Vroomin350

iTrader: (28)

gville, looks like you are very knowledgeable as far as coilovers, I have the megan EZ, I heard someone say that they are "dual adjustment".

What I am trying to get at is that I feel like the springs might be too soft, read a little on "preload" but I dont understand/grasp the concept.... any help would be GREATLY appreciated, I am mauling my front tires.

GSteg

iTrader: (15)

If the springs are too soft then the springs are too soft. Swap springs (within reasons) if you need a stiffer setup.

abounly

iTrader: (27)

You can only change springs if it is +2kg or -2kg before re-valving it.

If you want something stiffer i say go with BC/PBM and get it custom. People are asking way too much of megan ez.

Vroomin350

iTrader: (28)

Thanks for the replys guys. I don't see how wanting to understand preload is asking too much of these coils.

Gville350

iTrader: (10)

From my research the BCs are set to install out-of-the-box without messing with "preloading".

If you believe your springs are too soft, they probably are. I opted to get a 12k/8k spring setup with pillowballs on my BCs. From alot of research on C-L here, I found alot of Megan EZ owners not being happy with the 10k fronts...but not a single one disliking the Megan LPs with the 12k/8k setup.

HMFIC

Ok. Let me see if i can draw you a picture on preloading.

Preloading on all coilovers should always be set to Zero. very little to zero load on the spring. Where does the load come from?

Take a look at your coilover from top to bottom. You have the top hat ,then you have the spring, then you have that plate that holds that spring...it's called a perch. Then you have the locking nut under that, then the locking nut under it to prevent the whole coilover from spinnin, then you have the rest of the coilover that bolts to the arms.

Ok...look at the spring and the perch that holds the spring and the locking nut under the perch. If you loosen the locking nut AND the perch, you can start moving the springs because nothing is holding the spring tight. so basically if you loosen the perch enough, the spring is loose. Well when you tighten the perch that holds the spring, you start to press the spring to the top hat. when the spring is no longer moving, sliding up and down or anything...you just put some load onto the spring. very little, just enough to make sure the spring doesnt move. THAT is preloading the spring to Zero. you WANT to be set at Zero. if you kept turning the bottom perch more and more and the spring starts to compress, you are putting more and more load on the spring.

This will result in less travel of spring and shock and your ride will be bouncier and can prematurely wear out the spring and shock.

Unfortuantely with 10k on the springs, they dont seem to do the car justice if you're rubbing all over the place. I dont have that issue because my tires and wheels don't stick out that far but the ride is nicer than the magnet springs/oem shock combo.

I hope that explains the Preload for you.

lobuxracer

iTrader: (2)

It could explain preload, but it's wrong. Preload won't make the ride any bouncier because it doesn't change the spring's rate which is what makes the ride "bouncy" - or more correctly, too much spring rate for the damping in the shock.

Preload changes ride height. That's pretty much all it does in street cars. Saying zero is "right" is assuming a lot of things and odds are you're wrong without testing. No matter what, the spring is going to compress to the same installed length regardless of preload (unless preload exceeds the weight on the corner which no one would ever want to do for any reason). The only question is how much will the shock compress from full length to arrive at this compression, so we're back to ride height. The other consideration is if the suspension ride is good, but bottoms out on large bumps - you'd add preload to increase the available travel and stop hitting the bump stops, but only to the point where the spring hits coil bind when it is fully compressed. Coil bind means the springs rate goes infinite because you can't physically compress the coil any more - it is essentially solid metal.

If you want to substantively change the ride, you'll need to change the spring's rate. You can cut it to increase the rate, or replace it with a stiffer or softer spring depending on what you're trying to achieve. In all cases, if the damping does not work with the new spring, the damping will need to change either by adjusting externally or replacing the washer stack(s) in the damper. But that's not related to preload.

Sffd103

iTrader: (16)

I love my Megan LP's and I'm SLAMMED!

CarbonDtls

iTrader: (4)

BCs for the win.

UtoyZ

iTrader: (11)

i have Tein SS and if i had to do it again, i'd go with BC, simply because i can't go low enough on my Teins and i want higher spring rates

HMFIC

I'm going to have to disagree partially here. Setting the preload at Zero and then installing into the car, lowering the car puts load correct? Adding positive preload and then lowering the car back down, you increased more load onto the springs.

The more load, the more the spring compresses, the less travel the springs have. You don't lower the car with these coilovers by adding or subtracting the preload. you set the preload and you adjust the WHOLE coilover and not even touching the height of the spring itself. Having more load has and does make the ride bouncier. i'm not referring to the travel of the shock and allowing the adjustability to it being harder or softer, because if you only allow the spring to travel and compress at a certain length and height, so will the shock. the more you compress the spring, the less travel either the spring and shock will have.

So explain to me how the spring can compress and travel at the same height when you put more preload on the springs when you shorten the distance from the top hat to the bottom perch with the spring being held by the bottom perch....

IF, you were referring to koni's and ground controls where you can adjust the height of the car by lowering and raising the bottom perch, which is what is used to adjust the height of the car vs these coilovers, then i can see what you're talking about.

lobuxracer

iTrader: (2)

No, adding preload can't possibly increase the load on the springs. I see you are falling for the same trap I did when I first discussed this with a suspension engineer. The spring is going to compress the exact same amount regardless of preload unless preload exceeds the load on the corner. The corner will just sink less because the minimum force to move the shock is now the weight minus the preload. Adding preload will not add weight to the corner, so the only thing it is changing is ride height.

Bouncing is not a result of preload, it is a result of more spring rate than damping. Again, preload can't change the rate of the spring, it can only change the minimum amount of force on the shock.

Also - what are you doing when you change the bottom perch on a shock? It's identical to increasing preload with a threaded collar - you're moving the bottom perch closer to the top perch which increases preload.

As I said, I argued this with a suspension engineer some years ago and got my head sorted out properly. Preload does not affect ride quality, only ride height (and maximum force the spring can produce when fully compressed if it does not coil bind before it fully compresses). Spring rate and damping rates determine ride quality, and if they're improperly matched, ride quality will suffer.

Vroomin350

iTrader: (28)

thanks for schooling me guys, learning little by little. and here are the questions I can come up with...

If I loosen the perch highlight in RED, I noticed I can twist the coil into the blue bottom body.



Now if I did that and then raised the yellow perches to "raise" the car, wouldnt the spring also be more compressed therefor becoming a bit more stiff on compression??

Just noobs questions..

HMFIC

you're loosening the perch that is highlighted in red so you can twist the coilover either clock wise or counterclockwise. which will either raise or lower the car. do NOT turn the perch holding the spring because all you're doing is just lessing or increasing the preload. you loosen it too much the spring just starts bouncing around because the bottom perch holding the spring isn't keeping tension *load* against the top hat.

if you keep tighting the perch holding the spring, the more the load. do NOT use this method to adjust height on the car. set turn the perch holding the spring until the spring is tight...usually comes from factory this way..and factory says its set to zero preload...which is what you want to start with.

so once all the springs are set this way all the way around, then you loosen the perch *in red* so you can turn the whole unit together so the thread goes turns down or up out of the bottom body. that is the proper way to adjust height...not tightening the spring or loosening it because you have coilovers, not ground controls which require you to tighten or loosen the perch holding the spring to adjust height, which also increases or decreases preload.

If you want to lower the car more, take the Bigger wrench and you turn the perch holding the bottom of the spring and turn it clockwise *from right to left*

If you want to Raise the car more, take the Smaller wrench and you turn the locking ring Under the perch holding the spring and turn it Counterclockwise* from left to right*

Once you've measured and found the height that you want, then lock the bottom perch that was in Red onto the blue bottom body.