There has been discussion/debate on how Jaguar's stillborn 1966 Le Mans Prototype would have acquitted itself against the Mk1 GT40. I added my own take here - Jaguar XJ13 - Building The Legend
Since posting, I have come across a taped interview conducted by Philip Turner (former "Motor" Sports Editor) with David Hobbs. Hobbs, of course, was chosen by Jaguar to test the XJ13 and he was helped in this task by Richard Attwood - both former Jaguar apprentices. The legendary Norman Dewis' role was, in truth, very limited. In Hobbs' own words, Norman Dewis had, " ... always been a little bit piqued that he hadn’t been allowed to drive the car in the first place. Of course he rolled it into a little ball. The one that you see now, of course, is a complete rebuild ..." Bill Heynes had previously approached Jack Brabham in this regard when they realised a "proper" racing driver was needed to help develop their new car but, in the end, Hobbs was recruited by Lofty England. At the time of the tests, David Hobbs was counted amongst the elite of racing drivers.
A transcription follows ....
Hobbs The next time I drove a Jag was some years later … 67. Got a call from Lofty again. Would I like to come to MIRA? About 6 o’clock on Sunday morning. That was the XJ13. The original V12.
Turner Was it a surprise? Did you know about it already?
Hobbs Well I knew about it inasmuch basically they had started it before I left Jaguar in 1962. I mean the thing had been kicking around since then. In fact, when I tested in 1967, I’m not exactly sure of dates and things here, but I got a feeling it had been “under wraps” at that date for about two years.
Turner Kept under a dust-sheet in Experimental. When I went to ….
Hobbs When they finally decided to run it, it had already been built for some time. At least a year or two and they started to build it when I left in 62. And, I think, wotsisname, Norman Dewis wanted to … but they decided that, to test it, they really outta get a racing driver. Although going round MIRA, really, was particularly tame for a racing driver of course. And we went there four or five days actually. And, the lad in charge, of course was Mike Kimberley. And now your actual Managing Director of Lotus. He was just a lad then. Old Mike. Always tapping his teeth with the end of his pencil and saying, “what is it doing going over the bumps? .. would you say it wants more in or more out?”. And it was pretty basic. I mean it had the Dunlop Racing tyres of five years previously and the old Dunlop disc brakes. Pressed steel D-Type wheels. It had E-Type front suspension – rubber-mounted – polybushes - and it had the E-Type rear suspension.
Beautiful-looking thing. And a helluva engine of course cos that was a four-cam. It really gave a lot of horsepower. It gave about 500 … 525?
Turner About 500.
Hobbs Yeah. It gave quite a lot of horsepower. It went extremely fast. We went to MIRA about four or five times. Sir William came once .. Mr Heynes used to watch it. Then they made the decision to drive it at Silverstone so they decided to get two drivers – me and Richard Attwood, another Jaguar apprentice. So off we go to Silverstone and I can’t remember the exact times but I think we did round about a 1:36 – 1:35 – 1:36. The lap record at the time was help by Paul Hawkins in his red GT40 – about 32 or 33. So we weren’t all that far off the pace. If you consider it had these old pads, old wheels, old brakes. The suspension flexed far too much of course. And of course it had no attempt at any sort of spoilers on it. Very sleek. It was incredibly quick of course down the straights.
Richard and I gave a job list of things to do. We wanted wider tyres – we wanted modern wide wheels for a start and modern racing tyres. I think those two alone would have seen us down to the lap record. And another … I seem to remember the bias front to rear brakes was poor. It wanted a lot of, you know, a good tidying up. We reckoned it would have been quick.
They went back to the factory and, at that time, the take-over … and that was the beginning of the decline of Jaguar Cars. Really sad. Along with the whole of Leyland. The whole place just ground down. They had no idea of the innovations – they were all just numbers-men – counters. As far as making cars that people wanted they just didn’t have a clue.
They put it under a dust sheet and it stayed there. Until Norman Dewis took it to MIRA. He’d always been a little bit piqued that he hadn’t been allowed to drive the car in the first place. Of course he rolled it into a little ball. The one that you see now, of course, is a complete rebuild.
But the car, and there’s no doubt about it, but Jaguar were beset with the same problems – mental problems – then, as they have now. They can’t go to Le Mans unless they could guarantee winning and everybody said so. Clearly, you can never guarantee winning the race. The only way you can get close to it is to go! You can test, and test and test until you are black in the face but you really aren’t going to know just how the car is going to perform You are just going to have to go. To win the race you are going to have to go.
But I really think the car would have been an absolute wow. I mean, at Le Mans, the thing would have had it. Because the GT40 in those days was an iron-block Ford that was only giving about 300 brake horsepower. I mean, this thing gave nearly 200 horsepower more than the GT40. There’s no doubt about it, it wouldn’t have been as quick as the Mark 2s, which of course raced in ’67. But it would have been very fast and, just by updating it, cos I’m sure it had been sitting in the shop for a couple of years – just by updating it.
But they had a problem. You’ve got to use Firestone or Goodyear racing tyres for example … Dunlop weren’t making good racing tyres then … for that type of stuff …
Turner You did 160? It’s still the record isn’t it?
Hobbs It is. Yes.
Turner Did it feel incredibly quick?
Hobbs It seemed pretty quick. Smoother.
Turner Acceleration along the straights then braking for the bends? Braking quite hard? Or?
Hobbs Not really, no.
Turner Was it enough to lift off?
Hobbs It was quite quick.
Turner I’ve been around at 120 but not much more and even that felt fairly fast.
Hobbs Yes – very narrow isn’t it? ….
Turner So – what did going down the straights feel like?
Hobbs At the straight at Silverstone I would bet we were doing about 150. And, of course, lap speeds of 1:36 is very quick. I don’t know what it is, 1:36? Have to look at a lap chart. A Group C now does about 1:15 .. so … 36 is quite a lot slower.
I think, the way it went, and the way that lap record stood at the time , I think with some mods and if we sat down and made a racing car I think we would have just about cracked 1:30 – probably high 1:20s …
Turner What was it like aerodynamically?
Hobbs Very fast but no downforce of course. No downforce at all.
Turner Was it lifting at all?
Hobbs Well it probably was but it behaved like a normal racing car of the time. But, there again, the GT40s did have some downforce. They started to have downforce. Well, that was just about the time when people were just starting to tweak downforce. It grew spoilers on the back and stuff like that. The Jaguar was as clean as a whistle. You’d have probably found if you’d put some little Lola-type front spoilers on it and one on the back it would have been absolutely quick around the circuit. To be sure. Malcolm Sayer was the stylist who designed it of course and things like that would have been an anathema to him. The clean bullet-shape was the shape that racing cars were supposed to be and he might have taken a bit of persuading to get any sort of spoiler. Which, in those days, although the word wasn’t applied, was a spoiler…. See the Lola, T70, by then had the big spoiler on the back and a little spoiler on the front…. So I’m sure a little spoiler would have given a big advantage. And they hadn’t even started ...
A serious contender in 1966? What do you reckon? 
