FCM Move - Summer Special - Crucial Ride Harmony Concepts - Miata For Sale

[Obioban]

Don't remember exactly why, but I think I'm running an Ohlin's spring perch for a specific spring I wanted.

I remember. Eibach has a line of "extreme travel" springs that only come in one perch size, and I wanted to run them so I could get the perch above the tire so I could run an 9.5 ET35 wheel with 275/285 up front (as pictured above)-- while running within the allowable travel of the spring. That made it so I could set camber by pyrometer instead of needing to crank the camber to make them "fit" without rubbing and have less downgraded scrub radius.

Ohlins' perch is 65mm, which works fine with the 2.5" eibach spring, were a thread match for the H&R shock body, and I had them sitting around my garage

[bigjae46]

Not dumb at all - yes, they are usually designed for 60mm on the BMWs. Porsches can use 60mm or 70mm but BMW seems consistently 60mm.

The H&R front strut housing is designed for a 60mm spring perch. There's enough aluminum present to turn the front spring perches to fit 2.25 inch ID springs (57.3mm) which I've done for numerous customers. I do that here on my Clausing lathe.

The H&R rear height adjuster is set for 60mm but I really recommend an articulating spring perch which then you can use 2.25, 2.5, or 60mm if you want (I think). I prefer 2.5 inch to get the most spring travel in the rear suspension and avoid coil-bind. The weight savings in the rear of 2.25 vs. 2.5 inch ID is pretty minimal.

Up front where tire / wheel clearance is more of a concern I get going with 2.25 inch ID springs. Of note, on my E46 330i with non-M suspension components, I'm using 2.5 inch (63.5mm) springs on Bilstein PSS (I made a ring to space outward from 60mm to 63.5mm). I use a 10mm spacer to fit 285s BF Goodrich R1 or a standard 5mm spacer to fit my usual 255s Rival S.

Oh, and the H&Rs comes with a front and I'm pretty sure also rear dust boot. The front dust boots measure just under 57mm so should also barely fit a 2.25 inch spring.

Thanks. Aren't there more spring choices with a 2.25" spring vs a 60mm? A little extra clearance up front would be nice.

The initial high cost is to get all the technology and interaction with me to dial things in.

I just think it is cool getting your own custom dampers. The first thing I'll do is tell everyone I am running $1300 coilovers with no damper adjustments and watch them roll their eyes. The same way they roll their eyes when I tell people I run a 450lb front spring...everyone says it is way too soft.

[Bry5on]

Posting here rather than direct in case someone else is interested. Is it possible to achieve a max 1.6F/1.8R Hz setup and absolutely stock ride height using the H&R damper setup? Do they have enough travel? Like Obioban clearance to the wheel is important to me as I value my light-to-drive minimal front scrub radius. If there’s not enough travel with the H&Rs, are you open to doing a regular Bilstein and going down to spring rates as low as the Dinan off the shelf setup (175/475 lb/in)? It’s easy to get that setup back to stock ride height.

[heinzboehmer]

I'm possibly working up to a FCM setup for our 128i. Every setup that fits that car is a hand me down 135i setup (350 lb heavier car), which is generally a maybe slightly tweaked maybe unchanged e90 (or, worse, e90 M3) setup-- designed around an even heavier car. Nothing is remotely optimized for the 128i, much less my slightly lower riding M sport variant.

After experiencing the comfort of a track capable setup (my M3's setup is basically the same as Shaikh's, just with 25 lb softer springs up front), I'm quite curious what a street only setup would be like. Lexus, but with handling and body control?

That would be awesome. The Fat Cat E46 is miles more comfortable than my 128i on all stock stuff.

[Suspension Decoder]

I remember. Eibach has a line of "extreme travel" springs that only come in one perch size, and I wanted to run them so I could get the perch above the tire so I could run an 9.5 ET35 wheel with 275/285 up front (as pictured above)-- while running within the allowable travel of the spring. That made it so I could set camber by pyrometer instead of needing to crank the camber to make them "fit" without rubbing.

Ohlins' perch is 65mm, which works fine with the 2.5" eibach spring, were a thread match for the H&R shock body, and I had them sitting around my garage

Good to know. I think I've seen it - their 'XT' line? Used them for a few applications previously. Great synchronicity (or copy-cat!) that the Ohlins pitch was the same as H&R / Bilstein.

I'm fantasizing about 305+ but first need moar power Where do you have your bar(s) set and what springs are you running with that wide Hoosier setup? Alignment (if you are ok sharing it)? I think you posted your staggered spring setup last page but might be a nice reference for this page as well...

[Suspension Decoder]

Thanks. Aren't there more spring choices with a 2.25" spring vs a 60mm? A little extra clearance up front would be nice.

Yes, definitely more options / better resolution plus the added clearance. 25 lb/in increments vs. 55.8 (1kg/mm) lb/in increments. I am personally fine with 2.5" springs as well but 2.25" is even simpler to implement with the H&Rs.

I just think it is cool getting your own custom dampers.

]

Thanks! I think it's pretty darn cool, myself! And usually prevents issues down the road as I am thorough enough in my interr.. err.. consultation process that I get a 'forward-looking' idea of where you might be in a year or two (or more). In some cases, I just tune a bit firmer in the event you plan on stiffer springs, or if you take weight out of the car then the effective damping increases and is a natural complement with firmer springs.

The first thing I'll do is tell everyone I am running $1300 coilovers with no damper adjustments and watch them roll their eyes.

You can even dirty them up a bit and just say you got some used H&Rs off fleaBay...

The same way they roll their eyes when I tell people I run a 450lb front spring...everyone says it is way too soft.

Amazing how little some people really know about what makes a race car actually work, isn't it?

I swear, one day I want to see someone win a race with ABSOLUTELY DEAD DAMPERS and just using Flat Ride - like my 'Why Flat Ride Matters' accidental-experiment.

Or instead of dead rear dampers, use dead / drained front dampers and just enough rear damping to give a nice smooth settling response (while still avoiding jacking down). The grip will be insane, and the car will transition great. Flat Ride is the ultimate cheat code - even with aero, as long as it's not F1 levels of aero which none of us mere mortal have anyway!

[Suspension Decoder]

Posting here rather than direct in case someone else is interested. Is it possible to achieve a max 1.6F/1.8R Hz setup and absolutely stock ride height using the H&R damper setup? Do they have enough travel? Like Obioban clearance to the wheel is important to me as I value my light-to-drive minimal front scrub radius. If there’s not enough travel with the H&Rs, are you open to doing a regular Bilstein and going down to spring rates as low as the Dinan off the shelf setup (175/475 lb/in)? It’s easy to get that setup back to stock ride height.

A great question - the standard H&R front struts are shorter than a typical Bilstein B6 / B8. In cases where someone wants a near-stock ride height, I can and have obtained replacement shafts from Bilstein which can recover some of the lost droop, about 20-30mm in most cases. That's about the limit, so generally you'd end up perhaps 1/2 inch lower than stock with a 1 inch longer front shaft. The rear is less of an issue IIRC, as the rear damper body lengths are nearly the same between H&R and Bilstein B6/B8. I might be off a bit, but the front is more where the travel issue resides. There's tons of droop on the rear H&R and if needed a longer shaft can be substituted there as well but I doubt it's necessary.

Keep in mind, the bump stop interactions with springs under ~300 lb/in front, 550 lb/in rear are significant. Factory front bump stops contribute from 200-250 lb/in once they begin engaging, the rear about half as much. Even at stock height, I don't think there's more than 15-20mm of strut travel before bump stop contact. When I see such soft rates, I KNOW the bump stops are being actively used. That's not necessarily bad and yes I can and have done FCM Elite tunes on Bilstein B6/B8 for various BMWs and other vehicles. Dinan makes / sources their bump stops but they're not magical - a suspension with front spring rates under ~350 lb/in is absolutely using the front bump stops in any corner (and in a straight-line on any rough road).

To me, a virtues of using a coil-over are:

1. Ensuring extremely linear handling throughout the range of suspension travel. The bump stops I use up front are ~40mm long, ~80-100 lb/in. Relative to a ~350-400 lb/in front spring, the bump stop engagement is effectively transparent. Ergo, linear suspension response
2. The ability able to corner-balance the car (an absolutely joy!) and impossible / impractical with lowering springs (shimming under the springs?!)
3. The ability to compensate for left-to-right weight differences which I can't with the same springs left vs. right as is the case with all aftermarket lowering spring vendors (that I know of)
4. Flexibility to raise the car in case I decide to drive to Lake Tahoe or go ice racing on a frozen lake this winter!
5. The ability to select alternate/longer shafts means near-stock heights are possible so bump travel can be maximized while also using sufficiently-firm rates to avoid constant bump stop engagement

Bry5on I'd recommend you do a front and rear bounce test on your car (usually easier with a helper) to see your 'garage' frequencies which can give an indication of actual road-going frequencies. You'll obviously excite the suspension more in actual driving but these tests are still illuminating.

Your question is an intriguing one and perhaps if you're interested, you could first buy the H&R and do some direct comparisons of the damper dimensions to what you have (I only have Bilstein / H&R E46 M3 dampers here) to see how much longer the H&R front and/or rear shafts would need to be to achieve (near) factory ride height. There are two internal bronzed bushings that the strut insert is guided along and if the shaft is too long, the lower bushing might not be capturing the strut insert all the time, which could (?) lead to extra wear on the bushing. I think there's enough room to raise about 1 inch but in most cases so far, I haven't gone any longer than that. An area you / we could certainly investigate.

Obioban have you done any bounce tests on your M3, or could you? Perhaps we can use your setup as a baseline to see what a higher / near-stock setup would look like for Bry5on.

NOTE: in case this isn't already common knowledge, the B8 has the same damper body length but the droop (extension) travel is reduced 20mm compared to the B6. They add an internal spacer on the shaft of the B8 hence why the B8 is intended for a shorter (lowering) spring so the spring is less likely to flop around at full damper extension. The B6 is intended for stock-length springs (non-lowering).

[Suspension Decoder]

That would be awesome. The Fat Cat E46 is miles more comfortable than my 128i on all stock stuff.

That's really cool to hear. I'm going to have to spend some time and $$ to get your triangulated mount made! You're the chassis stiffening snob that I am for suspensions Stiffening the chassis ought to reduce some of the uneven-rough roughness I'm feeling from the big GC front bar.

[Bry5on]

A great question - the standard H&R front struts are shorter than a typical Bilstein B6 / B8. In cases where someone wants a near-stock ride height, I can and have obtained replacement shafts from Bilstein which can recover some of the lost droop, about 20-30mm in most cases. That's about the limit, so generally you'd end up perhaps 1/2 inch lower than stock with a 1 inch longer front shaft. The rear is less of an issue IIRC, as the rear damper body lengths are nearly the same between H&R and Bilstein B6/B8. I might be off a bit, but the front is more where the travel issue resides. There's tons of droop on the rear H&R and if needed a longer shaft can be substituted there as well but I doubt it's necessary.

Keep in mind, the bump stop interactions with springs under ~300 lb/in front, 550 lb/in rear are significant. Factory front bump stops contribute from 200-250 lb/in once they begin engaging, the rear about half as much. Even at stock height, I don't think there's more than 15-20mm of strut travel before bump stop contact. When I see such soft rates, I KNOW the bump stops are being actively used. That's not necessarily bad and yes I can and have done FCM Elite tunes on Bilstein B6/B8 for various BMWs and other vehicles. Dinan makes / sources their bump stops but they're not magical - a suspension with front spring rates under ~350 lb/in is absolutely using the front bump stops in any corner (and in a straight-line on any rough road).

To me, a virtues of using a coil-over are:

1. Ensuring extremely linear handling throughout the range of suspension travel. The bump stops I use up front are ~40mm long, ~80-100 lb/in. Relative to a ~350-400 lb/in front spring, the bump stop engagement is effectively transparent. Ergo, linear suspension response
2. The ability able to corner-balance the car (an absolutely joy!) and impossible / impractical with lowering springs (shimming under the springs?!)
3. The ability to compensate for left-to-right weight differences which I can't with the same springs left vs. right as is the case with all aftermarket lowering spring vendors (that I know of)
4. Flexibility to raise the car in case I decide to drive to Lake Tahoe or go ice racing on a frozen lake this winter!
5. The ability to select alternate/longer shafts means near-stock heights are possible so bump travel can be maximized while also using sufficiently-firm rates to avoid constant bump stop engagement

Bry5on I'd recommend you do a front and rear bounce test on your car (usually easier with a helper) to see your 'garage' frequencies which can give an indication of actual road-going frequencies. You'll obviously excite the suspension more in actual driving but these tests are still illuminating.

Your question is an intriguing one and perhaps if you're interested, you could first buy the H&R and do some direct comparisons of the damper dimensions to what you have (I only have Bilstein / H&R E46 M3 dampers here) to see how much longer the H&R front and/or rear shafts would need to be to achieve (near) factory ride height. There are two internal bronzed bushings that the strut insert is guided along and if the shaft is too long, the lower bushing might not be capturing the strut insert all the time, which could (?) lead to extra wear on the bushing. I think there's enough room to raise about 1 inch but in most cases so far, I haven't gone any longer than that. An area you / we could certainly investigate.

Obioban have you done any bounce tests on your M3, or could you? Perhaps we can use your setup as a baseline to see what a higher / near-stock setup would look like for Bry5on.

NOTE: in case this isn't already common knowledge, the B8 has the same damper body length but the droop (extension) travel is reduced 20mm compared to the B6. They add an internal spacer on the shaft of the B8 hence why the B8 is intended for a shorter (lowering) spring so the spring is less likely to flop around at full damper extension. The B6 is intended for stock-length springs (non-lowering).

I attempted a bounce test a while back but couldn’t seem to achieve a repeatable frequency with the dampers installed. I taped the iPhone to the car and recorded accelerometer data and it showed that I couldn’t excite the natural frequency very well, so I tossed the data.

My current setup is stock (M3) springs with an 1/8” spacer raising the front. I’ve also played with a few different bump stops to try to improve the transition from spring to spring+bump stop (I’m back to stock bump stops now). I’m definitely on the edge of the bump stops in hard corners both by the math and by feel. This car is my daily and I’m chasing smiles, not lap times, so I’m targeting lower rates and more of a traditional but capable sport/comfort balance. So I started by stiffening the chassis before springs/dampers and I’ve been super happy with that choice.

Really I’m dissatisfied with the damping performance over poor quality roads and I know there are at least a few others in the boat with me (you met two of them) that would love an extremely well sorted street setup. If we could nail a recipe that keeps everything easily under 2 Hz for a 33-3400lb car, I think there’s a nice recipe there.

edit: I’ll see what I can do to get my hands on different Bilstein damper options to compare against the stock and koni dampers. I think that there’s only one non-coilover Bilstein option for the M3 and it’s the ‘reduced travel’ version, if memory serves. Note that even with Dinan 175 lb/in springs, the springs are effectively unloaded completely in full droop. So some strut shortening on the order of 10-20mm is really a non-issue as the preload is so low still.

[tlow98]

I attempted a bounce test a while back but couldn’t seem to achieve a repeatable frequency with the dampers installed. I taped the iPhone to the car and recorded accelerometer data and it showed that I couldn’t excite the natural frequency very well, so I tossed the data.

My current setup is stock (M3) springs with an 1/8” spacer raising the front. I’ve also played with a few different bump stops to try to improve the transition from spring to spring+bump stop (I’m back to stock bump stops now). I’m definitely on the edge of the bump stops in hard corners both by the math and by feel. This car is my daily and I’m chasing smiles, not lap times, so I’m targeting lower rates and more of a traditional but capable sport/comfort balance. So I started by stiffening the chassis before springs/dampers and I’ve been super happy with that choice.

Really I’m dissatisfied with the damping performance over poor quality roads and I know there are at least a few others in the boat with me (you met two of them) that would love an extremely well sorted street setup. If we could nail a recipe that keeps everything easily under 2 Hz for a 33-3400lb car, I think there’s a nice recipe there.

edit: I’ll see what I can do to get my hands on different Bilstein damper options to compare against the stock and koni dampers. I think that there’s only one non-coilover Bilstein option for the M3 and it’s the ‘reduced travel’ version, if memory serves. Note that even with Dinan 175 lb/in springs, the springs are effectively unloaded completely in full droop. So some strut shortening on the order of 10-20mm is really a non-issue as the preload is so low still.

they make a b6 which is part number 35142102 front left, and matching right front and rear b6, as well. Those are the normal travel ones(?). They say they’re for stock ride height for the m3. They are NOT the inverted models from the pictures, but those are often wrong.

Suspension Decoder do you think these are the newer “crimped” models?

did someone say comfortable and capable street setup? Here here!

We’re def stuck with 30-40yr old damper tech without coilovers.

[Obioban]

Good to know. I think I've seen it - their 'XT' line? Used them for a few applications previously. Great synchronicity (or copy-cat!) that the Ohlins pitch was the same as H&R / Bilstein.

I'm fantasizing about 305+ but first need moar power Where do you have your bar(s) set and what springs are you running with that wide Hoosier setup? Alignment (if you are ok sharing it)? I think you posted your staggered spring setup last page but might be a nice reference for this page as well...

Yeah-- the XTs.

Rear bar is a stock M3 sway with some adjustable end links I fabbed up so not have preload-- so no setting to be had there. Front bar.. I don't really know where it's set. I tweaked it stiffer/softer over time till I was pleased with the understeer/oversteer, then never touched it again.

Alignment, I similarly have no idea. On the street, camber is full positive (as that's still more negative than stock, due to the 15mm lowering of the car vs stock). On the track I've set it by pyrometer, getting even temps across the tire face. Once I found a place that was reasonably consistent, I marked it on the camber plates so I could start the day there. But... no idea what camber that actually is. Much less than most other people I see at the track in e46s, because my car is high enough that I still gain reasonable camber under compression.

Caster-- whatever the most I could get is.

Toe I set to be 0 at my track camber setup, which gives me a bit of toe in when I set the camber plates to the street camber setting.

Don't mind sharing anything, just don't actually know... because I've never really had a reason to know.

Full setup:
FCM stage 3 shocks :P
GC race front bar
stock rear bar with adjustable end links
350 Front left
325 Front right
700 rear left
650 rear right

Don't have the spread sheet in front of me right now, but my memory is that gave me (with my corner weights) exactly the same left/right, at 1.9 front, 2.1 rear, and something like a .77 front roll couple.

... Sadly I don't normally run the Hoosiers. NTO1s are my go to "normal" track tire

[bigjae46]

NTO1s are my go to "normal" track tire

Are you running 275/40R17s? If so, Falken RT660s are cheaper, last just as long and are a little faster.

[Obioban]

Are you running 275/40R17s? If so, Falken RT660s are cheaper, last just as long and are a little faster.

I’ll give them a try… next time.

i already have a brand new set of NT01s ready to go on when i need them…
(and I moved back to 18s, entirely because I was tired of fighting for tire options on the 17s)

[cobra]

What is being done to the dampers to cost $2800 on top of the cost of the dampers, if spring rates, roll bars, and ride height stuff is already known and published on the forum?

Is it the "ripple reducer"? What actually is it?

[Suspension Decoder]

What is being done to the dampers to cost $2800 on top of the cost of the dampers, if spring rates, roll bars, and ride height stuff is already known and published on the forum?

Is it the "ripple reducer"? What actually is it?

When someone send dampers in to a suspension shop to be 'revalved', they expect the compression and rebound (and nitrogen pressure / gas force, which most racers / enthusiasts aren't aware of) to be tuned to their vehicle application.

Or, if they're buying a new coil-over package, they expect the damper forces to be 'valved' to 'match' the springs being provided in the setup. I put those terms in quotes because the vast majority of people do not know what proper or optimal damper forces are, or how to specify that. They rely on the suspension shop or the aftermarket coil-over vendor to provide a complete package where everything works together.

Except, it never does, and they don't provide advice on how to make it all work together as a package.

===

As a reminder in case there are some who have forgotten, I created the Ride Harmonizer spreadsheet years ago and shared information on Flat Ride, provided the means for E46 M3 enthusiasts / racers to set up spring rates and sway bars plus consider bump stop interactions in a more optimal way than simply 'use the same front springs on both sides' in the event that your left front (for example) weighs more than the right front. The BMW race setups used to be universally HORRIBLE front-biased / pitch-oriented. On the original M3 forum, the circa 2016 thread where people had switched from pitch-based (800/900 front/rear spring rates) to more Flat Ride-oriented setups and all the positive benefits was exceptionally useful. Many, many people began seeing Flat Ride as viable and beneficial for performance driving, let alone improved comfort, stability, and road-holding. I'm not sure how much information has been shared elsewhere, but I'm fairly sure many have benefited from the information I've freely shared, both here / on the original forum and via my Youtube channel.

If someone wants to work with me to create a fully integrated selection of spring rates & length, damper tuning, sway bar(s), and other variables, that is what you pay for when getting the FCM Elite Stage 2 damper optimization. I spend a significant amount of time with each customer to understand what you have, what your goals are, and what we need to buy or adjust in order to achieve your goals.

In the beginning I would offer an FCM Elite 'revalve' before I understood the 3 Keys of Ride Harmony and mandated Flat Ride above all other considerations. That was setting compression damping based on the specific vehicle weight (why I require corner weights), then rebound forces to create the overall settling response desired (smoothness vs. sharper / fast settling), then minimizing gas force while preventing cavitation. That would have been considered the FCM Elite Stage 1.

With my discovery of the high-frequency modification being done in the off-road circles (via drilled holes in shock pistons), I tested then introduced the 'Ripple Reducer.' That is what makes the FCM Elite Stage 2, and that is my entry-level service which itself is superior to every damper I've ever examined or seen data on. In particular, because my process involves getting data about your specific car and your usage, everything is built-to-order.

If you get a suit tailored, it's going to cost more than picking it up off the rack. I've set my pricing to a level that I'm comfortable with given the amount of goodwill I've put into the enthusiast community and to reflect the value of having a suspension vendor who cares about how each components in your suspension will work together vs. selling you a random part or an entire catalog.

Videos on Ripple Reducer here:

and some further explanation and graphs on my blog, 'The Perfect Ride', here:

https://the-perfect-ride.com/2016/12/28/merry-christmas-2016-and-a-happy-new-racing-year-travis-and-deana-kelley-visit-fat-cat-hq-an-overview-of-our-fcm-elite-build-process-and-new-elite-upgrades-for-their-nd/

As I have also indicated, I normally charge a minimum 30 min ($150) consultation when going over all these details with a customer. For this community during the Summer Special offer, I'm waiving that consultation fee. As most who've actually taken the time to pick up the phone and speak with me know, conversations often go well over an hour. It matters to me that a potential customer understand the unique advantages of the Ride Harmony / Race Synergy approach, whether for street comfort, racing, or anything in-between.