Using GC top hats would make that a non-issue (not trying to be obtuse, I really am just not quite getting it yet)?
This is the best explanation of what I'm referencing that I've found so far (can a degree of camber be removed with rear camber bolts and whatever is stock up front or is that too much too remove?): "02+ Impreza wagons and sedans have the same rear struts and tops, but the wagon springs are taller to the best of my knowledge. Struts are the same even though the sedan has a wider track because the mounting points in the wagon chassis are moved inward (and upward?) a bit. Using these on a first gen will result in about a degree or more less negative camber." -- http://forums.nasioc.com/forums/showthread.php?p=17495768#post17495768 EDIT: as I read further someone says yes to camber bolts. So, 02-03 D-Specs, GC sleeves with springs that fit 01 top hats, camber bolts (F&R or just R?), my existing top hats and I'm golden? (please say yes )
Yes, there is a LOT of slop and delay and isolation...everywhere...with the stock bushings/mounts. Steering rack bushings alone do a good bit, but an ALK will take that one step further and really lock down the front end. Yes, you can use camber bolts to adjust camber as needed. There was a good read somewhere about this that got very specific, but I'll probably never be able to find it again. Camber plates could be a future upgrade option if needed. You're pretty much bound by the tire and offset you run. Too much neg and you're against the strut housing, too much pos and you're rubbing fender. The TiC folks are actually very friendly and enthusiastic about Subarus. I'm sorry your experience was...off. They're probably one of the most loved vendors for Subaru. However, it's just a couple of guys doing a LOT of work behind the scenes. Maybe you hit an off day of theirs. They're definitely worth a second chance.
It sounds like camber bolts should be enough. Wish I would've seen that on day 1 of research instead of day 4. Oh well. I'm hoping the tranny & engine mounts I got help some of the feel, but the more I drive it as a manual the more I think I should've aimed for the rear diff first - at least I think that's what's bouncing all around. And I won't rule out TiC just yet, and perhaps with SEMA just ending they are very busy catching up and were simply curt. I read all over that they're well liked and I see they've supported the community and brought some neat setups to market. So, it looks like the final upgrade list is looking like: Tokico D-Spec struts Ground Control coilover sleeves 318 lb/in F & 280 lb/in R 9" linear GC/Eibach springs (IIRC) F & R camber bolts TiC Tokico adjustment extenders 20mm OE front sway bar & bushings Perrin front end links 22-26mm Whiteline rear sway bar & bushings '04 OE rear sway bar bushing mounts Whiteline heavy duty rear endlinks Paranoid Fabrications cowl stays Generic E-Bay F & R strut tower bars :banana: (hope I like it :ugh
Why those spring rates? Think you'll need that big of a rear bar? Why a 20mm front bar? Do you understand why you are picking this setup? It's helpful to work through a little physics with this prior to becoming dead set on a specific setup. Note I'm not asking if it's right or wrong. However, these things should be chosen specifically to your own goals and preference in ride/handling/behavior. It's no fun if you toss on a bunch of parts and the car drives undesirably. In many cases, it requires you to understand yourself. Do you know how you drive? Do you know what you want in terms of firmness, responsiveness, harshness, balance, movement, etc..? I'm trying to make you think on purpose. I want you to question everything. I want you to get to a point where you know, not just think. I know I'm asking too much though. I know this setup will not be your "ideal." You have no idea what that is yet. You can only compare to stock.
Heh - yeah, to be honest, some choices - like rear sway bar - were based quite a bit on what was available used over a short window of time. I think if I could've picked I would've tried 21-23mm. Seems that was a pretty reasonable range for spirited street driving. The percentage differences in rates on North Ursalia's site made the upper end at 26mm seem like it would be too stiff and the steps between too big. I'm definitely installing it at 22mm. Thinking that might be a tad rear-biased I grabbed a reasonably cheap 20mm FSB as an option to try - see which I prefer, stock 19mm or 20mm. Guess if I don't like the big rear I can resell for most or all of what I paid, run the OE, and look for something smaller. Springs rates - I'm still kinda reading and deciding. Some people here have recommended a bit lower, and I realize it's quite a bit stiffer than stock. But I've also read a few woeful tales of people running too soft of springs for these struts and really not liking it at all. I'm aware now that I may be way off on springs, but there's no end of options with the ground controls and they're not all that much new ($200-250+ for 4). I'll pick something and it may work and it may not and I may have to try some different ideas year. Even a couple weeks ago I thought I could pick parts and be done, but the plethora of choices and the seeming fact that everything interacts to create the entire feel of the vehicle has made me pretty sure that while I may get close, I'm unlikely to get exactly what I ultimately want on the first shot - if what I want even stays constant. Like you say, I really have little to no idea how the car's going to feel when it's done - I'm hoping I'm close to right. There's a whole lot about how the car feels right now that I want to change. My way of attacking that is plunging into a big project of tossing a lot of parts at it. Is it the ideal method or the most cost effective - probably not. Guess that's just me. Will I be happy with it and have learned a lot in the process (and be as happy about that as anything)? Yeah, most likely. Oh - and the exact spring rates (if I recall them correctly) were particular ones recommended by John @ Ground Control. I discussed my desires for the car's feel and handling and he suggested those as one in particular for the 9" length and my MY as ones they developed specifically to avoid clunking issues. With the extra weight in the trunk he suggested going same F&R rates, but with the big rear sway I was concerned about getting too rear happy and I don't want to have to lower tire pressures too much to compensate so I thought I'd try the traditional lighter springs in the rear. Ground Control has been very, very helpful.
Stumbled upon TiC Fender braces used on NASIOC for $20 less than TiC's website or Paranoid Fab. Ordered. Also ordered Ingalls Camber Bolts from Summit Racing. cheap. Good chance I'll order the D-Spec's from TiC tonight. Hopefully will finalize with Ground Control tomorrow. Trying to make as informed of a choice as possible regarding spring rates, but it's tough being such n00b in lack of experience. Might go a bit lower than what I was initially thinking - not totally sure yet. Can anyone point me towards a good rear diff clunk solution for the GC chassis? I see lots (like the Perrin SRS) for the 02-07 WRX's, but the rear subframe setup is different in GD's and GC's from what I can tell.
Tic has Kartboy rear subframe bushings. they're "klunk killer", which also includes the diff bushings says 02+ specific, but I don't see anything for just the subframe bushings. I don't know all the details of bushing differences between the chassis styles....but might be worth some more research.
Yeah - more research. Maybe I'll back-burner it for a while. I've figured out how to shift it without making too much noise. Besides, I'm already taking on an awful lot with this round.
I kind of doubt this. as long as you have the correct offset you should be fin against the strut. On my 225/45/17s which tend to be a little wider than stated. I still have good clearance on the strut, the the point were the tire would have to be wider to cause any issue. you are most likely rubbing on the fender liner. Also just an FYI about the ALK. If you intend to auto-x I have heard that any sort of ALK will change the class you are competing in.
Good to know about the ALK. I'm not planning on doing that in the near future, though. Maybe some steering rack bushings, thought about the rear end stuff, but meh - I'm feeling a bit overloaded with everything I'm about to dive into already so I'm being cautious about adding more just yet, plus since bushing flex if eliminated just ends up being shock to other parts of the system (like internal components potentially) - figure I might be better served learning how to control that better with driving technique when it's easy to feel. I was reading a lot the last couple days about spring rates and frequency and sway bars and all of that. Came to the conclusion that it's pretty stinking complicated (at least to try and make precise mathematical calculations on). I'm pretty sure I'm in the right ballpark, though. Going to finally put the rear sway bar on tonight. It may be tough to really understand how that alone affects handling at the limit now that the snow tires are on and the weather's a bit cold for the summers. I've been trying to get a feeling for what flexes and movements in the vehicle come from which areas - struts, tires, etc. Not always easy to tell from the driver's seat. I mean, some seem obvious - and it's easier to narrow down the sensations that are reproducible. It's kinda wild how different the same corner can feel just based on how I drive it, and of course changing the tires makes a world of difference. Even a few psi difference on the summer rubber made quite a bit of difference in handling in more ways than one. Hmm .. time to call Ground Control.
you will notice a huge difference with that rear sway bar in. Ibetthatyoursnowswillbesqueallinginpaintonight.
Seems the HTS002 D-Spec's would've fit: http://www.rs25.com/forums/showthread.php?p=1520523#post1520523 That guy just did it. DSP-10's will be fine, though (and cheaper). Put the swaybar on last night. Passenger side bushing mount was a serious PITA. Didn't help that I decided not to bring my locking lug socket with me - once I got the wheel off it was cake. Problem was, one of the bolts on the OE mount was under the fuel filler neck and it wouldn't come out. I took the wheel off, removed the plastic shield, then I had to remove one mounting bolt on the neck that was under the filler and the three up by the gas cap. Then the neck easily moved out of the way of the bolt. Still need to go whip it around some more corners, but so far I can say that the rear DEFINITELY feels more solid and the front end pulls the car through turns in a much better manner.
I guess it's time to whore a pic of my coilovers - GC coilover kit with Koni inserts stuffed into hacked up stock strut bodies. Notice the lack of spring perch... Stuart.
Thanks. Here's a better view of those... PDE v2 Camber Plates (yes they're designed for the '02+, but they fit just fine and because they're twisted slightly, they add caster). I couldn't use the v1 since they didn't come with holes in the top plate for the Koni adjuster. Stuart.
You were totally right. That was cake. Like 5 bolts and a nut and everything went in perfectly. $33 shipped - figured it was a no brainer to try. Got the things and thought no way can those skinny, flimsy pieces of plastic make any difference. :eek3: Holy cow do they ever though. Got me wondering what other rubber bits are worth replacing. I'll be doing engine & tranny mounts on Saturday.
Another update: Group-N tranny and engine mounts are totally FTW!! Of course, it turned out my tranny mount was really sloppy - the Group-N eliminated my mysterious clunking. Only downside so far is a dash vibration at idle. The engine sounds much better (not at all harsh) with the new mounts. Had some trouble getting the engine mounts in, but I won't go into detail since it wasn't that big a deal. Unfortunately, it seeming more and more like I overshot the spring rates by a good deal. These seem far too stiff for daily driving on our roads. At speeds under 30 I'm bouncing off bumps and losing traction. I also seem to feel my tires compressing an awful lot going over bumps. Its like the tires suck up a bunch and then bam - straight into the chassis. Smooth highway its great, but anything else is varying degrees of crappy. I have a good feeling that I'll be replacing those with something softer come spring time. I should've just gotten exhaust instead of struts. Sad thing is if I'd have gotten the exhaust I also would've now gotten Delta cams and a reflash to support it, but instead I have to wait for all that since it doesn't seem like a good idea to do cams before exhaust. So, instead of having 50% more power I have a 50% less comfortable ride and no real improvement in traction or handling for 90% of my driving (at least during the winter).
Yes, Group N for the win. Cabin vibration is a side effect. You can look into some automotive sound deadening options for it though, but it is somewhat of an en devour tearing out the interior and such. Getting in engine mounts = removing pitch stop. Yes, not a major thing, but something someone installing may or may not think about. Rough ride and tires losing contact with the road = too high of a dampening rate. Adjust the Konis down a touch until you stop "falling" after bumps. Basically, if you set it too stiff, the car "falls" after every bump (excess rebound prevents suspension from extending fast enough after the compression stroke from the bump). If you set it too soft, the car "bounds upward" after every bump (excess oscillation after initial compression/rebound stroke). Once you dial in the dampening rate, the car should feel like it "floats" over bumps. That is your ideal. Get the front and rear ends to do that and you're golden. The ride will be significantly better once you get it set correctly.
Thankfully, I think I'm narrowing in the right damper settings. I started off WAY too stiff. lol So, I'm starting to think its not that my springs are too stiff (good thing - still maybe a bit long for my tastes, though), but that my D-Specs have been set too stiff. I'm more around 2 full turns from full soft rather than 2 full turns from full hard! It's starting to get in the range of as comfortable as stock but still WAY tighter. Slow bumps still have more cabin movement, but at least I'm not hopping over them. I am trying to feel the movement of the vehicle and relating that to the mathematical graphs of perfect damping that I'm familiar with from my calculus and physics classes, which is pretty much exactly as you describe it. Funny thing with the engine mounts. Too much to type for me right now - but it wasn't the pitch stop, lol. We ended up grinding them some and still had to get just the right amount of lateral leverage on the engine to get it to pop back into place. It was almost like the engine mounts were too wide - there was a sort of notch on each side on the cross-member and one mount would fall just inside the notch were it should (driver's side), but the other (passenger side) was resting on the notch, too far outwards (towards the fender). Engine mounts make the car sound better, IMO. Little more vibration, but not an annoying one. (Oh - and my car's already like 60% dynamatted, other 40% [under the front seats & firewall] will be done next summer - I do it all myself).
Well, 3 weeks later and I'm still unhappy with this setup. Right now I'm running basically full soft on the struts. If I stiffen the struts at all it only gets worse. The whole car is just too reactive/bouncy/twitchy. Is like the rear end weighs nothing and its rocketing into the air over every single bump at any speed. I mean, that's a slight exaggeration - but this isn't: I felt more confident on the stock suspension. It does sort of bound upward on every bump - but if I stiffen the shocks it just gets worse - and I mean it quickly approaches horrible and dangerous. As it is at full soft, it feels unsafely reactive at higher speeds (80mph+) - like it might bounce of the damn road if I hit the wrong bump at the wrong time. The front end actually seems okay when its set a bit stiffer than full soft - but its hard to be sure cause the back end is bouncing all over. The only thing left to try is to put the sub box back in the trunk to add 100-150 lbs. But - I shouldn't have to add weight to tone down the suspension. I'm at a loss - I would guess the springs are just too stiff, but the way it feels makes me think the shocks are too stiff (but they're at full soft, which is supposed to be a bit softer than OEM). Could the springs just be so much too stiff that there's next to no compression of the suspension happening on bumps? Anyone out there with more experience adjusting dampening wanna go for a drive and feel whats going on - help me out?
Rebound dampening is TOO LOW!!! ...despite what you think. If the car is bounding upward after bumps, the rebound is too low. No matter what you think about this, adjust it higher. The only time you will stop adjusting it higher is when the car starts to feel like it's falling after bumps. This is the only time the rebound is set too high. You'll also have to differentiate the front and rear too, because if one end is bouncy, it can make the whole car feel weird. You'll have to get them even so the car handles neutral. The car will feel very weird until you get this set well too.
Yeah - I've TOTALLY been feeling the difference when I get the front or rear further off than the other. It feels WAY wacky when they're bouncing at different rates! I actually cranked the rears alone 1&1/2 turns stiffer for the drive home to see the difference. I'll keep trying higher in various increments - it didn't make sense that full soft would still be too much dampening.
Harsh ride doesn't equal stiff dampening. There are different kinds of "harsh." Until things get set correctly, the ride will feel very funky. It just takes time. I'll put it like this: As you tune up from a too low of setting, the car will bound after bumps. As you increase dampening, the excess movement will lessen. When the rebound is set correctly, the car will almost "float" over bumps. Once you start stepping above this, the car will start to feel hard. Over every bump, the car feels like it's falling a little. If you drive aggressively, you will notice the car begins to get skittish. The car gets more go-kart like but does become unstable as the tires start to become less in contact with the road after bumps. Basically, you find the sweet spot where the car floats. It's easiest to start with the front and then do the rear afterwards. Watch the nose of the car. When the damping is too low, you will see it oscillate all the time. Once you get around the sweet spot, it will stop. When you're above the sweet spot, you'll know it from the falling. However low is harder to gauge, so the visual aid is helpful. Once the front is set, start adjusting the rear. Put something in the back of the car to gauge it's "float" factor, lol. Like a bucket of change or a tool box, something that can hop around and make noise. As you get it more ideal, the noise will lessen. You can also look out the rear view mirror and kind of see the back end bouncing around too, but that sort of depends on what the front's doing too so it's less reliable.
Thanks for all the advice on this - seriously. You've been a big help. One thing that's been throwing me off, is at full soft I get the upward bounding in front, but not like a constant bouncing/oscillation - but if I stiffen the front a good few turns, I get into a range where the undulations on the highway cause the front end to just continuously oscillate up and down at a sort of fast pace - very bobble head. I've been thinking that's a symptom of having the front and rear dampening too far off from each other and the car's acting like some sort of weird sprung lever system - like its see-sawing back and forth between front & rear. Last day or two I've got the rears set steady and have been inching the front's stiffer (by 1/2 turns) trying to find the point where I no longer feel the bounding upwards after a bump. Sounds like I should keep on that track. I'll be doing lots of highway driving this weekend, so plenty of time to twiddle with it. lol. Last time I went out of town I had the GF reset the rear shocks to full stiff and then dial it down about 5 turns while I was driving! That was not cool - I think I'll pull off the road this time to make big adjustments!
I'm not certain of the sensitivity of the adjusters on the Konis. However, on the D-Specs, even an 1/8 of a turn is decently significant. You can start off with a full turn at a time, but drop it down in steps and you get above and below the ideal. Step to a 1/2 turn, 1/4 turn, 1/8 turn, and even 1/16 turn to get it exact.
100 miles on the freeway today. A couple tweaks to the rear and one stop to tweak the front, and I feel like I may be closer than I've been so far. I may try this setting with very minor adjustments for a while. It will be a good test going back across that wasteland of 94 between Rogers and the cities (that road is ****). I don't even know where I'm at right now - too many little adjustments and I lost track. I'll have to count the turns back to full stiff to see. As for sensitivity - 1/2 a turn is very noticeable. My last two adjustments (one front, one rear) were a 1/4 turn and were still pretty noticeable, and I may try 1/8 stiffer on the fronts in the morning.
Well, I feel like I've got it dialed in about as well as it ever can be. I've done a lot of little adjustments back and forth and tweaked and tried. I know now some particular road's bumps VERY well. lol What seemed great was 4 from stiff front, 6 back - but it was a tad underdamped, moreso in the back. I was still getting lots of upward bounding (with a sort of delayed feeling). I played with the backs from 6 for about a week now. I tried going up in little bits - it kept bounding, but each increase stiffer made the bounding more sharp, violent, and with less delay. Then, I just went like 1 & 1/2 turns stiffer than 6 in the rear. At that point, the rear would hop off bumps and lose traction. I went down from there and kinda of circled a point about 5 & 3/8 turns from full stiff (5/8 turn stiffer than the 6 I started with). This felt about the best for the rears, but the fronts felt a tad underdamped still, so I stiffened them about 1/16. Better. So, where its at now feels about the best yet. It's very good as far as front to back matching. The car reacts as a whole unit at most speeds, versus very distinct front & back feelings when its off even a little. But, its still FAR from perfect. Repeating undulations on the highway send my car rocking up and down. There's a couple of particular bumps that still cause me to loose contact, at least partially, with the road at highway speed. Some cause me to literally fly a bit up out of my seat. In town, it can get pretty bobble-heady on those repeated sharp bumps across the road (a situation where the rears feel underdamped again, but turning them up as little as an 1/8th turn brings me to bouncing the rears off and losing contact more. The car often feels twitchy and over-reactive on the highway, but making things softer very quickly brings the delayed bounding upwards back. I'm pretty sure I'm still a little bit undamped overall, but I've stiffened it as much as I can to reduce the bounding without going too far into the bouncing right off of bumps area. Still, though, I've never really felt like it was falling after bumps, no matter how stiff I get it (and I've had it ALL the way up). It goes from bounding upwards after bumps to bouncing off of bumps as I go from too soft to too stiff. I'm still kinda frustrated with this setup, but I do feel like I'm getting the hang of adjusting the struts. The undulating highway thing nerves me out - its like the front sort of falls a bit when going over a hump but then it bounds as it crests the next hump and it turns into an oscillation. Its done this to varying degrees at EVERY setting I've tried. It seems to be impossible to get rid of, I can only change to a degree how it feels. It did it to a lesser degree with the stock setup, too - but that was just uncomfortable as a passenger. This feels like its throwing the car around somewhat dangerously.
I just feel like I adjust and adjust and adjust - and actually get it feeling quite a bit better, but then its still got all the same fundamental problems - they're just slightly less awful when adjusted well.
Yeah, that's sort of how it goes. I'm surprised you have the rear that low though if the spring rate is 280 lb/in. Your front is even lower then I'd expect give a 318 lb/in rate. Example, I'm at around 2 3/4 front on 280 lb/in springs, 5 5/8 in the rear on what is assumed to be around 200 lb/in rear. Now my weight balance is different, so the dampening will change a little depending if you have 500 lbs or 600 lbs over that tire. Still, it seem quite low. I'll also note that some of the bounce you get is more forward-rearward jostle if the dampers aren't set well relative to each other. I would kind of figure you'd be closer to around 2 turns on the front and 2 1/2 to 3 turns rear for those rate springs. What ranges have you used so far?
Tried pretty much everything between full soft and 3F/5R meticulously. Stiffer than that I've had trouble with, but I hadn't tried it recently. So, the other day I decided to start at 2.25F/3.25R and try to go from there. Wrong. Car was so violent that I couldn't drive it over 40mph or make any sense of what I was feeling as far as adjusting the F/R balance - just too violent. Scary. I'm sure it was just F/R seesawing, but I couldn't make any sense of what was too stiff or soft. Headache, literally. I went back to 3&7/8F/5&3/8 and now I'm trying to move up in steps that keep the front and rear as closely balanced as I can. First I went 3/8F/1/4R stiffer and the rear was more underdamped than the front, so then I went 1/4F/3/8R stiffer yet. The rear was still kicking up on me on the way to work this morning, but the front felt decent where it was at. I turned the rears up another 1/4 and I'll see how it is this afternoon, but I'll probably need to bump the fronts 1/8. Then it should be reasonably F/R balanced and significantly stiffer - if its still underdamped, though, I'll continue this way stiffer yet until either the feeling changes to "falling" or if it gets violently off again. So, right now, I think I'm at 3&1/4F/4&3/4R. So yeah, I'll probably need to keep going stiffer for a bit. It felt better overall - but there's some telling roads I have yet to take it down, and the slightly more underdamped rear, now that its a bit stiffer, is kicking up a bit - but I'm assuming for now that even though its stiffer its still underdamped and that continuing to stiffen it will eventually find a point where that goes away - if I can keep it F/R balanced enough to be driveable. lol
What tire/wheel package? By violent, you mean just a rough ride? When the damper is too high, the car will fall after every bump. The car will feel unsettled and skittish. It actually feels like it's not touching the ground a lot of times. It will feel "violent." With high spring rates and low profile tires, there will be a certain level of harshness. It just comes with the territory. It also depends on the roads you drive on. You just need to be cautions with going too low too. That too will make the car feel weird. You really need to work between falling over every bump and bounding after every bump. You need to say to yourself this is where it's too high because the tire falls too slow to get back to the ground after a bump and this is too low because after the bump, the car bounds upward and creates a bouncy ride. I would also not ignore tire pressure either. I just want to say that right can be violent. My summer tires are a bit of a rough ride relative to my winter tires.
By violent I mean very severe reaction to road surfaces - like my butt leaving the seat (or vice versa) repeatedly (as in sometimes the car comes up off another bump and literally the seat hits my ass as I'm still falling back into it from the last bounce :cough: 169 :cough: ) - and I'm over 200lbs, so its really throwing me. Not just uncomfortable, but dangerous - car seriously undriveable over 40mph - had to slow down and pull off the highway and put the adjustment back to something I knew worked well enough to get home. :ugh: I'm guessing it was just severely off front to rear as I was just stabbing at thin air with the numbers I jumped to and it was definitely a seesawing motion. Gradually working up is going much better so far. I don't think I've hit the "falling" point yet, but my previous attempts to go stiffer have resulted in the violent handling, so I was hanging around the lower settings - always resulting in combo's that may have been balanced f-to-r but we're still underdamped (hence always with the "bounding" and feeling like its more different shades of the same kind of "bad"). Wheel/tire right now is stock RS 6-spokes with Graspic DS2's 205/55/R16's. 36psi front, 32 rear - I know thats stiffer than the door jamb numbers. I've played with pressures some, and I've always preferred them a bit stiffer, even the winters. Summers last year I ran stock wheels and BFGoodrich G-Force Sports 225/50/R16 around 41psi/36psi. This summer I've got 17x7 +48 5zigen FN01R-C's with some craptastic 225/50/R17 (rubbed on stock suspension) summer tire on it now. Probably have to run those tires this year, too, since I'm spending everything on the engine swap. I'm pretty sure I can distinguish the "rough ride" caused by a stiffer suspension setup from the "holy cow this sucks" caused by incorrect dampening settings. I'm just taking a REALLY long time fiddling and still having trouble. I'll go with my current method trying to inch my way stiffer until "falling" and see where that gets me after a few more days. Moving in increments and trying to keep it balanced has so far kept the violent seesawing in check - but I'll see soon if that holds true through another full turn or more stiffer. Being entirely new to all of this I'm not so surprised its proving difficult for me. Guess I won't underestimate the value of a tried-and-true spring/strut combo for a given vehicle & purpose should the situation of choosing those parts arise again.
Ok the first thing I must say is that doing this in the winter is not good. All suspensions will ride rough this time of year, especially with your spring rates and shock settings. First thing to know about D Specs is that they run really stiff for the first 3 months or so after that they settle down. When I got mine I was at full soft and now I am up at 5.7 from full hard in the front and 4.7 in the rear. I have 375 front springs and 300 rear. I change in 1/8 increments. I am paranoid so I often make my adjustments from fully clockwise just to make sure I am counting correctly. I would think that your spring rates would be stiff for the average street car. I don't think I would have gone over 250 for the front and 200 for the rear. The D Specs work just fine with softer springs. BTW pick a stetch of road to tune on and stick with it. If you tune out expansion joints your performance on side streets with pot holes may suffer. Tuning your suspension is all about compromise, you will never find the perfect setup. If you want it to feel like a buick on the freeway it will not be good in a performance mode. It doesn't sound like thats what your looking for just trying to make a point. Good Luck Mike
My D-Specs didn't really change at all after the first few miles. I've heard lots of stories of people needing to readjust them. From new till now, I've always ended back at the same spot. I want to drive people's cars. :laugh: I do understand how bad it can be, but all i can suggest is live with what you chose. You picked a race level spring rate, live with the race level ride. If you want it fixed, you'll need to step to taller, softer tires. I find the rough roads as the easiest to tune. Rough corners help too but getting skittish on a corner isn't the safest check. You'll really have to step past the violent stage and get to the falling point. You need to see both sides and realize that correct is somewhere in between. The ride is most improved and least violent near ideal. Above or below, the ride can become quite crappy. This means overly low is also not a fun experience. Plus part of the experience is how well the front is tuned relative to the rear. If you're too far off, the car can drive really, really weird too. This too can lead to seat bounce. Quick and dirty guide to front - rear balance. Drive down the road and swerve back and forth. Which end feels stiffer? If it's the rear, bump up the front a little. Try again. At some point, the front and rear will feel pretty even dynamically. This is where you want to be. 169's bad? :laugh: I don't know. I've got some rough roads around me that I use that makes anything I've experienced on 169 tame. I'll say I don't frequent 169 much, but I don't recall any roughness that stands out.
lol @ 169 comment. I'm in the cities. Slim pickins for bad roads. It represents one type of bumps that I'm testing against. Its got this stretch I travel often that is quite different from the rest (94's got a similar stretch, but I rarely travel it). I've got a handful of road/speed combo's I am trying. Once I can actually get a reasonable feel for what my "race level ride" is I can decide on whether or not to live with it. Honestly, I'm way okay with some bobble-head and sharp jolting in town as long as I can stabilize it at highway speeds and faster. Everything I've tried so far is just obviously wrong. If I get close to right, maybe I can get a better idea if my springs are okay or not. My initial hunt and peck randomly wasn't working. Now I'm logging everything and trying to be more logical and consist - hopefully that gets me farther.
I want to drive your car. You will find less bobble once you balance the front-rear well. Sometimes you can one side good but then the other side is a bit off and adding a bit of extra movement. Sometimes rough roads are just rough roads and you have to live with some level of harsh ride. We have enough crappy roads around in Mankato and there's a couple good stretches coming into Rochester that are pretty crappy and quite unforgiving to firm rides.
lol. If we're ever in the same area you're certainly welcome to drive my car (we never go anywhere around Rochester). Its not very fast, yet... It is always nice (for me at least) to get someone else's take on things, too. It is feeling better stiffer right now - but most changes have felt better initially and then worse after a day or two, so I'll see ... Like I said, I'm pretty sure I'll be able to tell a harsh, stiff ride from a wildly wrong dampener level - and I'm now assuming I've just been at a wildly wrong (too soft) dampener setting the whole time.
One thing you'll have to do is separate "comfort" and "working correctly." analyze the system in terms of proper function. Get it to function the best. Comfort will be a secondary system, not done through damper setting. Yes, you can set the dampers low and get this loose, floppy feel to the car that feels more comfortable, but it also lacks control and depending on the bumps, the car can flop around and make the ride worse. Set the damper stiffer and stiffer. Don't stop until the car falls. You should get to a point where the car feels like it's falling over bumps all the time and that the tires are not in contact with the road part of the time. You really do need to experience the above ideal part too. Know what too stiff feels like. Then work your way back down. Find the point where the handling starts to feel sloppy and instead of falling, you can sense the car bounds after a bump. You really do want the point in between these where the car almost floats. Now the car will still move around over the bumps, but there won't be a sense of the tires dropping too slow and the car falling nor a sense that the car is bouncing and moving excessively after bumps.
^ This is correct. Once your dampers are set to match your wheel rate, you do not need to adjust them again. If the ride is too harsh, buy softer springs.
Or tire/wheel package. For example, my winters are pretty nice to ride on. My summers, I would call harsh, enough so where it's annoying. However, that's sort of what you have to live with given the particular setup.
That's what I'm getting at when I say "wheel rate," which is the natural frequencies at the wheel. The natural frequencies are affected by the springs, static mass ofthe car, and unsprung mass.
I get it. I'm still searching for the "working correctly" setting. I know dampeners aren't really for adjusting the ride quality - I got the D-Specs so I could adjust them to different springs - understanding fully that there's only one proper correct dampening setting for a given rate. After all of this, I'm pretty well able to feel the compression of the suspension when I hit the leading edge of a bump, then at some varying point before the crest of the bump I can feel the suspension uncompress - which is what the "bounding" I feel is - the body of the car being propelled upwards by the springs because the dampeners are not stiff enough to restrict the expanding spring. (I think, anyway - that's the best explanation I've come up with so far.) Various roads have undulations which at road speed tend to propagate this - bouncing the car before its even settled from the last bump. Depending on the timing, this results in various shades of uncontrollable awfulness. Working towards stiffer seems to be helping, but until I reach the "other side" I can't really speculate too much. I'm just moving up slowly because my past attempts at jumping up a large amount land me with HORRIBLE F/R balance and a nasty violent see-sawing.
Speaking of, got any good reference links? When I first was researching what to buy I ran into some NASIOC threads about calculating wheel rate and natural frequency and what ranges of rates were considered good for various purposes, but there was a lot of debate about the correctness of the formula's and whatnot so I never bookmarked it and haven't come across anything similar since.
