$60 coilovers off craiglist

[ikayto]

how stiff were the ground controls? my interpretation of why the GC felt better was because the GC did a better job at holding your car up then ebay coilovers--less resistant to force pushing down with better spring rate. Shock wasnt meant to work overtime or by itself.

Lol, no a soft spring with a stiff shock will not blow faster. The shock dampens the spring's motion. The spring's natural motion is to return to neutral, that is, it is not under compression or tension. A stiffer shock will dampen this motion more quickly.

i sort of understand this part now, forgot the spring doesnt push down on the shock itself, but whenthe spring compresses the shaft of the shock goes down since the car's body is also.

mmk, i see your point, but ebay coilovers arent stiff captain ><

[mndude07]

another piece of the formula is ride height, spring length, progressive style springs, and x.x

Yes, true, but our argument is about situations in which the spring force is higher than the damping force, and vice-versa.

If you compress a spring with no damping at all and let it go, its going to oscillate(bounce up and down) and eventually stop. If you now put a damper on this spring and repeat the process, and the the damper is too weak, the spring will again oscillate and come to a stop, but slightly faster than with no damper. Finally, if you match a damper with a greater force than the spring, when you let the spring go, the spring is going to come to a stop much faster.

If the shock and spring were perfectly matched in force, then one oscillation would occur and then the spring would stop its motion. This is called critical damping. If the damping force is higher than that, then the spring undergoes less than one oscillation, and it is said to be over-damped. However, since the force of the damper is greater than the spring force, not all of the damper's force is used to dampen the spring, which means the damper isn't working as hard basically. This is why stiff dampers on soft springs are OK in terms of longevity (not necessarily on comfort).

I am enjoying this argument lol, I'm very confident that I'm correct. I'll even check with a few of my fellow students tomorrow. We are on our school's FSAE team....this is what we build:

[mndude07]

ive been in a car with ground controll coils and blown oem springs.

it rode 1000000 times better than an accord with ebay coils and brand new agx's.


i hope that helps, eyekaytoe and emendude.

Either the Ground controls were incredibly soft, the ebay coils were incredibly stiff, or your idea of a good ride is very different from mine.

[noobcake]

how stiff were the ground controls? my interpretation of why the GC felt better was because the GC did a better job at holding your car up then ebay coilovers--less resistant to force pushing down with better spring rate. Shock wasnt meant to work overtime or by itself.

i dont remember the rates off the top of my head. they were on a DA.

and this is how i see it.

team ikayto.

but what mndude is saying is the same thing. only different.
a spring with a lesser rate will bounce up and down more than one with a higher rate. the one with the higher rate, will just travel faster.

lol i dont think you guys are even arguing. both of you are just explaining different ways a cheap setup will cause bounce.

edit: and i meant the setup thats less bouncy is better.

[ikayto]

I guess i am thinking in extremes, a super soft spring with stiff shocks will eventually blow because it's working more than it should be in an ideal set up. too much shock shaft travel is dentrimnetal to the shock, it has seals and fluids that get pressurized when the shaft retreats inside the shock body.

but a stiff spring and stiff shock are better in longeivity than the aforementioned set up, correct? since they're matched together in canceling each other out.

what is your definition of a bounce....

stiff cars shouldnt be bouncin a la what you said earlier about your ebay springs being so stiff they made your car bounce.



stiff to me is like yous said, ideally less than 1 oscillation or none--THUD! :]

[mndude07]

i dont remember the rates off the top of my head. they were on a DA.

and this is how i see it.

team ikayto.

but what mndude is saying is the same thing. only different.
a spring with a lesser rate will bounce up and down more than one with a higher rate. the one with the higher rate, will just travel faster.

lol i dont think you guys are even arguing. both of you are just explaining different ways a cheap setup will cause bounce.

No, a stiffer spring will bounce more, provided they are compressed the same. Lets take two linear springs. One is 200lbs/in, and the other is 1000lbs/in. Thats (for example) 200 pounds of downward force needed to compress the spring one inch. Lets compress them both one inch and then suddenly release them with no damping. What happens?

[ikayto]

true, more potential energy in the stiffer pring.

but we're debating on ebay springs sir!

i feel the car bounced more because the shock was just constantly trying to dampen the spring and car but failed.

[mndude07]

I guess i am thinking in extremes, a super soft spring with stiff shocks will eventually blow because it's working more than it should be in an ideal set up. too much shock shaft travel is dentrimnetal to the shock, it has seals and fluids that get pressurized when the shaft retreats inside the shock body.

but a stiff spring and stiff shock are better in longeivity than the aforementioned set up, correct? since they're matched together in canceling each other out.

what is your definition of a bounce....

stiff cars shouldnt be bouncin a la what you said earlier about your ebay springs being so stiff they made your car bounce.



stiff to me is like yous said, ideally less than 1 oscillation or none--THUD! :]

Whether the spring and shock are "matched" or the spring is softer shouldn't matter in terms of shock longevity since shocks spend most of their time in the low-speed range anyway; that motion is going to happen regardless. A shock has to slow down and come to a stop for a very brief amount of time before it can change direction. Since shocks are always damping the spring up and down (in rebound and compression) they are always changing direction thus constantly slowing down most of the time.

[mndude07]

true, more potential energy in the stiffer pring.

but we're debating on ebay springs sir!

i feel the car bounced more because the shock was just constantly trying to dampen the spring and car but failed.

Exactly. The spring was underdamped, which means the shock was not strong enough.

In general, if the ride is bouncy, either get a stronger damper, or a softer spring...not the other way around.

[noobcake]

No, a stiffer spring will bounce more, provided they are compressed the same. Lets take two linear springs. One is 200lbs/in, and the other is 1000lbs/in. Thats (for example) 200 pounds of downward force needed to compress the spring one inch. Lets compress them both one inch and then suddenly release them with no damping. What happens?

the thing is, they WOULDN'T compress the same. the spring with the lesser rate will compress more than one with higher rates. givin that its on the same car.
lol now your steering off into more details and out of the subject. you need a constant car to put different springs on......theoretically.....

[mndude07]

the thing is, they WOULDN'T compress the same. the spring with the lesser rate will compress more than one with higher rates. givin that its on the same car.
lol now your steering off into more details and out of the subject. you need a constant car to put different springs on......theoretically.....

You're right, it will, but the stiffer spring requires a higher force to dampen it. Also, the length of the spring varies. A 200lb spring that lowers the car 2 inches must be longer than a 1000lb spring that lowers the car 2 inches. We have to keep the ride height constant otherwise this argument is skewed. I gotta go to sleep though its 2:20am here lol.

[ikayto]

Exactly. The spring was underdamped, which means the shock was not strong enough.

In general, if the ride is bouncy, either get a stronger damper, or a softer spring...not the other way around.

underdampened... You're placing a lot of pressure on the shock to perform with a bad spring, I understand you can do it that way, but stiff enough springs must be present as well for optimum performance.

I'm saying the car's weight is being pushed down on to the shock now without the aid of the spring. Granted i guess a stiff enough shock can help offset this, but not by much. Springs are critical...

[mndude07]

underdampened... You're placing a lot of pressure on the shock to perform with a bad spring, I understand you can do it that way, but stiff enough springs must be present as well for optimum performance.

I'm saying the car's weight is being pushed down on to the shock now without the aid of the spring.

It sounds like you're talking about a scenario in which the spring is so soft, or put under so much force, that the shock is forced to compress also until there is no suspension movement....aka bottoming out.

If you set a car down on the ground with only dampers and no springs, the shock would compress into equilibrium with the car body. Then the whole car body is acting as a spring, so you might as well put 5000lbs/in springs on your suspension...and no shock will dampen that lol.

[ikayto]

yea, i'm referring to that. i think in extremes.

i may be wrong, you may be right, i'm just going off of what i think i know ahah

seems like we're both saying the same things but i dislike the idea that a soft spring is being underdampened which causes a car to bounce. more or less the car isnt being supported enough by the spring and thus comes down into the shock itself.

[slammed4thgen]

yea, i'm referring to that. i think in extremes.

i may be wrong, you may be right, i'm just going off of what i think i know ahah

seems like we're both saying the same things but i dislike the idea that a soft spring is being underdampened which causes a car to bounce. more or less the car isnt being supported enough by the spring and thus comes down into the shock itself.

youre wrong.