height adjustable shocks
 

are the tokicos or konis height adjustable

The Koni have three different settings. One that is stock height and two that are a little bit lower.

Keep in mind that the 3 height "settings" (spring perch locations) on the Koni yellow shocks aren't easy to change. You have to disassemble the shock/spring package to take the load off the perch, then move a "C" clip from one position to either of the other two possible positions. Basically, it's a royal pain in the ass, so it's best to get it right the first time. :)

The Tokico's are not height adjustable. As Jim mentioned, it's not that easy of a task to adjust the height on the spring perches. IMO, if you need height adjustability, just get coilovers.

The perches on the Konis are not meant to allow for adjusting corner weight, they merely give you 3 choices for ride height. Personally I set my ride height and then leave it.

If you do wish to adjust the ride height on the Koni you remove the shock(s) and then compress the spring. Slip the perch to the setting you want and release the spring. No other disassembly required or actual spring removal required. I guess if you wanted to change your ride height every weekend it could be a problem...

Wouldn't that depend on whether or not you had a spring compressor handy? If not, then you do have to disassemble the shock/spring package to release pressure on the perch.

Let's say you set it on the middle setting to be on the safe side, but after putting the shocks/springs on the car you find out that it's sitting too high. That could be a problem too, couldn't it? :D

Exactly, especially since there are some very reasonably priced models available now.

BTW, Koni yellows + Ground Control coilover conversion kit = "teh suck". :D

That's no different than buying lowering springs; you don't know what you have until you put them on. The Koni has three height positions. The tallest is stock, the middle one about a 5/8" drop and the lowest one just over an inch drop. This assumes stock springs of course. Lowering springs could be dropped that much lower if desired.

Spring compressor. $12. Harbor Freight. Free if you think ahead and go to the auto parts store and use theirs.

I bet anybody with any sense could remove the Koni and adjust the spring perch in the same amount of time (or less) as it would take them to put the car on scales and adjust a true coil over. Even if not using scales you'd still have to be on a level floor and constantly measure and bounce the car while adjusting all the collars. Anybody without much sense will of course take much too long no matter what they do (and screw everything up in the process) :p:

You can get some height adjustability (and damping as well) with a Koni at a cost of about $550 a set. You can get true coilover ride height and corner weight adjustability with a coilover that will cost a very minimum double that (or more) and in many cases still have a product with inferior build quality and life compared to a Koni. The Koni has its own limitations, but you can't beat it without spending a lot more money.

Hey Damon, didn't you put your konis on a lower perch when you bought them and had bad rubbing or bottoming out or something?

I would think lower would be better for center of gravity for auto-x and track, but you seemed to be happier after putting them on the highest perch, because of rubbing, if I remeber correctly?

Unless you got a different version of the Koni yellow shocks than I did, the recesses in the shock body were only about 1/4" apart. The range of adjustability is only about 1/2" total, not 1".

You know better than that jim. Motion ratio!

The shock is only midway down the arm compared to the wheel so a small change in height at the perch equals a much bigger one at the wheel.

Ohhhhhhhh yeah. I have stock springs and I lowered the car all the way for the hell of it. I then ate through the front fender liners at an autox a few days later, and that was with stock tires and wheels! Guys who lower their cars much must run absolutely hellacious spring rates or they never track the car.

I still have the holes in the liners just behind the headlight to remember that day by. I was wearing through the tops as well. Luckily it hadn't got all the way into the wiring harness above the fender yet but I did chew some of the wire insulation off.

while the motion ratio effects the wheel (spring) rate it does not effect the linear relationship re the lower spring perch and the ride height. the car sits on the spring. since the shock is inside the spring and the perch is around the shock... lower the spring perch one half inch and you lower the car one half inch.

howard coleman

That's not true in most cases.


Your statement is only true if the spring/shock assembly happens to mount to the suspension in the same location the hub attaches (many McPherson strut and most leaf spring suspensions for example). The exact same reason the motion ratio makes the wheel rate different from the spring rate is also why a small change at the perch equals a larger on at the wheel.

Here is a pic where the perch adjustment vs wheel movement is 1:1 :

http://www.whiteline.com.au/images/misc/wheelrate.jpg

Here is an image that represents most wishbone suspension systems. As you can see in this case when the spring is compressed X amount the wheel itself moves 1.5(X). This is a direct result of the wheel being mounted at the extreme end of the arm and the shock/spring midway along the arm. The motion ratio also accounts for the difference in spring rate and wheel rate.

http://www.presspley.com/dr/reports/...er/image74.gif

The suspension arm is mounted to a fixed pivot and swings through an arc. If the wheel mounts to the end of the arm and the spring mounts some where closer to the pivot the wheel will always travel further than the shock/spring for a given amount of deflection. The only time this is not true is in the case of some true strut suspensions, live axles with vertical shocks and when pushrods and bellcranks are used (the entire advantage of bellcranks is in allowing the motion ratio to be quickly and easily changed).

Another example. If the red line is the shock/spring unit than a small change in length here will always result in a larger change at the end of the arm where the wheel is mounted. If it does not then the motion ratio is 1:1. If the motion ratio is not 1:1 then there MUST be a difference between the distances traveled by the wheel and the spring. Motion ratio is merely mechanical advantage.

http://home.tiscali.be/be067749/58/c2/whrte.gif

you have given an excellent exposition as to wheel rate and spring rate. :)

the relationship of ride height to spring perch adjustment w a double a-arm coil over has nothing to do w the fact that the wheel is outboard of the shock/spring mounting position w regard to the lateral link. sure, the motion ratio relates to this.

the car, however, sits on the spring. if you raise the lower perch you raise the car an equal amount minus the very slight angle of the spring.

howard coleman

Shit. That's true. :o: Sorry. I'm so used to thinking of everything from the other way around: what happens at the wheel end. If the car is sitting still then raising or lowering the perch must raise or lower the chassis with respect to the ground the same amount.

good debate guys. now has anyone else tried the lowest perch setting, and did you have any clearance issues like DamonB?

I would definitely not run the fronts at a lower perch setting. The rears are fine on the lowest perch setting to make the car more level. I haven't ever bottomed out the rears, but have the fronts, even on the highest perch setting.

cool thanks

i love when intellectuals get into a debate, there is so much to learn.

what if you are runiing eibach springs with this setup (konis), will you want to lower the konis at all?
what is a happy medium for a street car on eibach/konis (front and rear)?

25 inches measured at the top of all 4 wheel wells don't forget to readjust the camber when you change ride height.

howard coleman

There's no debate when you're flat wrong as I was :p: Howard was right. With respect to chassis ride height adjusting the perch height a given amount will raise or lower the chassis the same amount. It will vay slightly the more the shocks are tilted from true vertical but it will be very close.

I knew I was right... I just didn't care enough to argue about it. :p:

it's ok that you were wrong because you still gave out information that i never knew or even thought about. now i feel smarter (even though i had to read this thread six times to figure out all the formulas, theories and calculations). at least it wasn't another will this size fit or can i drop my car to the ground on 20s with no fender mods and how much does it cost if i wanted to do it.

and if i were to get quized on everything that was said, i would probably still flunk, thats why i'm reading this thread again.

I have Eibach springs on my car, but the back of the car just doesn't sit as low as I would like. The front seems fine to me. If i get the Koni's and put the back struts at the lowest setting and the fronts at the highest will it level out my car?

https://www.rx7club.com/attachment.p...hmentid=105194

It will be close, I did the same thing with my HKS springs. The lowest perch will lower it ~1/2" in the rear, so....

But the suspension arm that the bottom of the spring sits on is also connected to the body, so the motion ratio applies.

I haven't considered this too deeply yet, but I am fairly convinced that the wrong conclusion has been reached in this thread. Someone draw some pics of the geometry with a vertical shock, double wishbones, and ride heights that result in the suspension arms being an equal amount above and below horizontal.

-Max

It's not the wrong conclusion Max, at least not on my car....I went from the highest perch to the lowest perch at the rear with no other changes and the car dropped pretty much exactly what Koni claims -- 1/2", which is the distance between the spring perches.

The springs compress the same amount at any ride height because you've got the same chassis weight compressing the springs. So the length of the shock/spring assembly changes the same amount as the change in the spring perch position. And thus the motion ratio applies, and the change in perch position is multiplied into a larger change in ride height.

-Max

If you guys thought my photos were bad... :)

The picture below shows two different ride heights, set by changing the position of the lower spring perch on the shock/spring assembly. The spring will be exactly the same length at both ride heights, because the same chassis weight is sitting on it. The simple suspension is just one arm and no tire is shown (but it would be at the left side of the picture). The right side is the chassis. The only thing that changes is how much shock is sticking out below the lower spring perch, and thus what position the shock bottom is in. The change in position of the shock bottom is multiplied by the motion ratio of the suspension to produce a larger change in ride height.

https://www.rx7club.com/attachment.p...hmentid=105268

Okay, here's my diagram of why the motion ratio applies when you change the spring perch position. If you think (or know :)) something is wrong with this, please explain what is wrong. It seems pretty simple to me -- the motion ratio applies when you change the ride height by adjusting the spring perch. The change in perch position (say, 0.5" down the shock body) multiplied by the motion ratio (say, 1.4) equals the change in ride height (1.4 x 0.5" = 0.7").

-Max

max, I think you're just thinking the same way I was and haven't gone full circle yet. The motion ratio is true when we are comparing wheel travel vs shock/spring travel. However, when we are discussing ride height we are talking about the chassis merely resting on top of the springs. If we imagined the chassis was a table top and the legs were the springs, then shortening the legs a given amount will lower the table top the same amount. This is the same as the car because ride height is merely how high the chassis is off the ground and the chassis weight actually rests on the spring perches.

Changing ride height by moving the perch a given amount will move the chassis about the same amount. I say about because the springs are not vertical, they lean inward slightly. Because of that the ride height change will actually be greater than the spring perch height change but not a whole lot. The leaning of the shocks/springs explains why the change in ride height on the Koni is greater than the small amount of distance the perch moves.

You getting old and lazy? :p:

But that isn't right. It isn't like a table with legs. The chassis is connected to the suspension arm, so if you move the chassis up, the suspension arm changes angle and multiplies the change. The chassis weight resting on the springs means that the distance between the lower spring perch and upper spring perch will be the same no matter what you set the ride height to. But, since moving the spring perch changes the amount of shock that is sticking out below the spring perch, you will move the suspension arm like a lever, multiplying the change in spring perch position to give a greater change in ride height.

Here's a new awesome graphic to show why the table leg analogy is false:
https://www.rx7club.com/attachment.p...hmentid=105333

-Max

You're right, it's exactly like changing the length of the leg labled as "2", but the change in length is not multiplied. The wheels and suspension don't move, they're just sitting on the ground. If we shorten "2" the chassis drops an equal amount. The suspension will move slightly because its inner pivots are bolted to the chassis, but for all intents and purposes the suspension doesn't move at all, the perch merely drops and the chassis comes down with it. Normally we think of the wheel moving in relation to the chassis, with ride height we're moving the chassis in relation to the wheel. Since the wheel and suspension is not really moving there is no lever acting between the spring and the wheel, the chassis is merely moving closer to them.

The chassis is connected to the arms but those arms really bare no weight, they just transfer the wieght of the chassis out to the wheel bearing. The chassis rests on the springs and the springs rest on the perches. Everything else can be ignored. If we were to put a half inch spacer between the upper shock mounts and the chassis you would expect the chassis to raise half an inch, right? All we're doing in that case is raising the chassis by inserting a spacer. When we remove the spacer the chassis would drop back down the same amount. Raising or lowering the perch is exactly the same thing. It confused me too at first.

The change is multiplied, unless your chassis is made out of Jello and you can raise the chassis without moving the suspension mount on the body. Forget about springs for a moment, and consider that if you change the length of 2 and the other arms in that picture have fixed lengths, the table will raise up off the ground MORE than the amount of change in "bar 2". This sholuld be clear -- it is the basic concept of how a lever works.

The weight of the chassis rests solely on the springs. So, the compressed length of the spring with the car at rest is not going to change no matter what you set the ride height to. If your coil-over was 12" long before, and you move the spring perch up 1", your coil-over will now be precisely 13" long with the car at rest. The compressed spring length has not changed, and you moved the perch 1", so the length of the coil-over will also change by exactly 1" with the car at rest.

Take those together, and you will see that the motion ratio does apply when moving the spring perch.

No! That would be exactly like changing "rod 2" by 1/2", which clearly translates into raising the height of the table by more than 1/2".

The chassis will drop back down 1/2" relative to the spring perch, but what is being ignored here is that by dropping the chassis relative to the spring perch, you are also changing the angles of the suspension arms, which means the height of the spring perch itself will drop (in the case of removing the spacer, or moving the spring perch down the shock body).

The motion ratios are not very large here (1.4:1 F and 1.6:1 rear, I think for the FD?), so it's effect is not going to be very large. But the effect is definitely there -- the motion ratio is in full effect for changes in the position of the spring perch on the body of the shock!

I think that may be where we are getting mixed up: change in position of spring perch on shock body VS height of spring perch relative to the ground.

For height of spring perch relative to the ground, then I agree completely that the motion ratios don't apply. The car is just resting on the springs, changing ride height doesn't change compressed spring length, and so a 1" drop of the spring perch will give a precise 1" drop in the car's ride height.

But when I change the position of my spring perches, my perspective is that of changing the position of the perch on the shock body (I even measure the change on the shock sometimes). The motion ratio does apply here. If I move the spring perch up by 0.5" on the shock body, the ride of the car will increase by 0.5" * 1.4 = 0.7" at that corner.

-Max

i hate to interupt such an intelectual conversation but i have a noob question. i have the konis and tein s-tech springs. can i lower the perch and lower the car?

The Konis have adjustable (3-position) lower spring perches. So yes, you can lower it, unless you are already on the lowest perch setting.

-Max

Yes, you can lower it further using the spring perches...but I wouldn't, at least not up front. I would run the fronts at the highest perch setting and maybe lower the rear to match the front ride height. You don't want to lower the front because you run out of suspension travel and start hitting against the bump stops with the tires hitting the fender liners. Not good.

one more question... i have tein s-tech's on my car which lowers the car about 1.5 inches. will the konis drop it any lower?

That's the same question you asked before, isn't it?

From what I gather:

S-tech springs + stock shocks = 1.5" drop
S-tech springs + Koni shocks on highest spring perch settings = 1.5" drop
S-tech springs + Koni shocks on anything but the highest perch settings = more than 1.5" drop

-Max

I'm with Max on this one, despite his sub-standard graphics. ;)
You can figure it out without even including the springs and perches. Pretend they aren't even installed on the car.
The chassis is sitting on a jack at ride height, and the tires are on the ground. Measure the length of the shock. Now jack the car up one inch. Now re-measure the length of the shock. Because of the motion ratio the shock will be longer by something less than 1".
Fwew, look how short that was... and I didn't even use MSpaint. :p

Hey, I used the GIMP, not Paint!

-Max