rebsfan4
Member
LOL.....I didn't even make the connection. Sneaky.....LOL
I have a chassis question for the chassis gurus on here.
- Thread starter paulkish
- Start date
LOL.....I didn't even make the connection. Sneaky.....LOL
I didn't even realize I had set up a different account on my phone... lol
Ted Hamilton
Helmet Painter / Racer
Paul -- I don't mean any disrespect, but I don't buy into your posted theory on kart dynamics. I do buy into you knowing what setups "work", due to your practical experience.
I also buy into my 3.5 yrs. of mechanical engineering education and several years study of vehicle and race car dynamics as to what's going on with roll centers, Cg's, VCgs, and the physics involved.
Everything happens due to forces imparted through the tires' contact patches, and all rotations occur through the respective yaw, pitch, and roll centers. That's simply the laws of physics and karting must obey them.
I'm not going to answer your response to my post point-by-point and I'm not likely to change my views based on your previous arguments. But I've driven "3 wheeled karts" with the LR off the ground and know for a fact that the RR can easily induce a yaw -- it HAS to, because it's pushing at a tangential vector around the rotational center of the kart and the front wheels are free-rolling so they don't resist the RR's push. Indeed, that's how sprint karts HAVE to corner with any efficiency. And to a certain extent, karts are karts. I won't post a FBD here.
As to rebutted #5, I personally have driven in a drift on dirt, and it can be power-induced or can be weight-transfer induced, or can be a combination of the two. Watch any footage of a sprint car in action from the rear and you can see the tires spinning beyond their max grip level...Tire smoke is produced at extreme cases. Good drivers try to minimize wheel spin and maximize forward drive. And they usually modulate the throttle to do so, viscerally sensing the limits of traction and dancing on that line. That's what makes high HP racing fun, at least for me. I'm not some uneducated bumpkin guessing what's going on here -- I'm applying learned physics and observed phenomenon to a racing discipline. Which is why I say you'll have to do some more convincing or present alternate scenarios for what you think is going on and how that respects the laws of physics, for me to change my views much. I am all for civil, even passionate, but still respectful, discourse on chassis dynamics -- it's a personal interest of mine.
I'm curious how you derived your theory?
~Ted
I also buy into my 3.5 yrs. of mechanical engineering education and several years study of vehicle and race car dynamics as to what's going on with roll centers, Cg's, VCgs, and the physics involved.
Everything happens due to forces imparted through the tires' contact patches, and all rotations occur through the respective yaw, pitch, and roll centers. That's simply the laws of physics and karting must obey them.
I'm not going to answer your response to my post point-by-point and I'm not likely to change my views based on your previous arguments. But I've driven "3 wheeled karts" with the LR off the ground and know for a fact that the RR can easily induce a yaw -- it HAS to, because it's pushing at a tangential vector around the rotational center of the kart and the front wheels are free-rolling so they don't resist the RR's push. Indeed, that's how sprint karts HAVE to corner with any efficiency. And to a certain extent, karts are karts. I won't post a FBD here.
As to rebutted #5, I personally have driven in a drift on dirt, and it can be power-induced or can be weight-transfer induced, or can be a combination of the two. Watch any footage of a sprint car in action from the rear and you can see the tires spinning beyond their max grip level...Tire smoke is produced at extreme cases. Good drivers try to minimize wheel spin and maximize forward drive. And they usually modulate the throttle to do so, viscerally sensing the limits of traction and dancing on that line. That's what makes high HP racing fun, at least for me. I'm not some uneducated bumpkin guessing what's going on here -- I'm applying learned physics and observed phenomenon to a racing discipline. Which is why I say you'll have to do some more convincing or present alternate scenarios for what you think is going on and how that respects the laws of physics, for me to change my views much. I am all for civil, even passionate, but still respectful, discourse on chassis dynamics -- it's a personal interest of mine.
I'm curious how you derived your theory?
~Ted
paulkish
old fart
Ted, I mean you no disrespect.
"I'm curious how you derived your theory?" It just fell into place many years ago and from my view things just fit neatly into it. It's was only possible for me because of Bob and kind folks on here, putting up with my questions and hard head. There are so many who were kind to me over the years on here, I can never repay them. And if I tried to acknowledge and thank all of them, them I'd not only miss some who have helped but many. Before that on Pete Mullers site which preceded Ekarting. 20+ years trying to figure out how stuff works. I'm never sure about anything, but I do think I understand exactly where your coming from and your thought process.
It's also from the first day my son and I talked about how and what to do to make stuff work out on the track. Up front I realized it's not my nature to take notes and looked to understand how stuff works. I do respect your backbone and the guts it takes to put the work into getting an education. I did not and still do not have the work ethic to learn what you have. I admire those who have been able to properly school themselves.
... That being said my theory is not about any of what you mentioned in your kind post. My theory deals with application and all of the things you mentioned do or cause one thing to happen. They are what is needed to make a staggered solid axle, work in the ideal way my theory suggests.
I'll try it this way. Lets say you have a hammer, a nail and a two by four. There are a lot of forces, angles, roll centers etc., to make things short, involved with pounding the nail into the two by four. We can discuss all day what may have happened if the hammer strikes the nail off center and bends the nail. And we can adjust all we want and will still keep striking the nail off center, until someone says, Hey just hit the thing in the center. Then and only then, unless by luck will someone have the knowledge of where to focus all the forces, angles, roll centers etc..
What I've done with my theory is say exactly what you need to do to make a staggered solid axle roll in the proper direction around the track. It's no different then saying to someone using a hammer, hit the nail in the center. All of what is done swinging the hammer has one purpose, which is to hit the nail squarely in the center. All of what is done setting up is to make each tire on your staggered solid axle, hit the track at the right time to make the axle roll in the direction you want it to go.
The coin has only two sides. You either push the tires into the track with the right force at the right time and cause the axle to roll in the direction you want to go. ... or ... You have to force the axle to turn and go where you want it to go. My theory tells you how and when the each tire, needs to be pushed into the track when decelerating, in between and when accelerating. Your knowledge, tells you how to go about doing it.
If you want to be fast you have choices to make. To do what's needed to make the axle roll in the direction you want to go by applying weight to the rear tires, is one choice. To do what's needed to force the axle to go in the direction you want it to go with the front tires, is another choice. And you can use a combination of both. But the ideal one, if you can do it is the first.
Separate out your tools and your two options for turning the axle and I'm sure you will see it. And I think you will also see the first option is the only one to shoot for.
Depending on your equipment, you may or may not be able to do it, but it is what needs to be sought.
"I'm curious how you derived your theory?" It just fell into place many years ago and from my view things just fit neatly into it. It's was only possible for me because of Bob and kind folks on here, putting up with my questions and hard head. There are so many who were kind to me over the years on here, I can never repay them. And if I tried to acknowledge and thank all of them, them I'd not only miss some who have helped but many. Before that on Pete Mullers site which preceded Ekarting. 20+ years trying to figure out how stuff works. I'm never sure about anything, but I do think I understand exactly where your coming from and your thought process.
It's also from the first day my son and I talked about how and what to do to make stuff work out on the track. Up front I realized it's not my nature to take notes and looked to understand how stuff works. I do respect your backbone and the guts it takes to put the work into getting an education. I did not and still do not have the work ethic to learn what you have. I admire those who have been able to properly school themselves.
... That being said my theory is not about any of what you mentioned in your kind post. My theory deals with application and all of the things you mentioned do or cause one thing to happen. They are what is needed to make a staggered solid axle, work in the ideal way my theory suggests.
I'll try it this way. Lets say you have a hammer, a nail and a two by four. There are a lot of forces, angles, roll centers etc., to make things short, involved with pounding the nail into the two by four. We can discuss all day what may have happened if the hammer strikes the nail off center and bends the nail. And we can adjust all we want and will still keep striking the nail off center, until someone says, Hey just hit the thing in the center. Then and only then, unless by luck will someone have the knowledge of where to focus all the forces, angles, roll centers etc..
What I've done with my theory is say exactly what you need to do to make a staggered solid axle roll in the proper direction around the track. It's no different then saying to someone using a hammer, hit the nail in the center. All of what is done swinging the hammer has one purpose, which is to hit the nail squarely in the center. All of what is done setting up is to make each tire on your staggered solid axle, hit the track at the right time to make the axle roll in the direction you want it to go.
The coin has only two sides. You either push the tires into the track with the right force at the right time and cause the axle to roll in the direction you want to go. ... or ... You have to force the axle to turn and go where you want it to go. My theory tells you how and when the each tire, needs to be pushed into the track when decelerating, in between and when accelerating. Your knowledge, tells you how to go about doing it.
If you want to be fast you have choices to make. To do what's needed to make the axle roll in the direction you want to go by applying weight to the rear tires, is one choice. To do what's needed to force the axle to go in the direction you want it to go with the front tires, is another choice. And you can use a combination of both. But the ideal one, if you can do it is the first.
Separate out your tools and your two options for turning the axle and I'm sure you will see it. And I think you will also see the first option is the only one to shoot for.
Depending on your equipment, you may or may not be able to do it, but it is what needs to be sought.
paulkish
old fart
Quoting me: "Separate out your tools and your two options for turning the axle.".
I like to write and the more I do it the more fun it becomes. The thought I quoted never got put together like that for me before and it made the time involved with this whole thread worth while for me. I think it's true and I think it may be the first time ever, everything we do racing LTO's, has been categorized in those three basic categories. I've always had hints in my mind putting my thoughts about how we make stuff work into those three categories, but now it looks cut and dry. Cut and dry in the sense your working with many tools to make your staggered solid axle turn or rotate while traveling around the track. And there are only two ways you will be using your entire combination of tools to make it turn. I'm not going to repeat the two ways again, all you have to do to see each of them as separate ways is to quit rationalizing why there are not two ways to turn a solid axle. If your going to race LTO, your going to have to get unglued from it being >mandatory<, to lift up the inside rear tire and do thing as would be done on "Real Race Cars".
What I'm writing on here has nothing at all to do with your personal ability to use a staggered solid axle, in what I call the ideal way. It's all about showing and arguing with the LTO world, it's possible.
For you to be able to apply all you do making your solid staggered axle roll easily on the track, to what I'm explaining as ideal, you have to first accept the ideal as possible. ... now I have this bridge I want to sell you. ...
How'd I do Ted? Am I better presenting my case? Is it flawed?
Assuming it is please show me where it's flawed. Sure I'm hard headed and set in my ways and because of that I'll most likely argue why the flaw is in reality, one of the many facets cut into a beautiful gem. ... But I'll eventually if you have the patience with me see how the flaw degrades the value. Heck, you may even convince me all I have is a common piece of glass because this is all IMHO and ain't necessarily right anyway. ...
Thank you for replying and putting up with me. I hope the process on here is fun for you the same as it is fun for me. I want to add this. I absolutely do not(well, maybe once) enter into discussions on here, "just for the fun of arguing". I'm only arguing my point hoping to confirm it or learn along the way. I'm not joining into the process for the fun of it, the process hopefully will turn out to be fun. If not I generally say something like I'm sorry and end up crawling back into my hole, until the sun shines in again.
I like to write and the more I do it the more fun it becomes. The thought I quoted never got put together like that for me before and it made the time involved with this whole thread worth while for me. I think it's true and I think it may be the first time ever, everything we do racing LTO's, has been categorized in those three basic categories. I've always had hints in my mind putting my thoughts about how we make stuff work into those three categories, but now it looks cut and dry. Cut and dry in the sense your working with many tools to make your staggered solid axle turn or rotate while traveling around the track. And there are only two ways you will be using your entire combination of tools to make it turn. I'm not going to repeat the two ways again, all you have to do to see each of them as separate ways is to quit rationalizing why there are not two ways to turn a solid axle. If your going to race LTO, your going to have to get unglued from it being >mandatory<, to lift up the inside rear tire and do thing as would be done on "Real Race Cars".
What I'm writing on here has nothing at all to do with your personal ability to use a staggered solid axle, in what I call the ideal way. It's all about showing and arguing with the LTO world, it's possible.
For you to be able to apply all you do making your solid staggered axle roll easily on the track, to what I'm explaining as ideal, you have to first accept the ideal as possible. ... now I have this bridge I want to sell you. ...
How'd I do Ted? Am I better presenting my case? Is it flawed?
Assuming it is please show me where it's flawed. Sure I'm hard headed and set in my ways and because of that I'll most likely argue why the flaw is in reality, one of the many facets cut into a beautiful gem. ...
But I'll eventually if you have the patience with me see how the flaw degrades the value. Heck, you may even convince me all I have is a common piece of glass because this is all IMHO and ain't necessarily right anyway. ... Thank you for replying and putting up with me. I hope the process on here is fun for you the same as it is fun for me. I want to add this. I absolutely do not(well, maybe once) enter into discussions on here, "just for the fun of arguing". I'm only arguing my point hoping to confirm it or learn along the way. I'm not joining into the process for the fun of it, the process hopefully will turn out to be fun. If not I generally say something like I'm sorry and end up crawling back into my hole, until the sun shines in again.
ttownwideglider
New member
Ok Paul with the utalization of slugs on the rear of karts these days is it better in the setup to try a keep the ride height of the chassis as close to level with the ground as possible? Another words raise the chassis on the left side to account for larger tire stagger on the right. What will this do to weight transferr on the rear end? I understand that it will cause a change in cross but will this transferr more weight to the right or equalise the weight on both rears. What about moving the right side axel to the rear does this change the speed of the right rear in its traveling radius. I know it will cause the kart to turn left but does it also increase the radius and rpm of the RR? I just bough a Seraph and havent got to test it yet just trying to think of starrting set up on rear end.
ttownwideglider
New member
Since this thread has evolved into a discussion on rear end geometry. Can we discuss the effects I have ask about above? Would like to get a hold on these elements before I get to hit the track if it ever warms up here in okie land. Have never owned a kart that has adjustable rear axel so this is new to me. come on guys give me some input on these questions. Help a fellow to understand the effects of moving the rear axel around. Paul ignored me and if any of you have some thoughts I would really appreciate it.
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paulkish
old fart
Quoting me: "Separate out your tools and your two options for turning the axle.".
I like to write and the more I do it the more fun it becomes. The thought I quoted never got put together like that for me before and it made the time involved with this whole thread worth while for me. I think it's true and I think it may be the first time ever, everything we do racing LTO's, has been categorized in those three basic categories. I've always had hints in my mind putting my thoughts about how we make stuff work into those three categories, but now it looks cut and dry. Cut and dry in the sense your working with many tools to make your staggered solid axle turn or rotate while traveling around the track. And there are only two ways you will be using your entire combination of tools to make it turn. I'm not going to repeat the two ways again, all you have to do to see each of them as separate ways is to quit rationalizing why there are not two ways to turn a solid axle. If your going to race LTO, your going to have to get unglued from it being >mandatory<, to lift up the inside rear tire and do thing as would be done on "Real Race Cars".
What I'm writing on here has nothing at all to do with your personal ability to use a staggered solid axle, in what I call the ideal way. It's all about showing and arguing with the LTO world, it's possible.
For you to be able to apply all you do making your solid staggered axle roll easily on the track, to what I'm explaining as ideal, you have to first accept the ideal as possible. ... now I have this bridge I want to sell you. ...
How'd I do Ted? Am I better presenting my case? Is it flawed?
Assuming it is please show me where it's flawed. Sure I'm hard headed and set in my ways and because of that I'll most likely argue why the flaw is in reality, one of the many facets cut into a beautiful gem. ...
Thank you for replying and putting up with me. I hope the process on here is fun for you the same as it is fun for me. I want to add this. I absolutely do not(well, maybe once) enter into discussions on here, "just for the fun of arguing". I'm only arguing my point hoping to confirm it or learn along the way. I'm not joining into the process for the fun of it, the process hopefully will turn out to be fun. If not I generally say something like I'm sorry and end up crawling back into my hole, until the sun shines in again.
Just read through this and had forgot all about it. I had a tough time understanding what it was about through the first few sentences. But once the thought of the post set back in, I have this to say excellent post. I'm sorry I'm so unable to present the concept well enough. I think recognizing it can be the most significant thing you can learn about LTO racing.
Ted Hamilton
Helmet Painter / Racer
Why do you say that, Krug?
paulkish
old fart
Krug2k, I went back and read my post which started this thread.
_____________________________________________
I have a chassis question for the chassis gurus on here.
Do you think it is a must to provide weight to operate the RF tire, from the LR area of the kart? I realize when in the process of slowing down you would normally expect to get some help operating the RF from the LR area. But thought it will happen, is it a must?
That's leading to asking, do you think in most cases enough weight could be supplied from the LF area of the kart to operate the RF?
I'm hoping for a yes answer on both questions which would support an idea I have, but ain't sure what I'll get.
thank you
paul
_________________________________
I tried to be open minded reading it again. I do not see any problem with my original question.
I don't generally ask a question like that unless I see multiple potential answers. There's a lot of smart people on here with a lot of racing experience. I was genuinely interested in what might be said.
What the thread lead too was not my original intent. What problem does it cause and I guess Ted asked best, why do you say that?
paul
_____________________________________________
I have a chassis question for the chassis gurus on here.
Do you think it is a must to provide weight to operate the RF tire, from the LR area of the kart? I realize when in the process of slowing down you would normally expect to get some help operating the RF from the LR area. But thought it will happen, is it a must?
That's leading to asking, do you think in most cases enough weight could be supplied from the LF area of the kart to operate the RF?
I'm hoping for a yes answer on both questions which would support an idea I have, but ain't sure what I'll get.
thank you
paul
_________________________________
I tried to be open minded reading it again. I do not see any problem with my original question.
I don't generally ask a question like that unless I see multiple potential answers. There's a lot of smart people on here with a lot of racing experience. I was genuinely interested in what might be said.
What the thread lead too was not my original intent. What problem does it cause and I guess Ted asked best, why do you say that?
paul
paulkish
old fart
ttownwideglider, I don't know where to start answering your two posts. Between the two they cover most all areas normally debated on here.
What I read is you got a new kart and it's a phantom. Go with factory setup base lining your kart as best you can. Then put it on the track and look for, find and fix on track problems. But I'll take a stab at one of the areas you asked about. You asked about ride height and when do need to compensate, because something you did altered ride height. The answer is if what you did fixed your original on track problem and did not create another problem, you don't need to concern yourself about the ride height change. There's no set rules and nothing is absolute, cut and dry. Ltg on here Todd Godwin sells a basic book and a more involved book about stuff. I suggest you look into his books.
paul
What I read is you got a new kart and it's a phantom. Go with factory setup base lining your kart as best you can. Then put it on the track and look for, find and fix on track problems. But I'll take a stab at one of the areas you asked about. You asked about ride height and when do need to compensate, because something you did altered ride height. The answer is if what you did fixed your original on track problem and did not create another problem, you don't need to concern yourself about the ride height change. There's no set rules and nothing is absolute, cut and dry. Ltg on here Todd Godwin sells a basic book and a more involved book about stuff. I suggest you look into his books.
paul
Allow me to rephrase, its responses to threads like these that cause people to stay away from karting. I guess what I am suggesting is that its not rocket science. 99.9% of those who win in this sport don't pay any mind to this type of for lack of a better term "karting science." It just makes our sport seem more complicated than it really is. Here is some advice that will make anyone in this sport better: keep it simple.
Jordan Krug
PS: in rereading my previous post, I can see how it may have been inferred that I was bashing those involved in this thread I apologize as that was not my goal. Carry on.
Jordan Krug
PS: in rereading my previous post, I can see how it may have been inferred that I was bashing those involved in this thread I apologize as that was not my goal. Carry on.
flattop1
Dawg 89
first start with 0 in rr and 1/8 numbers down lft r
no its not better to adjust ride height even to compensate for stagger.
the tilt or rake is going to (in my mind) cause delay in transfer which subsequently will allow it to reload faster. and allow more transfer when it does.
the rr adjustment will loosen or tighten your chassis forward for tight
no its not better to adjust ride height even to compensate for stagger.
the tilt or rake is going to (in my mind) cause delay in transfer which subsequently will allow it to reload faster. and allow more transfer when it does.
the rr adjustment will loosen or tighten your chassis forward for tight
ttownwideglider
New member
Thank you for the advice Paul. Have one of Ltgs books coming. Just wanted to get some advice from the experts on here where to start track testing on the rear end. I have Phantoms base line setup #s but doesnt say anything on rear end geometry except lr and rr percentage weights. Trying to visualize the picture as Paul suggested with the rear end setup.As i stated i know moving rr to the back will induce a natural left turn to the chassis. But dont know what keeping the chassis level will do to the percentages on the rear end. Looking at my picture raising the chassis on the lr will induce more weight on the rr. But will it speed up the transfer or slow it down. Will it increase the rpm of the rr enough to allow less stagger on the rr. These are the answers that i would like to know. I must be asking top secret info no one wants to post for others to read on the fourm. Flattop wrote this post at the same time as you thanks for the help. 1/8 down onon left r will raise the chassis off the ground . O lead or lag in rr and use this to compensate for loose or tight.
Paul,
I just briefly read your post.
Here is how I look at it, when looking at it from the dirt side vs the pavement side or even coke syrup you have to consider the balance between the RR/LR. Meaning on dirt you need more weight on the LR depending on the groove the LR and RR is running in. On dirt you have to consider the RF and its grip value relative to the drive the LR is providing. You can lock down the kart by having too much RF grip relative to either the LR or RR grip.
On dirt the RR and LR has more of a grip imbalance than it does on pavement or even on syrup.
The real trick is understanding the tire loads relative to the grip present and balancing it all out.
Mike McCarty
Chassis manual (Only $17.95)
www.kartcalc.com
I just briefly read your post.
Here is how I look at it, when looking at it from the dirt side vs the pavement side or even coke syrup you have to consider the balance between the RR/LR. Meaning on dirt you need more weight on the LR depending on the groove the LR and RR is running in. On dirt you have to consider the RF and its grip value relative to the drive the LR is providing. You can lock down the kart by having too much RF grip relative to either the LR or RR grip.
On dirt the RR and LR has more of a grip imbalance than it does on pavement or even on syrup.
The real trick is understanding the tire loads relative to the grip present and balancing it all out.
Mike McCarty
Chassis manual (Only $17.95)
www.kartcalc.com
paulkish
old fart
Krug2k, no issue at all.
Your right about how it's too easy to get over involved. I have said many times on here, IMHO the fastest way to get fast is take notes and learn what worked well and what didn't for specific situations.
I'll add now, the way to get real fast or better yet to be real consistent, is to know why what you did, did what it did. And guess I'll add another thing. And if you know how everything works and what works, then you'll want to know exactly how each of the four tires needs to be used. ... I think the last is the most important about learning about this stuff, but in the scheme of things learning about stuff, you don't realize its importance until last.
and maybe ? ...
Your right about how it's too easy to get over involved. I have said many times on here, IMHO the fastest way to get fast is take notes and learn what worked well and what didn't for specific situations.
I'll add now, the way to get real fast or better yet to be real consistent, is to know why what you did, did what it did. And guess I'll add another thing. And if you know how everything works and what works, then you'll want to know exactly how each of the four tires needs to be used. ... I think the last is the most important about learning about this stuff, but in the scheme of things learning about stuff, you don't realize its importance until last.
and maybe ? ...