Car Advice

Why the MX-5’s soft suspension doesn’t matter, and what’s missing in the power debate

The MX-5’s soft suspension makes for a lot of body roll in corners. Some people say this is a bad thing, but those people are wrong.

THE CONVENTIONAL APPROACH to sportscars is to make them as fast as possible on racetracks, which means stiff suspension. The reason is that when a car turns a corner there is a weight transfer to the outside of the car. Initially there’s not much weight transfer to the tyres on the outside of the turn as the body is rolling on top of the wheels. Then once the limits of the suspension are reached more weight is transferred onto the outside tyres, so there’s a lag between when you turn in and when you load up the tyres.

That is not good for handling, particularly quick direction changes where you can’t gradually transfer weight from side to side. There’s also changing suspension geometry under compression and braking to deal with.

Soft suspension is also a problem for hard braking for much the same reasons – you brake hard, and the car pitches forwards for a moment and then, later, you get weight over the nose which helps you brake. The rear pitches up too, further reducing weight on the already light rear end. And as most hard braking is into a corner, you now need to manage a sideways weight transfer as well. What you definitely don’t want to do is jump off the brakes and attempt to turn because that highly compressed suspension will rebound, making the front end very light and dramatically reducing grip right at the point that you’re trying to turn it, resulting in understeer or ploughing straight one. The correct technique is to reduce the braking effort as you increase steering lock, a process known as ‘trail braking’.

So to set a fast laptime on a racetrack you need stiff suspension to minimise body roll and pitching, which is why today’s racecars such as V8 Supercars barely seem to pitch or roll relative to their ancestors 30 years ago. Look at this video:

So how can I say everyone is wrong about the MX-5 when it is so softly sprung the coils seem to be made of feathers?

There’s several reasons. The first one is that MX-5s have never been about setting fast times on glass-smooth racetracks where stiff suspension is an advantage. The MX-5 is a real world sportscar, and normal roads have potholes, corrugations, rough bitumen and more. Stiff suspension here is a problem, because when you hit a bump the suspension can’t absorb the shock but instead transmits it to the entire vehicle, lifting or dropping it, changing instantly the weight on the tyres, and as the weight changes, so too does the grip and you start bouncing off line. Over rough roads, stiff suspension is slow, and not just slow, but uncomfortable and even scary if you try to drive fast.

The next reason that the MX-5 can get away with soft suspension is because it is very light, only about 1050-1100kg – yes Mazda promote lower figures but not everyone drives the 1.5L base model manual. Lightness is what’s called a virtuous circle – the lighter a car is, the smaller the engine, brakes, and components you need, and as those are light the car itself becomes lighter. To their eternal credit, Mazda are one of the few manufacturers left that truly understand the virtues of lightness as evidenced by their “gram strategy” of reducing weight wherever possible. The rest of them build heavy cars and then spend money to create trick-sounding active suspension to try and keep the car in balance, or torque-vectoring differentials, tech that wouldn’t have been needed had they put the same effort into weight reduction. So in the case of the MX-5 there’s not much weight to roll around so the soft suspension doesn’t matter as much.

Then we come to real-world usability:

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I hate driving over these things in my 86, and I’ve got adjustable suspension that can make the ride slightly softer than standard. In the MX-5 it’s no worry at all, the light car with its soft springs simply dances over the bumps. Yes, we all like a blast around a racetrack, but 98% of the time you want a car like the MX-5 to be usable as a daily driver and with some sportscars you pay a very heavy penalty for your 2% fun time.

The final reason why the MX-5’s suspension isn’t a problem is fun, which means driver involvement. With soft springs you can feel the car pitch and roll, and while that’s not to everyone’s taste the movement is action you can feel and that’s what driver involvement is all about. I used to own a Land Rover Defender which weighed 2400kg and had no swaybars – if you want to see body roll that would be the vehicle – yet it was fun to gently tip in and out of corners. Not fast, fun. Two different concepts. I can assure you the MX-5 is one of the funnest handling machines on the market at present, at any price point.

So there you have it. Next time someone whinges about the MX-5’s soft suspension tell them it’s a wonderful design decision that helps make the car just about the most fun you can have with four wheels on public roads.

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Why everyone gets the power question wrong

There’s a few sure-fire argument starters and one is whether the likes of the MX-5 have enough power. Instantly, everyone jumps in with an opinion which is broadly – yes, or no.

Which are both wrong.

I know it’s 2016 now, but most answers need a little nuance and thought and this is no exception. In the case of sportscars and power there are two very important factors to consider before you end up in a stabby-fingered, red-faced debate on your way to Godwin’s Law.

The first factor is what you intend to do with the car. If your intent is public roads, mostly suburban streets then that’s quite different from trackdays at the likes of Sandown Raceway with its long straights. I would suggest that the MX-5 is more than adequately powered for any public road, any motorkhana and any hillclimb event. The only point at which I feel you’d really want more grunt is high-speed race circuits, or if you are large of frame and often need to climb long, steep hills. Yes, this is opinion, but the point is before you say any car is underpowered you must first define the situation in which you feel it lacks power, and then decide if you’re ever likely to be in that situation. One more point here – consider your level of experience too. If a highly skilled track driver says a car is underpowered for a racetrack that’s right for him or her, but if you’ve never driven a racetrack before then my experience is that novices are so far behind the car a lack of power is the last thing on their mind.

The second factor is that the power figure is pointless, it’s about the sensation. My favourite examples here are the Toyota 86 and a supercharged Range Rover.

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Yes, I know it’s in mud, but if it was on dry bitumen that supercharged V8 would see off many a sportscar.

The Rangie is faster to 100km/h, but the 86 feels quicker because it is lower and there is more drama. In the Range Rover you plant your foot, then you notice the scenery seems a bit blurry and the speed needle is pointing to the right. It’s fast but doesn’t feel it. In a sportscar you want fun, a sensation of speed. It’s the racecar where you want speed and everything else be damned, a very different type of vehicle.

Related to this point is power delivery. The likes of the MX-5, Elise and 86 are light and not very powerful. Yet in any gear below fourth above 2500rpm you press the accelerator and the cars accelerate as if poked with a stick, you get a pleasing immediacy between throttle application and car response, and that never gets old. You can feel, and see the car’s nose rise, the rear squat and you’re away (the soft suspension helping the sensation of action). Granted, there may not be much more grunt left once your foot gets all the way to the floor, but for daily driving it’s the initial response to throttle that makes you smile.

In contrast, let’s take the likes of Lexus RC F, WRX auto or Mustang EcoBoost auto. You put your foot down in these cars and there is nothing, then smoothly but surely the revs build and you are away. Each of these will beat the lighter, less powerful cars from 0-100, but it’s a Pyrrhic victory because you’ve not had as much fun in the process, and on public roads you’re far more likely to dart from say 70 to 80 than sprint from 0 to 100.

This really highlights the pointless focus of measurbators on 0-100 times and power/torque figures, it’s like trying to judge a photograph by the rule of thirds alone. By the way, it’s no accident the cars cited above are automatics because in general at the less-premium end of the market the manuals provide sharper response to throttle than the autos. A back-to-back drive of the four Mustang engine/transmission variants or the WRXes will prove the point in short order.

It should be noted that this point about quickness of response to throttle applies more on public roads than racetracks, because on tracks you will be keeping revs high and looking to squeeze the throttle on gently out of corners anyway.

So there’s a fair few words on the power question, and ultimately it is your preference. The only certainty is that you should form your opinion using more than just the car’s specifications.

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MX-5 Technology

The MX-5 is a simple little car. Wisely, Mazda spent all their time on making the car light and focusing on handling, instead of fixing inherent dynamic problems with an array of electronic driving aids.

So the MX-5 has no driving modes, no torque-vectoring, no active differential, no dynamic suspension, the exhaust note is real and there are no steering modes. Where other manufacturers serve a poorly cooked steak then attempt to cover the damage with spices and herbs, Mazda serves up the meat done to mouth-watering perfection.

If you take a wander around your local motorsports events then you will not hear people bragging about torque vectoring – you’ll hear the words “how do I turn that s*** off” because what people want is a pure driving experience, or as they say in Japanese, “MX-5”.

That’s why this section on tech is admirably short. Here’s what the MX-5 has of note:

TCS

Traction Control System. This detects excessive wheelspin and cuts the throttle to reduce torque and wheelspin. It is also capable of detecting when just one wheel is spinning and braking just that wheel, a process which helps drive out of corners or maintain traction on slippery surfaces. We have more on the difference between traction control and stability control here.

DSC

Dynamic Stability Control. This is Mazda’s term for electronic stability control (ESC). This system takes input from a variety of sensors around the car – each wheel speed, steering wheel angle, throttle position, yaw and more – then brakes individual wheels to keep the car going where the driver wants it to.

Both TCS and DSC can be disabled using this switch.

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And then the dash displays this:

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There’s just two modes, on or off, no intermediate sport mode.

AAS

Automatic MX-5s have AAS (Active Adaptive Shift) which is the usual modern adaptive gearbox. The system uses data from all the usual sensors – wheel speed, throttle position, steering wheel and the like – then attempts to pre-select a gear, for example a low gear when punching out of corners. It will also hold gears to assist with engine braking when descending. The system will also learn your driving style and if you drive hard it’ll start to hold gears for longer before changing up, and change down earlier – however, this adaptation is based only on the last few minutes driving, so nobody can teach the car bad habits!

HLA

This is Hill Launch Assist. This system holds the car on a hill using the brakes, giving you enough time to shift your foot from brake to accelerator so you can make a hill start without using the parkbrake.

ESS

Emergency Stop Signal. Illuminates the hazard lights when under heavy braking, cancels them when braking finishes.

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MX-5 on a summer’s evening. That’s how you make memories.

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Robert Pepper

Robert Pepper