Y space out rear left shock?

[Japko]

Why? As far as I know, spring rate does not change through compression, so this would only increase ride height and limit compression.

Any thoughts from the think-tanks?

[chvy4wd]

Some people say that it helps with torque twist. When you mount the shocks toward the outside of the axle it doesnt have as much leverage vs. mounted toward the middle. So the shock doesnt compress as easily. If that makes sense.

[fortysixandtwo]

Forgive my ignorance as I am new to RC crawling but is this a trend or something? To angle out the rear left shock?? I am a little confused.

[Japko]

I know it's SUPPOSED to help with torque twist, but i don't see how.

[Deezul]

don't angle it out. Just add a spacer above the spring. It makes it stiffer on that corner and does not TT as bad

[One-eyed Jack]

Originally Posted by Japko

Why why why? As far as I know, spring rate does not change through compression, so this would only increase ride height and limit compression.

Any thoughts from the think-tanks?

The spacer does increase ride height. In doing so it also increases wedge which makes the left rear wheel support more weight under static conditions. When the crawler begins to torque twist you have already compressed the spring some with the spacer therefore it must twist more to overcome the spring tension. This will limit the right front wheel lift in proportion to the additional spring compression. The spring "rate" does not change. Assume 5lb rate and three inch compressability. To compress one inch takes 5lb, to compress two inches takes 10lb. If you already have it under 5lb compression you will not see any increase in compression until you exceed 5lb.

[MystRacing]

Also to add to the post above. Wheel rate is how much pressure it takes to lift the wheel a set distance, or more correctly how much pressure it takes to compress the suspension a set distance. It's a function of the suspension geometry and the spring rate. On a solid axle the distance from the center of third link / pumpkin would be equivilent to the a-arm length in the picture below. The closer the shock bottom is to the wheel the less leverage the wheel has to compress the spring and consequently the higher the wheel rate, or in laymans terms the more pressure it would take to compress the suspension. So moving the bottom of the shock out does stiffen the suspension; whereas adding a spring retainer just pre loads it instead of actually making it stiffer.



You can work the numbers and figure out how much if you wish. Also if you really want to play with a brain teaser as the suspension compresses the angle of the shock changes which causes the suspension to become more progressine or regressive as it compresses. Because the angle between the axle housing and the shock increases as the axle twists the suspension is progressive or gets stiffer as it twists. If you look at the truck from the side the suspenion becomes more and more regressive as the suspension is compressed because the angle between the shock and the centerline of the links becomes less. The point being the shock angle has a huge effect on how the vehicle handles.

Just as a side note moving the top of the shock out also increases the stiffness of the suspension but not as much because it's just changing the angle which has less effect than changing the distance on the bottom of the shock. (This is assuming the shock is leaning in and doesn't go over vertical.)

[rc4x4crawler]

I think I know what you mean. There is a way to do this without raising the car. It is to space the shocks away from the chassis and out further on the axle. This will almost guarentee a loss of torque twist. This also makes it so that your suspension doesnt become stiffer.

[MystRacing]

Yeah now that you mention it. If you move the top and bottom out the same amount. It makes the suspension stiffer if you twist the axle housing. I you keep the axle housing level and compress the whole rear suspension it hasn't changed the stiffness.

[treeafodo]

Spacing out the shock makes it a little "thougher" so that when you gun the throttle it's harder for the chasis to lean to the left, which is torque twist

Simple explantion but i hope it helps

[twistedsmily]

wow my brain hurts lol

[irok]

This has all been discussed alot,just do a search on 'torque twist'
you'll come up with all kinds of solutions and opinions.

[constantmotion]

Originally Posted by One-eyed Jack

The spacer does increase ride height.

The spacer doesn't increase ride height. The only way it would is if the shock has a little bit of droop at normal stance (it'll extend the shock to full length). The spacer just adds more tension to the spring.

[rc4x4crawler]

Originally Posted by treeafodo

Spacing out the shock makes it a little "thougher" so that when you gun the throttle it's harder for the chasis to lean to the left, which is torque twist

Simple explantion but i hope it helps

No actually spacing the shock away from the chassis side plate and on the out side axle mont gets rid of most torque twist.

[naggalowmo]

Originally Posted by Deezul

don't angle it out. Just add a spacer above the spring. It makes it stiffer on that corner and does not TT as bad

Unless you are using progressive springs, spacers will not make it stiffer. It will only preload the shock and spring but spring rates remain the same.

[Japko]

Originally Posted by naggalowmo

Unless you are using progressive springs, spacers will not make it stiffer. It will only preload the shock and spring but spring rates remain the same.

That's what I meant. So the idea isn't to stiffen, but to preload.

I am not sure what this means when going downhill and to the left - can't be good as the car is biased towards the right side.

[One-eyed Jack]

Originally Posted by Japko

That's what I meant. So the idea isn't to stiffen, but to preload.

I am not sure what this means when going downhill and to the left - can't be good as the car is biased towards the right side.

Any time you tweak your chassis there is a trade off. If you change the value at any corner it will change how the truck and/or chassis reacts. The trick is to decide which is more important. Torque twist is a shafty given. Put a MOA on the back,torque twist gone. No "ONE" setup is good for everthing.

[One-eyed Jack]

Originally Posted by constantmotion

The spacer doesn't increase ride height. The only way it would is if the shock has a little bit of droop at normal stance (it'll extend the shock to full length). The spacer just adds more tension to the spring.

I think that is what Japko was implying. The shock was not fully extended. As far as I know the shocks lenght has the most to do with ride height. If he had a spring on it that did not droop some it was probably too stiff in the first place and a spacer would not affect ride height. I have not tried it but a solid rod would probably snub the torque twist ? Be kinda rough on the articulation