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View Full Version : Coilovers 101. Someone teach me something


Jeff240sx
10-11-2004, 10:35 PM
Allright. So I got my coilovers. K-Sports, after 6 months of waiting.
Now, how low do I want it? The advice I get from my gf's brother is as low as it gets. That's retarded. I'm thinking the top of the tire to the bottom of the fender. On 245/35/18 and 265/35/18 that's alot of wheel.
Next up is dampening. Supposedly 36-way adjustable dampening. What the hell is that? Dampening the absorption or the extension?
Then I have these little black plates with a circle on one side, and the same circle on the other side, with an opening in it. I'll snap a pic tomorrow, but I don't know what that is/would be either.
-Jeff

AKADriver
10-11-2004, 11:01 PM
Most coilover manufacturers supply with the instructions a recommended ride height setting. Start there. If they don't... I dunno. You'd think they'd support the product better than that.

Then when you have the car aligned, set the preload to cornerweight.

36-way damping means there are 36 settings. I hate the term "-way", 'cuz it's really 1-way adjustment in 36 increments... anyway. Usually if you only get one adjustment, it's compression and rebound together.

drift into a curb
10-11-2004, 11:02 PM
Let's keep it simple.

Lower as low as YOU can handle. Imagine the tire to the bottom fender, the suspension still has to settle once it has load on it, so most likely it'll tuck. Make sure your exhaust doesn't hang too low or else you're scrape everywhere.

As for adjustable damping, the K-sports are most likely adjustable one way on compression/rebound.

Wait. Circle black plates? Pillow upper mounts? Are you trying to show off your setup? Have fun.

Jeff240sx
10-11-2004, 11:09 PM
I do have pillowball upper mounts, but letting that out wasn't my intention. Sadly I'm nearly asleep here, so I won't get one out of my car and snap a pic of it. But it's about 5"x.75", with the aforementioned circles.

Dampening compression would equal what change in ride?
-Jeff

Jeff240sx
10-11-2004, 11:11 PM
Then when you have the car aligned, set the preload to cornerweight.

English?
<--- Coilover noob. Got a good price, and my rear shocks were blown, so now I have to learn about what I just put on my car.
-Jeff

rainier
10-11-2004, 11:12 PM
don't drop it too low at first. just drop it a little and let it settle then drop it after a while as low as you want it to be

sticky240
10-11-2004, 11:24 PM
the black metal brackets are for your brake line.

I was wondering too when I got mine

AKADriver
10-11-2004, 11:32 PM
Preload: your coilovers have two height adjustments - one at the lower spring seat, and one at the lower bracket. The lower bracket only adjusts height. The lower spring seat adjusts height and spring preload against the damper. This can change the car's static weight distribution.

Cornerweight: they put the car on scales and adjust the preload on the springs on all four corners so that the combined weights of opposite corners (crossweights) are the same. i.e. left front + right rear = right front + left rear. This makes the car more balanced and predictable. A race car alignment shop can do it blindfolded.

IMO unless you have some adjustable arms in the suspension I'd keep the lowering to around 1.75". That's not very low at all - still a couple fingers between the tire and fender with a 25" tall tire... but it maintains proper geometry.

Compression damping controls how quickly the suspension can react to a bump. Rebound damping controls how quickly it can bounce back after a bump. I recommend setting the damping in the middle at first and working from there. If the car feels "wobbly" in hard driving or "floaty" on the highway, turn the damping up. If the car feels "twitchy" in hard driving or "ass-punishing" on the highway, turn the damping down. Keep the settings equal front and rear for now.. you can adjust the car's under/oversteer characteristics in different speed corners with damping adjustment, but that's something that takes track time to sort out.

KiDyNomiTe
10-12-2004, 12:00 AM
As low as you can go seems about right, but get the rest of your suspension, tension rods, tie rods, RUCA, and toe arms. Those are the most important, then send it to an alignment shop and get what you want. If you want to really make the best of your car, get adjustable tie rod ends (kazama makes them, I think SPL does too).

Var
10-12-2004, 09:40 AM
The spring tries to compress and the bump valving in the shock applies force against it. Then the spring tries to de-compress and the rebound valving in the shock applies force against it.

Strong bump = uncomfortable ride and will cause your car to feel unstable around corners with less than perfect pavement.

Ideally you want your rebound to be around twice as strong as the bump. This makes for a nice ride and good handling. Good shocks are usually valved this way so you can get good handling even out of fairly soft settings.

You should set your adjustment on the coilovers to suit your road conditions. Pretty much every click on the adustment makes every bump on the road bigger and meaner. Ideal setup would be stiff enough for minimal roll while still giving the shocks room to absorb over 90% of the bumps and dips in the road. You'll get your perfect setting in less than a couple weeks if you keep messing with it.


Also if you care more about valving. As i understand shock valving it's like black magic. Some companies get it down good and you can have more performance and ride comfort at the same time compared to a shock/spring setup with the same rates. So ..

The shock is valved on a slope. The valving ranges from low speed to high speed. Low speed valving is when the elevation of the road changes or when you make a turn and the shocks have little to do but stay tight. High speed valving is when you are going over rough terrain and the shocks are working the hardest. Low speed valving ideally should be tight, especially on the rebound side..this way the inside corner of your car is helping to prevent body roll and not just the bump valving of the outside corner. I imagine too stiff of a low speed rebound valving would cause the inside of your car to lift off the ground. High speed valving should be set fairly soft so it will absorb bumps while still keeping stiff enough to keep the car level. i'm always looking for more info on shock valving if ppl have something to share/correct me on

allmotorKA
10-12-2004, 10:56 AM
Preload: your coilovers have two height adjustments - one at the lower spring seat, and one at the lower bracket. The lower bracket only adjusts height. The lower spring seat adjusts height and spring preload against the damper. This can change the car's static weight distribution.

Cornerweight: they put the car on scales and adjust the preload on the springs on all four corners so that the combined weights of opposite corners (crossweights) are the same. i.e. left front + right rear = right front + left rear. This makes the car more balanced and predictable...

I thought that coilover height adjustment (not spring preload adjustment) is used to cornerweight the car. Although adjusting the spring preload can also adjust the height of the car, I don't think you want to adjust spring preload to adjust crossweight values. Spring preload affects bump force and rebound stroke...which I would want to keep the same between left and right sides.

90RS13
10-12-2004, 01:33 PM
I thought that coilover height adjustment (not spring preload adjustment) is used to cornerweight the car. Although adjusting the spring preload can also adjust the height of the car, I don't think you want to adjust spring preload to adjust crossweight values. Spring preload affects bump force and rebound stroke...which I would want to keep the same between left and right sides.

You're right. You corner-weight with total height. If you preload an assembly on the same end (FL), more than the other (FR), it won't be more predictable because the springs won't react the same (1 side will be stiffer) to the same conditions. Example, when you go around a lefty the car might act rigid, and the when you hit a righty, it'll act softer.