ratios, if you have a 35" tire with 25 psi in the front and the same tire with 50psi in the rear, what is the difference in effective radius (thus changing effective gear rations correct)? What about that difference when you're going down the track at full load? Same for 60" weight boxes and the percentage rule for different wheelbases, hitch distance from centerline of rear axle, reese hitch versus trick hitch, and so on....

What we're all saying is that when considering how someone sets up a truck, there really isn't a "perfect" design. Just because it works on paper, doesn't mean it works on the track. And yes, in my pulling truck I ran mismatched gears and have also ran mismatched tire sizes. What it comes down to is you gotta get on the track and see what works, or trust those that have been there!! :Cheer:
 
PSUCE said:
What everyone has been saying is that this has been done by many going back 30 years, and by more than a few points champions. I don't know how much truck pulling you have been around, but watch some other videos and just watch how the front of the truck lifts at it begins to move the sled. This results in a loss of traction in the front compared to the back. The SMFWDs in the video above are set up a lot different than street class trucks with factory suspension, watch a few videos of them. There are also so many different ideas and concepts to suspension, hitch, and weight design that it will boggle your mind if you really get into it. I have ran many a FBD playing with different designs.

You asked about the forces (weight) on the front versus rear, and yes there are those that have ran numbers to try and figure it out. They are the ones that try everything to get the maximum traction out of both rear ends. Do you also know that no one truck pulling runs the same air pressure front and back? This is also for the same reason as mismatched gears, to try to get as much traction in the front. When doing your calculations on ratios, if you have a 35" tire with 25 psi in the front and the same tire with 50psi in the rear, what is the difference in effective radius (thus changing effective gear rations correct)? What about that difference when you're going down the track at full load? Same for 60" weight boxes and the percentage rule for different wheelbases, hitch distance from centerline of rear axle, reese hitch versus trick hitch, and so on....

What we're all saying is that when considering how someone sets up a truck, there really isn't a "perfect" design. Just because it works on paper, doesn't mean it works on the track. And yes, in my pulling truck I ran mismatched gears and have also ran mismatched tire sizes. What it comes down to is you gotta get on the track and see what works, or trust those that have been there!! :Cheer:
Click to expand...

:clap: Excellent post, Thank you!
 
PSUCE said:
What everyone has been saying is that this has been done by many going back 30 years, and by more than a few points champions. I don't know how much truck pulling you have been around, but watch some other videos and just watch how the front of the truck lifts at it begins to move the sled. This results in a loss of traction in the front compared to the back. The SMFWDs in the video above are set up a lot different than street class trucks with factory suspension, watch a few videos of them. There are also so many different ideas and concepts to suspension, hitch, and weight design that it will boggle your mind if you really get into it. I have ran many a FBD playing with different designs.

You asked about the forces (weight) on the front versus rear, and yes there are those that have ran numbers to try and figure it out. They are the ones that try everything to get the maximum traction out of both rear ends. Do you also know that no one truck pulling runs the same air pressure front and back? This is also for the same reason as mismatched gears, to try to get as much traction in the front. When doing your calculations on ratios, if you have a 35" tire with 25 psi in the front and the same tire with 50psi in the rear, what is the difference in effective radius (thus changing effective gear rations correct)? What about that difference when you're going down the track at full load? Same for 60" weight boxes and the percentage rule for different wheelbases, hitch distance from centerline of rear axle, reese hitch versus trick hitch, and so on....

What we're all saying is that when considering how someone sets up a truck, there really isn't a "perfect" design. Just because it works on paper, doesn't mean it works on the track. And yes, in my pulling truck I ran mismatched gears and have also ran mismatched tire sizes. What it comes down to is you gotta get on the track and see what works, or trust those that have been there!! :Cheer:
Click to expand...

That would make sense as to why you would make a gear change by .3 , and you seem to be the only one with WHY to do something like that.

Everyone else has no definitive answer and is doing or seems to be doing because they've been doing it this way.

You're the only one that has a answer or understanding as to why make the split
Eventually we might have gotten somewhere but it's dead now

________________________________________________________________
The problem is you can't understand how it works and your number just dont allow it! Well guess where you can stick your numbers and your lack of experience on dirt.

How many 4wd drives have you ever built?

And what works on asphalt doesn't work on dirt! How many off road trucks have you ever seen on a slick?
Click to expand...

I have a very good ability to understand performance in many areas of use, but not answering or just being thick gets no one no where

Asking is how you get to making things better but we'll never turn up anything new now.

I haven't got into sled pulling, im not against it , nor dislike it but something i personally not built for.
Personally im into things with high speeds, but asking questions is what TURNS up answers and ideas that could be beneficial.
.
Had you said you run the .3 for the reasons given by Psuce there is a understanding of why you would purposely run a otherwise binding driveline to overcome bind.
 
Supershafts said:
That would make sense as to why you would make a gear change by .3 , and you seem to be the only one with WHY to do something like that.

Everyone else has no definitive answer and is doing or seems to be doing because they've been doing it this way.

You're the only one that has a answer or understanding as to why make the split
Eventually we might have gotten somewhere but it's dead now

________________________________________________________________


I have a very good ability to understand performance in many areas of use, but not answering or just being thick gets no one no where

Asking is how you get to making things better but we'll never turn up anything new now.

I haven't got into sled pulling, im not against it , nor dislike it but something i personally not built for.
Personally im into things with high speeds, but asking questions is what TURNS up answers and ideas that could be beneficial.
.
Had you said you run the .3 for the reasons given by Psuce there is a understanding of why you would purposely run a otherwise binding driveline to overcome bind.
Click to expand...


You keep referencing binding. How much HP is used up in a 5% split bind, how much in a 7%, how much in a 10%? What about on a tight track, what about on a loose track?

You comment on PSUCE post. More to think about, why is he only figuring the radius at the point perpendicular to the track surface for the gear ratio? When the tire is aired way down it contacts the track at a larger point along the circumference of the tire. As you move away from the perpendicular point(tangent in an ideal world) the radius from the center of the axle is increasing, why can't you use that for the radius? So now you have a variable gear ratio, since the radius changes?

There are many times folks have figured stuff out, and don't want to explain it to others. IE let them figure it out for themselves with their own time and money. I don't know how many times I have looked at a truck setup, and just smiled and walked away, as I could see what someone was intending to do, but completely misapplied, or misunderstood the theory.

My tires spun going down the track, no binding going on as all of the tires were spinning....
 
This amazes me lol

I am no sled puller at all but damn it man, if something is proven and has been for 40 years don't argue it. Sometimes things don't work the same way in real life as they do when calculated out on a sheet of paper.
 
Supershafts said:
That would make sense as to why you would make a gear change by .3 , and you seem to be the only one with WHY to do something like that.

Everyone else has no definitive answer and is doing or seems to be doing because they've been doing it this way.

You're the only one that has a answer or understanding as to why make the split
Eventually we might have gotten somewhere but it's dead now

________________________________________________________________


I have a very good ability to understand performance in many areas of use, but not answering or just being thick gets no one no where

Asking is how you get to making things better but we'll never turn up anything new now.

I haven't got into sled pulling, im not against it , nor dislike it but something i personally not built for.
Personally im into things with high speeds, but asking questions is what TURNS up answers and ideas that could be beneficial.
.
Had you said you run the .3 for the reasons given by Psuce there is a understanding of why you would purposely run a otherwise binding driveline to overcome bind.
Click to expand...

:doh:

I didn't think I had to spoon feed a given to you. You being as smart with all of this as you are. I figured you would have all that figured out.

Maybe do a little more research before trying to reinvent the wheel when you have never seen one!
 
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