Hey,

So I just purchased a set of used coilovers, and I'm already having some concerns. I know that usually coilovers are preloaded from the manufacture, but during the beginning phase of installing my coilovers, I had some issues.

I know that on my fronts, the previous owner made some adjustments to the height, but incorrectly adjusted the vehicle height by changed the perches and thus affecting the preload.

Basically the perches were lowered to the point where the spring have a depth of travel from the top hat to the top of the lower perch.

If i want to re-"preload" the suspension, do i just adjust the perches to were the spring is snug fit between the top hat and lower perch? or is there some type of "torque" in order to achieve the correct spring preload?

I usually adjust my coilover height, by adjusting the lowest perch above the bottom shock body, and turning the entire spring and upper perch setting to achieve my desired height.

sorry if i dont make any sense, as im sure im not using any technical terms close to what im trying to talk about.

any input helps.

 

duno what you're talking about...

 

not sure what you are talking about...but it isn't necessary to have the spring rigid inbetween the top mount and the lower perch. as long as the spring sits in the seat correctly once the car has been put on the ground...

I would go with tightening the perch until the spring fits snug, then lower the vehicle...see about the level of the car then adjust from there again...


soz if that doesn't answer the Q...jst a bit vague with your description...

 

There's no set number, i can't answer your question really w/o knowing all the varible, i sugguest you to do more research on it before listening to anyone esp when we have no idea what is your set up as far as hardware goes. but for the starter: it's slightly more complex than that but ..well, let's do some math:

given: 2800 lb car at 50/50 wd=700 lb per corner

i believe n1 are 12k per mm so it's about 672 lb per inch(good o american inch)

how much you preload depends on how much suspension travel you'll get before you ride bumpstop aka infinite spring rate. Let's call the total travel stroke, the length of that will be determined somewhat by the ride height. you can have a oem body length damper, a shortened damper(easy part to check)

Assuming you lowered your car about an inch, with the shortened body damper of the apexi you should have about 2.5 to 3 inches(double check on this) from full droop to full compress(again, the total stroke). at rest your spring will compress about a little more than an inch(700 lb to 672 lb/inch), which leaves out not much(1.5-2) for stroke after the car is on the wheel(at rest) vs full droop(on jackstand).

in short i would suggest some preload, esp when you drive your car hard enough to ride the bumpstop anytime during normal driving condition. Again, you need to fine hone this system, if you feels like it's too much, please by all means go to a pro and have it set up. Buying the hardware is only half of the story, most people will cheap out and try to dial in but if you can afford it, have someone knowledgeable do it for you and have it corner balanced and all.

 

you just install, forget that whole jacking up the balljoint crap, just drive around for an hour and then tighten the top hat/alen 14mm if its lose.

 

the only way to set the preload correctly on coilovers is to have the car corner balanced (i believe its called). post in the auto crossing section I got some good info from there. You can adjust the right height as you wish but you cant adjust the preload without scales. Most people just slap on their coilovers and call it a day. If you want to get the most out of handling you get the preload setup specifically for your car.

 

lol thanks for all the help and input guys..

i just fit the spring snug inbetween the perches then adjusted the height accordingly.

ill have the alignment done next..

thanks again!