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View Full Version : How long to make coilovers



Naemion
05-30-2010, 10:52 AM
I got a set of D2 coilovers for my celi but while doing my engine swap I took off the front struts and found that the coil had been cut. I need to know how I can calibrate my coilovers to do a 1.5" drop, without having to put them on and take them off type thing. Can I just measure them and if so what is the standard length of the struts?

Shadowlife25
05-30-2010, 11:52 AM
I'm usually decent at deciphering oddly phrased questions...

Gotta admit, I have no idea what the heck you're asking about. :shrug:

KoreanJoey
05-30-2010, 02:33 PM
You should be able to adjust ride height just fine on the car... At least on most coil-overs it's not a problem.

Murgatroy
05-30-2010, 04:51 PM
I can adjust ride height with my Megans while they are on the car.

Naemion
05-30-2010, 10:55 PM
With mine you have to turn the bottom spindle by turning like a screw. I don't want to mess with the spring rate so it has to be set before it is put on the car.

Shadow, I am asking how long the stock spring/strut assembly is when it is out of the car so that I can set mine 1.5" shorter.

METDeath
05-30-2010, 11:30 PM
Would you mind taking a picture of your coil overs?

The Captain
05-31-2010, 12:07 AM
Should be able to turn the entire strut body in the threaded bottom part. Spring preload should be able to be left intact.

Naemion
05-31-2010, 12:10 AM
http://i39.photobucket.com/albums/e177/Metallica_fanzs/New%20parts-4-14-10/NewParts008.jpg
http://i39.photobucket.com/albums/e177/Metallica_fanzs/New%20parts-4-14-10/NewParts010.jpg
http://i39.photobucket.com/albums/e177/Metallica_fanzs/New%20parts-4-14-10/NewParts007.jpg


Should be able to turn the entire strut body in the threaded bottom part. Spring preload should be able to be left intact.
I know but I want to have it set right so i don't have to keep unbolting it to adjust them over and over.

Shadowlife25
05-31-2010, 01:10 AM
I think the point everyone is making, is that you can adjust them once they are in the car.
You don't need to unbolt anything after they are mounted.

Also, I'm pretty darn sure that even at the near max extension, you will notice a drastic lowering of ride height using those.

Naemion
05-31-2010, 03:47 AM
You can't adjust them because if you look at them, the whole bottom of the coilover needs to spin freely. This is where the bottom of it is bolted to the car so if it is bolted to the car, it cannot spin.

Shadowlife25
05-31-2010, 04:30 AM
*EDIT*

Sorry but I am feeling mis-understood.
I am glad that The Captain explained your instructions to you Naemion.

Best of luck and enjoy your setup.

Naemion
05-31-2010, 04:57 AM
You can adjust it that way, but that will also adjust the spring compression rate, which I do not want to do.

The Captain
05-31-2010, 06:56 AM
You shouldn't have to unbolt anything.

Disclaimer: This is my humble opinion. I've been setting up motorcycle suspensions for 20 years. Cars aren't that much different.

A high res pic of the top pic would be helpful. Ignore the spring adjustment collars. Is there a locking collar just above the hub carrier mount (the bottom)?


Try this. If there IS a locking collar where the shock body threads into the bottom, loosen it.

Sit on the floor. Hold the upper mount with your hand and the lower part with your feet. See if you can rotate the threaded shock body in the lower mount. Hopefully the whole spring/shock assembly will rotate. It should spin on the upper pillow ball mount and the bottom mount.

If this is the case all you have to do is remove the tire, unlock the bottom collar and spin the coilover up or down to achieve the desired ride height.

Start by establishing a baseline. Do this on all four corners.

Ride height adjustment:

1.Pull your old strut shock rod to full length and measure from the top bolt hole to the top of the rod.

2. Loosen the spring perch collars on the coilovers. Adjust the length of the coilover so it's 1 inch less than the stock unit from hole to top of the coilovers rod. Install on the car.

3. With the suspension at full droop, adjust the spring collar so the spring touches the top spring perch. Then tighten 1/2 turn. This is because you don't have a top out spring. If the suspension goes full extension, your spring won't be flopping in the breeze. Which may be bad on landing.

4. Drop the car on the ground and measure from the fender lip to the top of each rim.

5. To adjust height, remove the wheel.

a. If you need to go lower, loosen the spring collars. Loosen the bottom collar and spin the body into the bottom the desired amount. Repeat step 3.

b. To raise, just loosen the bottom collar and spin it up. Repeat step 3.


Spring preload:

Spring pre-load is a different animal and requires two adjustments. Now it comes to desired ride quality. Let's say the back is too soft but height is good. Take off the wheel. Unlock the spring collar and tighten so there is more static pressure on the spring. This is "pre-loading" the spring. MEASURE how much you preload. Put the wheel back on and drop the car. It'll probably sit higher because of the preload. Measure the height change. Take the tire back off. Here's where you combine.

To lower, you have to re-loosen the spring. Lower the shock body the desired amount. Now re-preload the spring the amount you measured. Remount the tire and test.


To raise, just unlock the bottom and turn the desired amount. Re-preload the spring the measured amount.


If you have more than an inch of preload, your springs are too soft. By preloading the spring you are shortening it, reducing your droop travel. If the ride is to harsh, you need softer rate springs. A tire not touching the road, be it a bump, pothole, sharp corner, quick rise is not providing any grip. The key is finding the balance to the surface you're operating on.


It's a PITA. But once it's set up properly, you're done forever.


Please tell me you already have an upgraded swaybar first.

Naemion
05-31-2010, 06:59 AM
^This man, he makes sense...

The Captain
05-31-2010, 07:13 AM
^This man, he makes sense...

Even with insomnia?

Once you get that, we'll discuss damping.

Do you have an upgraded rear swaybar? A lot of people try to reduce body roll only using stiff springs. Problem is this reduces compliance and upsets the chassis on bumps. The Whiteline unit I have transformed my car. I can actually use softer springs for a more comfortable ride, although southern roads are pretty smooth. I'm willing to bet those springs are stiffer than stock. If you think the springs are too soft, get a swaybar before trying stiffer springs. Hell, get one period. Even a none adjustable stiffer unit would be better.

Naemion
05-31-2010, 07:35 AM
Insomnia? What's that? I was just "borrowing" a sprint phone to work with Boost mobile, gotta love HTC!

Cool, and Not yet, that's next on my list, and what about camber?

The Captain
05-31-2010, 07:57 AM
Insomnia? What's that? I was just "borrowing" a sprint phone to work with Boost mobile, gotta love HTC!

Cool, and Not yet, that's next on my list, and what about camber?

Also depends...

What's the cars primary function? What's your tire budget? Your tire?

I have -1.5 front and -1.0 rear. The inside of the tire wears first. The RT615's last me 5300 miles. More negative camber puts a flatter tire patch on the road in high G turns. Less going straight.

I drive it on sunny days in the mountains. It's almost unstable in a straight line but turns like a cat on carpet, on meth.

If you run hard/all season type tires why run high negative camber numbers if the tires are incapable of strong grip? If you run an intermediate tire go a little more negative. Maybe -.75 front and -.50 rear.

The reason for more negative camber up front is that most cars are designed with understeer. Weight distribution comes into play as well. This setting puts more grip up front, keeping the front of the car in line, delaying the "push".

This is why a swaybar is critical.


A lot of this is trial and error. The key is a baseline and keeping notes of changes.

METDeath
05-31-2010, 09:28 AM
Oh, as The Captain is saying, get a rear anti-sway bar, the Suspension Techniques is larger than the Whiteline and is adjustable (just don't lose the installation instructions). I have it and it's AWESOME!!one

Naemion
05-31-2010, 09:35 AM
I would, but I don't have the money right now for it, unless someone wants to donate one, lol. But if you read my first post about needing the measurements because the person before my cut the coils....

GrpA4
05-31-2010, 10:10 AM
Awsome reading Captain, thanks :D.

KoreanJoey
06-01-2010, 06:35 AM
Captain, the reason for the static negative camber has more to do with suspension design than anything else. With a good double-wishbone suspension you can get away with far less camber and more caster. Problem is, as the suspension compresses on a MacPherson strut suspension they don't gain enough camber to compensate for the roll of the vehicle.

Most people racing on MacStrut cars run high static camber (I myself ran 2.5* with very even tire wear) or very, very stiff springs(talking 700-800in/lbs) to reduce roll/camber loss.

The Captain
06-01-2010, 12:00 PM
True dat.