By on August 24, 2012

Our newest segment, “Suspension Truth”, comes to us courtesy of Shaikh J Ahmad.  An engineer by training, Shaikh is the owner of Fat Cat Motorsports, and a self-styled “Suspension Wizard”. Shaikh creates custom suspension components for a variety of cars, including the Mazda Miata and RX-8, the Nissan 350Z, Mini Cooper and Honda S2000. Back when I had my 1997 Miata, I ordered a set of coilovers from Shaikh, based on his reputation for creating suspension setups with a previously unheard of balance between ride and handling. The Fat Cat coilovers are one of the few products I’ve ever bought that were able to live up to the hype. Over the next few weeks, Shaikh will delve into the science of suspensions, and provide his own analysis of a number of production cars.

What’s your least memorable train ride? Simple question, right? If you’re reading this, I’m going to assume all of them. Unless a screenwriter threw you into an adventure film without your consent, it’s what we’d expect. This brings to mind a popular driving metaphor – ‘handles like it’s on rails.’ That’s our ideal in suspension tuning, to be glued to the ground and also as comfortable as possible. Easy when you’ve controlled every degree of freedom as with a train track and groomed earth beneath.

But what about your least memorable plane flight? Again, I’d hope most of them. How about the most memorable one – turbulence anyone?  Whether chop, CAT, or simply bumpy air, turbulence can be annoying, as in delayed beverage service, or utterly terrifying. The unpredictable, jerky movements of an airplane caught in Mother Nature’s fury sharply draws your attention to the immediate environment. You aren’t relaxed anymore, thinking about the miles of air between you and the ground. You have to trust in your pilot, crew and the plane itself to handle the situation, working in harmony to return you safely back to Earth.

In between these extremes is the spectrum of what an automobile suspension can offer.  As a driving enthusiast and amateur racer in my 20s, I only wanted suspensions that made my car handle better and go faster. Comfort was secondary and in fact I believed (as many do) that to be fast you must be uncomfortable. Ah, brainwashing by race companies and the follies of youth! Having trusted marketing hype from both automakers and aftermarket companies, I’ve come to see patterns in the past 15 years of my pursuit of Suspension Perfection. Ultimate speed and ultimate comfort. How are they linked, if at all? Can I make my trip to the race car unmemorably smooth and also have razor-sharp handling for a backroad jaunt, autocross run, track session or hill climb? What about safety, responsiveness and predictability?

Any automaker has to fulfill the task of keeping a vehicle on the road. They can do it in a bare-bones fashion, like a budget economy car that doesn’t inspire much confidence but gets you from point A to B. At the very high end, we have the Holy Grail: a buttery-smooth ride with incredible handling. Normally you pay superlative prices (Aston Martin, Ferrari, etc) for this achievement, but I’ve found that cost has very little to do with making an exceptional suspension. You need to understand the designer’s mandate, see if that matches your needs, then choose components (or a vehicle itself) that deliver. But we don’t get handled a personality test results for a Honda Civic, Toyota Camry or Porsche 911 Carrera. We have some bias based on past experience, what we’ve read, felt or been led to believe. But what really goes on in that murky black magic area of suspension design? By starting with an examination of the psychology behind a vehicle, why it exists, we can understand certain design choices then make targeted improvements to a production-based road car to the point it feels truly amazing.

Please note, this kind of suspension harmony matters whether one get groceries or chases championships. It’s been a fascinating process of discovering the truth of how grip produces both great ride and handling both. For a street-driven passenger car, how the suspension deals with the road, mile after mile, creates a somatic experience that can promote either ease or dis-ease. I’d rather see a driver smiling and relaxed after a trip than stressed and hurting. A relaxed (not numb), in-control driver is a safer driver and a happier human being. There’s also a very important somatic experience to the race car driver, who needs to have hyper-confidence in their machine’s responsiveness to dance it on the edge of adhesion.

One video in particular was very illuminating to me. It was of a journalist who had a chance to drive a few laps in a Formula 1 car. Once the lengthy process of preparing him for the experience was complete (simplified as it was in his not-very-physically-fit case), he took his laps, whooping the whole way through. Once he stopped the other reporters asked a seemingly rhetorical question ‘you just drove a Formula car! Wasn’t it really harsh?’ to which our lucky journalist gives a surprising answer: “No, in fact it was quite smooth once you were up to speed!”

Is it that really all that surprising to hear this truth? To give a driver confidence and ultimate speed, the proper suspension has to keep the tires in contact with the road. What’s good for the rather-soft tires (imagine driving around on a partially cooked egg) is good for the very soft driver.  Going stiffer than is necessary robs grip and induces more discomfort. The just-stiff-enough setup will reward the aggressive, competitive or racing driver in many ways.

We’ll continue our explorations next time with a topic that is even more subtle – what does it mean to have a “Sport Suspension” and do you really want one?

Get the latest TTAC e-Newsletter!

57 Comments on “Suspension Truth #1: Planes, Trains and Automobiles – The Psychology of Suspension Tuning...”

  • avatar

    Interesting post.

    I note with interest that the all new Honda Accord now comes with struts instead of the old double wishbone that they have been using for years.

    I imagine that it will come with the new “damper” bits that they used on the Acura ILS.

    I’m fairly ignorant about suspensions, so who even knows if I could tell the difference, but my suspicion is that some of the cat-like-sure-footedness of the Honda Accord may be a thing of the past.

    Perhaps idiots who beat the crap out of Hondas are ruining it for everyone else.

    • 0 avatar


      I have been a lurker for years, and now a frequent poster on Temple Of VTEC ( ever since the 2013 Accord spy shots started leaking; the car seemed to be a full 180-degree turnaround from some of their recent failures–so much so that I was waiting for the other shoe to drop, being a realist. (Actually, I’ve been anxious about every new Accord reveal since Honda dumped DWB for MacStruts on the Civic in 2001!) A couple weeks ago, it was leaked that DWB was being dropped, and it has indeed been confirmed that MacStruts are the order of the day! Needless to say, I, as a Honda enthusiast, am pissed about it! I’ve driven a strut-equipped 2007 Civic, and it doesn’t have the same planted feel as my former 1994 Civic EX, 2000 Accord and current 2006 Accord, all of which had DWB suspension.

      There is a press-embargo until September 5th, so obviously nobody knows how it drives, but Honda has stated that this will be the best-handling Accord ever, so perhaps Honda’s done SOMETHING to mitigate the downsides of this setup. Supposedly, though, they had done that on the Civics after some teething pains! So I’m skeptical! (Some threads even this morning are pointing to a “different” implementation, so who knows?! :-p )

      This’ll be an interesting (and timely) series!! :-)

      • 0 avatar

        1995 was actually the last year for double wishbones on the Civic. My sister had a 1996, first of the next gen that had McStruts.

      • 0 avatar

        I’ll have to put this on my list for test drives and suspension characterization. If anyone in the SF Bay Area gets one, I’d love to have it for a day (you can be here) to do our measurements on it.

        My guess is if the (rather intelligent but budget-constrained!) factory engineers claim better handling, they probably made geometry improvements on the newer car to compensate for the deficiency in camber gain from a strut-type suspension. Perhaps adding more static caster and better camber curves. The BMW handles quite well for a strut-car so it’s not impossible. Camber plates would likely take care of some concerns. I’m getting more familiar with strut vehicles as my own bias has been toward DWBs since falling in love with Miatas, S2000s, RX8s and the 560+ whp Nissan GT-R I was lucky enough to drive (and later tune suspension for!).

      • 0 avatar

        Civics had DWB in the 1996-2000 gen as well. Macpherson struts were introduced in 2001, along with hard plastics in the interior and questionable fit and finish.

      • 0 avatar

        Whichever Civic generation lost DWB, that’s when the Civic (and Honda in general) started to lose the plot.

        Honda is like an addict–they hopefully “hit bottom” with the fail that is the 9th-Gen Civic (which is having a normal mid-model cycle (MMC) “overhaul” a year into its run), and is starting on the road to recovery. However, with the downgrade to MacStruts on the “bread and butter” Accord, I will be skeptical until I see reviews from the ego-mags, as well as TTAC and TOV, then actually drive one (or several) for myself.

  • avatar
    Felix Hoenikker

    Great article,

    I can’t wait for the next one. While I am comfortable with the minutae of drive trains, I am very lacking in suspension knowledge.

  • avatar

    Wow, nice to see pieces by Shaikh here. He’s a highly respected suspension tuner/builder in the Miata world, and I look forward to him sharing his knowledge. Being on a bit of a budget, though, I’ve got Flyin’ Miata stuff on my NB…

  • avatar

    Good Stuff. Personally I’m never going to chase championships but I do love to be able to have a smooth ride and then go through a marked 35 mph corner at double that without the car trying to lean over on its door handles. Sedans that can do this put big smiles on my face.

  • avatar

    I welcome this series! Too many people think that firmer suspension = better. The whole point is to maximize tire contact with the ground, and this is equally true for off-road racing & rock crawling.

    I remember attending one fairground dirt-track heat race (bomber class) where one genius thought that by welding his suspension arms directly to the frame (or possibly installing solid members in place of the shocks) that he would have some kind of advantage. His car was literally hopping off of the ground like a bucking bronco and I couldn’t stop laughing. Some learn by doing, I guess . . .

  • avatar

    As someone who just replaced his bookshelf and had to move several hundred pounds of suspension design and vehicle dynamics books, I was prepared to hate this article. I did not. The level is about right, and the approach is novel.

    Well done.

    • 0 avatar

      “As someone who just replaced his bookshelf and had to move several hundred pounds of suspension design and vehicle dynamics books, I was prepared to hate this article. I did not. The level is about right, and the approach is novel.

      Well done.”

      Feds, your comment means a lot, thank you. I don’t have formal ME training. My degree’s in physics, with a secret desire to be a concert pianist. I have a PhD in Curiosity, extending across many many subjects. Principles of harmony, and balance relate to any aspect of life we consider art (including the ‘ hard’ sciences). Diving deep into one pool often brings us up into a totally unexpected area on the other side. That was a cool realization for me; e.g. a dropped cat is better-damped than most cars! (Thanks to my friend Jason C for pointing this one out)

      I’ll look forward to you and others keeping me honest and sharing your experience/impressions. The Truth About Cars feels like a website where we can have really solid discussions with a high S:N ratio.

  • avatar

    I remember reading a Sport Compact Car article back in the day, where they had a shootout that featured 2 Acura RSX-S with different suspension tune.
    Counterintuitively (at the time), the car with the softer suspension turned out a better performance AND was more comfortable.

    Just goes to show that stiffer isn’t always better.

    …waiting for the first inappropriate comment

    • 0 avatar
      Felis Concolor

      That comes as no surprise, having read decades ago about the higher performance Corvettes sporting softer spring and damper rates than their base counterparts. The cornering gains all came from careful tuning of spring progression and sway bar stiffness.

  • avatar

    A suspension is the most critical element, above all else, in terms of driving enjoyment, IMO.

    While it’s true that a terrible motor can rain on one’s enjoyment, it’s still possible to enjoy a drive in a car with a terrible motor, although you may not get from point A to point B quickly, if the suspension is an Ace-High straight. The converse is not possible.

    This is where Hyundai, above all other volume automakers, consistently falls down, whether one experiences the Genesis Sedan or Vera Cruz. Both of these vehicles (and other Hyundais) fail of their intended mission because their suspensions are not up to the standard of competitors in efficiently sorting out ‘heavy streaming data’ in terms of road imperfections.

    • 0 avatar

      While it’s true that a terrible motor can rain on one’s enjoyment, it’s still possible to enjoy a drive in a car with a terrible motor, although you may not get from point A to point B quickly, if the suspension is an Ace-High straight. The converse is not possible.

      TRUE. My wife’s Vibe may not have much motor and may rev at silly levels on the interstate but on a twisty road it is much more entertaining. Would a 200hp version be entertaining? Sure but the suspension is just fine and dandy the way it is.

  • avatar

    Shaikh, great article. I’d love to hear your thoughts on whether the Mazdaspeed3 sees discernible benefits from any suspension tweaks or upgrades in a purely street (rough, poor pavement) application.

    • 0 avatar

      That would almost be a universal ‘yes’ to any production car seeing benefits, esp. for rough surfaces. We did retune some Bilstein struts/shocks for an MS3 customer some years ago and he lived in the NE. Loved it on backroads and track. This is where a slight ‘rally-bias’ in damper tuning makes a big improvement.

  • avatar

    I too was prepared not to enjoy this article, you sure surprised me. Thank you for taking the time to write this interesting and thought provoking article.

  • avatar

    ooops, I forget to mention that this article is one of the best I’ve read, ever, in terms of emphasizing specifics and the nuances of suspension “set ups” and characteristics.

    Another article that is brilliantly technical “enough” but easy to understand for the average person that one won’t find on Car&Driver.

    p.s. – When do we Americans who love creamy ride quality get some Citroen C6s. damnit?

    • 0 avatar

      A little Citroen love for DeadWeight…


  • avatar

    I’m looking forward to Shaikh’s contributions. There is a long history of automakers bragging about detailed engine stats and specifics. Power, efficiency, displacement, cylinder count, turbos, number of camshafts, ignition type, you name it. Yet you hardly ever see anyone brag about suspension details beyond the vague marketing descriptions like “sporty”, “track-tuned” or “refined”. I guess for most drivers, handling is secondary to pressing the gas pedal and going.

    • 0 avatar

      Depends I suppose – I’m not a suspension enthusiast per se, but I like a nice controlled yet compliant ride.

      Prior to swapping the suspension on my previous S-197 Mustang GT, I found it rode nicely but at any speed above 85-90 on a nice twisty and bumpy road the car would lose its composure. A switch to Ford’s own aftermarket suspension (FR3) cured a lot of high-speed ills in that car as did switching to a proper summer tire. Another nice feature of that suspension was the ability to tune out some understeer with its three position adjustable front sway bar.

      This same suspension was fitted to the Shelby GT (not to be confused with the GT500 or GT350) – had they been shod with a good summer tire, the SGT would have been the best handling car of its generation (the 05-09 Mustangs), instead for whatever reason Shelby chose to stick with the so-so BFGoodrich KDWS.

  • avatar

    I was just thinking, has this guy ever heard of the magical suspension developed by Bose?

    • 0 avatar
      Speed Spaniel

      Whatever happened to that? I remember reading something years ago about Bose developing revolutionary suspension technology? I heard it was suppose to create a very smooth ride without any highs or lows….(okay, the latter sentence a bad joke, the rest true)…..

      • 0 avatar

        If I remember right the Bose system used so much power that it cut mpg greatly. The Bose suspension is an active suspension, using electric actuators instead of hydraulic or air pressure. The system worked very well, but the cost in initial dollars and lost mileage was too great.

      • 0 avatar

        Au contraire, it was a great joke. BOSE: Buy Other Sound Equipment.

      • 0 avatar

        And there’s probably no way to make it work more efficiently. No matter how you cut it, the Bose system was moving the weight of the car. A lot of work, and a lot of energy.

        I think the most we’re ever going to get in this area is GM’s MagnaRide system, which gets rave reviews and can do some neat tricks. (Didja know it will selectively damp each wheel differently as the car dives its nose into and bounds out of a curve in order to balance out all the forces acting on the car – fascinating stuff.)

        And I think GM has patents covering the area thoroughly, because no one has brought out a competing system. Even Ferrari buys MangaRide from GM.

    • 0 avatar

      I did hear of this (though after the fact). There’s a video on YT about it as well. It did see very heavy and rather costly, although it did an amazing job of dynamic control from what I can recall.

  • avatar

    A little wordy, but otherwise Great!

    I have been waiting and asking for EXACTLY such an article/series from TTAC.

    Excited and looking forward; Thanks!!!

    • 0 avatar

      Wordy is my middle name! I do my best to be succinct but I have a LOT to share my friend! I write both for pleasure *and* to inform. Ever listened to Beethoven’s 9th Symphony? Not comparing myself to the maestro but if you feel that’s “got too many notes” you’re on the wrong blog ;)

  • avatar

    From my occasional forays into the Honda forums, most suspension “tuning” appears to consist of adding random parts as money becomes available–bigger wheels, stiffer shocks, thicker sway bars, etc….

    I’m guessing that to do it better than the manufacturer, you need access to lots of different parts so you can find the best combination. Or Mr. Ahmad.

  • avatar

    I am not “trolling” or whatever but why are mx5 products seem to be higher priced?

    and why are coilovers up to 5k?

    2 questions;
    Are the fat cat coilovers just white labeled blistens/ some Chinese white label manufacturer just done to their spec? Never heard of them, for $2100 a pair sounds awfully steep to get a 20k car working better. A shock is a shock- same process to make a cheap one as an expensive one. Almost same materials, definitely same process. Just purchase slightly better steel, steel sells for $450 a ton, so don’t tell me its the actual materials. Same with carrillo- the steel and treatment is not expensive, QC/QA isn’t either.

    So what is it? Is it american pricing dogma? The old Cost plus margin= selling price.

    Whereas successful foreign companies ask at what price can we dominate the market? (see jap fax machine market takeover from american manuf.)

    (no duh duh comments-, well if you can do it for that then you should…)

    Maybe I am missing something, where is the secret sauce, and why is it worth so much, especially when up against the MSRP of the car(MX5)?

    • 0 avatar

      Really good dampers are expensive to very expensive, no matter what vehicle. $2100 a pair isn’t anywhere near the high end.

      They are expensive to make, as they require extremely precise manufacturing, and the specialty pieces for aftermarket tuning aren’t made in large volumes.

      Be thankful Miatas don’t come with magnetorheological dampers – plain ‘ol OEM replacements are about $1800 a piece.

      • 0 avatar

        But look at other “high precision” goods, guns for example. A custom 308 or a 50 cal rifle is machined down to the hundred thousands of an inch- and lasts for thousands of rounds.

        A car shock on the other hand lasts, what a couple yrs- street.
        I have a difficult time with high end being so much better than low end, or the tolerances meet or exceed a rifle- also the fact that all shocks are basically the same design. A tube filled with a piston sealed with a rubber bushing that goes up and down. the spring is a spring, X quality of steel (not made by the shock maker) but heated and bent around a spindle and cooled- perhaps treated in some why for hardening, and plastic wrapped.

        Also what happens to cheap shocks when they die? What happens to expensive ones?

        For the majority of cases- it means the seals weaken and the dampening of the shocks is lessens because of hydraulic fluid leaking. and metal fatigue in the springs.

        So in both cases its is cheap parts- rubber/silicon and spring steel.

        Those tubes are not relying on 0.00001″ machining but rather 20 cent rubber O rings.

        Hence what you get in a rebuild kit.

    • 0 avatar

      Actually for nearly anything, Miata parts are extremely cheap by sports car standards. It’s part of why they’re so popular among amateurs on race tracks. It doesn’t sound like you know much at all about suspensions or manufacturing processes, because a quality shock isn’t “nearly the same” as a cheap one.

      If you really want to gasp, take a look at what high end bicycle suspension costs. Or the $800 rear shock I bought for my motorcycle.

    • 0 avatar
      el scotto

      Using that logic, 20k is a lot of money for a tiny car when steel is 450$ a ton. A modified Miata will probably be the best handling car most of us mere mortals will ever drive. A used one with owner installed suspension mods is still relatively cheap and more justifiable than a motorcycle; it has a heater and a top. Sears used to sell under good, better, best; car parts are kinda sold like that. Check out, a bunch of friendly folks with ready advice. They will say something is great or shyte.

      • 0 avatar

        A used one with owner installed suspension mods is still relatively cheap and more justifiable than a motorcycle; it has a heater and a top.

        Which is why I can never cross a Miata off my list when thinking about cars I’d like to own.

      • 0 avatar

        The best description I’ve heard of a used Miata is, “It’s a great rack to hang expensive race parts off of.” A $3,000 shell can have $30,000 worth of aftermarket parts on it (or of course much less). You can make it pretty much anything from a fun sunny-weather cruiser to a turbocharged or V-8 powered track weapon. I’ve got about $12k all-in on my ’99 Miata (prices are higher in Canada), and with spring rates that are double that of stock and attendant sways, shocks and body bracing, it rides well for a light, low sports car, and puts a smile on my face whenever I get in it. I always get a kick when passengers say things like, “It’s this turn coming up, this one right here… Why aren’t you slowing down?… Holy crap!”

        For the prices that you can get a nicely-kept example in the US (sometimes as low as $5-7k), coupled with cheap, readily-available parts, and an online community that’s second-to-none, you really can’t go wrong.

  • avatar

    Great start to a series. When I was at GM I mostly did durability and temperature test, but I did get to do a bit of ride & handling – big fun, even on trucks!

    Myself, I’ve always favored the “Gentleman’s Express” approach for sporting suspension, even though ironically I’ve owned some mighty harsh cars (’79 and ’89 WS-6 Trans Am anyone?).

    You need stiff springs if you spend a lot of time on the high banks, otherwise, not so much. They do help with basic high speed wheel control when you can’t afford good dampers, and I suspect that’s why so many factory performance cars have them. That, and marketing/expectations.

    Last weekend we bought the wife an ’02 Lexus GS300. I expected an insulated barge but it’s actually quite fun to drive. It’s got that Gentleman’s Express thing down, albeit with the six it’s not so very “express” by modern standards. Still, I was very pleasantly surprised and it started me looking for tuning parts for an LS430. Sadly, ’twas not to be.

  • avatar

    Yes, I very interested in the suspension tuning of cars. I have Koni / eibach , sway bar setup on my car. Due to lack of info on the interwebs I have no idea on stock spring rates vs aftermarket springs. Shocks dont seem to be rated or matched to either fixed rate or progressive rate springs. My Konis were mentioned once to be matched to my Eibach but they dont mention progressive springs anywhere I found at the time.
    Also the interaction of increased swaybars diameter can overwelm the rebound rate of the shocks. As most shocks to not have two adjustments for compression and rebound I think I am not even close to optimized.
    Another factor is the lowering of cars which then reduces the need for more swaybar.
    So at this point I am probably like most driveway Modders, too much sway bar, too much spring and mismatched damping rates.
    I will be waiting for the next article…

    • 0 avatar

      You brought up some very good points, about matching shocks with springs and also sway bars. The more stiffness you couple into the suspension the more control the dampers have to provide. From my understanding of load through the suspension arms vs. the body, as you lower you also increase the weight transfer happening through body roll which means you do need more roll resistance otherwise there’s more roll center changes which causes the handling to behave oddly at the limit.

      Every Koni I’ve tested along with other off-the-shelf dampers, are really intended to be stock replacements. In some cases they don’t even provide the same amount of damping as a stock shock, especially in compression which is what helps you not bottom out and reduces the incidence of jacking down. If you throw on stiffer springs and stiffer sways, the effect ends up being a jittery, bouncy, unstable mess.

  • avatar

    As someone who bought a Protege5 after hearing about its spory handling, I dreaded the purchase within months. I never knew how bad a sport suspension would be in a Canadian winter city riddled with potholes all summer.

    At the same time, when I hit the Montana highways during the winter to Jackson, Wyoming, I understood the thrilles of the sporty suspension in the winding mountain passes.

    I am currently about to sell the car in a month, the car just isn’t fun in normal driving in Winnipeg.

    • 0 avatar

      This is the definition of a jacking-down setup. When you need some low-speed compression resistance, like on a broken road, it’s not there. When the road is smooth you can take the extra rebound to give you confidence, but only in that situation.

  • avatar
    Vipul Singh

    Great initiative, TTAC! And a good article from Jamal. Looking forward to more of “Truths”

  • avatar

    Timely article.

    Last car I bought had just the right balance between ride and handling, so much so, that I bought it right after the test drive. Later I discovered it had upside down Bilsteins and became a believer in the advantages a more costly component can offer. A factory option available 38 years ago!

    Looking forward to more….

  • avatar

    Really looking forward to more as this is pretty much in line with my own philosophy regarding suspension tuning.

    Back in the days when I was tinkering with my first car everyone was putting stupid low and stiff springs on their Civics thinking it would handle better. I went through a couple suspension setups searching for that elusive balance between ride and handling, messing with sport springs and coil-overs. My final setup ended up being slightly stiffer OEM springs from an Integra coupled with KYB AGX shocks and an OEM rear sway bar again from an Integra. It was pretty close to what I was looking but if I could of I’d of made the rear shocks even softer. All in all however I had a car that could be driven anywhere all year round on the crappy roads of Quebec and could still be fun/capable on the occasional track day.

    • 0 avatar

      Very good data point. Often just a 10-20% increase in stiffness can be very effective, but lowering the ride height without using enough spring rate to reduce deflection is a recipe for a more jittery ride. I’m betting your rear suspension might have been riding the bump stops.

      Also, one effect I’ve noticed on stock Civics (pointed out by a friend who owned a 90s era version) is how the rear oscillates several times after hitting a large-ish bump. It’s a symptom of too little compression and more rebound but not enough overall damping to provide a smooth-but-rapid settling behavior. So you are bouncing off the bump stops a lot. With the AGX, it’s very likely the rebound was stiffer than the compression, similar as on the Miata, which would cause the rear to behave like it’s much stiffer than stock.

  • avatar

    Thanks for making me feel welcome, and providing more questions/ideas to ponder!

    I got an email from Charles regarding ‘are their ideal factory suspensions?’ I haven’t tested everything out there, but here is my reply to him. The next article (or perhaps couple) on Sport suspension philosophy will go into this more. I may even provide some dyno graph comparisons if that’s not too techie for folks (or the editor’s) taste!


    Hi again Charles,

    Thanks for your interest, looks like we got you curious! You’ve got the car i wanted to have, an E46 M3! We have a 330i with Sport (not ZHP) package as our next FCM shop car. I’ve tuned E36 M3s, Z3s, MRoadsters but the E46 and newer chassis are my next goals.

    I need to update the (Suspension Truth) PDF but it still has good/accurate content. In further investigations on low/mid/high speed (shock) tuning (and my experiences with the Sport package on the BMW plus a 993 Porsche we did late last year that had the Euro-spec M030 package) I’ve come to understand a a few more points on how I believe the factory engineers think.

    Yes, the low-speed is usually tuned pretty nicely for good transitional response BUT they bias more toward rebound than they need to, which causes more ‘pattery/jittery’ feeling in the suspension and chassis on rippled surfaces (taken at say 20-40mph). This bias toward rebound also causes more jacking down at highway (or greater) speeds. To get a certain suspension frequency, you either have a small amplitude bump/dip taken at high speed (freeway) or a larger ampitude bump/dip taken at lower speed (city driving). The end result is the same, and cycling the suspension up/down even in the low-speed range (1-3 in/sec) will cause jacking that reduces ride quality and grip.

    (Side note: The 993 we tuned came with M030 suspension. By road and shock dyno tests, it has a strong tendency for high-speed jacking down. When we adjusted this with some FCM Elite-tuned Bilsteins, there was no road patter and larger bumps taken with greater ease via better proportional high-speed rebound vs. bump).

    Pretty much every factory suspension I’ve seen is biased to do this (other than, ironically, VW Passat or likely Jetta which have a good amount of compression and not too much rebound usually – but those are supposed to be comfy, not sporty!)

    On bigger amplitude/higher-road speed bumps where you get into the high speed shock range, the German sedans/coupes give a fast settling response BUT that can cause high-speed jacking down (which the BMWs seems to suffer from, likely Audi as well, not sure about Mercedes) and loss of comfort.

    Maybe because my standard is so high given my hyper-picky approach to ‘The Perfect Ride’ ;) I find it hard to say a factory setup is really optimal. You’re basically giving the keys to the kingdom to a driver when you do that – so I’d expect that in Ferrari, Lambo, Bentley, really really high-end cars. I think the factory RX8 R3 Bilstein-based suspension is quite good from what customers have told me. But you’d want need to trust your body for feedback. Also, if you haven’t directly experienced my version of suspension nirvana, then it’s more a theoretical comparison. I know we could truly optimize your M3. My local customer/friend Praneil is a good track/autox driver and the tune on his Bislteins is more TME-rally-type than Jack-Downs-Ville. I can’t wait to fully characterize our E46 and then tune the PSS we have waiting.

    I think as part of my column I will go and test drive cars (esp. if the readers suggest particular ones) and give an honest assessment. I can also mount our 3-axis lab-grade accelerometer which gives 500 Hz resolution and can indicate whether the chassis is jacking down or not (vertical gs), plus indicate lateral/long gs.


  • avatar

    It was said of early Ferraris that they rode and steered like Mack trucks until ~80 mph, then really smoothed out.

  • avatar

    I only buy cars that Bilstein makes a shock for. Once the standard fish oil things go away, the car is then improved.

    Compliance is more important than stiffness. The suspension should keep the wheel on the ground, not hammer the occupant.

    A tradeoff occurs frequently, where soft means compliant till about 85 mph, then it’s oingo-boingo. The trade is stiffer at low speeds. A really good car can give you the stability at WARP without rattling teeth at low speeds. Done cheaply, you get one OR the other. I drove an AMG recently, where with a switch, you either get boulevard, german, or rally car handling. Not cheap, but works. I got a C63 to act like a Miata (almost) on a tight road with broken pavement.

    Bose suspension would be sold at prices that make Koni cry, be defended by fanbois to the end, and be about as good as a standard sport OE suspension, but bought by folks for whom that would be new and different. For audio comparison, google “monster cables”.

  • avatar

    Very excited about this series! I became acquainted with the exciting world of suspension when I became obsessed with my WRX suspension. There were many parts to the whole thing, springs and arms and bushings, but the I came to learn the shock is the really the center of the suspension tune. From tuner spec’d Sport Bilsteins I made the jump into custom valving and it was an amazing ride, so to speak.

    I am interested in two aspects of the whole thing:

    What do you think of the “coilover” wave? Very popular, but the dampers are usually “adjustable” rather than properly tuned and valved and not up to the quality of a Bil, Koni, or Ohlins. Some of the chinese brands are coming up in the world though.

    How do you think the OEMs tune their suspensions and particularly damping? You allude to having figured out why they do what they do. In some ways they do work against enthusiasts but they are obviously smart people so what is the general philosophy there?

    • 0 avatar

      “How do you think the OEMs tune their suspensions and particularly damping? You allude to having figured out why they do what they do. In some ways they do work against enthusiasts but they are obviously smart people so what is the general philosophy there?”

      That’s what I’ll be discussing in the next post, in a few days. In brief summary, I believe OEMs know how to make scary fast *and* compliant cars but design to the expectations/assumed abilities of the target audience – sometimes including how much they paid for the new vehicle. Invariably, the design promotes understeer (push) vs. oversteer (loose). I’ll give some examples in the next post.

      Once issue I really have with mass-market products is they are just that – like spam. You might get it perfect for one person’s set of variables (damping, spring rates, ride heights, sways, alignment settings) but no way will it work for everyone. You’re making major assumptions about (or have tremendous trust in) what that designer had in mind for the package. Some can do a good job and they’ll have the product satisfaction to back that up. But in many cases, I wonder how much do they really know about how the ingredients of a suspension interact? Are they just copying something without knowing why *that* exists? Do they even understand nuances of why the OEM made certain choices? Does the mass market man ever say ‘we suggest this sway for this car, these alignment settings, adjust the bump stop length for this power level, these are the actual ride heights it’ll be capable of.’

      The interaction is usually not very sophisticated, so you get, frankly, a dumbed-down result. It can make you happier than what you have, which is great. But by no means is it optimized for you or will it necessarily provide safe enjoyment and durability with product support.

  • avatar

    I’ll share my thoughts about the cost question posed earlier. I had owned and tested various shock makes before settling on Bilstein for our personal cars plus our customers. Why? High-quality, repeatable, durable, serviceable, adaptable to many purposes (usually plenty of stroke that can be limited, bodies that can be shortened if needed). We designed our own gun-drilled chromoly and now chromed-stainless steel shafts plus external reservoirs to make a top-quality single or double-adjustable damper, depending upon the need at hand. I saw the long-term potential and ran with it. No regrets at all.

    I won’t touch Koni, JIC, Tein or anything else. Not that they can’t do a good job to varying degrees but that having understood general design intent, I see more inherent flexibility and capability with a monotube Bilstein. They’re available for so many vehicles and it’s great to say ‘if you can get us a Bilstein, we’ll bring you into the FCM Elite!’ By their nature, they’re intended as OEM-replacements which is perfect when someone really just wants better damping control without hot pink super-stiff springs, low stance and 32 zillion ‘way’ ‘dampening adjustment’ (blech!). Bilsteins help us get results on so many different platforms.

    Plus they have excellent parts support. Our happy customers are our best sales force – we built to their needs and they love it. You can’t wow people with a so-so product experience.

    My goals in providing suspension products are what I want for myself. Exceptional effectiveness, durability/longevity (last a life-time, serviceable if needed), safety via quality materials/construction/assembly and future-proofing (upgrades possible, no ‘throw-away’ mentality). The idea of buy once, buy right. I think most people have found at least one if not multiple areas deficient with lower-cost products. Thankfully, the market allows us to buy at the level our resources and time-frame dictate.

    • 0 avatar

      Isn’t that the truth?

      I’ve had a bunch of cars, from a first-gen ’74 Civic (interesting with a big enough sway bar and Weber carb) to a RWD Celica with the pickup-truck engine, to a 914 with a modified Microbus engine, but the best-handling one (before my current RX-8) was a Golf that I put Bilsteins in. It was hard to believe how much difference that made, and I did not do another single thing to that car. And it only had *decent* tires. Actually, I take it back: the 914 would take curves faster, just the Golf was more fun. Not to mention a back seat.

      But I do believe I’ll be browsing your website for my (used, stock) RX-8; I’ve had it a half-year now, and the “handling is just perfect” thing is starting to wear off a little.

      • 0 avatar

        A wide spectrum of experience there, good to compare behaviors we like (or don’t). The added displacement of a monotube, especially one with good tuning balance, gives a very direct feeling to the car’s response. That’s one aspect that most people are noticing even if they aren’t aware of it.

        The RX8 is an awesome car and one I’d love to own (although not for commuting – hello, gas guzzler!). With that nice rigid chassis you could use a ‘GT’ type Elite suspension that would allow frequencies in the 1.8-2.0 Hz range which is firm but still Flat Ride-friendly and very streetable. Probably even retain your stock front bars and likely go down to the smaller 12mm NC or no rear bar.

      • 0 avatar

        Actually, the gas thing isn’t nearly as bad as people make it out to be. I *do* use it for commuting (and little else), and it’s great: I have a 12-mile commute on 3 highways, which means 4 80-mph ramps, with 3 65-mph cruises of a few minutes each between them. Almost as much fun as you can stand in 15 minutes twice a day. There’s nothing like flying past an A6 or an M4 who thinks he’s going fast on a (2-lane) flyover ramp.

        Since there’s nothing special about driving an RX-8 fast in a straight line on a smooth highway (my ancient Civic would do that, faster than I dare drive regularly today), I just keep it down to 65 on the straight and level, and consistently get 23.5 mpg (+/- 0.2), which means I can go 3 weeks on a tank. Another thing the RX-8 has in common with the 914 is that they’re both as much fun going straight down the highway at 65 as they are at 85.

        P.S. My degree is in Physics, too, so I know that for 10 highway miles, going 85 mph (7.06 min) saves only 2:10 vs. going 65 (9.23). Two minutes seems a reasonable trade-off for keeping the points off my license, even ignoring the saving on gas. And it might save time overall, factoring in the time I don’t have to spend with the nice officers.

        P.P.S. According to I get 1.2 mpg *better* than the auto industry average vehicle, and better than the average Nissan or Suzuki! “Gas guzzler?” I stand up to defend my RX’s honor. I beg you to retract, dear Sir.

Read all comments

Recent Comments

  • Inside Looking Out: I think F35 uses system like that to predict failures and order spare parts before the failure...
  • Lou_BC: “Yes because people like you defunded them…” Ah yes, the “defund” argument. The same...
  • sgeffe: “You’ll LUV this time-share!” (Until you see the 400% YOY increase in maintenance fees!)
  • Lou_BC: @Matt Posky – a positive drug screen in a fatality might get included in substance abuse statistics....
  • EBFlex: “So “meanwhile in automotive news” is a jab to Posky to stick to stories you deem germane but you...

New Car Research

Get a Free Dealer Quote

Who We Are

  • Adam Tonge
  • Bozi Tatarevic
  • Corey Lewis
  • Jo Borras
  • Mark Baruth
  • Ronnie Schreiber