I've read the coilover install thread, as well as a few I searched out, but there are two questions I'm still not sure of.

1: Setting the pre-load. I read that some coilovers don't even need a preload. I'm going with the T1R's. Do they need a preload, and how do you set/determine how much to set the preload?

2: Height adjustment. I measured my car, and noticed that all four corners aren't equal. I expected this front-rear, but not side-side (for example, the passenger side rear is like .2 inches lower than the driver's side rear, or vice versa). If I want to lower it 1.25 inches, do I lower each corner exactly that much to keep these small height differences, or is this just from a worn suspension, thus making it better to have the side to side height equal?
Thanks.

 

i had the same issue when i put on my pss...what i did was, i waited for few weeks for the coilover to settle down...it was actually off by less than quarter inch side to side and different corners..after few weeks, my suspension settle down and it was not off as much as it used to be...since it was not that much, i decided to just leave it as is and get the car aligned...its highly recommended by bilstein to do the adjustment to compensate the height of each corner...if i were u, i will wait for the suspension to settle down then do adjustment to even them out and then get it corner balanced or alignment...as far as preloading the suspension, i would do it, even if its not recommended because i dont think it will affect the performance whn u preload the suspension...

 

You need to preload the suspension if the dampers don't have sufficient compression travel when the car is at rest. Regarding the difference in ride height, you really shouldn't pay much attention to it unless you are on a surface that you KNOW is perfectly flat and level (ie. an alignment rack). Did you load the suspension up before torquing the bolts?

 

I haven't installed the suspension yet, that's why I was asking these questions beforehand.
About the preload, that's set with the bolts on top of the shock tower, right? And how do you determine the amount of preload, do you just tighten the bolts until it compresses the spring a certain amount, then make sure it's that same amount all around?

 

I misunderstood your original post. I thought you had already installed them, and they resulted in a difference in ride height.

Look at the "Setup / Preload" link in my sig. I don't know anything about the T1

 

Damn laptop mouse pads ...

Look at the "Setup / Preload" link in my sig. I don't know anything about the T1R coilovers, but if they are designed similarly to the JICs, you will determine preload similarly.

 

So should I adjust my suspension for the exact amount of height left-right when I install the coilovers, or should I take into consideration the small differences in height that the stock suspension seems to have?
And, is there a way of accurately knowing how much to preload the suspension, or is it just trial and error?

 

It is not trial and error. Install the suspension with no preload (spring perches just tight enough to hold the springs in place) with exactly the same setup left and right. Once you are finished and drive it around the block, park on the flattest / most level spot you can, and figure out how much you want to raise or lower the front and back. Also inspect the amount of damper travel that you have on the front and rear when the car is sitting on the ground. You should be able to adjust the preload and ride height to what you want in just one step. If you want to raise the ride height by .5", unscrew the damper body by .5" on both sides. If you want to increase damper compression travel by .5", tighten the spring perch by .5" on both sides. The only tricky part (slightly) is changing preload without changing ride height. For example, if the ride height is perfect, but you want to increase damper travel by .5", then you will have to tighten the spring perch by .5" and screw the damper body into the base by .5" to compensate. Likewise, if the ride height is .25" too low, but you want to increase damper travel by .5", then you will have to tighten the spring perch by .5" and UNscrew the damper body out of the base by .25" to compensate.

 

I got this backwards... What I meant to say is:

Likewise, if the ride height is .25" too low, but you want to increase damper travel by .5", then you will have to tighten the spring perch by .5" and screw the damper body into the base by .25" to compensate.

 

I've a similar question too, you might help from those advise.

https://www.s2ki.com/forums/index.php?showtopic=394835