Miata NA suspension options

Hi Tim,

I'm the 'head Fat Cat' at Fat Cat Motorsports, or FCM. Have you ever experienced one of our FCM Elite coilover setups? It sounds like a really ideal match to everything you're looking for. If not, I'd highly recommend popping over to Miata.net or email me directly so I can put you in touch with one of our customers so you can sample a truly optimized suspension. Being Bilstein monotube-based, we can easily service these Elite coilovers if needed, but also being Bilstein-based, they easily run many many miles without issues. I think we've had 6 shocks out of >2000 that needed servicing. That's why I started with them and no other brand.

Why am I such a fanatic for what we do? Here's my favorite review so far!

While there are companies that sell a variety of parts and others who have a coilover package, we ONLY specialize in making amazing suspensions, nothing else. I look at how other relevant components interact but that focus has drawn me deeper into the psychology and philosopher of suspension design, beyond what color are my springs and what ride height can I get. Appearance matters but much suspension magic (or misery!) is hidden inside that innocent-looking oil-filled cylinder.

We use top-level motorsports-grade data acquisition systems as part of our research, combined with testing and relentless tuning/optimizing. Last year we purchased an AiM EVO3 data acquisition system and (4) Penny & Giles suspension potentiometers to get the kind of data needed to analyze suspension movement. That's been a very illuminating process!

My background is in science (BS Physics, San Jose State) and I've been an empirical researcher before I could walk, wanting to see why gadets worked. I 'should' have gone the mech engr. route but as most things, took the path less traveled and it's made quite a difference. I play with spreadsheets then make revisions in our shop, using our Roehrig 2VS dyno to test out ideas.

Originally, FCM starting as a bump stop company, klooking at a part most people ignored or cut in half. in different rates and spring rates to achieve various handling behaviors, we then improved upon the 99-05 'NB' shock mount design to reduce NVH and maintan the improved grip Mazda intended with the new design. Then, I started apprenticing with a champions motorcycle racer/shock builder (dirt and track). That's when I found out size really does matter, how a well-tuned monotube will kick a well-tuned twin-tube any day of the week. By twin I don't mean Ohlins TTX, that's a whole other animal! I was racing, tuning, revalving and understanding my own Miata, for street, autocross and track, before I began this company in 2006 with the sole mission to provide exceptional quality, high-performance, grip-optimized suspension products, tuned to each driver's needs.

Video overview: FCM Elite consultation process

Have you heard of Flat Ride? That's a parameter we consider in our builds (just like OEMs) especially for street-driven performance cars. The rear ride frequency needs to be higher than the front for good ride quality.

The video above illustrates how I approach a new suspension, which, again, is unique in my experience with the vehicle aftermarket. I can't take all the credit, I've had many advisors, teachers, supporters and detractors, plus direct contact from our Elite customers who I really enjoy building relationships with - via phone call and your number in my business cell. This isn't simply a job, or a hobby, it's totally an obsession!

Is it worth it? Ask our customers :) To date, we've built 511 uniquely-tailored sets of shocks or complete coilover packages, with unique damping/spring rates/lengths/bump stops/alignment settings set to each driver. We don't just hand you something out of a box, made just like the person before and after you, saying 'it'll be great!' We KNOW each person is different and it's our pleasure to adjust our product to your particular nuances.

If you plan to keep your Miata a while and want something that really is built to fit you, I'd enjoy working with you.

Yes, I write a lot - much to say! I hope you check out some of our Youtube 'Suspension Truth' videos and get in touch with me directly. I've got to get in back the next couple days to build shocks so I'll be off the forums but answering phone/emails.

Regards, Shaikh

BoxheadTim wrote: I know, I know, it's been asked a thousand times before... Over the winter, my NA will have to get new suspension - it's mostly DD'd with some track use, hopefully more track use next year than this year. I replaced the clapped out NA suspension with used MSM suspension. That one survived two PDXs before I was riding around the track on bump stops. It's still OK on the street but its motorsport life is over. For daily use, I want a fairly compliant ride - the roads around here aren't bad, the ones in CA a lot worse and apart from the local track that is "only" 70 miles away, all the other tracks are 200+ miles away one way. I don't want to arrive there feeling like a well flattened steak, plus my wife doesn't really appreciate a bone jarring ride either. We're both getting old . For the track, I obviously want well controlled suspension that'll survive the rigors of the track for a while and doesn't beat up the occupants of the car too much. My tracked Miatas (well, Eunos Roadsters) in the UK had either NA-specific Gaz coilovers (ok ride, never used the height adjustability, adjusted well enough between track and road) or KYB AGX (hated those, and no, I didn't put them on the car but bought the car with them). So far I'm thinking about the following options - in all cases I'd be looking at upgrading the sway bars independent of the choice of shocks & springs. - Yellow NA Konis with NA stock springs, better bump stops and maybe the NA top mounts for the rear to improve travel. That should give me a compliant ride and I can stiffen up the damping for the track. I've had an FD with yellow Konis and stock springs, liked it on the road but no idea what it was like on the track - too scared too take in on the track . - Something like the FM Stage 1.5 kit (well, actually the 2.5 kit to get the sway bars as well). - FM's V-Maxx Xtreme Sports package. People seem to like the shocks, they're adjustable but I'm not sure that I'll gain much from coilovers over regular shocks/springs - ride height would probably get set once and then left alone, *maybe* the car would get corner weighted but again, that should be more or less a one time setting. - Sod it, get the Öhlins coilovers for the car and be done with it. I haven't got much experience with Öhlins on cars (only on bikes), plus they leave a crater about three times the depth compared to the V-Maxx. Not sure I'm getting enough out of the additional investment. We're talking a car with a stock engine here, I'm contemplating a VVT swap but no force induction. The other thing to keep in mind is that we might replace the car sometime next year with an RX8 or S2k, depending on how things are going and which other cars are waving white flags. While I'm happy to throw some money at the Miata, it should be fairly proportional to the value of the vehicle (so $3k suspension on a $4k Miata might not be what I want). Thoughts? Comments? Sod off to a Miata forum ?

To clarify what seems a common misconception about our products: we have had excellent success at the track as well. Our customers have won/been winning PT/TT along with simply going faster with less jostling around. The tuning a track customer gets will vary from our autocross setups, usually with more high speed rebound needed at the shock velocities are higher / impacts sharper for track. We can adjust the shim stack to emphasize whatever damping range is required for the application.

I had 'Senna', our '95 M-edition Miata, at Mazda Raceway Laguna Seca for the big Miata event earlier this year. I drove in off the street with a 1000/500 FCM Elite 3140 setup and 195 Toyo R1Rs, gaving rides both Saturday in the wet and Sunday in the dry. The car had no sway bars and worked incredibly well. No one could guess what spring rates we had although Laguna is rather smooth but even on the street the setup is surprisingly compliant. On the track it was just smooth, settled, predictable, and so easy to go very fast - as fast as 110whp will take you!

Proper damping is proper damping is proper damping. XIDA are good setups, although I have spoken with people having oversteer issues which I came to attribute the bump stops - same front and rear. I've sold several sets of tuned FCM stops to XIDA customers the past two years. I believe the XIDA are in general overdamped in high-speed rebound and, depending upon the vehicle, underdamped in compression. Again, having suspension pots on Senna allows me to take that data, look at where grip goes up or down with damping settings and apply it to various situations (track, autocross, street) with real data, develop metrics and apply those to any vehicle in any situation.

A track customer (Mark Burke) just dropped about 1.5 second on his home track changing from a standard Spec Miata to FCM Elite suspension. Same front spring (700), different rear spring, improved damping and better-optimized bump stops.

On the topic of targa/hillclimb, same thing - and this is where some might howl the most in protest. Just because someone has used a setup doesn't mean it's the best, or best-suited. Most of our hillcimb customers drive their cars on the street as well, pound real-world backroads or bombed-out city streets. They and I have experienced twin-tube vagueness, harshness (due to deficient compression damping) and fade in the shock oil. Track customers notice the fade, vagueness and harshness very quickly - a few laps at best. There is NO replacement for properly managed displacement (oil flow within a shock). With the restrictive foot valve a twin-tube has to deal with, it inherently will not flow enough oil to build damping force as consistently as a monotube does. I'll be creating videos to illustrate this, as pictures are certainly worth thousands of words. We've had a number of FCM customers who previously had AFCO and didn't like them.

Shaikh

PS A side note on damping quality, our tuning has evolved over the years. In the beginning, we were rather aggressive with using compression damping, since we finally had shocks (monotube Bilsteins) that could actually deliver it instead of.bottoming out like twins are prone to. Now, we've toned down the force levels, aided by data acquisition and lots of user feedback, further improving the blow-off characteristics while getting 'friendlier' with moderate amounts of rebound. The result is easily described as a high-end, Germanic feel (BMW, Porsche, Mercedes). As some GRM readers know, our FCM suspension was evaluated to be faster and more comfortable than the PSS9 and we've made many improvements in our setups since 2009.

Joe Gearin will be acquiring that turbo Miata and we'll be getting our paws on it again!

Jaynen wrote: PM sent about your FCM stuff. I may be interested as well we will see depending on timing. I am trying to drive the car as stock as I can for a bit to learn it. While I have no doubt Keith and the guys have done an awesome job especially if you can go with the AFCO's locally I have seen some great FCM setups that also ride really nice. I want to keep mine tolerable for the wife as its going to stay weekend toy/autox car more than it sees HPDE It might sound kind of dumb but I would probably choose based on what I wanted to do most AutoX = Fat Cat Motorsports because thats what I know Shaikh has done a ton of work with and guys at the National level have won with his stuff Targa/Hillclimb = Flyin Miata AFCO because again I know Keith has done it HPDE/Track Day = 949 Racing Xidas because those guys are tearing up time trials and racing racing racing

Welcome to the GRM forum, Shaikh.

The oversize bodies of the AFCOs - the largest and longest ones used on Miata shocks, I believe - mean that a lot of the claimed problems with twin-tube shocks aren't. Bigger bodies = bigger valves = better oil flow. Aluminum bodies and a very large fluid capacity also minimize overheating problems, and complete separation of the oil and the gas mean there's no concern about cavitation. I've said it before and I'll say it again: implementation is the most important thing. The stuff inside is only a tool.

By making the shocks highly adjustable in both compression and rebound separately, it's okay to use the same basic shock for multiple applications. It gives our customers more options down the road if they decide to change things up, and allows the same shock to be fine-tuned for autox or track use without rebuilding. This also allows us to keep parts on the shelf for immediate shipment. We do offer the option of custom valving and the shocks can be rebuilt or revalved with a quick turnaround by a number of rebuilders across the country, as AFCO is well-known and supported in other forms of racing. A nice byproduct of the non-pressurized twin-tube is that, if the shaft seal does get damaged, the shock still functions.

BTW, I'm going to be offline for the next week. I'm actually going to be in Shaikh's neck of the woods So I may not have the chance to chime in here again until I get back if there are any questions.

Ugh.

How many years has it been and I'm still hearing about how monotube is the only answer?

The dead horse is still dead.

There's more than one way to skin the cat (no matter its BMI), and different people succeed with different tools.

Also, I'd hesitate to compare any track suspension to the godawful mess that is a SM suspension. I believe a blind, drunk, 3-fingered monkey could design a better suspension than that. It's not chosen because it's good...

Thanks, good to finally take advantage of our sponsorship here!

Ok Keith, we both know that the size of the OD on a twin tube doesn't tell the whole story of how much fluid is actually displaced in rebound and bump. You've got an outer wall, then the inner canister where the smaller diameter piston resides. Just curious, how much fluid is displaced per inch of stroke on the AFCO? and just as important, what is the F vs D graph of the AFCO when it's attempting to build compression force? I recall a graph from a long time ago that showed a lazier build-up which is exactly the reason a twin is more prone to bottoming than a monotube. Perhaps if you're concerned about a damper failing then going with a degassed shock makes sense.

Would you care to address the limitations imposes by the foot valve on a twin tube?

We can provide adjustables as well, I simply find it unnecessary unless a customer either simply wants it or they're chasing track or solo championships. This is due to the optimization we've done. So the added cost of adjusters doesn't have to be part of the build.

BTW, my point about custom valving is that we do it STANDARD, for ALL builds, it's not an option ;)

Happy trails!

peter wrote: Ugh. How many years has it been and I'm still hearing about how monotube is the only answer? The dead horse is still dead. There's more than one way to skin the cat (no matter its BMI), and different people succeed with different tools. Also, I'd hesitate to compare any track suspension to the godawful mess that is a SM suspension. I believe a blind, drunk, 3-fingered monkey could design a better suspension than that. It's not chosen because it's good...

Hmm, someone likes abused animals ;)

Monotubes are not the only answer, but neither is saying 'construction doesn't matter, what matters is how it's tuned.' Ugh let's put that dead horse to rest! It's simply not true. Without admitting the limitations of any design (yes, monotubes have them just like twins) is being driven around by a blind monkey. Many ways to skin the cat, but some are messier than others.

While I'm not a fan of the stock Bilstein HD valving, the Spec Miata package is effective, making one faster plus easier to drive isn't trivial.

Please, be kind to the wildlife!

Hi,

Interesting discussion. I have been intrigued for very long time about dampers and have done some experiments with mono and twin tubes. Wanted just to leave a short message in reply to "how much oil the twin tube displaces" in relation to the OD or the inner tube.... Truth is, due to the design principle of a twin tube, the oil volume displaced in the compression stroke (through the compression valve) is exactly the same as the volume of shaft that enters the damper during the same compression stroke and has nothing to do with the diameters of anythinig else.

This may be difficult to picture at first, but to make it easier to comprehend, simply remove the entire piston from the damper. Imagine there is no piston. Now you push in the shaft and as the shaft goes in, the oil has nowhere to go, but through the foot valve (compression valve).

Basically a mono-tube damper will work in compression without a piston inside. Then you need the piston for the rebound, of course. And because in general the shafts of twin tubes are much thinner than those of monotubes (because they have to be) - the displacement of the compression stroke of a conventional twin tube for a small car is very small, many times smaller than the one in a monotube.

Cheers.

tt.

Hi Guys,

Glad Shaikh came here to explain his philosophy regarding suspension setup. I had several people interested in buying my setup once I got it removed....well it is off and listed here and Miata.net.