Suspension Truth #1: Planes, Trains and Automobiles – The Psychology of Suspension Tuning

Shaikh Jalal Ahmad
by Shaikh Jalal Ahmad

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?

Shaikh Jalal Ahmad
Shaikh Jalal Ahmad

I'm a Suspension Wizard, obsessed with creating the maximum harmony, enjoyment and safety between you and your vehicle. I founded Fat Cat Motorsports in 2006 as an outlet for my passion to understand suspensions and create high-quality, durable and innovative products that are truly 'Elite.' I believe any driver deserves to know the Truth about Suspensions and to realize any car can be made to handle like a Porsche and ride like a Mercedes, or darned close!

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  • Power6 Power6 on Aug 27, 2012

    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?

    • Shaikh Jalal Ahmad Shaikh Jalal Ahmad on Aug 27, 2012

      "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.

  • Shaikh Jalal Ahmad Shaikh Jalal Ahmad on Aug 27, 2012

    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.

    • See 2 previous
    • Jeffiekins Jeffiekins on Sep 21, 2012

      @Jeffiekins 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 http://www.thetruthaboutcars.com/2012/03/want-to-save-gas-dont-buy-american-announcing-the-true-heroes-and-true-villains-at-the-pump/ 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.

  • MaintenanceCosts It's not a Benz or a Jag / it's a 5-0 with a rag /And I don't wanna brag / but I could never be stag
  • 3-On-The-Tree Son has a 2016 Mustang GT 5.0 and I have a 2009 C6 Corvette LS3 6spd. And on paper they are pretty close.
  • 3-On-The-Tree Same as the Land Cruiser, emissions. I have a 1985 FJ60 Land Cruiser and it’s a beast off-roading.
  • CanadaCraig I would like for this anniversary special to be a bare-bones Plain-Jane model offered in Dynasty Green and Vintage Burgundy.
  • ToolGuy Ford is good at drifting all right... 😉
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