modified struts & suspension

great work John, looks like you didnt have time for fireworks.
Like said, there is a huge difference from the 2 night shots. it really brought the camber in.
questions... it must of changed the toe also right? because (-) camber would be good for cornering right and what you mentioned was it didnt drive planted.

awesome job ....
 
last night with the wheels so much better from the upper arm mod I drove it a bit hard. once or twice I felt it bottom, I was trying to get it to hit bottom to see if it was low enough yet, if it didn't bottom then it'd still have room for drop... wasn't sure but I thought maybe it might have been the shocks bottoming but I did feel it bottom twice... I did have the air shocks all the way down at just a minimal 20psi. if it didn't bottom I would consider cutting 1/4 coil in the rear, but I was able to get it to hit bottom, so it's low enough

when I parked it I looked at the sidewall for wheel contact & didn't see anything last night so I just figured the shock bottomed. I then got a look at it during the day & I see that it wasn't the shock bottoming at all, but the tire did contact. there was no contact on the sidewall from the lip at all, the rolling was good & the tire clears it & goes all the way up into the well past the lip, the tire contacted on the outer part of the tread itself, & it contacted all the way up in the well where it curves... this mark on the tire is the factory undercoating from inside the wheelwell


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this is like the perfect height, just low enough to touch occationally at 0-20psi, means it's as low as possible so then I aired up the air shocks to 70 psi, which is the middle of there useful range & the results are the absolute lowest my fx can be without touching or rubbing anywhere. the perfect height.... at 70 psi there is no contact at all & it only makes the back come up less than 1/8" from where it sits with no air, almost same height really... but firmer...





so I aired it up to 70psi, 3/4 tank of fuel, me & my son went out driving.... drove a lot, bumpy & hwy & speed bumps, smooth highways & rough roads too


the back is low, def feel that the front is up higher now....

with 70 psi in the rear air shocks the ride was very different. don't know if you'll believe me or think I'm exagerating but today my fx rides better than it has ever rode since the day I got it. took me a few minutes to realize why this dramatic improvement in overall ride, it felt so balanced & felt great, I was surprised, but then I figured out why:

when I first did my H&R's I was pretty impressed with the ride, firm but not harsh. it felt balanced & rode very nice, but was still just way too high...

when I cut the front 1/2 coil though it raised the spring rate of the front a bit, I figured it to be a bit over 15% increase in the front spring rate. after the spring cut the front did feel better, handled better & a bit more tight but you could actually feel the difference in spring rate between the front & rear, the front was slightly harsher than the rear, & it compressed slightly less than the rear. I could feel the difference, & the front & rear didn't feel perfectly connected but eventually I got used to it & it didn't seem so bad, it was a compramise to have the lower stance. the rear always felt slightly "softer" than the front though, which in itself is a feeling of front & rear not connected, for it to feel well conected they would have to feel the same and as one... but it didn't cause the front springs were cut while rears weren't...

well now, the air shocks at 70psi necissary to hold ride height are actually adding a bit to the spring rate of the rear. believe it or not, this is actually evening out the spring rate front to rear & the suspension feels great, better than before. it feels balanced, the front & rear feel like there actually working togeather better than they ever have, the ride has changed... the front no longer feels harsher & the rear no longer feels softer, the whole thing just feels really really nice & even... it feels like a big bmw sedan or something, it has never felt as good as it does now. this is a nice bonus that I didn't even calculate for or expect. this rear setup worked out to be really perfect


at 70psi the rear alignment looks very close to correct in these shots, & I think the rear looks low enough now too. in order to go any lower than this I'd have to flare the wells inside & out a bit, get rid of the moldings all around, custom bodywork... not going there for a while though I think, I think it'll sit sweet with the front dropped a bit & I can't believe how good it rides at this height. the front drop will not alter the ride quality at all as long as I don't cut the spring any more, so the front will still be another 1 1/4" down from these shots... I'm still amazed at how good the alignment is at this drop without any adjustment work other than the upper arm relocate

these shots are final rear ride height, at 70psi....


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John

do you think if you didnt go as much in the lower holes, you could avoid the upper mount relocate? I was thinking of doing half of your drop with a slight offset to the rear...do you think it would work ok?

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... you really need to move to the west coast ! :laugh:
I like the new avatar:tup:
 
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the rear is a dual, unequal length, non parallel wishbone suspension. you should not alter the length of any arm without really knowing the cause & affect.

the wheel is located by triangulation. the 2 lower arms & then the one upper. I wouldn't recommend you shorten either lower arm without shortening the mating lower arm an equal amount at least, & even then I don't think I'd really recommend that even without modeling it & confirming the geometry affect.

by just shortening that one arm slightly you will really change the whole geometry. I think it is very likely that if just that one arm was shortened, you'd find that you now have the problem of the wheels actually toeing in & out as the wheel traveled up & down through it's motion, not good... the 2 lower arms work togeather & I wouldn't recommend you do what your talking about, I know many refer to the front arm as toe & the rear spring bucket arm as camber but that is not entirely acurate. yes, the rear arm does affect camber way more than the toe & vice versa, but you should also realize that each one does also affect the other to a certain extent too. so think of the rear arm as 80% caster & 20% toe, while the front can be though of as maybe 80% toe & 20% caster... each does affect the other. if you don't do the upper arm mod then you should just keep that lower arm exactly the same length eye to eye & do all your corrections by moving the inner pivot points, just like any other car with this type of suspension that is lowered would normally be done...

I'm not saying it's impossible, but without modeling it & really confirming the cause & affect I wouldn't just guess with something like this... the upper was a lot easier to model & calculate cause there is only one. the wheel is triangulated looking straight at it like this: A with the top being the upper point & the 2 lowers being the 2 lower points... it is not perfectly symetrical like an A though, it's more like an A that is tilted with the center axle point being off center & closer to the rear arm, but that's just to give you a basic idea... if this had been a front wheel then I'd have a lot more calculating to do before even my upper mod cause it will also have an affect on caster, & this would make a big difference if it was a wheel that steered, but since the rear is a fixed axis, caster is not a huge factor...


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short answer, don't screw with the geometry unless you really know & understand the cause & affect of what your doing... keep the eye to eye distance the exact same if your going to mod that lower arm is what I would recommend for sure...
 
understood.
if I dont mod the rear arms (but cut the rubber spring seat), do you recommend getting the Suzuki G Vitara's rear shocks (because they are shorter)? I know they also make a KYB mono-tube I want to try if it would benefit.
 
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wow, was pretty embarassing walking in to my fabricator & admitting to him that I fucked up with my measuring on the front struts :tongue: I don't have the time to fix the front struts myself so I gave it to him to correct... surprisingly he was understanding in that we all make mistakes I guess, but I'm the one that is always preaching measure 10 times & cut (or weld in this case) only once... oh well.... he'll fix it anyway:tonguey:




when it comes to the shocks, there is also a lot that goes on there to calculate for too. the length, mounts & stroke of the grand vitara shock may be fine for the fx lowered, but that doesn't mean that the valving & dampening are really appropriate too. I really wanted to do air shocks cause they allow me to preload the suspension & add to the loading of the suspension with them, somewhat at least half compensating for these differences. just reg shocks alone might wind up being a bit too soft really, as the suzuki is a much lighter vehicle overall & not really designed with such a sporty & stiff ride like the fx. will they work in this application?, yeah, as far as bolting in & mounting & traveling through the stroke they will, but I can't really say for sure how much the lighter valving & dampening action of a shock designed for a lighter & softer vehicle will hurt your ride... it may be a bit bouncy & travel up & down too much compared to the fronts as mine do now if there not pressurized to at least like 50psi...

btw, gm's application of this air shock setup is also for a 1996 pontiac sunrunner, again, a very light vehicle too... the part # I used is delco #504577

I'm not really saying that the 03 suzuki grand vitara application is the "right" shock for this job, just that it's close enough to work & that's what I used... I'm willing to bet that there is a shock out there that is even better for this application, especially if you don't want to do air shocks, but this was the best I found so far with the limited research that I did... maybe viet knows of a better shock that may work better & be a bit more agressivley valved & dampened? I approached this with these shocks being a good starting point, if they did work out great then fine, & if they needed improvement I always thought that I would deal with it as it comes... they were at least good enough to at least allow me to do the drop in the first place... so far from what I've seen I think they are working out pretty well for mine... I still need to get it aligned & finish the front & then use it a bit more to decide if I need to consider doing anything further with the rear shocks though... I hate to say yeah, get these even without air, cause there probably not the best for this job really...

it's one thing to just get it very low, but it's quite another to get it very low & also have it ride nice...

---------- Post added at 05:13 PM ---------- Previous post was at 04:23 PM ----------

ok, I've found misc. camber bolt kits from intrax, ingalls & eibach, all for the fx application... just ordered a few of each... from what viet said I think one of the rear bolts are longer than the rest so I got a variety & a few extras too so I can mod them if necissary... when i'm done I think I'll have a pretty good formula for dropping the fx & keeping a good ride too...

should be able to get the struts done, installed & even get it aligned soon... now I'm thinking that the fx has much more wheel travel in stock form than say a g, which might be why the factory specs are calling for a bit less static camber, more body roll through the turns in a stock fx than a stock g which is mainly what the factory specs are based on, but now my suspension will travel much more like a g than an fx, so I will probably add slightly to the factory camber specs, bring it more to like g specs...
 
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alan, I just realized your talking about not modifying the arm at all. if you don't modify the arm at all then the stock shock is fine, even with the upper spring seat cut, you can modify the stock upper shock mount easily & that's just enough travel, that's how I had it before this added drop & modified arms.


the shock becomes an issue only if you go lower than that.


if your going to do the front strut mod, on stock diameter tires, then the drop pelon did is perfect, & about as much as you can go in the front, 3/4" added drop, any more than that will not have enough tire clearance to the spring seat of the strut. & then of course the option of cutting 1/2 coil or not for maximum drop... now what you should do to the rear depends on weather you cut 1/2 coil from the front spring too or not...

---------- Post added at 11:23 PM ---------- Previous post was at 11:10 PM ----------

also, keep in mind that everything I do I can add another 1/2" to what you can do because i'm running a 29.5" tire, the stock diameter is 30.5", so i have 1/2" less tire above & below the wheel :smile: that's why I can do 1 1/4" front strut mod, your restricted to 3/4", my tire is shorter... when I finish I'll sumerize everything with what options there are for what amount of drop & formulas for each.

basically with stock diameter tires the possible drops based on front #'s are:


~1.2" for just drop springs, ~1.8" with 1/2 coil cut drop springs, ~2" drop springs uncut with the strut mod, & finally 2.6" with drop springs, 1/2 coil cut & the strut mod... so were talking approx 2 3/4" drop is the maximum you can get & still have a decent ride providing you have the tire clearance & not so aggressive wheel . how low do you want to go?

---------- Post added at 11:35 PM ---------- Previous post was at 11:23 PM ----------

what happened with my fronts is, when I first looked at doing this, I was concerned about the axle clearance to the strut bottom, I did realize the spring seat was going to come down too, but I remember thinking that looked like it had a good amount of room, it looked like it wasn't the limiting factor, so I calculated it as the axle was the limiting factor...

once I thought that I never bothered to confirm the spring seat to the tire any more, I remember intially thinking ~1 1/4" - 1 1/2" or so & the spring seat clearance looked fine at that, but then later I thought I could also cut the bottom of the strut bracket off & get another 1/4", not even thinking again about the spring seat to the tire. I screwed up cause I had him do the 1 3/4" & trim the bottom, then I put it on & the tire was too tight, it went on & was pressed right up against the spring seat, couldn't even rotate... I had him take 1/2" out now, go back to 1 1/4", & that should be fine... with my tire this is the equivelent of 3/4" with your tire...
 
just throwing this out there....

if I had the camber and toe adjustment bolts, wouldnt I get away with doing what I mentioned earlier? locate rear bolt slightly back (I talking about 1/8 or 1/4 inch)
I really just want to relocated the hole about 1" in. I dont plan on cutting the rear springs

as for the fronts, I want to keep from cutting the spring if I can. I want the H&R spring rate for the front and rear to be unchanged if possible.

I was also thinking of making a plate (to make new holes) for the rear and front and utilize the stock holes for additional bolts for support. (longer bolts of coarse).
I have a few Nuts and Bolts only shops near me and they carry every bolt imaginable.

cant wait to see your setup once complete.
 
Im definitely doing the 3/4 in the front. I was thinking of making a plate drilled with 4 holes, 2 are for bolts thru the old location holes. Thinking of using a metal collar in between those holes. of coarse the top of the bracket on the strut will have to be cut off.

Im on the fence about cutting the front springs...

as for the rears, can I do a 1/4 from the hole and still be ok w/ camber bolts. So ya, thinking about

I will wait and read your summary when you complete your setup.

---------- Post added at 12:42 AM ---------- Previous post was Yesterday at 11:20 PM ----------

I think this " ~2" drop springs uncut with the strut mod" is the best option for me. I was thinking ever just modded upper rear support would be ok w/o messing with the lowers.
 
ok, so 3/4" front strut mod, keeping the springs uncut... just cut the rear spring spacer for 1/2" in the rear, mod the upper factory rear shock mount(easy) & your done. you don't need to do too much more for that height, you'll sit almost exactly like I did before this arm mods... maybe ~1/4 lower in the front than mine did up until this weekend low but not really low... ~2" total drop front, rears around 1 3/4".... still better than just springs...


you CAN NOT bolt the strut mod on, no way, it HAS to be welded... you can not pass 4 bolts through the knuckle the way your saying, there is no way the existing holes can be used for this mod attachment... must weld the strut no matter what... basically what you'd be doing is almost the equivelent of cutting a 1/2 coil drop wise, but not adding to the spring rate with a cut, so keep the stock H&R ride...







if you really wanted another 1/4" to 1/2 " in the rear to even it & remove the slight rake that you'd be creating then you'll have to mod the lower arm & the shock may bottom, opening up the whole shock swap deal...
 
thanks.... for deciphering my posts lol *I get a little confusing when I post past 11pm, maybe due to my medication:wink:

so for the fronts, just mark a straight line through the old holes and go up 3/4. if I cut the springs too, then I will need a camber bolt?
the back will need some more thought on my part.
 
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yeah, best way is either cut the old off on the 2 sides or cut 2 square notches & then insert new metal & weld.

the inside of these 2 holes mate to the knuckle, & they mate to only a small circumference around the hole, about the surface area of a large washer each. the inside of the strut has to be a smooth solid flat surface for it to clamp to so there is no movement. the holes should be pretty acurate too, but the clamping force is what makes it solid. struts should be done right or your sacrificing safety... any movement & your setting it up for failure ... 3/4" isn't hard to have done professionally too I think. a tig welding job is better than a mig but mig can work too.




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past 5 days I've been actually working on installing this drop, 4 if you don't count sunday :smile:

it's pretty much done. what I started out to do way back in november of last year when I first ordered a set of custom wheels & tires.... it's only right now that there really done! suspension, wheels & brakes... done... final stance & ride, done. I can now look at the fx & really see how the final product looks of what I envisioned when I ordered the wheels & tires almost 9 months ago....


ok, maybe done is not 100% done done done:cool: still need to align it tommorow, & there are always small tweeks that I might do like adding a second shock to the rear arm, but this is about it... front may need 10mm spacers, come down another 1/8th" maaaybe? but gotta see what the alignment does first...

this is pretty much what I had pictured in my mind for the most part when I ordered the wheels almost 9 months ago, it's filthy from 4 days of surgery but :


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it rides amazing... it rides & handles better than it ever has... the alignment looks pretty close visually & it even feels great overall but the front strut install now made the front toe out a few degrees I think, feel that in the steering a bit & feel the rolling resistance slightly at hwy speeds. tommorow I'll align it myself & see... I have a bunch of different bolts but I really don't even know what needs to go where for sure, I think the front might be very slightly more negative camber than should be & I think the rear actually may need a little more negative camber maybe...



now it needs a little fine tuning, but it's pretty much there. no rubbing no bottoming, no scraping, no anything touching anywhere, just really nice big sport sedan ride. the lower center of gravity from this drop makes it almost feel like I upgraded the sway bars in a way, it feels lower & doesn't roll as much, but it rides exactly like it did before as far as ride quality, better even. the rear compression added with the air pressure of the shocks is a help compression wise & adding to the spring rate, but the shorter shock of a lighter car in the rear means not enough rebound dampening compared to the front kyb struts. when I really pay attention I can feel this. it's like on a dip, whole car goes down evenly & asorbs well, but then when it returns the back wil come up a bit more than the fronts, then settle in... fine tuning this is to add more rebound dampening. it feels great but this will just fine tune it to be as good as it can be. there is room to add another shock I think, doubling the rebound dampening... also doubling the compression dampening too obviously, may only need to run 30psi static instead of 70psi.
 
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