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Thanks for the compliment Karl.The spring perches are reinforced and I use heavier ubolts.Am having a problem with the front spring mount cracking the weld though.Needs reinforcement there too.Chris

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Ok non-engineers get a pass, but you engineers need to study a little more! Many people got this right, but nobody got it for the right reason.

First of all... Lets talk basics.

Torque= Force x Distance

So if you have 500 ft-lbs of torque. That is equal to

500lbs x 1 ft

OR

1 lb x 500ft

You can easily see that with a given input torque (from the axle) the force to counteract that force gets LOWER as the length gets longer.

Practical example:
You have a tight lugnut you need to get off. It is applying a torque to stay tight. You have to counter act this torque with a wrench and a force. We all know as the wrench gets longer, the force gets smaller.

Torque=Force x Distance.




Everything above as Stated is Correct IMO

Everything below as stated is mostly incorrect.IMO

I will give my arguements on this tommorow And its all good, I look forward to sparring with you dizuster, you know your stuff. mike








What you need to think about though is the distance from the application of the torque center, to the point the force is being applied. In this case, the critical area for high force is near the front eye of the spring. That's because the spring is at it's weakest point with only one leaf section there.

So if you think about the geometry, the spring is in an arc. As you space the axle upwards, the axle center actually gets closer to that front eye of the spring! Think about if you were to measure from the eye of the spring straight rearward, it's a shorter distance then if you measure on the angle downward. This means as you space the axle upwards, the distance gets shorter.

Torque=force x distance.

The torque is the same no matter where you put the axle. So if you space it upwards and the distance is shorter, the Force is actually increased.

So yes, the forces on the spring get worse with the lowering blocks, but it's not because the distance get's longer, it's because it gets shorter.

Hope that's not too confusing, if anyone wants a picture (Free Body Diagram) just ask and I'll draw one up and post it...

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Ok non-engineers get a pass, but you engineers need to study a little more! Many people got this right, but nobody got it for the right reason.

First of all... Lets talk basics.

Torque= Force x Distance

So if you have 500 ft-lbs of torque. That is equal to

500lbs x 1 ft

OR

1 lb x 500ft

You can easily see that with a given input torque (from the axle) the force to counteract that force gets LOWER as the length gets longer.

Practical example:
You have a tight lugnut you need to get off. It is applying a torque to stay tight. You have to counter act this torque with a wrench and a force. We all know as the wrench gets longer, the force gets smaller.

Torque=Force x Distance.

Ok now for the specific example, Maximum E. almost got it right in the begining, he was on the right track.

You can see from my example above that the longer distance would have less force on the spring (less wheel hop). So many of you are thinking, then why when I add 2" of lowering blocks does the wheel hop get worse (Just as mentioned by the old guy above who probably hasn't read this far because he only cares what he knows, not why it works)

What you need to think about though is the distance from the application of the torque center, to the point the force is being applied. In this case, the critical area for high force is near the front eye of the spring. That's because the spring is at it's weakest point with only one leaf section there.

So if you think about the geometry, the spring is in an arc. As you space the axle upwards, the axle center actually gets closer to that front eye of the spring! Think about if you were to measure from the eye of the spring straight rearward, it's a shorter distance then if you measure on the angle downward. This means as you space the axle upwards, the distance gets shorter.

Torque=force x distance.

The torque is the same no matter where you put the axle. So if you space it upwards and the distance is shorter, the Force is actually increased.

So yes, the forces on the spring get worse with the lowering blocks, but it's not because the distance get's longer, it's because it gets shorter.

Hope that's not too confusing, if anyone wants a picture (Free Body Diagram) just ask and I'll draw one up and post it...

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I'm no engineer but I have enough experience in auto repair that I think I can comment...I don't agree with this:
"So yes, the forces on the spring get worse with the lowering blocks, but it's not because the distance get's longer, it's because it gets shorter."

I agree that the distance between the axle center and the spring eye get shorter, but it's the force that the axle perch exerts on the center of the spring that causes the windup,not the spring against the eye. Spacing that perch farther from the spring will make it more prone to rotate IMO. Can a car be built with a 2"lowering blocks and be strong enough that it will hold together and run 8's? Sounds like it.Is it optimal? I don't think so.

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As you space the axle upwards, the axle center actually gets closer to that front eye of the spring! Think about if you were to measure from the eye of the spring straight rearward, it's a shorter distance then if you measure on the angle downward. This means as you space the axle upwards, the distance gets shorter.

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And there's no need for a free body diagram, it's a Mechanical Vibrations problem, not a Statics problem where everything is assumed to be rigid.

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