TR action control

Nobody, particularly in the parochial world of the TR Register, gave much thought to the winning potential of the TR7 in V8 guise. A few years back an ex-works rally car showed the flyweight fourand six-cylinder TR men that horsepower (or, more importantly, accessible torque) was present in abundance. “If only I could find a way of getting that down to the ground, sorting out the handling, there’d be a winning car there,” thought double TR champion Mick Richards. The idea occurred to him after an eventful Snetterton confrontation with a TR8 in his faithful, and successful, four-cylinder TR7.

His rivals would curse that day.

Since then, he has racked up a further pair of Cox & Buckles TR Register titles (1991 and 1992). Richards has become unassailable in his originally developed TR7 V8 hardtop. And I do not use the word ‘originally’ lightly. This is the first production-based racing car I have driven without anti roll bars…

To find out just how effective the winning recipe has been, Richards made the ultimate club competitor commitment: he chose a wet and foggy Cadwell Park to let a journalist out in his Triumph. Despite a number of understandable minor tantrums at being deprived of its regular master, the £17,000 TR7 took a comfortable pole position in the wet and a rumbling flag-to-flag win in the dry 10-lapper that comprised the championship finale. None of this would be recorded on the results sheets, as the BRSCC’s official bulletins refused to accept that Richards had handed the car over.

Fortunately we have the video and garland to prove the victory, otherwise we might not have believed it had ever happened. More seriously, it does make you wonder whose relatives would have been informed in the event of an accident?

Proud owner/driver Richards observed of this TR7’s redeveloped suspension, modified in association with regular mechanical partner Geoff Lee: “It has stopped the dreaded bump/droop/under/over/everything steer which makes the standard TR7 so difficult to drive.” Remedial chassis work began with the live rear axle, which was radically modified. Its location links were reversed to run aft of the axle, clasping the top of the halfshaft casings, rather than the standard position ahead of the axle, locating beneath said casing. “The axle also has seven inches of movement to achieve full articulation and maximum traction under droop,” revealed the owner/driver. “It is additionally located by our version of the A-bracket to the lower section of the cliff,” he added, before turning to the front end. The original front anti-roll bar was absent in all but its outer extremities. These are attached to the lower track control arms of the MacPherson struts and serve as auxiliary wishbones. The principle is the same as Ford employed with its ‘compression struts’ on the old rally Escorts, the RS 1600i and first generation Escort RS Turbos. Their chief blessing is to stop the strut arms ‘walking’ under heavy braking.

Richards and Lee believe the other vital aspect of the chassis is to have the roll centres at equal levels above the ground, front and rear. The result was a supremely balanced, and unique, TR7 chassis upon 7Jx13 alloy wheels. With no anti-roll bars, front or rear, this TR7 was still willing to give reassuring support to the gallant Hoosier road pattern tyres for dry use and Michelin PB 20s in the wet. At Cadwell the Michelins proved a vital element in qualifying, always biting through the watery surface and wet leaves that characterise the full ‘Mountain’ circuit in autumnal downpours. By afternoon the circuit had dried to the point where we could remount the Hoosiers, but they performed totally differently to our expectations. The problem was that we had first experienced them on a warm day at Mallory Park, when they were marvellous. The times recorded in Leicestershire were similar to those we used to record in a 500 bhp Sierra RS500 (also on road tyres), averaging around 88 mph for a track that has the tightest of hairpins. In Leicestershire, I was hugely impressed with the Richards Triumph, for it is only rated at 250 bhp at the rear wheels, plus a mountain of torque. To equal the lap times of a car that is a whole decade younger, and with around half the power to boot, struck me as being most impressive. It was also a key reason for my asking to drive the TR7 V8 again.

The 3.9-litre Triumph was constructed around a variety of origins. It started life as a 1979 lhd American export with fuel-injected, four-cylinder power. As a racing V8, it is still fuel-injected, using the ex-Range Rover ‘hot wire’ system. Acquired by Richards three years ago, it required treatment to make the basis of a racing TR7. The rhd conversion was sanitised. An implanted, but rough, Rover aluminium V8 was swapped, with a considerable sum of money, for an ex-TWR crossbolted Group A block. “This has been bored out to 3.9 litres, equipped with Carillo pattern con rods, Omega forged pistons and the Group A wet sump. The camshaft is a Crane 248 and it has solid lifters with adjustable pushrods. The cylinder heads have been extensively modified by Peter Burgess Performance Engineering, with great emphasis put on mid-range torque and smooth power delivery,” explains Mick. This year, whether or not Richards makes his planned move to TVR Tuscans, the team plans to update the aluminium eight. The 248 degree duration camshaft will be associated with a number of valve-train changes to provide power beyond 6000 rpm. “At the moment it dies a death above 6000,” continues Richards.

As things materialised in the race, we rarely used much more than 5500 rpm, and that was enough to provide some exciting moments on the modest 225/4513 Hoosiers. Next season, 6500 rpm and a 20 per cent power bonus are anticipated. To slow this fast Triumph, the regulations do not permit more than a mixed disc and drum brake system. However, the AP four-piston front calipers and mandatory rear drums operated with the matched efficiency of an all-disc system, unobtrusively contributing to the rewarding lap times. At least, they did until I had covered all but the last two laps of the race. Then they began to squeal a bit and pedal travel disconcertingly grew in direct proportion to my speed into one memorable downhill right-hander.

The cockpit was as comfortable and capable as the chassis and V8. The only snag for a stranger was the large number of dials, plus the multitude of warning/recommended running points taped across the dials. Sensibly seated by Ridgard and restrained by Willans harness, the view over the bonnet was limited by the steeply raked screen and yellow top band. Within, the dash was dominated by period TR7 dials. There was the old black and white 140 mph speedo, 7000 rpm counter, voltmeter, fuel contents and other assorted gauges. Most were redundant, as a central selection of racing dials, covering water and oil temperatures plus oil pressure, had been inserted. All spoke happily of our health, save the electrics. Fortunately Geoff Lee noted amidst my early morning whinges about practice without wipers and a self-locking door that electrical charge was not being delivered in sufficient quantities. This meant that I raced with the knowledge that turning on the headlamps was almost certain to finish our day. When Geoff came to load it up onto the trailer at the end of the day, there was not enough spark to click the starter motor, never mind ignite the V8.

A standard rev-counter was also used, complete with additional green stripes to indicate peak torque (4400 rpm) and maximum bhp (5600). “It’s not really worth using much more than six,” added Mick, “but you’ll find the limiter at 6750 rpm in emergencies.” A tiny Mountney wheel circled within centimetres of the cockpit’s cold air venting. Other neat detailing included a beeper to call attention to low oil pressure and the separately controlled interior and engine bay provision of electric fans.

The modestly weighted (2200 lb) Triumph slithered into moderate oversteer via the soft action of a Salisbury limited slip differential, but It was more likely to slide out of line under heavy braking for the leaf-strewn second gear sections of Cadwell than power into a spin. In fact, we met a Spitfire coming the other way out of the slowest corner. I had to accelerate out of the mess (I couldn’t stop quickly enough, breaking all the rules with more power and lock in this emergency) via the inside grass. The Triumph remained co-operative, but it was the only section of the on-board video footage that made Richards pause for thought before we went out for the afternoon race…

Even the rebuilt TR7 (ex-Rover SDI) fivespeed ‘box selected each ratio obediently. Obviously, former Abingdon employee Ken Tomlinson knew what he was doing when he assembled this quintet to racing specification without changing ratios. After two seasons, it was still proving reliable with no shortcomings. It was the best of these SDI boxes that I have encountered, but that’s not saying much. Shifts are notoriously time-consuming and notchy.

Meanwhile, the Rover V8 burbled happily, amiably delivering impressive torque from 2000 revs upwards, culminating in 270 lb/ft by 4400 rpm. It was the accessible power of the engine and obedience of the chassis that made it so easy to drive around the daunting damp swoops and crests of Cadvvell. Practice conditions can be gauged from the fact that we recorded pole position at an average 62.49 mph whilst the best lap in the race (by Peter Cox, in his shimmering TR4) equated to 74.4. Although the opposition was much more heated in the race, our Hoosiers were not. Their performance was extremely forgiving, but nothing could disguise the fact that we should have come armed with the softer compound autocross covers, or the Michelin dry tyres that suited some of the flyweight pursuit.

Flyweight? Certainly. Richards showed us around some of his regular opposition in the paddock, and we could see why our loaned TR7 V8 was unlikely to lead off the grid. According to Mick, the Cox TR4 weighs some 680 kg and has about 180 bhp. And the TR6 of Richard Wright was credited with 850 kg and 200 bhp, ie at least 300 lb lighter with 50 bhp less. In fact, a 2200 rpm start in the Richards machine was enough to get us within a car’s length of the above opposition. V8 power asserted itself as we ascended the first hill. Settling down in an unaccustomed lead, I found that tyre grip was notable by its absence, yet the balanced chassis allowed a lot more liberties than I had been permitted in an RS500 at the same circuit (albeit the shorter version) in 1991. At first the advantage over my start line rivals grew comfortably. Then the alternator started cutting the sparks above 5000 rpm, and the field grew large in my mirrors once more.

Cox and Wright redoubled their efforts in their open TRs, both lapping faster than I did. However, it was too late to prevent the visitor winning after I 8 minutes of racing at an average of 73.55 mph. We had just two seconds in hand by the end. JW

For more details of the Cox & Buckles TR Register Race Championship (in association with Penrite Oil), contact the Competition Chairman. Mike Hughes, Hollybush Cottage, Norbury, Whitchurch, Shropshire SY13 4PW.