TUNING TOPICS

Tyre Conversions
J. W. samples the latest transatlantic tyres

NOW 112 years old and distinguished amongst tyre companies by not contesting the original equipment (0E) car manufacturers’ market and by staying firmly in profit through the cut-throat recessionary tyre marketing period of recent years, B. F. Goodrich at Akron, Ohio, are aggressively involved in offering a new generation of rubber designed to be “unsurpassed in performance”.

Marketed under the name Comp T/A and distributed in Britain through centres in Glasgow (Birkenshaw), Sydenham, South London (South Global Tyre Marketing) and Warley, West Midlands (S&S), these new 50 and 55 per cent ultra low profile radials are aimed straight at the Pirelli P7 tyre of Porsche repute. A check through the trade advertisements shows some dealers are offering the popular Porsche 225 / 50VR 16 Comp T/A for under £140 while charging £173.50 for the equivalent Pirelli P7, although the American company generally expect to be priced exactly at P7 levels, or with a slight premium.

The T/A was designed with constant reference to the P7 and is claimed by the makers to offer superior dry and wet weather grip — which one can scientifically test — and superior ease of driving at or over the 0.8G average cornering limit that most enthusiasts reach in their everyday road driving (a Grand Prix 1982 car would typically reach 3G). In the latter case, where the car is sliding, it can only be a subjective matter as to how easy it is to control owing to driver ability and surface changes.

BF Goodrich hired the Paul Ricard Circuit in Southern France and six Porsches from Messrs Hertz. et Freres and proceeded to let us try and prove their point for them with P7 and T/A compared back-to-back on 911SC (Lane Change test); 928s automatic (Slalom) and some Porsche 944 laps of the 3.263 km. Petit Circuit, which retains an 800 m. straight with the very quick right, Courbe de Signes at the end. We also had some standing water sprayed onto the track for the 928s to tackle at 65 m.p.h. or so on a mild corner tackled as a left and a right (the romantically named 9b of the Grand Circuit).

The test results were not measured by watches or any other paraphernalia, but on both the Slalom, the Lane Change and the slower circuit corners, plus the wet test and in overall wear, the Comp TA was demonstrably superior. It seems particularly good through standing water and in becoming only slightly scuffed when the Italian tyre is feathering itself rapidly into expensive baldness.

While exit speeds from the 60 m.p.h, coned-off tests were up to 5 m.p.h. better with the Goodrich, a remark applying also to the slow corner onto the main straight of the circuit, the subjective side of the argument went clearly to Pirelli in my book. More people spun off using the Goodrich and more of my colleagues commented favourably on the informative breakaway characteristics of the Pirelli. So — as ever in my experience — there is a penalty for providing a tyre with high adhesion and good wear character. That penalty tends to be a more sudden deviation from one’s chosen path when the higher limit is reached.

BF Goodrich have done a remarkable job in developing a tyre to challenge the best in Europe and have backed that up with some remarkable race and rally performances (16th overall at 1982 Le Mans) with what I believe to have been production tyres, but they still have more work to do in providing a cover that will forgive the errant driver who suddenly finds that he has been over-optimistic. In road terms it’s very unlikely that you will reach the capable limit of these tyres, but I am told that you may have to accept some ride limitations compared with European rivals.

At present, the BFG Comp T/As are sold in seven sizes from 195/50 VR 15 to 265/50 VR 15 on 15″ diameter wheels, or the choice of 205/55 VR or 225/50 VR on 16″ diameter wheels. Alternative sizes and 60 profiles will be available in the New Year. —J.W.