Handling Modification is Changing Forever

We've seen it before in the aftermarket modification industry, but this one's crept up on us without anyone noticing. To draw the parallel, it's best to look back a few years.

Remember when exhaust shops selling made-to-order big pipes were so prevalent? Where I lived as a kid there used to be half a dozen within just a few kilometres, bolting extractors and "big-bore" twin 2-inch systems on the locally-produced V8s. It was a given: if you wanted more performance, you dropped around the local exhaust 'shop and let them do their stuff.

A better note and more power.

But then things started to change. With the advent of engine management - especially MAP-sensed management - people started to find that in some cases, the exhaust might have made more noise, but the extra power wasn't there. I well remember a major Adelaide manufacturer of mufflers and extractors buying a chassis dyno - they wanted to prove what the power gain was on each and every car for which they made products. Trouble was, of course, sometimes power stayed the same - or went backwards.

A few years later I was talking to the man who'd been the R&D chief of that company. He'd since left and set up his own firm making exhausts - but he'd dropped the dyno testing.

"We've moved right away from that," he said airily.

In the decade since, the number of companies selling integrated power-up packages - exhaust, intake and engine management - has skyrocketed. And for good reason. A complete package of mods has a vastly better chance of working on current-day cars.

So the fundamental story with exhausts is that the technology of cars altered sufficiently that these aftermarket additions could no longer be guaranteed to work. In many cases, of course, a new exhaust will give a power gain. But in other cases it won't. And in probably the majority of cases, the gains can be far better optimised if engine management is also tweaked to better suit the altered breathing.

No surprises in any of that to regular AutoSpeed readers.

But now the same scenario is inevitably creeping up on another area of car modification. And what's that? Electronic Stability Control and aftermarket suspension modifications.

Ahhh, stability control. It's what I - and also Bosch, incidentally - regard as one of the most significant dynamics in car handling ever invented. For the tech detail have a good look at this story ["Electronic Handling"] but in short, it's a system that has the ability to detect when the car is yawing at an angle different to the one where the steering input would normally take the car. In other words, it can detect understeer and oversteer. When it does so, the system can brake individual wheels, causing the car to pivot back on course.

There's another technological parallel here. Anti-Lock Braking (ABS) was once greeted by some driving enthusiasts as a kill-joy.

"I can always outbrake ABS," they then said. "When I get an ABS car, I'll always have the fuse pulled out..."

That was being widely said 5-7 years ago - now the very same people are writing heartfelt posts to web discussion groups about how ABS just saved their life.

"Thank God for the ABS on my car," they say. "That bloke, he just pulled right out in front of me..."

In exactly the same way, Stability Control is yet to be recognised by the vast majority of enthusiast (and aftermarket companies) as something vital, something that's desirable - and something that's here to stay.

Recently I was at Whiteline Suspension in Sydney, driving of a couple of Whiteline-modified cars - a current Impreza WRX and a Mini Cooper S. The Cooper S has extremely good (optional) Stability Control - as in all cars with the system, integrated with traction control. I'd been asking Whiteline's head, Jim Gurief, about the philosophy that Whiteline adopted when working on Stability Control cars - surely, the development process must be different to other cars.

"Nah, you just switch it off," Jim said.

To say I was startled was an understatement. That's akin to developing big brake packages - and disabling the ABS during the development. But perhaps I was misinterpreting what he was saying?

The first drive was of the Whiteline-modified Impreza WRX. It was very good; perhaps a little skatey on the standard rubber but with excellent damping and possessing the ability to have either end throttle-steered. I have a high opinion of Whiteline's suspension prowess, so its proficiency didn't unduly surprise me.

And then I jumped into the Whiteline-modified Cooper S. We've had one of these cars on test before (in standard form as a press test car, that is), and I well-remembered the handling. The car normally sits very flat and has typical torquey front-wheel drive handling behaviour, well controlled by the Stability Control.

When we'd had the Cooper S on press test, we'd given it to Craig Dean for a drive - Craig's done extremely well at the Targa Tassie bitumen rally, coming second in one event and being placed highly in others. It was also the first car that he'd driven with Stability Control, and when he'd tried the car both with it switched on and switched off, he was vastly impressed with how well the car handled... with the system on.

And the Whiteline Cooper S? It had lowered, stiffened suspension and new sway bars front and rear - and was yet to get new dampers. And with the stability control switched on, it was awful.

Just awful.

Way worse than the standard car.

The Whiteline Cooper S had quite a lot of throttle-lift oversteer, and with the back-end coming around and opposite lock flicked on, the car shuddered and groaned as it almost ground to a halt in the middle of the road. The Stability Control system thought we were about to die - and took appropriate action.

And with the Stability Control switched off? I still thought that the car was terrible. It picked up an inside front wheel and spun it furiously into smoke whenever the hammer was down in the first couple of gears, and the amount of power understeer was dreadful - it felt like a very powerful, very stiffly suspended front-wheel drive car without much grip.

Now it's important to note that Whiteline is aware that this development car has problems, and have yet to finish their sorting. New dampers, for example, are on the way.

But for me it was a crystal-clear example of the fact that modifying just the suspension is fast going the way of the standalone bolt-on exhaust. Without also modifying the stability control, there's simply no way that an optimal outcome will be achieved.

I'd been thinking a great deal along these lines when the time came for me to attend a Holden Special Vehicles new model launch. I have written about this event in another story ["The Spin Circuit"] but suffice to say, none of the HSV cars have stability control. (Incredible, when some cars one-third the price are so-equipped as standard).

Anyway, Manager of Engineering, John Clark, was driving me around the handling track (which is pretty much like an average country road, even to the extent of having a centre white line) and demonstrating to me how good the HSV Grange is when you are ham-fisted. He went into a left-hand corner, yanked on some lock, and let the car plough understeer across to the wrong side of the 'road'.

"See," he said. "It doesn't do anything bad at all."

"Yes," I said. "And right now there's a truck bearing down on us - we're about to have a head-on."

I paused and then went on.

"And if this car had stability control we'd still be on the correct side of the road."

He gave me a totally blank look. You could almost see him thinking: "Huh? What's Stability Control got to do with proper handling?"

But you see there's absolutely nothing to stop Stability Control being set up for sporty drivers. The amount of yaw that the car is undergoing before the system activates is built into the software - it's a judgement made by the engineers when they're calibrating the system. And just as some Stability Control cars allow quite a lot of sliding to occur before the system starts to work, and other cars allow almost no slides, so a standard system can be modified to cope with the requirements of more sporting drivers... or suspension modifications.

And how can a Stability Control system be modified? In the aftermarket there already exists interceptors - the Xede, Unichip - which could easily be turned to this function. After all, the yaw sensor and steering angle sensors have outputs just as any engine management sensor has - and can be intercepted and altered in the same way.

Finally, don't think for one moment that this isn't relevant to you. How many cars today are sold without ABS? Hard to count them, isn't it? Well, in five years' time - or perhaps even less - every new car that today has ABS will have Stability Control as well. Think of today's Honda Euro Accord base model - it costs just AUD$34,250 and has Stability Control as standard.

And it also happens to be a car where the Stability Control has been superbly calibrated for sporting drivers....

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