Originally Posted by SMR 510RR (Post 10851677)

My responses are in blue.

2.The suspension is absorbing some of this pressure, we know this because the right tire is lifting up.
Absorbing?
Yes, absorbing. If the tire "lifts" while the chassis leans that means that there was extra downward pressure that is no longer going to push down on that tire because the spring absorbed the energy. A stiffer spring, swaybar, or suspension (roll center) is changing where the force goes.
Springs don't absorb energy though; they store it.

3. Not all of the weight that has transferred is being directly applied to the tire.

Clarification for what you mean exactly by "not ... directly applied to the tire"?

The pressure that would have been applied if we had no suspension (assuming a perfectly flat surface) would have been higher than the amount of pressure pushing down on the tire after you factor in the energy that was absorbed by the spring, swaybar, and suspension.
Again, springs don't absorb energy and swaybars just transfer it. Forces don't get absorbed and vanish.

4. With a surface that has ample traction (lets say for a moment that it is ideal and there is no slide) there is no need for the right tire to lift, in fact if it pushed down it would actually help us get MORE traction.

Yes and no. Yes because the higher traction surface you are on, the less need for weight transfer (or lift as you called it) and this is exactly why stiffer springs or swaybars are used on on high traction surfaces. If there is no need to generate more traction, you want to minimize losses due to chassis sway and the like. No, because with the chassis leaning over there is literally more weight on the right side. Since the sum of the forces must equal zero in a constant state system (which this is for a sitting chassis that is leaning over) there is more pressure being placed on the tire since there is more weight on it. There is no lost force. You are thinking of a state of acceleration when you say if it 'pushed down' it will generate more force. If the spring pushes down harder than there is weight on the chassis, the chassis accelerates upwards. In that instant you will have more traction, but as soon as you stop the chassis from accelerating up it is gone.

On the higher traction surface you naturally have more weight transfer than on the looser surface assuming that the vehicle weight and speed is the same. See this is where it gets confusing. Assuming that two of the exact same car/truck took the same corner at the same speed and everything was the same except for the suspension (one stiffer one softer) there would be the same amount of weight transferred assuming that neither lost traction. The inertia is being redirected from straight ahead to towards the left, but from what we know about inertia it does not want to move. Since the center of gravity is higher than the surface we are turning on the weight of the chassis is rolling to the right. Now here is the majic, the car/truck with the stiffer suspension is resisting the roll much more than the other car so more downward force is being applied to the outside tire and less to the inside tire than the car/truck with the softer suspension. Just because one car leans over more does not mean that it is transferring more weight. Focus on where the weight is going rather than how much is transfering. With a soft suspension it is constantly more even across the left/right sides of the chassis than with a stiffer suspension.

I'm sorry, but most of this is just incorrect suspension dynamics. Pardon the choppy response, but I'm going sentence by sentence. If the weight and speed are the same, a higher traction surface has more potential for weight transfer as you can carve a tighter corner. No, the same amount of weight is not being transferred. The softer car will roll more so the COG will shift more to the outside placing a greater load on the outside (see a later paragraph as to why), thus transferring more weight. Yes, the inertia is being re-directed. Yes, the COG is above the surface we are turning on. Yes, the car is resisting the roll much more but that does not translate to more pressure on the outside tire (again, see a later paragraph). It is exactly because the chassis is rolling that more weight is being placed on the outside tire. "Focus on where the weight is going" is where you need to re-think your physics. No, a stiffer car will have more even pressure on all 4 tires through the same corner compared to a softer car.

If you want to see this concept in action watch a fast drag car launch. Your initial thought would be that the best launch would transfer a bunch of weight to the rear, the suspension would squat, and the car would launch and be gone. In reality, most fast drag cars do not squat at all they actually stay rather level or the rear of the car lifts (anti-squat) getting the maximum amount of force to transfer from the chassis directly to the tires and then into the ground.

They don't squat because they don't need more traction. They are trying to resist blowing over backwards. If you don't need more friction at the tires you want to minimize those losses. Let's look at another drag racer; the snowmobile. We drag race them on all types of surfaces... asphalt, grass, snow, and even water. Comparing the asphalt drag snowmobile that has literally unlimited traction to a snowmobile on grass or snow that don't have unlimited traction you will see two completely different results at launch. The asphalt sled acts just like a dragster. The snow/grass racer squats so much the front skis are hovering over the ground as all the weight transfers to the rear to maximize the available friction.

They do need traction, on a perfect flat surface with tons of grip you get the most traction by maximizing how stiff the suspension can be. This may not translate as well because it is a polar opposite to our situation but I know this is true.

No, you don't maximize traction by how stiff the suspension is. You minimize chassis roll on high traction surfaces by how stiff the suspension is. If what you say were true they would be running much higher angles on the trailing links to stiffen it even more.

Of course it is different in our application because we are A. Talking about turning and B. on a sub optimal surface. The challenge becomes figuring out if the suspension reaction is too stiff causing too much weight to be applied or too soft absorbing more of the weight that should have been transferred. In all reality (not quite sure but it should be right) the same amount of weight is transferring from left to right its just where it gets absorbed or transferred that we are trying to control.

Again, too soft doesn't 'absorb' anything. The force gets to the ground no matter what.


Are you sitting at a desk? Good...Grab a pencil and grab a rubber band. Take the pencil and put it down on the desk so that the end is hanging over enough for you to grab it, make sure the rubber eraser is away from you. Now grab the end, transfer weight from your side to the end (lift it up a little and push down) and try to push it away from you. Now grab the rubber band and do the same exact thing. What one transferred more weight into the "tire"? Your rubber band (spring) is absorbing the energy and storing it for later, when the weight is lifted it goes back straight. Now I think one of the important functions of the suspension is to "dampen" the shock of the weight transfer so that it comes on evenly otherwise there would be too much energy too fast and you would loose grip very quickly. Its all about balance, the weight of the truck is always pushing on the ground its just a matter of where it is pushing. Remember this test was of two polar extremes.

This experiment needs some refinement. Here's my version:
Have a postage scale and a hanging scale? Good...Grab that pencil again. Take the pencil and put it on the scale so that the end is hanging off. Place one finger in the middle of the pencil and hook the hanging scale onto the end that is hanging off. Lift up with the hanging scale until just the eraser is on the postage scale and then continue to pull up on the hanging scale while pushing down in the middle of the pencil so it stays on the other scale. Look at the forces on each scale; they are identical. The pencil doesn't flex, so there is very little displacement, but the same force applied at one end is applied at the other. Now go get one of those plastic rulers that flex like crazy and usually ended up broken within days. Perform the same experiment. Once again the force you pull up on with the hanging scale matches the force measured on the postage scale. What changed? The distance you had to pull the hanging scale to get the same force. This is what springs do in a steady state: conserve forces. If I push on a spring on my desk with 1 lb of force, no matter how stiff or soft the spring is the spring will be pushing against the desk with 1 lb of force. A stiff spring my only compress 1 cm and a soft one may compress 5, but it doesn't matter. The force placed on top of the spring in a steady state is the force that is exerted at the bottom of the spring.

Here's that paragraph I referred to earlier:
There are 2 primary forces determining how much weight is placed on each tire - the weight of the car (center of gravity) and inertial forces based on acceleration. For a turn of the same radius and velocity the inertial forces are identical if the COG doesn't move up or down. When you soften up the springs/swaybars and allow the car to roll you are allowing the COG to shift. This is more blatant with soft springs and the COG moves towards the outside. The spring doesn't absorb/eat/dissolve/eliminate any force; it just compresses further if it is softer which places the COG even further to the outside. Better yet, the suspension arm is moving in as it compresses shortening the distance between the COG and the contact patch which means more force is required to supply the same 'torque' moment on the chassis. When people want to remove traction from either end of the car, stiffer springs or swaybars are used. Car is over steering mid corner? Stiffer front swaybar/springs or softer rear swaybar/springs.

Originally Posted by driver5150 (Post 10852281)

With the exotek chassis do people like the pro 4 4000 or 4600?

Originally Posted by Krio (Post 10851969)

My final responses in green before I should probably just pm you to avoid mucking up the thread. :lol:

Originally Posted by Vegatron75 (Post 10852923)

Have to say, the V2 center diff is working real nice. Ran the outdoor track for the second time last weekend. Was running 4 pins in the diff, this along w/ the 8mm mod makes for a whole nother truck.

Took the win with ease....... Loving it.......

Originally Posted by Arakon (Post 10849191)

25C is somewhat low for a heavy truck like this. Also, 3V is a very low cut-off point.. Since only total pack voltage is checked, it's very easily possible that one cell was at 3.4V under load and the other at 2.6V, which is still the 6V for the cutoff, but already harmful for the low cell.

Originally Posted by Wild Cherry (Post 10851006)

*compressed for sanity* ~CS
the last diss with the puppy thing ?
I ask you to give a better word for bind if you knew ... Treated you with respect & maturity ...

Just posting I'm wrong over & over with no correction from you to bring no reason or explanation is pale. Go ahead , post another puppy if you think, its the best you can do ....:lol:

I will just ignore those for now on. I like helping everyone I can and bring positive to the thread... I used a really good term Mantis & you claim is all wrong.

Also "bind" is the same word given to me from drivers way far better & experience then you or me ...
I even agreed with other description's given by Kiro & others ...

Have fun Craig and..... Just Calm Down :D

Originally Posted by CoyoteSlash (Post 10853501)

He's corrected you always telling you you're wrong with the reason why; in depth taking time out of his day to fix your crap so people searching and finding your crappy tech don't read it and take it as true. It's not his problem you can't understand it. He works hard for the lurkers in this thread to keep the tech 'tech' and not the crap you spew out of your keyboard and mouth. One or two others include their time to fix your mess too. (I just don't want to get you guys involved without a 'go-ahead'.)

More examples of your AE Divinity. Do you have statues of Hartson in your closet you pray to, too? Get over yourself WC. It's long overdue.

As far as puppies... This seems to be pretty valid when I read your tech:
http://img62.imageshack.us/img62/8810/1338641388898.jpg
- You gonna say that's all I can post too?

Go ahead and report me, tough guys. :lol:

Originally Posted by Wild Cherry (Post 10853786)

added 4 oz's + 2 1/2 oz already on me ride

Originally Posted by Jake S (Post 10853812)

pics or it doesnt fit :D

Originally Posted by Wild Cherry (Post 10853823)

used
1oz in ft & 1oz behind battery=2oz
1 oz along each side of battery = 2 oz
2 oz along back of chassis
1/2 oz by spur

Originally Posted by Wild Cherry (Post 10853786)

. . .

Pounded on some weight for testing tonight

added 4 oz's + 2 1/2 oz already on me ride

. . .

If your track has limited traction, dusty & slippery ?
Adding extra weight may prove to be very helpful, specially for outdoor .