19 replies to this topic

[dirtstudent2]

Can there be situations with a Late where moving the RR out gains grip?

 

I always see moving a tire out especially the RR as a way to free up, ease or smooth out excessive grip.  The way Lates are able to jack weight, are there particular conditions or in general where moving the RR out will gain grip.

 

The other side I see is if it frees the car up allowing it to go faster on a heavy track, it might be related to by the driver as gaining grip.  

 

just a question because of a discussion 

[blue by you]

siping an groving the tires add grip. everybody has there own way of doing this.

[jo73]

With track conditions, cushion and other factors. I would think some may move the right rear out and tuck the LR in as tight as possible. With today's SLM and the HP they are making. Who knows. Shocks in my opinion are to the point of being the most important factor in today's cars. Again, just my opion,

[The Legend]

The right rear gets " moved out " to loosen the car. The more it is tucked under the harder it sticks. The only time moving it out is going to tighten the car is if you race around the track backwards .... Once again another absurd pointless post

[jake shady]

lol , studder who never won a late model race making fun of those trying to learn. 

[dirtstudent2]

Thank you jo73, though I didn't respond to it I've been thinking about your response.  Until just now when legend explained how it's cut in stone and I should dummy up on it, I could't think of a reason for a driver to relate moving the RR out, to gaining grip.  So I figured I could invent a reason.    

 

The norm for my thinking, if someone who drove a late model would say that about moving the RR out is to not bring other things into the picture and just wonder why it could work that way.  Your adding in when it's done moving the LR in would also be warranted does shift my thinking and maybe make it able to fit in.  That is assuming I understood what you wrote correctly, which I'm not sure I did. 

 

I understand about rear steer and it's end result of moving the nose over to the left.  And how it can help not initially with grip at the RR, but with making more weight available to be projected to the RR.  Yes I know the arguments about how rear steer also directs weight straight at the RR, but I'm not asking this to argue dynamic weight transfer, physical weight transfer and how to flow weight where needed.  I asked this question only to find a reason or circumstances where moving a RR out might increase grip at the RR.  

 

There's available grip and there's available hp.  If you have hp available then especially on a late your going to want to be able to use it at the RR.  The main thing I see rear steer doing is to make weight available to get grip at the RR by providing it to the LR or more correctly the LR area.  I now see your suggestion that if it was moved out, along with it the LR would be moved in.  Just as moving the LR ahead moves the nose of the car to the left allowing weight to be made available for the RR at the LR area of the car, I now can see how tucking the LR in and moving the RR out under certain circumstances can do the same.  The same physics are involved to move some weight in the rear to the left a little, if you only move the RR out.  

 

Thank you for your input.  Until writing this I was only looking at gaining grip because of moving the RR out to enhance available grip directly at the RR itself.  That's not always what's needed in a reason to need grip or a reason why something helps grip.  Especially with a late, you may need to gain grip on a relatively heavy track, for reasons of being able to put down all your available hp.  

 

You can run your RR tire beyond it's limit of grip because of either lateral forces or hp produced by the engine.  How you go about trying to gain needed weight, involves both if your going to be putting it directly on the RR tire or made available to be put on the RR tire.  And how you have to do things, will change depending on the tracks over all available grip.

 

Thanks jo73 and thank you legend for the help.  Without your help I never would have been able to or would have even written this post. 

[jo73]

Dirt, I absolutely am not up on late model chassis. I was only thinking about tighter tracks and if that moving the LR in tight would help tighten the car up. I would think taking stagger out you could move the RR out somewhat. Just making conversation on a topic nothing more.

[03Rocket]

Just take the LR axle out and throw it in the weeds, then all available hp and grip will be solely given to the RR.....problem solved student!

[WannaRace]

lol , studder who never won a late model race making fun of those trying to learn. 

Was thinking the same thing...

[jake shady]

on the topic,  long flat track?   short high banked track?   there are so many varables.  car constructed correct? rr spring rate? j bar location?        changing offset is the old way anyhow.   use 5" offset on latemodels and change jbar angle and location instead. 

[The Legend]

Buy a fuking late model then jack off !!! Put 2 fuking whee spacers on the RR so it will be tighter than a bulls asshole according to you !!

[dirtstudent2]

Buy a fuking late model then jack off !!! Put 2 fuking whee spacers on the RR so it will be tighter than a bulls asshole according to you !!

 

Good post.

[Gasface25]

I think wheel spacers are still a very relevant way to tune ea dirt late model. A lot of the new cars and designs are all using wheel spacers in some capacity, some are going as far as to narrow the housing down and running a wheel spacer on each rear wheel and removing them when needed as an easy adjustment.

[dirtstudent2]

Deleted

Edited by dirtstudent2, 28 February 2016 - 12:18 AM.

[dirtstudent2]

I think wheel spacers are still a very relevant way to tune ea dirt late model. A lot of the new cars and designs are all using wheel spacers in some capacity, some are going as far as to narrow the housing down and running a wheel spacer on each rear wheel and removing them when needed as an easy adjustment.

 

Thank you for the reply.   Learning Late Model builders are increasing the amount rear wheels can be moved in and out, helps and because I learned something makes this thread worth while to me.    Thank you for the information. 

Edited by dirtstudent2, 27 February 2016 - 05:40 PM.

[ramsey31]

I believe the answer to your question is no.   All other variables the same, it ill be impossible to gain more  by moving the RR out unless like Legend said, you run backwards.    If you look at the physics of gravity, and centrifugal force generated during a left turn, the center line of the car acts like a lever.   The RR in a left turn situation acts like the fulcrum to the LR.   More like a catapult would.    The closer you move the fulcrum toward the center line, the more weight is loaded, and the easier that weight is to load onto the RR. The further out, the exact opposite, so the transfer of the lever would be slowed.

 

The available force carried through the turn is the same, the further you move the fulcrum the less Newtons are transferred to the track.    On a LM, you can manipulate the newtons transferred ultimately to the RR tire patch in a few different ways, and accomplish the same thing. 

 

To really see this is action, watch how often karters will slide rear hubs

Edited by ramsey31, 29 February 2016 - 04:23 PM.

[dirtstudent2]

Thank you very much.

 

I think I understand your presenting the RR as a fulcrum point and I can see the logic in it.  Thank you I've never looked at it from that perspective before.

 

I can immediately fit in what you explained but only in part.  I can fit in and use the RR as a fulcrum point only while decelerating.  For me to fit something new in even if I can only fit it in while in deceleration is everything and more then I can ask for.  If I'm understanding you correctly you presented moving the RR in to shorten the lever, making the shortened lever better able to apply weight to the LR and I'll add in hopefully with it agreeing with what you think, it will also do it quicker.

 

I have a problem trying to put the same thing I see hopefully the same as you, to it when the car is under acceleration.   I just can't envision it.  

 

By the way did you happen to read the post I deleted?  

 

Thank you I'm going to have to sleep on the new thought you presented to me.  

 

The reference to karters and sliding hubs.  I don't see dirt oval karters sliding the RR hub at all.  Basic kart design from manufactures most always dictates the RR is set in as much as possible.  I think that's it's pretty much cut in stone, the RR is in, set there and there is no need to move it out.  

 

The only sliding of rear hubs I see is at indoor oval high grip situations and with sprint karts that turn both left and right, also relying on unloading the inside rear to be able to turn.

 

thank you for the conversation 

Edited by dirtstudent2, 29 February 2016 - 11:03 PM.

[dirtstudent2]

Quick follow up reply to:  "I believe the answer to your question is no."

 

I think your answer is correct.

[dirtstudent2]

ramsey31 thank you for your reply and I'm going to take a chance and post what I deleted in post #14.  I hope it's a good read.

___________________

 

 

 

This thread was started because of a discussion with a old late model racer, who said he use  to be able to move the RR out and gain grip.  As I wrote in previous posts I understand and normally consider moving the RR out on anything racing oval ncluding a Late, as a way to free up the RR not increase grip.  If anyone read anything different into this and took it that I wrote moving the RR out and increase grip, it is not what I wrote and you read into it what was not there.

 

I've been into trying to learn how LTO's work long enough to understand how one adjustment depending on available grip, track configuration, available hp and how the total of what your racing has been setup; can give depending on the total picture opposite on track results and driver perceptions.  I said I understand it and much of it I do, dependent on how all four corners of what your racing need to be used on an oval track.  

 

The net of this thread is I understand much of what's happening with a LTO on the track and when a driver told me moving a RR out gained him grip, instead of jumping to a conclusion of ignorance and belittlement as some on here would do, I looked for a reason.  A reason not yet understood by me for why he would either gain grip by moving the RR out or perceive as a driver that grip was gained.  

 

I offered two possibilities, one was he was racing on a high grip situation and because moving the RR out freed the car up and he went faster, it was interpreted as a gain in grip because of being able to go faster.  Normally most racers will associate additional grip with the ability to apply additional hp and maintain additional momentum, but freeing a car up and going faster can give the same perception.

 

I do believe the driver I had discussion with and then looked for help on here, because of the ability of Lates to jack weight and I don't understand all the possibilities they bring to the table.  

 

While writing for help rear steer came to mind and it made me think of how rear steer is used to lay weight on both the LR and RR.  Because my experience watching Lates leads me to believe rear steer is more beneficial on a higher banked turn of higher grip, I thought about how moving a RR out under that specific situation, might enhance grip.  

 

I don't know and that's why I asked on this site.  My thinking was under a specific situation when rear steer is fully involved, on a high banked high grip track, shifting weight towards the LR by moving the RR out might instead of freeing the car up, actually enhance grip at the LR and in turn make weight available for the RR.  In that situation I see Lates with the hp doing all they can to apply the hp and keep the loaded RR under them.  Naturally, at least I think it's a natural process,  once a car loads a RR beyond it's grip capabilities rear steer will need to be reduced.  It will need reduced to be able to maintain weight towards the left and the LR in particular, to allow the LR to pick up grip lost at the RR.  

 

I think, but I do not have experience except for watching and talking to successful Late setup people, the following is true.  The whole point of Late setup from what I've observed is to dump weight on the RR and go.  Beyond that it's about being able to control use of the RF to balance dynamic changes in cross setting how tight your car is depending on track conditions.  And when grip goes away from the RR, to then engage the LR  more to try to maintain maximum hp being applied as long as possible.  In all Late, Modified, Stock, Emod or Kart, it's about balancing your acceleration and slowing down of the RR with your anchored or rudder LR.  How well what your racing can do it is totally dependent on being able to use stagger and ability to apply and transfer weight.  Some LTO's can do the two better then others because of rules of construction and the amount of stagger allowed.

 

I welcome criticism of reasons why part or all of what I wrote is not correct, if done I'll learn from it.  The only reason for this thread is because a late model driver told me he had or perceived a gain in grip when he moved the RR out.  I have no reason to doubt him and I'm looking for a reason why it might be possible, instead of proclaiming he's wrong and I'd be stupid to try to find a reason.

[dirtstudent2]

In the above post I wrote:  "Naturally, at least I think it's a natural process,  once a car loads a RR beyond it's grip capabilities rear steer will need to be reduced.  It will need reduced to be able to maintain weight towards the left and the LR in particular, to allow the LR to pick up grip lost at the RR."

 

I think there's two parts to what I'm seeing on the track when rear steer is used, in the situation I described.  The first is to move the nose of the car over to the left.  The second part of it which I did not reference is about how high your going to raise the left front corner.  I did not include it in the above, but I see using rear steer and left front corner lifting together, to apply weight as needed to both the RR and the LR.  When grip is reduced I indicated a need to reduce rear steer.  I don't see reducing rear steer as something mandatory when the RR goes away.  If it's a high banked track you may want to leave the nose out to the left over the bank of the track and just bring it down to try to engage the LR more.