With the diff replaced it’s back to Mallory for a further test, with mixed results. Immediately out of the pitlane into Gerrards for the first time, and it’s up through the gears and flat in 4^th round Gerrards, already better.

A lap to get my eye in, and by the time Mr David gets his stopwatch out we’re 2 seconds per lap faster than on race day, mid 56s, good enough for p2, and this on a track that the Bear was claiming had less grip than race day. Damn. Definitely a case of the whatifs and ifonlys.

I’ll admit I was pushing very hard, and it’s possible I could have taken two seconds off my race time with a sack barrow, but the car was clearly better. Gerrards was pulling the car out wide, but evenly, no wavering tail, no sliding front, nicely balanced, the wide line with too much speed on was sheer G force, not a handling issue. I would love to know what difference that 70kg penalty has made.

Towards the end of the first session though, the oversteer is creeping back in. I’m playing with a Tiger, dodging the FIA Ford GT, occasionally hassling the Bear as he plays with his own setup issues, in fact I’m very slowly closing in on him over a 5-lap run at the end, but the tail starts to get more lairy both at Gerrards and the hairpin. Now I know it was a progressively-worse problem on race day, difficult quali became hard race became lethal race, the issue was time-on-tarmac related, and this has just started to go the same way. A puff of dust at the essess marks me running in deep, good and sideways with the car over the limit. Time to calm myself.

I wonder, briefly, if this is brake-related, the pads were awfully low at race end, they would have been very hot, but I can’t work out how that translates to oversteer, unless maybe massive heat soak is over-pressuring the rear tyre? I have got strange wear on the nearside rear, the centre is bald which high pressure would indeed cause.

But I’ve changed pads, we’re on new stuff, and they should be bedded in by now. Curious. Pace is still decent, but it’s getting tricky.

Pressure read OK, so it’s not a temperature issue. A check round the car finds nothing leaking or exploding or on fire.

30 minutes of rest and go again, and it’s still a difficult car. Still in the 56s, but it’s getting worse, and the brake pedal is starting to feel a bit odd, going into Gerrards and the pedal seems rock solid and not working, as if the servo has quit, but then fine again. Reasoning that temperature is the issue, because I’ve pads that might still be bedding in, and that oversteer is back, I cruise for two laps, let it cool, and wait for the Bear.

Chasing him once through, and those brakes are still a bit off. Steaming into the hairpin and braking early, the pedal goes halfway to the floor, and my eyes the diameter of saucers. 110mph when you hit the brakes, it’s a hint over 5000rpm in 4^th and your pedal goes halfway and stays there, the car is barely retarding, and there’s that green green grass ahead of you and that concrete. It gets your attention. Fortunately, with time to think and react, there is a degree of twirling and stirring in the twirling and stirring centre, and amidst much tyre squeal we do actually slow down enough to get round. Admittedly we do almost make it out of the exit gate in the process, but as miss is as good as a mile.

Time to go in and find the real issue here, that wasn’t temperature or pads bedding in!

On the jacks, wheels off, and there is a spot of fluid on the tarmac. Given the cage has been out, it’ll be the flexi-to-cage join, so nip that up further, and a random helper leans on the pedal to check it for me. The long jet of fluid that blast out of the braided hose to the offside calliper tells me that it wasn’t my dodgy spannering, we’ve a damaged brake line. That’s game over, we have no spares with us.

A look round as I lie there in my puddle of disappointment, and there is fluid everywhere, but is that all brake fluid or diff oil? It’s been flung off the prop so it does travel a long way. It’s now 30 min since we came in, and wiping a filthy finger on the diff to ascertain the origins of this noisome liquid it is apparent that the diff is running at engine temperature, it’s as hot as if I were leaning on the cylinder head. That ain’t right. A fast phone call to the Power4Peanutter, and an explanation for worsening oversteer is immediately provided.

That’s definitely game over for the day. At least we now know that a sorted diff does provide the rear grip I crave, and that traction is relative to temperature gives me my answer. So far as testing goes, that’s all I really ever ask.

Home, and with another diff to swap it’s all rather familiar now, the only difference being that with a truly messed up back it does get a bit more difficult. With the old diff removed the oil is drained. It was new before that test. A speaker magnet dropped in it comes out covered in tiny pieces of metal. That’s clearly not wearing properly at all. The lesson to learn here then is that when the McGiverns tell you your diff is tired, they are right.

Finding another diff is a bit of an issue. Angelina’s is the dead one I just removed, that’s had it. The one I yanked after Mallory is also in trouble. The only one left is to borrow Megan’s, the one Bear ran the last two seasons, only spare now because he has Project X’s subframe in the car.

Using only telekinesis does make the job more tricky, but by eating Nurofen like smarties it is rapidly replaced, reassembled, and posted back under the car. It does cross my mind that there are very few on our grid that do all their own spannering. It’s a bit odd, I suppose, that we do.

Hopefully this diff is sound. Bear reported no issues regarding rear grip, so we assume it’s fine. If anything he has always complained of understeer.

Rear camber is set, oddly with no shims at all I only get two degrees, but then I do still have the remnants of my old inboard discs in there.

A cursory check of the front end and that shows markedly increased camber, she appears to have gained a degree since I last played back in April. That’s a little concerning. Front end is however spot on, and I think the explanation for this is pretty simple. The cure is expensive, so we’ll pretend it’s not happening.

Back together, three days to spare. New rear lines, both sides, just to be sure. Bled and fed and ready to roll. A hunt for the elusive power steering leak, without any joy, and finally addressing why my brake light is almost constantly on these days, just a tweak to the switch position to remedy it. Hopefully that will inform my pursuers in future that I really am braking and avoid any more paint transfer.

Ready to go. Silverstone is not exactly my favourite track. It’s a bit tedious. Not as bad as Mallory, but there are 4 corners, only one of them with any real speed on, I have two places on the whole track to try and remedy my power deficiency, Copse and the entry to the complex. Copse is undone again within 400 yards, showed that in the wet last year against Merrett, alongside so many times on the exit and watching him blow back past. Extra speed in the left hander is helpful, but there is no time to capitalise on it, because you’re straight into that eternal right, which I’m guessing is going to cost about a fiver per lap in tyre wear.

Testing then is to be on old rubber. I may have to revert to T1Rs, because the tyre bill so far this year is ludicrous.

The four 50 profile tyres lasted no time at all. By Anglesey race 2 – and this is without any testing of note, and one race having been wet, three of them were scrap, too tall, rolling the shoulder and ripped apart. A phenomenon we noted on the only other car we’ve spotted on the tall tyre, that of Matt Jefferys.

The transition to 45 profiles eliminated that at the front, the rears run at Oulton were the last of my initial 5 50 profile tyres, and they were both bald at race end. Not shredded, but simply slick, worn out proper and legit. That’s 5 dead tyres in 5 races. Again, very few test miles, under half what I would usually do.

45s all round for Mallory then, and there was a test morning here, but by race end, one more dead tyre. The diff hadn’t helped it, but that’s still another expensive meeting. Two more ordered brings me to 11 for the year after 7 races. I’m not having any more though, this is it. If they wear out, they wear out, and I revert to T1Rs, I just can’t keep spending like this. £1200 of tyres just after half distance, on vastly reduced mileage. That same cost would do me over two years on T1Rs, testing everywhere all day, and throwing in the odd track day as well. The value for money just isn’t here and it’s pricing me out of the game.

Running a class D car has become very expensive. The strain on the car is higher, throughout, everything that used to work properly no longer does. The Bear in his E machine has lower running costs, tyre wear is less, brake pads cost less, there are few bushes etc to wear out, it’s actually far cheaper to run the faster car! Bear’s brakes are bigger, better, and cost half as much to equip with pads, last better and don’t fade. I pay twice as much for inferior equipment that is on the verge of killing me.

But I swear, if one more person suggests that I slow down to preserve the car I swear I’m going to put their head on a spike. We came racing, the idea is to find the limit, the only issue is how much it costs to get there. The limit is now further than it was, and getting to it is putting a lot of stress onto every other component. The brakes are dangerous, the tyre wear is extreme, and there are breakages that should never be. I’m quite content to say that class D should not be on this rubber, at this weight.