ADA/Janspeed TR8 Turbo
Unfortunately we did not drive one of the works 3 1/2-litre rallying Triumph V8s. Instant ‘classics’ by most standards, but the writer did spend a fair amount of time travelling sideways with various intrepid pilotes of the four and eight cylinder TRs. Enough time to know that, when ADA Engineering’s Ian Harrower rang up with his offer of a trial run in the twin turbocharged Janspeed TR8, it was an offer that really could not be refused.
There were rnisgivings. Over the years there have been many amateur British attempts to get to Le Mans that have failed rather ingloriously. So the TR was approached with some caution. After all, it failed to qualify in 1980 at Le Mans. Yet there was the sheer enthusiasm of TR Register members. They had literally held a whip-round to make the French foray possible. No big money sponsors or smooth talking PRs here.
Despite pouring rain and a recalcitrant BMW, the writer arrived at Goodwood punctually to see the now BRG TR being warmed up. It was an impressive sight, the predominantly glassfibre panels shaking as the 3.6-litre turbo V8 ran rapidly and savagely to full warmth. I recollected this TR’s first appearance, then in patriotic red, white and blue, at a 1978 winter London Show at Alexandra Palace.
It was conceived, and is still owned, by Janos Odor at Janspeed to put a 600 b.h.p. Triumph amongst the Porsches at Le Mans. There simply has never been the money behind the project to realise that dream.
Jan tells us that the 3,653 c.c. engine (90 mm. bore by 71 mm. stroke) which we drove is actually the second similar motor he constructed. He commented, “unfortunately we never really made it the way I wanted to. The Cosworth forged pistons and that stroke meant a car of 8.3:1 — rather higher than I liked — and the SU carburetters are sucking in air, rather than pressurised. I would have preferred to run a Hillborn injection system if we had had the time and money. Power? Being honest, calculations at just over 1 bar maximum boost from the two high-flow Rotomasters indicate it should certainly have over 400 b.h.p. That’s using an lskenderian camshaft.”
Bottom end of the engine is special utilising an aluminium alloy dry sump pan that also takes on crankshaft bearing duties. The car was originally designed to operate both water and refrigerated intercooler systems, but only the conventional water-cooled layout was in operation.
Of the rest of the car credit goes either to Janspeed during the original show build or the infectiously enthusiastic Chris Crawford of the ADA, Shepherd’s Bush, concern. All have put their heart and soul into providing a decent chassis with practical aerodynamics and accessibilty for a 24 hour race.
The transmission caused a few headaches in trying to find a gearbox strong enough to cope. Thoughts of a Jaguar unit faded in favour of the “rock-crusher” Muncie T10 with four forward ratios. There is a triple plate clutch which is all too easy to fry with the high first gear and 2.77:1 final drive ratio. The LSD is exactly that of a 1962 E-type!
Suspension is still basically strut and live axle, but sophisticated in that March formula car hubs are fitted front and rear. The rear axle is located by four links, plus Panhard Rod, and the strut has a fabricated lower wishbone.
A massive 1 inch diameter anti-roll bar gave little wet weather feel for our trial, especially as the 450 lb front spring rates and 400 lb rears mask the surprising comfort Bilstein gas dampers can give, even in competition guise.
All-up weight is some 1200 kg. That removable bodywork is a combination of Janspeed and ADA conception, including the neat running boards which carry oil coolers on the passenger side. The 15 ins. diameter Compomotive wheels carry 10 ins. wide front or 14 ins. rear tyres. In fact the tyres were marked up as 16 in. diameter at the front, but we’ll ignore that Dunlop casing. It could not be true. . . could it?. . . Larger wheels on the front? Yes it could be true, but it was it intentional!
Brakes are simply massive Girling four piston units with servo assistance (really, and it works) for the 12 in. diameter front and 10 in. diameter rear discs. The all-ventilated disc system was an outstanding feature of the car.
Inside there are simply too many dials and switches to describe on this page, and a lot more than I would want to absorb while racing. Most importantly the car has a superb sit-up and beg driving position with the wheel comparatively close to the driver, and a very legible Jones tachometer, which we were instructed to leave below 7,000 r.p.m.
Our departure from the pits was extremely and deliberately spectacular. No lag could be afforded in releasing the clutch, and no way would the engine run under 3,000 r.p.m. So when the clutch was released I departed with the tail slithering in one direction and the steering full of corrective lock as the nose headed to complete our pit lane blockage.
Though the car sounds fearsome, and is hard to keep revving cleanly, the chassis and fine driving position allow one to feel at home pretty quickly, albeit at a very slow lap speed. There was a giant throttle pedal, and I did not tire of mashing that floorwards whenever the car seemed to be straight (rare). Then it would thunder straight to 6,000 r.p.m. in the first three gears, very quickly. At this point a kind of pressure cooker set of relief valves atop the carburation plenum chamber started chundering away, dumping vapourised mixture to a refrain rather like that of knocking-off time in a factory!
The engine ran sweetly at 70/80 degrees throughout a test that featured many more miles in second and third than we have ever covered at Goodwood. The gearing was very vintage Bentley in feel, so that you could almost count the cylinders chuffing away in a top obviously designed for Mulsanne. The highest reading I had in top was a mere 5,500 r.p.m., but I would not even guess at speed in such unfamiliar circumstances.
The test came to an abrupt halt when a front wheel bearing race collapsed, leaving little braking on that wheel and a good deal of wobble generally. I had enjoyed myself and hoped that ADA’s incredible persistence would be rewarded with something more worthwhile than bump-starting our BMW afterwards! Thanks anyway. . . – J.W.