I've now had a chance to look at the datalogs from Snett. I still need
to go through in a bit more detail, particularly to analyse the spin at the Essex where I nearly took out Dr. Bob, and to see which wheel was producing the tyre smoke during my first lap lunge at the
Esses in the non-championship race. I'm pretty sure it was the left-hand front, but I'd like to check. One thing which was rather pleasing was the data from the championship race, which showed a fastest theoretical lap-time of 1:17.74. The lap file (courtesy of Tim) which I use for Snetterton has 7 sectors, and the theoretical lap-time simply picks the best of each of the sectors, and adds those times together. Of course it's possible that there's a trade-off between one sector and the next, although the sector markers are deliberately placed on the straights to try and prevent that. Nonetheless, I suspect that the sectors can't be treated as being independent of each other as there is a slight correlation between a good time through sector 2 (Sears corner) and sector 3 (the Revett straight), suggesting that there's a trade-off between a quick time through Sears and entry speed onto the straight. It's not clear that this is necessarily the case, though, so at present I'm assuming that the theoretical lap-time is indeed a realistic estimate of the best time theoretically possible given the car/driver combination at that time. My best actual lap was a 1:19.32, so on one level it shows that I'm not putting a good lap together, but it also shows that both I and the car have the potential to go significantly faster if I can start stringing those fast sectors together and doing so on a regular basis. Easier said than done, but encouraging nonetheless. |
I've never driven at Oulton Park before - indeed, I'd only ever been
there once, years and years ago to watch a BTCC race. So booking some testing seemed like a good idea. The timetable
for Oulton Park featured one practice/quali session in the morning, together with two races in the afternoon, so
despite Robin from the 750 Motor Club offering a very good deal on entering the Allcomers race, I decided not to
on the basis that 5 sessions in a day would be a bit too much and that I'd spend Friday testing instead. In fact,
it turned that this wasn't really the best choice. Due to the fact that I had the Chambers summer party the evening before, I thought it was unlikely that I'd be able to get there for the first morning session, given that according to my sat-nav it would take 3.5 hours to get to Oulton from the Sheds. I'd planned ahead and loaded up the car onto the trailer and left it at the Sheds on Wednesday night, when it had been raining hard and I'd got soaked in the process. On Friday it was also raining hard and so I got soaked hooking up the trailer before setting off. However, the need for urgency had diminished somewhat due to the fact that I'd agreed to sell Austen the two morning sessions. This is something that I and lots of other people have regularly done, including at other circuits owned and run by Motorsport Vision, who own Oulton Park. However, the jobsworths at Oulton wouldn't let Austen sign on without speaking to me first and were saying that they'd charge a further £75 for a 'second driver', something they certainly don't do at Brands or Snett. A clue to the lack of customer service skills possessed by the customer-facing representatives at Oulton Park might be the fact that the girl who was in charge of registering my presence at the circuit took 10 minutes to find my name on a list of names on one side of A4. 5 minutes of that time was spent with her continuing to gaze in bovine astonishment at the single A4 sheet of paper after I'd pointed out that my name was next to the number '3'. The numbers in question being in numerical order from 1 to 26. So that was the first two sessions wasted. The third of the four sessions was also wasted as I didn't get there in time. Instead of 3.5 hours the journey took nearly 6. There were various reasons for this including one combine harvester, two tractors, and level crossing at which I sat stationary for 15 minutes, but mostly because it was raining. This meant that a certain proportion of the drivers on the M6, invariably in Korean or Japanese hatchbacks, decided that the safest and most appropriate course of action was to proceed along the middle lane of the M6 at a steady 40mph, oblivious to the chaos behind them, no doubt appreciating the nice empty motorway ahead of them, and no doubt smugly self-satisfied about their safe driving. It turns out that I didn't miss much, however, as the third session was red-flagged at an early stage and I think they only got a couple of laps in. |
Having finally battled past idiot motorway drivers and bewildered circuit
staff, I could finally go out on track and use the final test session of the day. Given the fact that it was pouring
with rain I put the wet tyres on the car, but didn't make any other adjustments to take account of the weather.
The rain actually backed off slightly for the test session, but it was still streaming wet on the circuit. The
picture demonstrates this rather well - the car's still matte black, but it's covered comprehensively with water.
And that was after it had started to dry out while sitting under the gazebo with its engine running before we went
out on track. Although I'd never driven Oulton Park before, I had a good idea of which way the track went as I've been busy over the last few weeks doing lap after lap of a virtual Oulton Park on rFactor. Although I know some people mock the benefits of learning a circuit by 'playing video games', I find it's fantastically useful. After all, there's only so much time I get to go testing. If through using games like rFactor I can spend all of it working out how hard I can push the car and fine-tuning my lines, rather than learning the track layout, then I think that's time well spent. As it was, I knew exactly where the track was going at each corner. That's particularly useful at Oulton - some of the time you're accelerating flat out over a blind brow, which isn't something you'd want to do without being pretty damn sure of what lies on the other side... In fact, on this occasion I think the rFactor gaming was more useful than the single test session I managed to do. The track was so wet, the car was sliding all over the place. Apart from confirming that the rFactor track model was remarkably realistic, the test session didn't really serve any useful purpose other than providing me with a bit more practice of driving in the wet. I haven't looked at the lap times, although I did note as I was trundling round that James Fowley's car was always at roughly the same point on the back straight as I exited the first corner, so I reckon I was going at about the same speed as him! |
For the first race, I lined up on the grid beside James Fowley and behind Adrian. I got a decent start, and got alongside Adrian, although James got an absolutely blinding start and got past both of us. Adrian and I went round the first corner (Old Hall) side-by-side, and the second (Denton's) here's us heading into the third corner, Cascades, still side-by-side. Although the Genesis doesn't look that much bigger in the photos, it's awfully big when you're racing alongside one. At times I was very much aware of a huge wall of bright Scooby blue on my right hand side! Naturally, Adrian was hard but fair - there was just enough room for a wee black Fury at the apex of Cascades. |
It was not to turn out that way. I made a few mistakes which allowed
Mark to close the gap between us significantly - I ran wide on the entry to Cascades, and then locked up going
into the chicane at Knickerbrook, missing the apex by a county mile. Then on the next lap there were slippery track
flags on the entry to Island Bend and, once again deciding that discretion was the better part of valour, I lifted
and trundled round at quite a sedate pace. There were yellow flags out, as Judi's car was up against the barriers
on the inside of the Shell Oils hairpin - it turned out she'd had a coolant leak and had skidded off on the coolant
her car had dumped. But while I had lifted slightly for the flag, Mark hadn't and going into the Shell Oils hairpin and into the Britten's chicane he was right behind me. This meant I had to take a defensive line going into Knickerbrook, but it didn't make any difference. I still don't really trust the Fury's brakes - while they're not as bad as they were at Brands, they're still not quite right and don't really inspire confidence. Mark was able to leave his braking later than me, and simply drive round the outside on the entry to the first part of the chicane. Judi having going off, that left me in last place, and so it stayed until the end of the race. I was able to get back on terms with Mark, and was much faster through Island Bend and had a go up the inside of the hairpin on a couple of occasions. But I couldn't/wouldn't brake late and hard enough to make the pass stick, and so last place it remained. 13th out of 13 finishers, and 16 starters. My fastest lap in the race had been just under 2 minutes - a 1:59:91 - which was nearly two seconds slower than Adrian's fastest lap. Tim hadn't set a time as he'd had a problem with his car on the out lap, which turned out to be nothing more than a loose plug lead. |
And apart from passing Paul Rogers, who was trundling round in an obviously broken Contour, doing his best to stay out of everyone's way, that's how it ended. 13th out of 15 finishers (but really only 14 as Paul wasn't really racing at the end), with Mark ahead of me and Judi behind me. My best lap was a 1:59.25 - a bit faster than in race 1 but still light years* behind Tim and Adrian. Their fastest laps in race 2 were a 1:53.69 and a 1:55.64 respectively. |
So, that's the end of the 2010 RGB Championship. I've still got the
Birkett 6 hour relay to look forward to, but other than that there's no more racing this year. I ended up with
40 points in the championship, putting me 22nd. I even finished 2 points above Adrian, although I suspect that
has more to do with the fact that I did one more race than he did than anything else. Still, only 72 points behind
Tim... ;) Thanks go to Austen's friend Dan for some of the photos and to Derek for the others - as ever the RGBers post their photos and videos on the RGB forum. No video from me from Oulton unfortunately - water evidently got into the bullet camera's innards and although the Neuros behaved itself this time, all it recorded was lots of jagged black and white lines. * Yes, I do know that a light year is a measurement of distance and not time |
And finally, more as an aide memoire for me than anything else, there's also a few things I need to do to the car before the Birkett. Nothing major - it ran fine for the whole meeting, but as ever there's always a few tweaks which either I'd wished I'd done previously and hadn't got round to doing (actually, most that) or ongoing maintenance which it's time to do. Anyway, things to do are:
So, plenty to keep me busy before the 29th, when it's time to go back to Silverstone for the Birkett... |
As usual, I've been spending some time analysing the data from Oulton.
One thing I've spotted which is rather strange is a difference between the front and rear brake pressures. Although
the balance between the front and rear pressures is adjustable by virtue of the bias bar linkage, the pressures
in the front and rear brake lines should at least be proportionate to each other. And, according to the DL1 data,
they're not... One of the reasons for putting brake pressure sensors in the front and rear lines was so that I could establish what the brake bias was, so that if I adjusted it I could always revert to an earlier setting. Generally I used the readings from the front brake lines to establish when, and how hard, I've been braking for the simple reason that the pressures are higher in the front brake lines and so it's easier to differentiate between signal and noise - the sensors are 300bar sensors, the output seems to be relatively noisy, and so the relatively modest pressures in the brake lines (up to about 40 bar) can get a bit lost in the noise. However, I suspect that after having stuffed it into the barriers because of having too much rear bias, I've been overly conservative and gone too far the other, so that I now have too much front bias. In order to establish whether my suspicions in this regard were correct, I've looked at the data logs and compared the front brake pressures with the rear brake pressures to see if I've got more front bias than I had in the early part of the year, before the current run of brake problems. |
A more significant brake problem is the excessive run-out I'm getting
on the front brake discs. It started off with one disc (the one on the RHS) having only a very small amount of
run-out (within tolerances, certainly) but with the other disc having rather a lot of run-out due to the damage
I'd inadvertently inflicted on the brake disc mating face while trying to install new wheel studs. I then fitted
the new HiSpec hubs and new discs, with the result that both sides now had significant run-out. This was, I'm sure,
responsible for the vibrations and brake judder at Snett and Oulton. Also, the fact remains that the HiSpec hubs
don't fit properly and require the brake calipers to be shimmed inwards by 5mm, along with the wheel speed sensor. So, prior to re-engineering the HiSpec hubs so that they fit properly (fixing HiSpec's cock-ups once again), I decided the easiest thing to do was to skim the old discs so I knew they were flat, then skim the mounting faces on the old steel hubs, and then fit them - the end result would be a bit heavier than the current set-up with the ali hubs, but I'd gladly trade in a couple of kgs for a car than doesn't vibrate quite so much at speed. |
The first thing to do was therefore to make up a device for holding
a brake disc in a lathe in order to skim it. Taking the easy way out, I bought a NOS Escort Mk5 front hub from
eBay, and then made up a shim to increase the diameter of the centre spigot - the brake discs on the Escort front
uprights fit on the back of the hubs, and the centre hole is larger than the wheels. The steel shim I made up is
actually turned from the remains of the spur gear
I used to make up the gear for the electric reverse. I took the two old brake discs to a friend's place as the brake discs are too big to fit on my lathe, but not his (cheers Steve!). When we mounted the brake disc on the mandrel and checked the run-out with a DTI there was plenty of runout, but it turned out that this was at least in part due to the fact that the mounting face of the brake disc was slightly conical - if you put a straight edge on one side of the mounting face, there was a visible gap on the other side. However, the braking surfaces of the discs appeared to be flat and true. So instead of skimming the disc faces flat on the lathe, a better option appeared to be to place the disc on the bed of the milling machine and machine the mounting face flat. Which is exactly what I did. |
Having machined the mounting faces on the discs flat, I knocked the
wheel studs out of the old steel hubs, put them in the lathe and gave the mounting faces on the hubs a quick skim,
installed some new wheel studs, unbolted the calipers from the uprights, removed the ali hubs and new discs from
the car, transferred over the special mounting bolts (they're M10 but have a 15mm AF bolt head), fitted the skimmed
discs onto the skimmed steel hubs, re-greased the bearings in the steel hubs, removed the shims from the caliper
mounts and the wheel speed sensors, fitted the new hubs and discs and replaced the calipers. End result is that
one side's fine, but the other side has significant run-out... So after all that work, I'm pretty much back to
where I started from. Evidently when I skimmed the mounting faces of one of the hubs it wasn't centred properly
on the lathe. So, one of my winter projects is going to be not only machining shims so that the HiSpec hubs fit properly and don't need the calipers and wheel speed sensors shimming (if that's possible) but also to machine some parts to allow me to fit the hubs in the lathe properly. Alternatively, I could just use Steve's lathe, as it's bigger than mine (particularly the chuck) which I suspect wouldn't require me to make any special mounting tools just to get the hubs mounted squarely in the lathe. Either way, despite having spent most of the weekend working away on the hubs and discs, they're still not right... |
I've also done all the other little jobs on the list above, except for
setting the car up properly - it's still not corner-weighted, but it's too late to do anything about that now.
One of the things I want to do this winter is make decently progress on my home-brew corner-weight scales - which
will of course end up being rather more expensive and not quite as good as some commercial ones... Although I tried bleeding the cooling system I didn't actually end up getting any air out, despite running the engine up to temperature and raising the header tank by a couple of feet while I did so. It's not really an issue when the car's running - it's just that when I stop the water temperature rises rather alarmingly once the engine's off. Might just be massive heat-soak though I suppose. But since I'll be replacing the Polo rad with the Rally Design ali radiator over the winter, it's staying like it is for now in any event. So, as matters stand, the car's on the trailer fuelled and ready to go, safe and sound in my storage unit. And the Birkett beckons... |
And so for the traditional 750MC season closer. The Birkett, for those
as don't know, as a rather unusual race. It's contested by teams of between 4 and 6 drivers, who can either drive
different cars (which is normally the case) or who can share cars (which does also happen). It's a relay race,
so when one car comes into the pits, the next car can leave the pits once the incoming car has passed the pit garage.
There's a wide range of different cars taking part, although, I have to say, not as wide a range as there used
to be - the Frazer Nash chain-driven cars are missing these days but definitely not forgotten. I still remember
watching the Chain Gang's drivers look over their shoulders towards the outside of the track to make sure they had enough space for the back end of the car
to swing round into - since they have no diff, every corner has to be taken in a glorious opposite lock slide.
However, even with their absence, there's still everything from modern wings'n'slicks racers to classic saloons
out on track - and a rather lovely little blue Turner Mk3, which was beautifully turned out. And there was rather
a lot of cars as well - there were 60 teams taking part this year, so there was anything up to 60 cars on track
at any one time. This number of cars could be accommodated because we were, for the first time, using the Grand Prix circuit at Silverstone. The Historic GP circuit in this case, not the new 'Arena' circuit which was used for this year's F1 race. I understand that it's likely that the Birkett will be the last time the Historic GP circuit is ever used, as it seems that the continued construction work to the circuit will mean that it won't be possible to use it in the future. A pity, as it's a great track. However, it's a track I'd never driven on before. I've driven the Silverstone National circuit, but that only shares two corners, Luffield and Copse, with the GP circuit - if you ignore Woodcote as a corner, and in the dry it's not really a corner at all, although that all changes when the track's damp. Given that I'd never driven the circuit before, some testing seemed like a good idea, so as well as doing my usual rFactor track-familiarisation I booked a day's testing on the Friday before the race. Unfortunately, it then turned out that I'd got two seminars to give that day, so I couldn't make it. Indeed, I wouldn't be able to get home before 8pm on Friday night, at which point getting the car from the Shed and troggling over to Silverstone seemed a bit futile. So instead, I stayed at home on Friday night, and set the alarm for 4 a.m. By 4.25 a.m. I was on the road, by 5 a.m. I had the trailer trundling along behind the car, and at 6.35 a.m. I arrived at Silverstone, still well before dawn. Car off the trailer, round to the pits, sign on at race control, off to scrutineering (no problems there) and back to the pit garage for 7.25 a.m., all done and dusted. Given that my qualifying session was due to start until 9.30 a.m., that left me 2 hours to wonder why the hell I'd got up so early. My qualifiying session was at 9.30 a.m. because I was car 'D' in our team, RGB East, number 51. The other members in the team were fellow cam7ers Tim and Adrian, fully-fledged race god Derek Jones, Class A man-to-beat Paul Rogers and David Wale in his BDN S2. Now the only way I was going to be as fast as Derek was to hire Robert Kubica as a chauffeur. Tim's not that much slower than Derek these days and can match him on a good day, while Paul's long list of outright victories this year puts him consistently at the pointy end of the field. David is also usually towards the front of the grid, and I thought it unlikely I'd be able to match his pace. However, I wasn't *that* much slower than Adrian round Oulton Park, and was hoping to put in lap-times similar to his. Provided it was dry... During the week before the race, I'd been nervously keeping an eye on the BBC weather forecast for Northampton. During the early part of the week the BBC were confidently predicting heavy rain all day on race-day. This was not a prospect I relished, as I don't like racing in the wet, quite apart from anything else due to the fact that I'm no bloody good at it. However, by Thursday the Beeb had decided that it was going to be glorious sunshine all day on Saturday, and this was still their prediction on Friday. In the end, neither of the forecasts was even vaguely correct, which just goes to show that all that money they spend on creating weather models would be much spent on a pair of dice and a look-up table - 'a 3 and a 5 - heavy showers in the west, sunny intervals in the east'. I suspect a pair of dice would be more reliable than the systems they've got at the moment anyway. To be fair, when I arrived at the circuit it was indeed dry with a clear sky. However, it had evidently rained overnight and the ground was still fairly damp. And it was still damp when it came to qualifying. I spent the out lap and the next three laps making sure the circuit went where rFactor thought it did. By and large it did, although because we were using the Historic GP circuit (rather than the not-quite-Historic circuit they'd run in testing the day before) we were using the cut-through at the entry to Club, which turned the entry from a sharp 90 left followed by a sharp 90 degree right into a pair of roughly 45 degree corners. Much faster than the version of the circuit I'd be using on rFactor, and one I never felt I got right during the whole weekend. Although by the time it got to my qualifying slot the sun was definitely out and shining brightly, it was still pretty cold, and the track didn't seem to be drying out much if at all. It was certainly still pretty greasy out there during qualifying. Once I'd bagged the three laps I needed to qualify, I started pushing a bit harder, seeing where the grip was and seeing where it was possible to carry speed through the corners. I think my best time during the quali session was a 2:38 - far from blistering, but apparently a respectable time when compared to the other RGB racers present. |
Derek started the race for us, and was lapping with his usual speed, when unfortunately we got a call that he was coming in. It seems that while dicing with a couple of Caterhams and a Subaru, Derek had a moment of intimacy with the back end of the Scooby. The result was that the front right corner of his bonnet looked a little like mine after my shunt at Brands. Although not quite that bad, the headlamp bowl was hanging loose and there were several large tears in the GRP. Two of our valiant pit monkeys, Duncan and John set to the bonnet with bits of ali, plastic sheet, gaffer tape and pop rivets and started patching it back together again. The plan was for me to go out fourth, so this elevated me to 'tortoise' status - be present in the garage at all times, ready to get in the car. With the next driver change, I became the hare - ready to go out on track at a moment's notice, sitting in the car with harnesses and helmet on. Given that I had to do this for half an hour - and it's really quite dull just sitting there looking at the pit wall - I brought a book, and sat in my car reading it before it was my turn to go out. Everyone seemed to find it rather amusing, but I found it quite useful - much better than just sitting there fretting and getting nervous. Thanks to Matt for the photo. |
By the time of my first session, the track was essentially dry. It was
still a bit greasy at Priory and Brooklands, but other than that the track was dry. I set off and started winding
the pace up. I was still learning the track, and learning where I could carry speed and where I couldn't. I never
really got Club right, and I was still having difficulty persuading my right foot that stamping on the throttle
on the entry to Copse was a good idea. However, I got my lap-time down to 2:14 - again, not exactly searing, but
pretty much par for the course and not that much slower than the others. By this point we were up to about 14th
of the 60 teams and recovering from Derek's Scooby incident. In between my two sessions it rained hard, twice. When I went out it had stopped raining, but the track was once again quite wet. There wasn't that much standing water, but there wasn't that much grip either. Having been warned of a slippery pit exit, I got onto the track only to head straight into a big moment round Becketts with flurries of frantic arm twirling. Then down the Hangar straight there was a front cycle wing off one of the cars lying in the middle of the track, and white flags out because 'Lucky' Bob Mortimer was limping round in an obviously unwell FuryBusa. A few cars got past me at Club and Priory, including a wallowing bloody great XJS, and then a silver MR2 fell off in front of me at Brooklands. So that was the first lap... Mr/Ms/Miss/Mrs J Cross (or so the number plate claimed), the driver of the silver MR2 had evidently gone off at Priory, and rejoined the track to appear from behind the XJS, promptly to fall off at the next corner, Brooklands. He evidently regained the track pretty swiftly, as he got past me under braking into Copse, but he (or she) evidently had quite a bit of practice on getting back on the track from a green moment, as he promptly fell off again at Becketts. I wonder if he (or she) ever completed a lap while managing to stay on the track? For a while all I was doing was trying to keep the car on the track, but after a while I started to work out where the grip was, how to carress the car round the corners rather than my usual dry weather technique of throwing the car at the apex and holding on hard. I was still going pretty slowly - 10-15 seconds slower than Tim each lap, which is a county mile even if the lap-times were over two and a half minutes. I had quite a few more interestingly slidey moments, particularly round Copse, although the slides round Copse were invariably as a result of too little throttle rather than too much. Looking back at the video now, it's easy to see some of the places I was losing time. At Bridge and Copse there are times when I'm only using half the available track, and it would've been possible to carry much more speed through Club. However, on the positive side I was rather enjoying myself at the end of my second stint - I was getting more confident about being able to catch the car when it got out of shape in the wet, even if some if not most of the slides were more to do with me not letting the car run out towards the edge of the track and unwinding the steering, rather than too much throttle as such. I think I'll wait a bit before putting the car up on axle stands for the winter fettling season - if I get a day free and the weather's looking grim, I might see if I can do a test day in the rain. I'm not saying it'll be fun, but it'll be good practice. After all, being a fair-weather racing driver doesn't really make a lot of sense in this country. |
So, season over and I've finally managed to race at the Birkett. And for those of you struggling to drop off the sleep, here's some in-car footage from my second stint to help you drop off... |