39 replies to this topic

[dirtstudent2]

Here's the picture thanks to Rick:  https://fscpictorial...25-15/i-9mJt6Kx

 

 

Sure the car is cattywompus and the rear wheels are trying to make it head towards the infield.  

 

But the back end by the picture is only trying to roll straight forward, which happens to be toward the infield.  The only thing steering the car and making the car go somewhere other then straight defined by the direction the axle wants to roll, is the right front tire.  

 

Rear Steer, yeah sure your dreaming.  If you think anything other then stagger and how the tires on the staggered solid axle are weighted is causing rotation in the back, yer dreamin.  ...

 

Look at the picture, there ain't nothing steering that car but the right front tire.  Don't matter how much the car gets jacked up and the front end moved off the center line, there ain't no such thing as Rear Steer, except on yer John Deer zero turn.  ...

Edited by dirtstudent2, 30 October 2015 - 01:01 PM.

[ramsey31]

I wont speak for Kyle, as I don't know his setup, but I will speak personally.   If done right, rear steer isn't the goal, only the result.

Edited by ramsey31, 30 October 2015 - 01:37 PM.

[dirtstudent2]

I just had another thought on it.  

 

If you step on the gas and it always wants to go towards the inside of the track, then I guess it could be said the rear is steering it.  Is that what happens in the drivers seat when a chassis setup to either make the left rear move forward or the right rear move back?  I see a lot of "stocks" now where it's dramatic how the left rear moves forward and the right rear moves back, when on the gas.

 

I think it's fine to make a stock do that if it's ok by the rules.  And those that don't either don't know how to do it, can't afford to make a car to do it or just don't want the car to do it.  Looks cool and I guess it can be fast for the class, depending on track conditions.  Only draw back I saw was just a little bit of contact goes a long way, to keep the car off the straight and narrow.

 

Thanks for the conversation, it's a long winter coming up.  ...

Edited by dirtstudent2, 30 October 2015 - 02:04 PM.

[NotToday]

The right rear is always pushing towards the maximum point of the trailing arm arc. Where as when the left lifts it is pulling away from the arc. Thats what u are seeing, the guys that run pavement down south actually shorten the right side wheel base to turn quicker.

[714d]

The idea is right, but when done to that extreme, the result is usually capable of a fast lap but is horribly inconsistent and a real handful in traffic. People often accuse folks of running birdcages and exotic suspensions when they see stocks move like that. It's nothing that can't be done in ANY car on the track if that's the style setup you choose.

The goal of running like that isn't to achieve rear steer near as much as it is to load the left rear tire and provide forward drive.

Edited by 714d, 30 October 2015 - 03:50 PM.

[dirtstudent2]

The right rear is always pushing towards the maximum point of the trailing arm arc. Where as when the left lifts it is pulling away from the arc. Thats what u are seeing, the guys that run pavement down south actually shorten the right side wheel base to turn quicker.

 

"The right rear is always pushing towards the maximum point of the trailing arm arc. Where as when the left lifts it is pulling away from the arc."

 

Do the forces to do it come from how the RR(right rear) tire is always pushed laterally into the track and the LR(left rear) tire is always pulled as best you can into or along laterally on the track?  And then do the forces I tried to describe, then cause the chassis to operate as you explained?

 

I hope your referencing lateral forces and how they can cause the chassis to operate.  I do understand what needs done to cause rotation from a staggered solid axle, resulting in the setting different slip ratio's at each rear tire.  I'm always very interested any time anyone even hints about how they think forces effect chassis operation.  I'd like to be able to look at how forces involve a hypothetical lateral slip ratio, but everything I find tries to address it combined with normal slip ratio.

 

Thanks for the conversation. 

[dirtstudent2]

714d wrote:

 

"The idea is right, but when done to that extreme, the result is usually capable of a fast lap but is horribly inconsistent and a real handful in traffic."

 

I think you made a very good observation and it's exactly what I was thinking when I watched the car in the picture I posted on the track.  By the way I did not select out the car because of anything odd or I disliked, it was just a good picture where you can see the axle wanting to roll in it's intended direction and the RF in this case forcing it to go in another direction.  I think the basic problem if there is one running setup like that is any effort at all from the fronts to control the direction of travel, both takes away from the limited hp of that class and even more critical takes away from over all available grip.

 

The proof though is if you run up front with it and if you win with it.

 

Thanks again, this sort of conversation is what feeds my addiction to racing.  It doesn't matter if I'm right or wrong about anything I write, what matters for me and I think others who may read on here is if there's conversation and you learn something.  

[LM RACING]

It helps a monster truck get around a tractor tire or barrel real tight. And it also makes donuts easier. Rock climbers use it to go up hills and rocks sideways and to prevent rolling over. It also helped chevy trucks take up 2 lanes when malfunctioning. Just a few things that come to mind lol

[The Legend]

It's also effected by how you drive the car....

[dirtstudent2]

I've heard the horrible words rear steer from three Winged and a non winged sprint car setup guru's.

 

Two mentioned it responding to a question I asked and the other said no way.  One who mentioned the words when I commented about isn't all or any rear steer bad on a sprint car, because any at all will put unwanted bind on the end of the torque tube.  The answer was yes in theory your right... and at that time before I could get more info about the "in theory" part, someone stopped by for some help and I moved on.

 

I really can't see any rear steer at all wanted in a sprint car, because I feel it can very easily lead to a chassis bind.  But I do respect the "in theory" I'm correct comment, because of who it came from.  

 

I don't know what subtle reason there may be for putting some rear steer into a sprint.  Might it be that no matter what, your going to have some so you make sure the "some" you must get does something to help?

Edited by dirtstudent2, 31 October 2015 - 06:25 PM.

[dirtstudent2]

Since I reference a question I asked prior to the rear steer comment I thought I'd post the question on here, to be linked to it.  My question, one I think I might know the answer to and I'm looking for conformation in the asking is, "Why do I see all Sprints, except one Lucas Wolf and a car Dave Blaney has used out east, have the long torsion arm on the left side?".  By the way both Dave and Lucas had stacked tube cars.

 

I got the response about rear steer because of that question.  I'm thinking axle travel up and down is determined by the length of both the torsion arms and the radius rods along with locating points.  Is it that if your going to use torsion arms of different lengths in the back, no matter what or how you setup the radius rods, your going to have to get some rear steer.  Which leads to if the long arm is on the left, the rear steer you can't get away from will move the nose of the car to the left and that's better then having it move, no matter how little, to the right.

 

Just guessing about a possible answer and I hope someone does post the answer.  

 

It's a long winter and I can't wait for time trials Thursday.  ...

 

edit:  The same question goes for Big Block Modified cars, which I also see the long arm on the left.  But Big Blocks and Winged Sprints chassis, are used a lot differently on the track.  Still I think the same question is valid.

Edited by dirtstudent2, 31 October 2015 - 10:32 PM.

[coconut]

Dirtstudent2 . Your talent is wasted . You shouldnt be quizing local racers , you should be quizing f1 teams & NASA

[jo73]

Dirtstudent. The question of equal length arms and radius rods in the back end of a sprint car has been going on for decades. Builders, many of them have built different variations of the front and rear torsion tubes. Stacked = equal length arms top and bottom. Offset arms, straight arms, torsion tube split. Torsion tube height. Tube relation to crankshaft center line. The thing about a lot of this is that most go back to some form standard chassis that have been used since the earliest of days. I believe a huge deciding factor in sprint car racing today is the size of the driver's nut sack. When you pull the wings off you see a great difference in who has a brass set.

[The Legend]

Jo how on earth does slowing the cars down 50mph show who has a " brass set " By that analysis the Boss wingless champion has twice the stones of the most dominate winged sprint driver of all time Donny Schatz ...

[Skull]

Jo how on earth does slowing the cars down 50mph show who has a " brass set " By that analysis the Boss wingless champion has twice the stones of the most dominate winged sprint driver of all time Donny Schatz ...

You do need a big set to run fast with or without the wing. Apparently you've never seen a wingless car flip. BTW, Schatz is not the best of all time. Steve Kinser is. In fact, I don't think Schatz was as good pure talent wise as Doug Wolfgang.

[The Legend]

What Schatz has done the last 10 years is insane and he's becoming more dominate not less. Schatz is still in his 30's kinser in his 60's none of kinsers records will stand unless Schatz pulls a Jeff Gordon and retires very early

[dirtstudent2]

Jo how on earth does slowing the cars down 50mph show who has a " brass set " By that analysis the Boss wingless champion has twice the stones of the most dominate winged sprint driver of all time Donny Schatz ...

 

The size of the "brass set" is directly related to talent, IQ, personality and seat time.  Drivers go through three stages.  

 

The first is learning.  During that time there open to most anything which will help them and realize they are at an entry level.

 

The second is the "I'm Fast" stage.  They have learned and are now pushing the limit, they know nothing about.   If they, their family, money and parts suppliers make it through the "I'm Fast" stage, then their prepared to move on.

 

The third stage they become recognized as Journeymen of their craft, continually honing their skills until time and injury catches up with them.

 

The three stages are not age dependent.

[manny]

Dirtstudent2 . Your talent is wasted . You shouldnt be quizing local racers , you should be quizing f1 teams & NASA

i know it's me. but nothing he says makes any sense. 

[The Legend]

Zero sense whatsoever ....

[Skull]

What Schatz has done the last 10 years is insane and he's becoming more dominate not less. Schatz is still in his 30's kinser in his 60's none of kinsers records will stand unless Schatz pulls a Jeff Gordon and retires very early

That all might come to pass, but he's not there, and might never be. Besides, Kinser also won a good number of wingless Sprint/USAC Silver Crown races, showing his versatility. He also won in an era where the cars were somewhat more crude than they are today. I've seen both drive and always felt that Kinser could carry a car if it was off. I'm not saying Schatz isn't talented, I just don't think he's in the same league as Kinser.