I was reading the CW's manual about what too do with a pushing car and one of the tips was to reduce the tension on the center spring. Can you explain to me why this would help?

It decreases droop.

I am hoping you will hear from some more experienced racers, but I was told that increasing pressure on the center shock spring puts wmore weight on the rear end giving you more tractionand less stearing. The opposite, less tension on the center spring, puts more weight on the front end giving you more steering. Hope that is correct as I have been using that information to tune. Ralf

exactly! Ride height also comes into play. Although the rear of the main chassis is raised with increased droop which would, in any other type of chassis, increase steering; the pod is tipped backward (adding weight to the rear wheels).

One other note to keep in mind is that turning the collar in either direction doesn't actually increase tension it just moves weight/changes ride height. A springs tension (rate) is constant unless its a progressive spring.

I was reading the CW's manual about what too do with a pushing car and one of the tips was to reduce the tension on the center spring. Can you explain to me why this would help?

It is a mis-type in the manual it should read...
Car is Loose or Oversteers



Install Wing to Rear of Car
Slide Wing Toward Rear of Car
Increase Wing Angle
Add Wedge/Tweak to Chassis Using Side
Shocks
Softer Side Shock Springs
Stiffer Front Springs
Softer Center Shock Spring
Decrease Center Shock Spring Tension
Try Harder Front Compound Tire
Try Softer Rear Compound Tire
Move Battery to Center of Car
Raise Front Ride Height
Lower Rear Ride Height
Move RF Suspension Out
Move RR Tire Closer to Pod
Increase Castor
Car Pushes or Understeers



Slide Wing Toward Front of Car
Decrease Wing Angle
Remove Wedge/Tweak to Chassis Using
Side Shocks
Stiffer Side Shock Springs
Softer Front Springs
Stiffer Center Shock Spring
Increase Center Shock Spring Tension
Try Softer Front Compound Tire
Try Harder Rear Compound Tire
Move Battery Toward Left Side
Lower Front Ride Height
Raise Rear Ride Height
Move RF Suspension IN
Move RR Tire Away From Pod
Decrease Castor
Steve.
TeamCW

I stand corrected... see, even magazine guys can get it backwards. LOL :freak:

One other note to keep in mind is that turning the collar in either direction doesn't actually increase tension it just moves weight/changes ride height.

It changes ride height, but it doesn't move weight....
You can't move weight, unless you actually "move" weight...

Wow....Until steve posted the correction I was sitting here reading this...I have been racing oval approx. 10 years.....And after drinking 5 beers...was thinking...Can I have
been screwing this all up for the last 7 years or so?.....thanks Steve...was about to
shoo myself in the groin.....Steves post is correct guys...

Thanks Steve. I had read that earlier and was wondering if it was a misprint.

Wow....Until steve posted the correction I was sitting here reading this...I have been racing oval approx. 10 years.....And after drinking 5 beers...was thinking...Can I have
been screwing this all up for the last 7 years or so?.....thanks Steve...was about to
shoo myself in the groin.....Steves post is correct guys...

Ya I must've been drinking a bit! LOL.

Dan I didn't mean it phyically moved it. I meant same way it shifts when change weight on each wheel when you change your side shocks.

Good point (about the scales) Eric, put your car on a set of scales, read the weight, then make a seriouus change to the center shock spring tension and THEN re-weigh the car. Ralf

Good point (about the scales) Eric, put your car on a set of scales, read the weight, then make a seriouus change to the center shock spring tension and THEN re-weigh the car. Ralf

I'm not trying to start some sort of physics war here,
but this idea that changing your center shock setting, or the spring itself,
somehow adds or takes weight off the front, is just not sound.

You cannot change the weight of an end of a car, or of the side of a car,
unless you actually move something like the RX, or ESC, or your ballast...

Now... you can change the CORNER weights with changes in springs,
but never end or side weights.

This came up once before, I wish I knew where the post was,
for the sake of accuracy, I did three scenarios, two times each.
One was with a center shock spring, one without, and one with no side shocks. (iirc)

The rear weight was the same for all three examples, which it should be.

Anyone that has ever worked on real race cars, will tell you the same thing.
You cannot change front weight, or rear weight, by cranking springs.

If your scales indicate that you can, you need to get new scales..... :rolleyes:

I'm not trying to start some sort of physics war here,
but this idea that changing your center shock setting, or the spring itself,
somehow adds or takes weight off the front, is just not sound.

You cannot change the weight of an end of a car, or of the side of a car,
unless you actually move something like the RX, or ESC, or your ballast...

Now... you can change the CORNER weights with changes in springs,
but never end or side weights.

This came up once before, I wish I knew where the post was,
for the sake of accuracy, I did three scenarios, two times each.
One was with a center shock spring, one without, and one with no side shocks. (iirc)

The rear weight was the same for all three examples, which it should be.

Anyone that has ever worked on real race cars, will tell you the same thing.
You cannot change front weight, or rear weight, by cranking springs.

If your scales indicate that you can, you need to get new scales..... :rolleyes:

By adding center preload you "transfer" weight to the nose, not "add" weight.

Now... you can change the CORNER weights with changes in springs,
but never end or side weights.

I know your not Dan, it is possible for everyone to talk about this like normal people :) Maybe theres a misunderstanding, we are talking about the same thing... corner weight. if you move collars it does "jack" weight to differnt wheels and that is what I was saying as you said above too.

Tornado- yes you are right I guess the mix up was just in wording.

In my experience if the car is tight running a harder center spring will really improve steering, especially at corner entry. I run the stiffest spring that track conditions allow.

Doug p

I have never raced REAL cars but I have NEVER seen a real car with a "center" shock. Howerver, the rules of physics must be out of wack in my workshop as I can change the weight on the front and rear wheels by moving the collar on my center shock while the car is on the scale? I guess the change is actually a "transfer" ? Ralf

Ralf- If you add the left front and the right front together, and the same for the rear, does it change the totals from the front to the back?

The misprint thing sure clears my thinking up a little. Since you printed the CW's tips and I a different question. It's not about the center shock this time. It says to try -Stiffer Side Shock Springs - for an understeering car. Why do you go to a stiffer side shock spring. Does going to a stiffer shock spring let the weight trasfer quicker to the outside tires thus increasing more tire traction. Do you change both side springs at the same time?

Ralf- If you add the left front and the right front together, and the same for the rear, does it change the totals from the front to the back? Will try that tomorrow, didn't add the weights on each side but if I remember correctly both weights went up, one side more than the other. Ralf

I know your not Dan, it is possible for everyone to talk about this like normal people :) Maybe theres a misunderstanding, we are talking about the same thing... corner weight. if you move collars it does "jack" weight to differnt wheels and that is what I was saying as you said above too.

What I was trying to do, was make sure that others,
who may not be familiar with some of this stuff,
do not make the mistake of thinking that if you
put a stiffer/softer spring on the center shock,
that it makes the front end heavier/lighter...
Some people read these posts to learn things.
I'm one of them..
And if they read something that is vague,
they are not being helped... :confused:

Lot's of times, we may use a term that 'we' have an understanding of,
but it may not be the 'right' term.
And mean something different in other circles.

I want those curious, to know, that changing a center spring,
has an effect on weight TRANSFER... during race conditions,
and not weight, by itself.

So if what one is talking about is actually 'transfer', then it needs
to be mentioned that way, so that it is more clear to the readers..

I'm trying to explain that if the rear of your car weighs 550grams,
that no matter WHAT you do to the springs, it will ALWAYS weigh 550grams.
Until you actually move something on the car... :thumbsup:

If you have lr 350, and rr 200, and change to a stiff rr spring,
your weights might be lr 400, and rr 150.
But the total will still be 550....
You can't make the rear 'heavier' by cranking a spring.

(Ralf.. the rules of physics are the same in your shop....
I'd sooner think that you may be seeing a variance in a
less than scientific measuring device, than a quirk in the laws of physics ;) )

Dan, you are right about using the correct terms. If we don't then people will get confused. :thumbsup:

The misprint thing sure clears my thinking up a little. Since you printed the CW's tips and I a different question. It's not about the center shock this time. It says to try -Stiffer Side Shock Springs - for an understeering car. Why do you go to a stiffer side shock spring. Does going to a stiffer shock spring let the weight trasfer quicker to the outside tires thus increasing more tire traction. Do you change both side springs at the same time?

Stiffer side shock springs in my experience, quicken steering response at corner entry. No you do not need to change both at the same time but it seems that the springs should be close ot one another, like a 17# and a 15#. If the car is tight a heavier LS spring will help steering and if it a little loose, especially at corner exit a heavier RS spring will help.

Doug P

I have never raced REAL cars but I have NEVER seen a real car with a "center" shock.

But.. you have a seen a car with two rear springs..
That center shock, is actually the 'two' rear springs on the car.
It just happens to be in the middle, and one is missing... :)

But.. you have a seen a car with two rear springs..
That center shock, is actually the 'two' rear springs on the car.
It just happens to be in the middle, and one is missing... :)

The center shock is a torque arm ... it controls rear end torque during acceleration, transferring this energy into the tires, increasing straight line traction. There is no up/down suspension on the rear tires.

The side springs control the car roll when cornering. The more the car will roll while cornering the more side bite it'll have. Rule of thumb is ... low bite to race surface require softer side springs, high bite to race surface require stiffer side springs. If you're setup using too stiff side springs, the car will slide all 4 wheels in the corner, you want to create the proper amount of roll (side bite) for your tire setup and track surface you're racing on.

Steve.
team CW

But.. you have a seen a car with two rear springs..
That center shock, is actually the 'two' rear springs on the car.
It just happens to be in the middle, and one is missing... :) Still do not think you can compare it to a REAL car in that I have yet to see a REAL car that has a t-plate with what is basically a "hinge" in the rear of the car? You will have to give me a better explanation than that. Ralf

The center shock is a torque arm ... it controls rear end torque during acceleration, transferring this energy into the tires, increasing straight line traction. There is no up/down suspension on the rear tires.
Steve.
team CW

Steve...
You have always answered my emails whenever I asked a question,
and I want you to know, I am not saying you 'are wrong'.
Your accomplishments in this hobby are remarkable.
But I do think it is 'your' theory, and I have mine.
I want to offer this for yours and others' consideration.
Open discussion makes us think, and learn... from each other.

I 'think' you are wrong in your assertion that the center shock is
actually a torque arm, and that there is no rear suspension.
There certainly is rear suspension.
If your car goes over a very small bump, the chassis stays in it's place,
and the rear wheels move up.
Granted there are no vertical springs, like on a car,
but the chassis is still suspended. Or else it would be on the ground.
By definition alone.

A torque arm is pretty much what it says it is.
It is an arm, that resists torque values.
In this case, the r/c cars, that resistance comes from the t-plate,
not the shock.

I ask you think about this.
If you disconnect the center shock, the car will still function
as it should. Meaning that the torque of the motor/axle combo
is resisted.
If you disconnect the t-plate, and leave the centershock connected,
the torque of the motor will just violently twist the rear pod.
As it has nothing to actually resist it's torque action.

The force applied to the carpet, from torque, is the result
of the rear pod trying to pick up the chassis.
Via the t-plate.
(again... visualize the car with no shock)
The weight of the chassis resists this torque,
so the energy is forced down on the tires.
Kind of like when you try to pick up a refrigerator.
If you weigh 200 pounds, and are standing on a scale,
when you try to pick that object up, the scale reads more weight...
The fridge doesn't move... you go down.

If the t-plate, were extremely rigid, enough so that the need for
a shock was gone, the torque reaction would be so instant,
and unpredictable, that the car would loose traction.
The idea of the shock, is to soften that reaction..
The idea of different rate springs, and different oils,
is to allow variable/tunable dampening of this action.
A real torque arm, is a solid connection to the rear axle.
The t-plate is a solid connection to the rear pod....

On our race cars, we used to play with different dampening
devices, and rates, on the torque arm.
Exactly like we do with the center shocks on r/c cars...
We tried rubber donuts, snubbers, and even coilovers.
(notice the similarity..)

It's very difficult to compare 'to the letter' r/c and real.
Because on an r/c car, as Ralf pointed out, there isn't a spring
for each side of the car. But again, that doesn't mean there is
no suspension... just because it doesn't look like a real car.
So what has to happen, is the t-plate
has to now do two things. It has to act part of the time as suspension,
Which is why it is allowed to flex some, and part of the time as torque arm....
Primary function always on torque arm.
Secondary, on suspension.
Because we need to resist torque, constantly,
but we don't need to have fully functional suspension,
in this particular application.

5 and 6 coil race cars (one for each wheel, and one or two for the torque arm)
are pretty common. And if you ever saw one, you would see that they are,
if you can think 'outside the box' exactly what we run... in theory.
In fact, years ago, they tried a system, where the torque arm was made
from Kevlar, so that it COULD actually flex. (Ralf.. the example you asked about :) )
This system was EXACTLY like our t-plate cars...
(if you can visualize outside the box)....

You are dead on, on the side shocks.
The side shocks on our cars, are much more closely related to an
anti roll bar (sway bar to some).
But... as in the case with the t-plate,
they also act partly as suspension componants in conjunction
with the t-plate.
Primary function, anti-roll.
Secondary function.... suspension.

Again... this is my theory... just sharing it for discussion.
But if you can ever check out a 5th coil setup on an oval car,
and try to look at the similarities... I think you'll see where I'm coming from.
And if you could see one of the old Kevlar torque arm types,
you'd see that it IS a t-plate... :thumbsup:

Dan you can disagree with Steve, I do all the time. I agree with most of what your saying, except this part "If you disconnect the t-plate, and leave the centershock connected, the torque of the motor will just violently twist the rear pod. As it has nothing to actually resist it's torque action." I think the Shock does add some resistance opposing the torque of the motor. The piston thru the oil resists the torque of the motor.

Dan you can disagree with Steve, I do all the time. I agree with most of what your saying, except this part "If you disconnect the t-plate, and leave the centershock connected, the torque of the motor will just violently twist the rear pod. As it has nothing to actually resist it's torque action." I think the Shock does add some resistance opposing the torque of the motor. The piston thru the oil resists the torque of the motor.

You can disagree with him, Mike, because you know him...
I don't want him (or anyone) to think this is anything but bench racing..... :(

Mike, maybe you didn't read, what I was thinkin'... :drunk:

I said disconnect the t-plate.
As in, remove the two pivot ball screws...
Leave the shock connected... and nail the throttle...
The pod will just go spazoid, right?
There is nothing "connecting" it to the chassis...
No place for the torque to be absorbed/resisted...

A torque arm, controls torque.
So this was just a visual/mental test, of which would do what,
independently of each other.
The t-plate, would always serve it's purpose.
Whereas the shock would not.
Which to me is the litmus, to which is what...

I agree with, as well, in that the shock oil/spring offer
resistance, but it is a variable, the part we mess around with,
with it's primary function to dampen the spring action,
and not contribute to it.

(except in that "sharing mode" where the t-plate is acting in
part like a spring, over bumps..)

Steve...
:thumbsup:

:) I stay on my position 100%.

We could talk about it for days... :p

Steve.

BTW ... I also know full scale race cars ...

I have a problem maybe someone can help me with. I am running a custom works and the car seems to be pretty good with the exeption that every once in a while the car will bicycle or traction roll coming off of the corner. I can't tell if the right front spring is collapsing or if it is carring the left rear. Thanks in advance any suggestions will be appreciated. -Joe-

######

I have a problem maybe someone can help me with. I am running a custom works and the car seems to be pretty good with the exeption that every once in a while the car will bicycle or traction roll coming off of the corner. I can't tell if the right front spring is collapsing or if it is carring the left rear. Thanks in advance any suggestions will be appreciated. -Joe-

Please detail the track layout and surface, tire setup (also, what traction coupound), spring setup, static chassis height, etc ...

Steve.

The track lay out is app. 156 foot run line. I am running Purple rr purple RF pink left front and pink LR. I have a white rf spring and a red lf spring made by Murdock. This is 4300 brushless class and we have to run Jack the gripper. Seems to be low bite carpet track. Also red RR spring and a gold LR spring. 2 degrees of camber on the rf and also the left front. I am not to sure on the height of the chassis, probably a little on the high side. When I lower it the front hits the track and the problem seems worse. Thanks Joe

:)

BTW ... I also know full scale race cars ...

I know... :thumbsup:

:) I stay on my position 100%.

We could talk about it for days... :p

Steve.


Heading out to Richmond in a few minutes,
maybe we can pick it back up next week...
You're a good sport, Steve. :thumbsup:

Dan.

The track lay out is app. 156 foot run line. I am running Purple rr purple RF pink left front and pink LR. I have a white rf spring and a red lf spring made by Murdock. This is 4300 brushless class and we have to run Jack the gripper. Seems to be low bite carpet track. Also red RR spring and a gold LR spring. 2 degrees of camber on the rf and also the left front. I am not to sure on the height of the chassis, probably a little on the high side. When I lower it the front hits the track and the problem seems worse. Thanks Joe

Purple RF tire in combination with a white RF spring sounds like real agressive to me.

I'd personnaly use red springs on both sides (0.010 sag on both sides, that's on a race ready car without the body). I'd also set the front chassis height so the RF is .010 to .020 higher than LF.

Last but not least ... Put your car down on digital scales and set your cross weight to 48.5% ... that's with a race ready car (body on, etc.). Your car is possibly just too loose, as soon as you get your car sliding with these tires you'll easily traction roll.

Steve.

Thanks Steve I'll give it a try. It just seems weird that I am doing it coming from the center of the corner off.
Joe