Suspension adjustments: some questions

Ok, maybe, or may you haven't read my other post but with the JIC FLTA2 you have quite some adjustment.

1) There are three perches, two upper, and one lower. What is the function of the upper two, and what is the function of the lower one? I am thinking the lower perch is adjustable for the height, but does that mean you turn the entire spring/threaded shock assembly down into the lower mount to adjust height, then retighten the lower mount?

2) Damping rear: I figured out that the rears have a knob on top of the pillowball. Is there only one adjustment for damping?

3) Damping front: How do you adjust damping on the front? There is a provided "key", but I assume adjustments need to be made from underneath the shock, unlike the rear.

4) Is there only one adjustment for damping on the shocks to make it stiffer/softer? I was sort of under the impression rebound and compression could be independent, but I am thinking, I guessed wrong (not a bad thing).

That should hold me over for a while.

Chris

Ok, maybe, or may you haven't read my other post but with the JIC FLTA2 you have quite some adjustment.

 

1) There are three perches, two upper, and one lower. What is the function of the upper two, and what is the function of the lower one? I am thinking the lower perch is adjustable for the height, but does that mean you turn the entire spring/threaded shock assembly down into the lower mount to adjust height, then retighten the lower mount?

 

2) Damping rear: I figured out that the rears have a knob on top of the pillowball. Is there only one adjustment for damping?

 

3) Damping front: How do you adjust damping on the front? There is a provided "key", but I assume adjustments need to be made from underneath the shock, unlike the rear.

 

4) Is there only one adjustment for damping on the shocks to make it stiffer/softer? I was sort of under the impression rebound and compression could be independent, but I am thinking, I guessed wrong (not a bad thing).

 

That should hold me over for a while.

 

Chris

1. The upper perch adjusts preload. The lower perch ride height, so yes, you turn the entire unit to raise/lower then tighten the lower lock ring.

2. & 3. I don't have the JIC coilovers, so I'm not sure. There should only be one adjustment point on each coilover though. Since the fronts are an inverted design the adjustments should be made from the bottom.

4. Some high end coilovers offer independant compression and rebound dampening adjustments. I don't believe that the JIC's you have offer that feature. Some coilovers adjust both the compression and rebound dampening together, while some really just change the rebound dampening only. Again, not sure which camp the JIC's fall in.

Great, that answer my questions, but then again, it created a couple others.

1) What exactly is preload? It seems to me to be just taking slack out of the system, maybe some travel. Is that it (since these are linear rate springs)?

And I need to call about some other things on how to's.

But thanks

Ok, maybe, or may you haven't read my other post but with the JIC FLTA2 you have quite some adjustment.

 

1) There are three perches, two upper, and one lower. What is the function of the upper two, and what is the function of the lower one? I am thinking the lower perch is adjustable for the height, but does that mean you turn the entire spring/threaded shock assembly down into the lower mount to adjust height, then retighten the lower mount?

 

2) Damping rear: I figured out that the rears have a knob on top of the pillowball. Is there only one adjustment for damping?

 

3) Damping front: How do you adjust damping on the front? There is a provided "key", but I assume adjustments need to be made from underneath the shock, unlike the rear.

 

4) Is there only one adjustment for damping on the shocks to make it stiffer/softer? I was sort of under the impression rebound and compression could be independent, but I am thinking, I guessed wrong (not a bad thing).

 

That should hold me over for a while.

 

Chris

1) the two upper that sits below the spring is the spring perch for spring pre-load and the lower of the two is the locking perch. when you move the spring perch up, you are preloading the spring. you spin the lower perch to lock the spring perch from spinning back down. They are there to basically "fight" each other so that the spring perch doesnt move up or down. The 3rd one at the very bottom is the locking perch for the ride height. The actual shock connector flange spins up or down to control ride height while the locking perch keeps the connector flange from moving up. Opposite forces cancelling each other out in a sense. Once the coilover is in, to adjust ride height, you loosen the very bottom locking perch and you turn the entire shock body to adjust the ride height (since the connector flange is already bolted on the car).

2) most street and entry-level coilovers are single knob for adjusting dampening. Only the higher-level coilovers have remote resevoirs for dual knobs or triple knobs.

Single = adjusts both bound and rebound proportionally

Double = adjusts bound and rebound (low speed and high speed together) seperately

Triple = adjusts bound, rebound low speeds, and rebound high speeds all seperately

3) it may be from the bottom or the top of the shock.. You will have to take pictures for me because I am not sure if the JICs are inverted in the front or not. If it's an inverted shock, most likely the adjustment is done under the car.

4) single knob dampening coilovers controls both bound (compression) and rebound together. It's a proportion usually. There's a ratio to how fast the shock takes in a bump (compression), but the rebound can be 2x as fast (as you dont want your tire to be floating up in the air too long and you want to push the wheel back down asap). It's a proportion to your adjustment. Only a few coilovers have duals. Motons, Ohlins, Penske, higher levels of Tein, Endless, and Sachs all have a model or two that can do double or even triple dampening adjustments. Expect to pay something like $8k for just Moton Triples Shocks (no springs or spring perch, just the plain shock with the remote oil resevoir).

Great, that answer my questions, but then again, it created a couple others.

 

1) What exactly is preload? It seems to me to be just taking slack out of the system, maybe some travel. Is that it (since these are linear rate springs)?

 

And I need to call about some other things on how to's.

 

But thanks

Spring Preload makes the car feel that is already ready for a turn. Zero preload is when the spring is at the brink of spinning on the spring perch. Positive Spring Preload is when you start moving the spring perch up to crush the spring to make the spring working already to hold the car up. The reason for spring preload is to take up the slack out of the car and make the car feel "tighter" or more responsive when the spring starts its job of resisting compression. It's not really taking up travel, rather, it's getting a head start of keeping the car from dipping or compressing earlier. You can preload a progressive spring as well, some people just dont like the initial squishy feeling and rather get the spring to do all the work of holding the car up while cornering, accelerating or braking. Linear Springs are just more of a direct feel and the driver will know from the feedback of what is too much braking, accelerating or cornering. Progressive will increase it's resistance as it's being compressed. Just think of spring preload as a "headstart" before entering a turn and such.

I usually preload my springs a few lbs or so, about 50 to 100 lbs worth to ensure the spring won't float when I get light on the wheels and this gives my car a more direct feel when I toss it into a corner. Too much preload on a very well lowered car can push the car up when coming off from compression, it will make the car feel like the springs are throwing the car around (if the springs are that stiff).

Spring Preload makes the car feel that is already ready for a turn. Zero preload is when the spring is at the brink of spinning on the spring perch. Positive Spring Preload is when you start moving the spring perch up to crush the spring to make the spring working already to hold the car up. The reason for spring preload is to take up the slack out of the car and make the car feel "tighter" or more responsive when the spring starts its job of resisting compression. It's not really taking up travel, rather, it's getting a head start of keeping the car from dipping or compressing earlier. You can preload a progressive spring as well, some people just dont like the initial squishy feeling and rather get the spring to do all the work of holding the car up while cornering, accelerating or braking. Linear Springs are just more of a direct feel and the driver will know from the feedback of what is too much braking, accelerating or cornering. Progressive will increase it's resistance as it's being compressed. Just think of spring preload as a "headstart" before entering a turn and such.

 

I usually preload my springs a few lbs or so, about 50 to 100 lbs worth to ensure the spring won't float when I get light on the wheels and this gives my car a more direct feel when I toss it into a corner. Too much preload on a very well lowered car can push the car up when coming off from compression, it will make the car feel like the springs are throwing the car around (if the springs are that stiff).

How did you preload your springs at 50lbs to 100lbs exactly? You can't really get a torque reading with the preload wrench. Im asking since I just got my ksports and id like to know how to set them up before putting them on the car.

How did you preload your springs at 50lbs to 100lbs exactly? You can't really get a torque reading with the preload wrench. Im asking since I just got my ksports and id like to know how to set them up before putting them on the car.

It's based on your spring rates. This applies to linear springs and it's just simple math.. progressive is harder to deal with since you'll need unassemble the coilover and put 100 lbs (or whatever weight you wish to preload) on the progressive spring and see how far the spring gets compressed. The distance you get is how much you need to preload it.

So should there be any adjustments made to the perchs when going with aftermartket springs (lowered springs)??

You mean just lowering springs on stock shocks? You can't adjust stock shocks as there's nothing to adjust.

Only time when you adjust spring perches is when you do something like Koni Red Shocks inserts (which has two different ride height spring perches) or Koni Yellow Sport Shocks (or anything like them). http://www.ground-control.com coilovers are known as 1st generation coilovers (sleeves like skunk racing and the such). Basically they are threaded sleeves that goes over the stock shocks and the sleeve sits on spring perch. The new springs that comes with the Ground Control Coilovers (or other 1st generation types) will also have an adjustable spring perch for preload. Ricers back in the days use to use this adjustment as a way to lower and raise ride height (which is the wrong intension since it's suppose to be for spring preload). Ground Control uses ERS (Eibach Race Springs) and comes in many sizes and lengths to match your needs with the aftermarket shocks (KYB, Koni, Ohlins, Tokico, Moton are the types). The "good" aftermarket shock bodies would have different settings of spring perch ride heights (either threaded or notched).

It's based on your spring rates. This applies to linear springs and it's just simple math.. progressive is harder to deal with since you'll need unassemble the coilover and put 100 lbs (or whatever weight you wish to preload) on the progressive spring and see how far the spring gets compressed. The distance you get is how much you need to preload it.

So since I have 7k springs, how much would I need to preload to be at 100lbs? Can you go threw the process?

finally installing my k-sport coilovers and this thread helped alot. especially xenonk's instructions.

ride height adjustment question though. how do you turn the whole body of the shock (after getting the mounting flange loose)? i don't know where or how to turn it. what's the easiest or best way?

w/o permission im posting a pic of one of DM's fronts in case it helps anyone to visualize. although im sure someone who knows the answer wont need it.

Holy ancient thread resurrection Batman!

As for your problem, if you're getting a bouncy kind of feel in the car it's one of three possible things I can think of.

1. The guy dialed your dampers down and thus it's not damping out the rebound like you’re used to. So all you need to do is dial them back up.

B. The guy loosened the top two rings and reduced your preload. So instead of the springs already being compressed when you enter a turn like you are used to, they have to start compressing from 0 and build to the appropriate resistance level resulting in you feeling the spring gradually compress in the corner. To adjust your preload, throw the car up on a rack so the wheels are hanging and back the upper stops off until the springs are loose. Then based on the spring rate of the spring, I think MR uses something like 200 lb-in linear springs (it's usually written somewhere on the spring), tighten the upper ring until you get the desired preload (i.e. for a 200 lb-in spring tightening the ring a 1/4 in = 50 lbs preload, 1/2 in = 100 lbs, etc.).

Third. The guy over preloaded the shocks and the springs are over powering the dampers after the initial entry into a turn throwing the car back up to the top of the suspension range rather than gradually extending. This probably wouldn't be described as much as bouncing so I don't think this is likely the problem but I'm just covering my bases as it has the same solution as B.

One easy way to tell if the rings have been moved is to look at the dirt buildup on the body of the coilovers and look if there are threads to the top or bottom of the locking rings that are cleaner than the surrounding ones. That will most likely tell you if they’ve been moved as it’s a PITA to adjust those rings without cleaning out the threads with some WD40 or something like it.

haha wanted to see if I could get a response on this thread first before cluttering up things with a posting... thanks for your time explaining! sounds simple enuf...

do appreciate

So instead of the springs already being compressed when you enter a turn like you are used to, they have to start compressing from 0...

If the spring has zero compression on it, what's holding up that corner of the car? Magic?

If the spring has zero compression on it, what's holding up that corner of the car? Magic?

Ok obviously the springs are compressed some due to the car resting on them but the starting from 0 was intended to illustrate difference between a non-preloaded coilover going through the normal compression cycle of a turn and that of one with preloaded spring. Apparently I should have thrown an "essentially" in there for all you way too litteral people.

Please refer to post #5 in this thread for a more exacting explanation of preload.