It may be a cliché, but I’ve just had the ‘holiday of a lifetime’. My recent credit card bill confirms this. Still, it provides an excuse for missing a month of blogs. Whilst it has been no hardship to get straight back into VHS business, I was pleased to receive a visit from an old friend and boss from my days at Longbridge (on a 1960 Royal Enfield, so I had ample warning of his arrival). Over a cuppa, we reminisced about many a ‘holiday’ that we had undertaken courtesy of our employers. I’d like to share a seasonal example.
In the days of MG Rover (2000 – 2005), we were given the task of creating a range of MG derivatives from the Rover platforms. Once launched, there was the challenge of improving and updating the cars to maintain their competitiveness. The addition of ESC (electronic stability control) was a key task. The winter test season prior to the launch of MG ZT 260 and Rover 75 V8 saw many of our cars in Sweden at our ESC supplier test track (just south of the Arctic Circle). It was necessary for us to join the final ‘sign off’ test for TRW ABS and ESC on the front wheel drive Rover 75 and ZT.
Sensible people would jump on a plane. We decided to make the journey in a Rover 75 V8 automatic (with cruise control) and an MG ZT 260 manual. As engineers responsible for the development of our cars, why wouldn’t we drive? It would be a great learning opportunity in our quest to develop excellent dynamics. Neither car had any form of traction or stability control (other than a mechanical limited slip differential) but winter tyres were fitted, so what could possibly go wrong?
Actually………nothing. To the disappointment of our colleagues at MG Rover and TRW (evidently there was a sweepstake to guess the time of our expected demise), we just drove from Birmingham to Arvidsjaur and reported for duty unscathed and on schedule. ‘Work’ then commenced on our front wheel drive test cars, assessing the effectiveness, stability and comfort of the safety system interventions. This took place on the various snow, ice and tarmac sections of the test track which is both land and (frozen) lake based. It would obviously have been rude not to try the rear wheel drive cars around such a wonderful facility, which we did at length (worth every hour of unpaid overtime).
I had been asked to check the functionality of the new cruise control system on the Rover 75 V8 auto. Imagine driving at a cruise controlled 70mph on a dual carriageway, then slowing to 20mph for a roundabout. The action of braking would cut out the cruise function. After negotiating the roundabout, the driver selects ‘resume’ and the car accelerates firmly back to 70mph. Great! But what if there is a skid risk? Monitoring of wheel speeds (via the ABS) would detect this and send a signal to cut out the cruise control. Did this function work?
The test was carried out on the long and wide snow-covered handling area of the frozen lake. With the cruise set to 70mph, I slowed to 20mph and then hit ‘resume’. A bellow from the car and it deployed all 410Nm of torque through the rear wheels. The car accelerated, but not in a straight line. Rapid steering wheel application arrested the sideways drift, soon followed by the need for reapplication in the opposite direction. And again. And again. Repeat a few times. Try harder.…. until 70mph was reached. So, the test had shown a system failure (thankfully corrected before cars were sold). Job done? Not quite. The challenge of full acceleration (in a rear wheel drive car on snow) with only a steering wheel to apply control, meant that we both felt obliged to keep testing……
What was happening with the ZT 260 during the Rover 75 auto mayhem? For some reason, our TRW friends (all experts in electronic stability control systems) felt the need to take turns (in a car devoid of said systems) at circulating the snow circles on opposite lock. It came to an abrupt halt late in the day, when enthusiasm overcame talent – nothing that a few cable ties couldn’t fix.
Unfortunately, MG Rover closed before the full ESC system could be launched on Rover 75 and ZT; but not before a song was written and performed about our rear wheel drive cars. However, the learning and development was then applied to MG6 1.8T produced by SAIC, but that (and the song) is another story.
We made it safely back to Longbridge with both cars (plus cable ties). Not a bad holiday after all.