Jaguar XJS Racing News update 23rd November 2009

TYRE WARS

Don’t read this as a criticism or a big fat bitch-slap to the face of the new R1R, it’s not. What it is, I hope, is something to get you actually thinking about the changes in the new regulations and not just blindly decide that newer is better without actually reaching that conclusion yourself.

The other thing though is that Kutuka were big fans of the T1R, we loved it. Cheap-ish, fairly durable, we'd made it work for us better than most, we've got reams of data on the thing, we were quite happy, all three of us to a man campaigned to stay on it, I personally begged ol' Terrence not to give us any more grip.

So yes, this is a bit of a look at the change with the mud-coloured spectacles on, but that’s intentional, I’ll withhold any conclusion til I’ve run the tyres in anger. For now though, consider:

We’re about to enter a transition phase for cars using up their T1R supply, and those who will go straight to the new tyre. There are some drivers with massive stocks of the T1R.

The R1R is being looked to with great hope by so many, as any supposed performance part always is, but will it do what everyone hopes?

It’s not a 888. You’re just not going to get that sort of grip, I’m sorry. It’s not a magic solution, you can't just bolt 4 of these on and you’ll be lots faster. You still have to make it work for you.

The saloon boys are looking to them with great enthusiasm, rightly, but then they’re coming from Vredestein, and they’ve been wanting our T1Rs for ages. Whilst a saloon might enjoy a lot more grip moving from Vredestein to R1R, that does not automatically mean that a T1R to R1R change will make anything like the same difference. XJS might not benefit much at all.

So Dave Bye testing R1Rs at Snett finds himself 2 seconds per lap and is looking towards the front of the XJS pack with that sort of pace, but put him on the same T1R and would he be doing the same? I expect so. Lots of grunt in those XJ6s.

Matt Skelton, and even our beloved Ray Ingham, report no actual outright grip improvement over the T1R, but greater longevity and consistency. Ie they’re not actually any faster than the T1R. Skeletor has indeed tested them. Strangely Dangerous Brian has a set, but he’s towing a caravan on his so we’ll ignore that data.

You may find an improvement over the T1R if you’re not using the T1R properly already. Certainly at Camp Kutuka we don’t suffer from rocketing tyre pressures, we can happily scream round for 15 minutes and know we’re going to be pretty much bang on target pressure, we’ve done a lot of testing to get this way, so consistency for us will probably not change. It might if you’ve not paid much attention to pressures so far.

What about better grip for those who don’t always find it with the T1R? Well, this seems to be the big hope, that the midfield runners will find more traction more easily and pick up the pace. But if there’s no outright grip change then those skating on the limits already are still going to be the ones who skate around the new limit too. If that limit is no better then their performance will stay where they are and the pursuing pack will get closer... just before they fall over the edge of that limit and run out of road because they were closer to the limit than they realised.

If the limit has moved then presumably those finding it now will find it there too, and move further away, preserving status quo. Not the band.

What of the wet weather performance? The big deal with the T1R is that it’s a great wet tyre, and it is. The only test we’ve had putting R1R v T1R in the wet was the Birkett.

Clearly that day the 888 was easily the tyre to be on, fastest in all conditions, we don’t know why it made the others look so stupid in the rain, but it did. Chris Boon’s 888s were shot before he started so we can ignore that aberration.

T1R v R1R then. In the 1^st half of the race the T1R was actually faster. If we pit Dave Bye’s saloon against my XJS on the same tyres, he would be faster. No question about it, those front running saloons have more poke than a class D XJS. In the wet the same should apply, probably more so, they’re softer cars with a more user-friendly wheelbase.

So Bye v Harrison/Woods in the rain at Silverstone, in the same sort of conditions, how does he fare? From our stopwatches 2-3 seconds slower. He has R1Rs, we had T1Rs. Which to me says no, the R1R is not the wet weather hero everyone thinks.

So are you going to need an unscrubbed set of T1Rs anyway?

Admittedly the track that day was very peculiar, hence the 888 grip proving superior in what should be road tyre conditions, so it could be a flawed result, and we don't know to what degree Dave was driving within himself, he's a respected driver not about to bin it and cost the team the race.

So what about longevity? Kutuka’s 2 6-pot cars have been remarkably kind to their tyres this year. Despite doing full test days at every circuit it was still Cadwell Park before we felt the need to use a 2^nd set of tyres, only because we wanted fresh rubber.

Even then those that came off were still viable, we put them back on again for Snetterton, and they’ll go further yet, the red car has had the equivalent of a full season plus every test day, out of one set of tyres.

To do better than that the R1R is going to have to last a full season, wet and dry alike. And then some, because of the cost. They’re the same cost as 888s. A full set is going to set you back £600 per car.

Current cost of the T1R, even once scrubbed, is about 65-70% of that, particularly now that the tyre has entered the mainstream and you can now shop around for them.

Unless therefore there is a performance advantage in the dry, why change tyre? Only once we run the R1R in anger will be discover if it is in fact any faster. The problem is once you’ve bought them you’ve got them, and if you don’t find them any better that was a lot of cash. We can only hope reports to date are wrong and when given serious grief at the hands of a Bear or a Lyddall they prove to be something else.

Once you’ve put a few hot laps on the R1R and the edges are looking a bit softer, it might be rich guy with the new set to put on in the rain, with nice square edges, who’ll scamper off. Have two sets of R1Rs? £1200? That’s the tyre budget for all of Kutuka this season.

Don’t get me wrong, this isn’t a rallying call to ignore the new tyre, we like new things to try and we’ll be giving it its fair crack, but we're not blindly just accepting what we’re told and believe it, you need your eyes open and trust what you actually see. It’s so easy to be told to bolt part X on to go faster and believe you are doing, the placebo effect is powerful when it’s stroking your ego in a race car, but check your lap times and that tingle through the seat, and make your own mind up.

Rest assured, gentle listener, we’ll be laying our hands on a set of R1Rs as soon as they hit general release and heading off for a back-to-back 2-car T1R v R1R test at Cadwell early in the new year. If you’re nice we’ll tell you what we found…