Cutting Coils: Let the hate flow....

[Gunman]

IMHO "closed, not ground".

Definitely cut from the open end, the closed end helps locate the spring.

[wparsons]

Originally Posted by Gunman

By cutting the coil, you reduce the over all length, thus reducing the amount of active coils, and this increases the spring rate.

Assuming the spring is completely linear, just cutting some of the spring off won't change the spring rate at all.

It'll change the total force needed to fully compress the spring, but not the spring rate.

[fumanchu1]

Originally Posted by go_a_way1

cutting springs also weakens them near the cut and makes them prone to snap near the cut

Yes, yes it does... ask me how I know

[go_a_way1]

Originally Posted by fumanchu1

Yes, yes it does... ask me how I know

Thankyou haha!!

I still wana see what happens when he cuts his springs so share after he is done

[fumanchu1]

@go_a_way1 this?: Coming up next at the 6 o clock news, a frs/brz jumps off the road after a suspension failure that sent the vehicle rambling down a cliff after a loss of control in a mountain road

[go_a_way1]

Originally Posted by fumanchu1

@go_a_way1 this?: Coming up next at the 6 o clock news, a frs/brz jumps off the road after a suspension failure that sent the vehicle rambling down a cliff after a loss of control in a mountain road

more like this cuz he cant corner anymore

[pushrod]

lol, I love how we're discussing a way of saving <$300 on a $25,000 car with potentially adverse consequences.

[Gunman]

Originally Posted by go_a_way1

Thankyou haha!!

I still wana see what happens when he cuts his springs so share after he is done

The car will be lower. Just like every other car/truck with cut coil springs.

[Gunman]

Originally Posted by wparsons

Assuming the spring is completely linear, just cutting some of the spring off won't change the spring rate at all.

It'll change the total force needed to fully compress the spring, but not the spring rate.

Per this formula, how does reducing the number of active coils, not change the spring rate?

Spring Rate = F/S = Gd4/8ND3 where:
F = spring force.
S = spring deflection.
G = torsional modulus of the material.
d = wire diameter.
N = number of active coils.
D = mean (average) coil diameter.

[go_a_way1]

Originally Posted by Gunman

The car will be lower. Just like every other car/truck with cut coil springs.

Lol no I mean I want to see if he breaks anything else or if they car becomes unbearably bouncy

[renfield90]

Originally Posted by wparsons

Assuming the spring is completely linear, just cutting some of the spring off won't change the spring rate at all.

It'll change the total force needed to fully compress the spring, but not the spring rate.

Uhh. You're contradicting yourself along with basic math/physics.

Spring rate is force divided by distance (lbs/in or N/mm across the pond). If the total force needed to fully compress the spring increases, and the distance needed to fully compress the spring decreases, then by definition spring rate has changed.

[Gunman]

Originally Posted by go_a_way1

Lol no I mean I want to see if he breaks anything else or if they car becomes unbearably bouncy

Of all the cars/trucks I've seen with cut springs, I've never seen anything break, and only unbearably bouncy if the bump stops aren't cut, or the frame notched in some cases.

[wparsons]

Originally Posted by renfield90

Uhh. You're contradicting yourself along with basic math/physics.

Spring rate is force divided by distance (lbs/in or N/mm across the pond). If the total force needed to fully compress the spring increases, and the distance needed to fully compress the spring decreases, then by definition spring rate has changed.

Where did I say the force needed to fully compress the spring increased by cutting it? It would be decreased because there would be less length to compress.

[Gunman]

You can play with this, reduce the number of active coils, and watch the spring rate increase:

http://www.pontiacracing.net/js_coil_spring_rate.htm

Cutting a coil spring, is the same as reducing the number of active coils.

Another:
http://www.racingsuspensionproducts....ing%20rate.htm

and one more:
https://www.easycalculation.com/phys...pring-Rate.php