SD bilsteins ride quality
 

I have had my SD revalves for over a year now. The car has been in the paint shop for 8 weeks now and after only 3 days of driving it to work (70 miles a day) my lower back cannot take it any more. Honeymoon is over! I cannot convince myself anymore that awesome handling is worth the unacceptable ride. The whole point of getting these was to get an acceptable street ride with crisp handling for my 1-2 track days a year.

What are the long term reviews for ride comfort from the guys that have SD revalves? Especially with setups similar to mine at 400lb/in 7" fronts, 300lb/in 9" rears, factory ride height (high as hell), FCM NB tophats, brand new poly suspension bushings.

I have had 4 different suspension setups on my 91 and this one is the harshest on my back, its not a rough ride, just the constant vertical accelerations are killing me, especially on the less than perfect roads on my drive to work. Even my first upgrade to AGX's with RB springs and cut down factory bump stops did not do this to my back. Sure it sucked when the suspension would crash over bumps and stuff, but I did not have all the vertical accelerations that are killing my back. I ran Ricelands for a year at similar spring rates to what I run now (425f/350r) and the ride was actually much better. I think the main improvement over the AGX setup was the fact that the Ricelands came with descent bumpstops (compared to OEM NA stops). Nothing performed like the Bilsteins do, thats for sure, especialy in the "confidence" department.

I am debating on going to softer springs to see if it will improve the ride quality, but am not sure if this will help at all. I have already tried all different ride heights, ended up going to 9" spring in the rear because I was having coil binding on the 7" 250lb original spring. I sent the shocks back the first time to be adjusted due to the ride quality being worse than expected. The final result is shown on the attached plot.


Please no discussions about Bernie being an a-hole or the fact that my dumbass just should have gotten Xida's! I know and I know, wish I had Xida's too, especially when spending just as much to end up with a setup that does not work for me.

There is a strong correlation between ride quality and tire grip on uneven surfaces. Damping that's optimal for grip will be very close to optimal for comfort. A little extra damping over that will give you the feeling of more "control", "confidence", and precision, but at the expense of some actual grip. There is no reason why a damping setup should be very uncomfortable for a given spring rate.

Looking at your damping curves, the fronts appear underdamped in rebound and both are underdamped in bump. (I can't remember offhand what the proper low speed slope should be for your spring rates). It may very well be that the rears are overdamped too. The fronts are supposed to be stiffer due to the higher spring rates which is a consequence of the higher motion ratio in front. It's not correct to have the same low speed damping front and rear. The damping mismatch will cause uncomfortable pitching motions.

My direct experience is limited to FCM's, Tein Flex, and a bunch of lower end shocks. The FCM's ride remarkably well and have the most predictable handling at autox, compared to all the rest, despite having the highest spring rates, with no apparent downsides.

The whole basis for me going with a Bilstein re-valve is the fact that a properly tuned suspension should exhibit good manners on the street as well. With the selected spring rates it should definitely be tolerable.

The attached plot is what the original curve looked like for my shocks. After my initial complaints of excessive vertical accelerations, Bernie took them back stating that the tune might be a little aggressive for my original spec of a nice grippy street car, perfect for mountain roads and acceptable on the occasional track day (I know, wonderfully vague on my part). He re-valved the shocks as shown in the first plot above (current configuration). While packaging the shocks up to send back to me he noticed that the bushings had been damaged on the shocks . This he claimed was due to me torqueing the suspension bolts without the car being at ride height and running at too low a ride height. The blown bushings were blamed for all the symptoms I was experiencing. These symptoms were there from the first day I installed the brand new re-valved shocks so I do not understand why gradually damaged bushings would cause the large amplitude vertical motions that are bothering me. At this point he wanted me to pay for the 2nd re-valve that was originally going to be done for free (oh at a 60% markup from original rates). I had to pay to get my shocks back. This meant that if the correct re-valve was done originally, I now had a re-valve that would not be correct and any additional changes would require me to pay an additional re-valve fee. See where this is going?

I got the shocks back, installed them, with minor improvements, still not 100% happy. When I challenged Bernie for info in order to educate my dumb@ss and in the quest to understand why the car is feeling like it does, the dialog deteriorated to the point that I will never be able to trust him with my shocks. I now have a set of shocks that I am not happy with that cost $1300 just for the shocks and no way of sending them back to get fixed properly.

Ok, sorry I’m getting bitter again. On topic.

Since sending the shocks back clearly is not an option. Is there anything I can do to make this more streetable? Would changing to lower spring rates improve anything? Is there anything else that can be adjusted/changed? It would be nice not to have my lower back on fire after my 35mile drive to/from work!
I wish I knew more about reading the plots to know what I need. That is what I get for “thinking” I knew what I wanted.

I have similar rates. 450/300 QA1, nb top hats, poly bushings, and fcm bumpstops. I think I'm running 5.5/5.75 at pinch welds.

My ride improved when switching from FM springs to the 450/300. My ride was much more harsh with the lighter springs. Iirc my shocks were tuned for the current rates because I figured one day I would upgrade from the FM springs. I believe I was riding on the bumpstops a lot with FM springs. What bumpstops are you running?


My only comfort comparison:

FM springs AGX shocks < SD shocks FM springs < SD shocks 450/300

Shaikh at FCM does Bilstein revalves. Maybe he can help you out.

djp0623 could you possibly post a plot of your shocks for comparison?

I am running FCM 36mm bumpstops, NB tophats with all the FCM bushings. I am running a ton of ride height (close to 97 OEM ride height) on order to get all the ride height possible and stay off the bumpstops.

I would hate to bother Shaikh, especially since I should have just spent the extra $100 or so and gone with him to begin with. Thats what I get for being cheap! I am debating on bugging Shiakh to at least get an expert opinion on whether the shocks are in fact tuned correctly or if I am just an idiot that did not know what I wanted to begin with.

Does Shaikh still revalve used shocks? I was under the impression he no longer does revalves on customer-supplied shocks.

I don't know. I bought new from him. Still, couldn't hurt to call.

I'll have to see if I still have the graphs. I know I do, but it's a matter of finding them in my junk.

My FM springs were better than the AGX shocks,so I don't think I realized I was hitting the bumpstops so much on the SD revalves. When I upgraded to the stiffer springs I was wondering how the hell the ride could be softer with stiffer springs over speedbumps, etc. That's when it hit me that I was hitting the bumpstops.


I want to say that my lower curves are much steeper (whatever that would mean)

Any chance you experienced the same thing, thought it was too stiff, then revalved softer? Which would only amplify the situation.

Shaike mentioned in a thread over on m.net that they sometimes cut the 36mm stops to 18mm (in the rear iirc) with the softer spring rates. I believe your/my spring rates are on the border of when to use cut down bumpstops to increase travel. He also mentions which portion of the bumpstop to use since they are progressive.

djp, what length are the 450 and 300 springs you used?

I rode in an autox devoted miata with FCM suspension (back when bearnie did the valving IIRC) he was on 700/400 and it felt great on the street, comprible to my teins. Which still isn't soft by any means, but is worlds above my Konis with anything but stock springs...hell even then the konis were awful.

I reviewed my old calcs and your current rear damping rates are about right for your rear spring rate. The front is a bit underdamped.

This was partially a coil bind situation with the OP. in my case with 550# front springs jumping from 300# to 350# in the rear improved ride quality.

I believe the are 7" QA1 front and rear. I can't find my shock dyno plots. if I come across them, I'll post them up.

Jason, "a bit underdamped" in the front, does that mean ok? At this point I will take "OK" over "screwed".

Our setups are nearly identical, except I don't have the polly bushings yet, and I'm on 400/300 FCMs in an NB. I have no complaints about my suspension whatsoever. I can get spring lengths, ride heights and bumpstop lengths if its helpful, but I'd imagine you would have plenty of travel if you aren't in the weeds already.

I had lunch with Shaikh @ MRLS back in April and had a great conversation regarding my suspension. I "erred of the side of caution" and went with 400/300 (maybe 275? derp) for dual use but I now see that I could go A LOT higher and still be comfortable on the street. We discussed this and he was willing to do a revalve for me on my current shocks, but that may be because I'm a current customer. He's a nice guy, but super busy. It can't hurt to ask.

What are you using for a seat? My Sparco makes the car feel a lot different than the foamectomied seat I was using before

Seems like you realistically have 3 options if you want to be happy.

1. Convince Shaikh to revalve your shocks. I have yet to read a bad review of his work.

2. Sell the SD shocks and purchase new FCM revalved shocks.

3. Sell the entire setup and purchase Xidas.

Otherwise, you're still going to have the bad taste of the SD interaction lingering.

#1 is to fix the coil bind issue-revalving from FCM isn't going to solve that issue.

#2 underdamped in the front isn't necessarily a horrible thing. That does allow for tuning without the rear bar for autocross.

It sounded like he had the coil bind issue taken care of... fix that first

True, but I'm not really talking about diagnosing what's wrong with the current setup. It just seems like OP has some lingering resentment over the SD situation. In my experience, even when a product is satisfactory, if the transaction and experience sucked, I'm never going to be happy with it.

I think it is time to get some linear pots. We are spending lots of time in qualitative arguments and not enough on quantitative ones. I am saving money for pots...

My 700/325 with SDs were quite comfortable on most roads. Yes, it is how a damper manages the energy from a spring that translates into a "good" ride. Now I am on 450/275 and the ride is not that different (I have asked Bernie for something else so there is a bit of a difference but not in a bad way, but a good way) but I have different goals for the car this year. Next year if funds allow I will try yet another set-up providing I switch tires.

FCM has 'em, and I've seen the data.

Less than optimal. If you need the front to be softer to not be underdamped, you may need to make the rear softer to balance the car.

I will take less than optimal over screwed at this point. It is very true what mgeoffriau is saying about the bad taste of the SD experience. It has taken me a year to get over most of it and still get pissed at times. I do not have money for anything right now and spent enough to buy some XIDA's. I am at the point that I can deal with it and long as I can have confidence that Bernie did not deliver me a crap tune, just to get the shocks out of his shop. I am not a full time racer with a degree in shock tuning and was hoping to rely on his expertise to magically provide me with the set of shocks that would be comfortable on the street and do awesome things on my track days. Communication was lacking and caused all the BS. I was at fault for running springs that ended up binding and that appeared to cause a large amount of issues.

Sunday I removed all 4 shocks to check everything. I found all 4 lower shock bushings had taken a beating again. I knew I had messed the original shock bushings up and had to get them replaced by Bernie. At the time he blamed everything on running the car at too low ride heights, but even after raising the ride height to at or above OEM I still had the same issues. I finally figuired out the 7" 250lb/in rear springs were binding back in December. I went to a 9" 300 lb/in spring in the rear which made a huge improvement. The fronts looked fine, but after pulling them off the car I noted fine lines on the top and bottom of each coil that I did not see when I found the rear ones binding. The fronts are 7" 400lb/in QA1 springs, which I thought is the lenght everyone uses in the front. They must have been binding all this time too. So who knows how that messed everything up.

Luckily I had bought a set of shock bushings and had another 550lb/in 7" spring to try in the front. My brother helped me swap out the bushings and springs.

After my 70 mile round trip to work yesterday I got the car up on the ramps and scales to check alignments and cornerweights. I was impressed that my eyeball height adjustment got the corner weights to 50.2%, I spent more time chasing my tail to get to 50.0% than what was needed and should have left it there to begin with. I checked all the springs for coil bind where I had placed some paint marker on the top surfaces of a few coils. Everything looked clean with no indication of binding. The FR wheel did hit a pretty good pothole that was hidden in a puddle of water so I pulled the wheel to check the bushing and it seemed ok too. At this point I am very confident that I have addressed the coil bind issues.

The blown bushings must throw everything off due to the resulting suspension travel that would not be controlled by the shock or spring. I understand now why Bernie made such a big deal about the bushings causing all the issues (well most). I am still feeling more vertical accelerations than I was hoping for, but I believe it is acceptable. Having three slipped disks and a fractured vertebrae, just doesn’t help at all. To get another data point I drove my dad’s 99 to work today. He has Koni sports at pretty much full stiff on factory springs with RB tubular front swaybar and RB solid rear bar. His setup has always been very comfortable (acceptable) on the street and is still fun to drive. I took it out on track two weeks ago during some fun runs during lunch and my only complaint was that it had a little too much body roll for my likeing. Still had lots of grip though. Ok, back on topic. I drove it to work this morning along my usual route. Even this setup is transmitting very similar vertical accelerations that are driving me nuts, not quite at the same amplitudes though. I know this setup is not perfectly tuned or the best out there at all, but it is at least calming my concerns that something is way off with my SD valving. If the much lower OEM spring rates on this setup doesn’t make that big a difference I might just stay at the 550/300 for a while and not worry about dropping to 300/200 rates, at least not right now. I will just save the money for chiropractor visits. I love driving my old crap car to work, sure my Jetta rides like a chariot in comparison, but it is not 10% as much fun. That’s why I got so upset about the whole SD experience, because it made me love my car less and even not want to drive it at times. That’s just dumb!

I was thinking about coming up with some way of measuring suspension travel, velocities and accelerations. It would be so much easier to just look at data instead of “feel”. Like I have mentioned before, these SD shocks handle awesome and are not harsh by any means. Even the vertical accelerations I am talking about are still smooth and controlled, it’s just more than I had expected. I need to find some cheap acceleration sensors or really cheap lvdt’s and make my own application either with my Motorola development board or even a PIC just to capture the raw data. That would be another great project I do not have time for.

“When you are in your teen years, you have time and energy but no money, as an adult you have money and energy, but no time and as a elderly you have time and money, but no energy”!!!

I was running 550/300 and upped the rear rates to 350. That seems to have improved ride quality for me-it has to do with bounce frequencies. I'm using 7 inch springs front and rear.

BTDT.

I use this 4 channel datalogger:
http://www.dataq.com/products/startkit/di145.html

and this 3 axis accelerometer:
http://www.sparkfun.com/products/9269

I don't have linear pots, but you can get a ride height sensor out of an E39 BMW.

No construction needed. I used the data I gathered to create various road models that I use in my simple suspension simulation.

Your rear shock dyno isn't much different than the NA miata R package:

http://www.cardomain.com/ride/742393...e-5#7423930048

100 mm/sec is 4 ips
1250 N is 280 lbf.

Vanishingly small bump damping.

Your complaints are the same as folks with said NA R package.

Big rebound, vanishingly small bump damping. This formula is used for cars with tall ride heights and soft springs, to get them to dynamically lower during slalom type maneuvers. It is also used in racing series' with a required static "ride height" ("must clear this piece of wood"), but with downforce. The soft springs, weak bump, strong rebound, and downforce, lower the car at speed. Such as NASCAR. Perhaps this is where Bernie's "this works great in racing" experience comes from. Horses for courses.

So, when I call a shock builder and say something like I want the car to handle well on aggressive driving on the streets and maybe a few autocross or track days, what should the final result look like? I am thinking that we need to do some pentagram type plots like the Tire Rack: can we do this in any reasonable fashion? Cost/logistics wise? I have a DL1 logger but linear pots would run me about 300 a piece. I can try to set up the DL1 vertically at various points in the car. Any other ideas? I am not ready to start another thread, but I would like us somehow to get FCM, SD, Emilio, whomever to develop some killer combos a la carte so the Miatae can always be the best handling cars out there.

If thread drift, let me know and I'll start a new thread.

If someone wants to send me some FCM or Xidas I'll do some street comparisons.

danny2747,

FCM's formulae for determining the target shock dyno curves based on desired characteristics, usage, car weight, and spring rates, are the result of years of testing and customer feedback. And if you ask different shock vendors, you will get different answers. Some may work better for some customers, others, not so well. As you can see, the formula that SD has used, has produced some serious negative feedback for street miata applications.

Because I had worked closely with FCM, I may be a bit biased; and, I can't divulge his trade secrets. I can only give general opinions, and technical reasoning.

One thing I can say - when someone says "Brand X/S/F/A/K/T is the best", and they haven't driven or owned a competing brand, take it with a grain of salt. Also, when you look at comparos of different valving/coilovers wrt ride qual and grip on bumps, remember there are many confounding variables: ride height, bumpstops, chassis stiffening, tires, and most especially, the butt-o-meter. There are probably even more variables if you look at track times or subjective handling.

I've seen guys gush "it's firm but not harsh", and then when I rode/drove it, it was utter crap.

One thing I will say was my biggest mistake is that I read all the reviews for custom re-valves, that pretty much just covered FCM and SD. What I took away from all the write-ups at the time was tha they both provided a shock that was tune for optimal performance for a set of parameters. If you can give the two of them the same parameters and end up with two different resulst, I would be pretty sure that at least one of them is not truely "optimal". Based on the assumption that they produced the same (or at least similar results) my cheap ass decided to save a hundred or two by going SD. Looking back now I can say that all the reviews that emphasize the great street manners that can be had with tons of grip are all by FCM users. Oh well, my mistake.

I would love to find a way to collect data and quantify the accellerations and find data that would allow us to compare the different re-valves on paper. Just like Jason mentioned even the slightest change in combination of spring, bumpstop, ride height and other parameters can generate a completely different experience that can be perceived very differently.

Ultimately though, it would be impossible to compare apples to apples unless you use the same car on the same track or stretch of road. This would be similar to the issues Emelio pointed out in a recent shock hirarchy thread. Sure would be nice if you could point to a spot on the performance vs. comfort curve and say Mr. shock builder here is my car specs, please tune the shocks to perform this way. From my experience and what I am hearing from others it seems like FCM has improved and tailored his product for the Miata customer base where Bernie has decided that he knows what he is doing because he is king and that is what we will get. I know I am not the shock master, but when I ask intelligent questions to try and understand and get treated like a DA, that really gives me confidence that someone knows what they are doing. Damn, there I go again, this crap sure has made me a bitter bastard!

Thread jack all you want. I am looking for sollutions, how we get there is less important. Oh, and if Shaikh would find it in his great old heart to send me a set to compare to the SD's, I would gladly do so with the most honest review possible!:D

Maybe we wouldn't all be armchair quarterbacking if Shaikh posted some dyno charts of his revalves but he refuses to given them even to his customers. One guy on this forum has both FCM and SD shocks and likes each but each are for slightly different combinations.

Shaikh now considers his dyno plots a trade secret, and it's his choice whether to show them or not, just as it's your choice whether to buy his shocks or not.

However, I can say, and I've been saying this from the start, that SD's very weak bump damping, is just not a good thing.

BUT F=PROD. SPEC MIATA!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! OMFGMFGL<MFLKfdakjfsaj
kfd
lca
cla,cdsacdsac

???

Just trying to remember anythign good that's come form spec miata and trickled down to us joe schmoes....seems like it's always the other way around.

Everytime I talk to a spec miata guy, I cringe with the lack of innovation and understanding.

I had a spec miata guy tell me to just get the spec suspension kit and it would handle great. I can't imagine how bad the ride quality would be with 700/500 rates and the off the shelv valving.

You are correct. On the street, its a ------- nightmare.
When I was a noob I took my car to a local shop for a clutch job. The owner said he had a Spec Miata so I figured he knew what he was doing. He offered me a ride around the block (to show off his impressive 90HP no interior pogo stick) so I took it. Ungh... that's how I figured out what I didn't want. Spec cars may handle well but they are just plain uncomfortable on the street IMO.

Not providing dyno plots? That seems kokey to me. I can get dyno plots from AST. Or Motons or Penskes.
I may have to buy a set of used FCMs and have them dynoed.

I recently read an article about KW's electronic shocks that can be tuned from a phone. They had 3 settings-street, sport and sport plus. With the touch of the screen the settings could be changed and the general gist is that as you get into sport the ride gets firmer and as you get into sport plus the ride is just plain abusive on the street. A shock set up soft for a backroad targa might not turn the fastest times on a fairly smooth roadcourse. I think there will always be a compromise of some sort unless you are dealing with ultra high end magnetic shocks like were available on some of the Vettes.

I would hate to see the pricetag on something like that. Hey danny, how about you sell those used FCM's to me for cheap or make a donation once you get them dyno'ed.:)

Hey Danny, I got some extra Billies if you need them for a revalve-maybe we could do a swap.

Update:
After my last spring rate change to 550F/300R with longer springs to prevent coil bind I finally got to the point that I realized I can't take the ride quality any more. I ordered some 180lb/in springs for the rear and swapped to 300F/180R this past weekend.

The new rates are just over half of what I was running and roughly double the factory spring rates. The motions I described before that were contributing to my back pain are not nearly as bad and seem tolerable for now. I will have to try it for a week or two to see what the real impact is. It still feels like the shocks are under damped. It feels like the shocks compress in a controlled manor, but during rebound there is little to no dampening and then it goes through another compression motion before the motion is stopped. This is the same thing I was experiencing before, it just isn’t as bad since the springs rebound a little softer now. Feel free to correct me if my thinking is completely wrong, I am totally confused after all the issues I have had.

I contacted Bernie to see if he could at least tell me that “yes, the final re-valve I got is too soft and is not doing the intended job”, or isn’t good for anything. He replied quicker than ever before, but declined to provide any assistance.

I emailed FCM a while back to see if they could help or at least provide the option to have these fairly new shocks re-valved. Shaik never replied, but I was expecting that since I wouldn’t want to deal with a competitors balls-up like that either.

So here is my original question, just as a sanity check:
For the guys that have the SD re-valves, how do you feel about the ride quality on the street?

sounds like you are describing konis.

That’s the funny thing. The Koni sports on my dad’s 99 don’t behave that way. Even the full soft KYB AGX’s on my wife’s 97 don’t even feel as bouncy.
Is there anyone in the Columbia – Lexington SC area with a proper monotube suspension that wouldn’t mind meeting up for a test drive so I can see what it is supposed to feel like and get a second opinion on mine.

The strange thing is that I am not too disappointed with the handling. It still grips like crazy even with old, hard and cold tires. Much better than any other setup I have tried.

I got in on the first/only GB for SD Bilsteins a couple of years ago and have been very happy with the results. I received my shocks about 6 weeks after ordering them and they have served me very well. I put about 5-6k miles a year driving mostly March-October with a few track days and autox's per year thrown in. I'm running 500F,300R with fender lip heights at 12.75/13.5. Daily driving is fine on good roads and better than the R-package bilsteins with 450/250. Ride is firm not harsh however frost heaves and potholes suck. I would love to try a set of Xida's to chase the holy grail but I'm a tight a$$ and probably won't go there. If you drive on rough roads on a regular basis, I don't think a performance autox/roadrace package will ever be tolerable in our cars unless you spend big $$$$ and even then, I'm doubtful.

Autocross<Road Course<Rally<Aggressive Street<Sporty<Comfi

This is how I rank them. So, anything set for quality Autocross or track work will only work well on the street if the speeds are kept at similar numbers.

That being said, I would not hesitate to have another set done by SD. If I can get enough scratch I will have him do a nice sporty setup just so I can hear how they suck at Autocross and how someone with a Camry beat us.

I would like to buy an extra set of Billies, but they would have to be the NB HD (?!?! I think?). That is because my set up is NB Billies and NB top hats on an NA.

I am also shopping for some Sparkfun stuff, to compare with Race Technology DL1 data I have been collecting. This year I am also using a Vericom 4000 for DAQ, to compare with the DL1. However this is secondary, to a work project where I will be playing with an active suspension system (yoohoo! yeay!).

My Miata is mainly for Autocross, yet the suspension is tuned for track work. A person that won a National Autocross event recently in his STX RX-8 was kind enough to wheel my NA around a local course and posted times within 2% of his! He commented that the ride was quite busy and that he loved it. Considering that he put down times 10% faster than me, all I can say is that I need to continue to work on my skills more than on my car. So the SD stuff works. The said RX-8 is on custom Penske dampers. So, if on a tight technical course, my STS NA can be within 2% of a national prep STX, after only 3 runs, we have something good here. Comfort be damned!

Remember that I am doing data analysis to determine the relation between tire grip (static, slip, dynamic) and damper settings.

Lastly, if SD hangs in, maybe we can really do a decent set of adjustable Billies that respond like a Penske. With the economy the way it is, I can imagine that sales are not too hot for any of our favorite suppliers.

I have 2 sets of SD billies on 550/350 and they work great on track. The sharp breaks in the road are a bit harsh but liveable, in fact, in some ways the SD's ride better than the Billies on my TA, those are also a bit harsh over broken pavement.

Jason,
I got a similar accelerometer and gyro combo and have been messing around with Arduino stuff a little. Where did you mount the accelerometers? Are you looking at chassis accelerations or unsprung suspension movements?

Both. I've mounted it on the rollbar, and on the lower A-arm.

How did you mount them to the A-arms? Did you have them permanently installed or just hooked up for testing? I would love to see pictures. Do you have an open thread on this?
I wasn't sure if these accelerometers would be able to measure over the range of accelerations seen on the suspension components or at high enough frequency to provide usable data.
What did you use for post processing?

Just for testing. I used tie wraps and duct tape.
I used Mathcad for examining the data. One of the things I used the A-arm data for was as "road surface" inputs to my quarter-car suspension simulations.

After running for two years with the much lower spring rates of 300/180 I switched back to the 550/300 springs. The softer springs really did not help much and I finally concluded I must be running into the bumpstops all the time. The body rolls much more with the lower spring rates. I made some ICS DIY hats with 1" front and 1.5" rear drop. I had to add a 1/8" spacer with the 36mm FCM front bumpstops and 1/8" spacer with the rear bumpstops that are now NB fronts (~56mm progressive).

The setup works 100x better now. Even with double the spring rates!!! The ride quality is significantly improved even on the roughest roads. The handling is so much more predictive and confidence inspiring. I can't wait to take it on my drive to work to have a true apples to apples comparison. Body roll is significantly reduced which makes steering response very crisp.

I am excited that I might actually be happy with my setup after 4 years!!!

The lesson here kids is to just pay for someone like FCM to sell you a complete setup with matched, springs, shocks, hats and other hardware. Dont try to save $100 here and there for a setup that you have to figure out yourself.

I love this forum and get great advice most of the time. It is becoming very difficult to weed through all the noob bashing and armchair expert opinions to collect good information. Just look at the recent "Better Bilstein Ebay Coilover" thread!

Or you know, buy Xidas and get a better product and not wait months for revalved bilsteins. Glad you got your problems worked out though!

Ya, XIDAs would have been 100 times smarter. I think I have more invested in this setup than what XIDA's were at the time!!!!!!!

Oh well, you live and you learn.