So, with the car back together we went down to Brands Hatch on Wednesday evening ready for an early start on Thursday morning. The weather forecast wasn't too good and, sure enough, it started chucking it down in the middle of the night. Come the morning and it was really wet and consequently a bit daunting.
Adrian was also there and we duly faced up to the weather and got stuck in. The day was split into three groups, each of which would have four sessions on the circuit. Essentially the first three sessions were wet; the first and third ones just wet and the second one really chucking it down. My times were OK-ish, at least going by looking at the times from the first race at Brands last year which was also very wet.
Luckily in the last session a drier line started to appear and everyone's lap times tumbled. I ended up at 59 seconds which was probably OK given the conditions. I could probably have gone quicker but I think I'd got into a bit of a wet-weather groove by then and starting to use more revs and consequently using different gears was difficult.
I did find that the circuit was starting to flow. At least it was while I stayed on the black stuff. I managed to end up on the grass a few times although I missed the kitty litter entirely; not a bad result that as there's a lot of it at Brands. Adrian wasn't quite so lucky and ended up running off at Druids and scooping up a truly huge amount of gravel with the splitter on the front of his Genesis.
Well, it was flowing apart from the last bit. I found the Surtees/Maclaren/Clearways complex really difficult to get right, and the data logs show a huge variety of lines and approaches none of which seemed to be right. The difficult bit is the last part which is really important as exit speed from Clearways determines the speed along the main straight. Not that any of the track at Brands is actually straight of course. Mind you, looking at the logs shows that even in the first wet session my maximum speed on the straight was about 107 mph which must be pretty daft in the pouring rain really. Oddly it wasn't much higher, if at all, once the track was drying which is why I think I was still driving in "wet" mode.
One
obvious thing from the data logs though is that I need to start concentrating on one particular aspect of my driving
that I've been ignoring a bit until now. This is braking. Even in the drier session at the end of the day the maximum
braking figure I got to was about -0.7g. These are the odd marks at the centre bottom of this G-circle. As you
can see, the majority of the braking effort is rather more at about -0.5 to -0.6g. I'm sure the tyres are capable
of rather more than this, certainly you can see that the lateral acceleration achieved is of the order of 1g. So,
I need to work rather more on later, heavier braking. The problem is, to be honest, after the outing where I stuffed
the Fury into the armco at Mallory I've been too tentative on the brakes. More driver training (and balls) needed
methinks.
However, that was all pretty encouraging. I didn't bend the car and it ran well all day. (The only problem was that the DL1 seemed to have a bit of a fit. I think some water must have got into the works. Luckily, it seems to have recovered from the experience.)
Now I just need to sort the car out for the race this coming weekend; which is what I've been doing all day today. After just cleaning it all up, there was a lot of mud, I set about the covered wheel issues. This relates to a problem identified at Mallory where a number of Furies were found to not comply with blue book rule about covered wheels. The upshot of this is that Fishers are making some spats to use with the rear arches. Theoretically we shouldn't make our own as the rules for class C say that we should be using standard bodywork. (Although, how that fits with things like my bonnet scoop is anyone's guess.)
Luckily, we've been given a stay of execution until after the coming race so I needed worry about the spats for a short while. However, I have always run with small spacers on the front wheels as the shoulders on the wheel studs fouled the wheel nuts without them. But, I need to make sure that the wheels are tucked in as much as possible and so I took the front hubs apart today and changed the wheel studs for shorter ones which have smaller shoulders. They all seem to work fine and the wheels are as far in as possible. However, the left front is more hidden than the right front and I probably need to try and move the bodywork across slightly. Not sure if I can manage that in any sensible way other than taking a big hammer to the hinge frame at the front of the car though.
Another thing today was to check the diff bolts. They all still seem to be tight, which is a relief. It may be my imagination but the rear of the car seemed "tighter" than before at Brands which could well be because it's done up tighter! Certainly while trundling through the narrow tunnels between the inner and outer paddocks at Brands (I remember when doing this last year was when I first became really aware of the horrible clanking from the diff) it all seemed tighter. Actually, the new exhaust made an obviously more rumbly sound here than the old one.
The gear indicator, by the way, was working very well at Brands and made driving there a much more precise experience. A couple of people had suggested that I might find reading the Palm display difficult but it was very clear, even in the murky conditions. Even better, the gearchange is now a delight to use. Much, much better than the old one.
I keep thinking about the Brands test and it does seem to me that, as well as thinking a bit more about braking, I need to start paying more attention to the car set up. Up to now I've just been thinking that the car could wait while I got better. However, given how well most of the Brands lap was flowing I probably need to start looking more analytically at the car's set up.
First up is to pay some more attention to the suspension set up. So, , I checked and adjusted the front wheel camber which was particularly imporantant after having had the hubs to bits to sort the wheel studs. One of the front ball joint tapers was spectacularly difficult to budge and I spent much of the day faffing about with that.
If I have time this week I'll also fabricate something rather better in the line of a toe gauge. It has occurred to me that as I always seem to have problems getting the nose of the car into a corner I should probably start paying a bit more attention to the toe settings. I have set it before but having a better gauge would make it a bit easier to adjust.
There's at least two obvious ways (apart from spending money and buying one!) to make a toe gauge though and I'm not quite sure which one to use. One is to have two sticks that attach to the wheels and allow you to measure between them. The other is to make something to actually measure the comparative distance between the front and rear of the wheel rims at each end of the car. The problem with the former is making sure the sticks are always straight. The problem with the latter is it's more difficult to compare the toe setting with the chassis itself which is important at the rear of the car.
Hmmm...
Well, I decided to do something completely different after some emails I received. I went
out and bought a small laser pointer for the grand sum of £9.99 and taped it to a piece of aluminium cut
to fit snugly on the wheel rim.
With this I could clamp the extrusion to a wheel and see where the laser was pointing. By moving the car backwards and forwards and doing a bit of trigonometry I can work out what the toe settings are.
So I did all that and found out that it was pretty much right. Next time I do some testing, though, I shall try changing the front toe just to see what it feels like.
Next thing to do, although I haven't started it yet, will be to work out some form of mounting
for this little video camera. It cost me the grand sum of £50 and should allow me to see at least a bit of
what happens on the track.
I shall work out some way of mounting it to the roll bar, but I haven't worked out how yet.
The video quality is, not surprisingly, pretty poor. However, hopefully it'll give me some idea of what's going on.
Finally, I spent a while fixing a bug that was in the Palm/DL1 software. The software includes a run-time display so that you can find out how long a race has been going on. Up until now it hasn't worked for some mysterious reason and I spent a while this evening finding the problem. Of course, once I found it, it was bleedin' obvious...
Well, the race weekend starts tomorrow so I just need to do a few more minor
fettles before we set off to Brands again. Unfortunately the weather forecast is pretty grim, so perhaps testing
in the pouring rain will have been useful.
I made mounting bracket for the video camera yesterday that just tie-wraps to the roll-bar. I also got hold of the form today that means that I've told Brands that I will be using a camera. Apparently they require you to sign something that says you won't publicise the pictures you take. I guess this means I won't be posting any of the video on this site! I will also have to show the scrutineers the camera mounting. What's more, if it does rain I won't be using it anyway...
Tomorrow I'll finish things off by doing a final bolt/brakes/steering check on the car.
However, I've also been looking at improving the data logging. I've figured out a way of measuring steering angle
but that will have to wait until after the weekend to be implemented.
I have, though, made a couple of improvements to the electronics on the DL1 adapter board as shown here in it's latest incarnation.
First thing was to include a diode in the Palm power supply. This had the problem that when the power supply was turned off it discharged the battery in the Palm which is not ideal. The diode stops this happening, although the forward voltage drop across the diode meant that I had to change the power supply output voltage a smidgeon.
The other thing is much more interesting. A friend (who works for Cadence Driver Development and is skilled in analysiing data logs has had a look at some of my logs and has commented (several times!) that I ought to be measuring the car's yaw rate directly rather than intuiting it from lateral acceleration and the GPS speed. So, I finally got around to doing so and the little daughter board you can see in the photo has a Murata angular momentum measuring "gyro" on it. This is connected straight to a couple of hte DL1's analogue inputs, and is even using the DL1's 5V output as its power supply. Hence this really was a rather trivial thng to fit and it really seems to work! At least from testing in the garage anyway. It's seems to be absurdly sensitive so it shoudl really be able to detect what the car's doing.
Well, it wasn't stunningly successful but I did go to Brands, take part in a race, finish the race and get the car all the way home without bending it. After the recent excusions that does, though, count as a huge success.
We went down to Brands on Saturday afternoon and parked up the paddock. The weather forecast for the weekend was not good, but in face the Saturday was mostly OK, apart from a little drizzle on the motorway down to Brands. On saturday evening we walked the circuit which was, as usual, illuminating.
It rained again on saturday night while we were in the motorhome in the paddock. However, on Sunday morning although overcast it looked as though it might stay fine throughout the day. This turned out to be the case which in some way was a bit of shame as I had managed to learn at least one way of driving round the circuit in the wet last week and I'd now have to relearn it.
Still I got the car prepped, which is alarmingly about putting rather a lot of electronics into it, got it scrutineered and over to the assembly area in time to wait for our session. Qualifying itself though was a real pain. I never seemed to get a decent lap. I was held up really badly on a couple of occasions and many times ended up on and even worse line than usual by a faster car coming past. It's becoming increasingly clear that although I can drive the car not as appallingly as originally my racecraft is just useless.
Anyway, I qualified 16th out of 25 with a time of 56.55 seconds. I suppose if nothing else that's a lot quicker than the 63 seconds that I managed on my first visit to this circuit last year.
Come the race and after a huge wait on the grid (it transpires that they were fishing a
car from the previous session out of the gravel trap) we were off and in a huge gaggle went around Paddock Hill
bend. I'd like to show you the video but I promised that nice Mr Palmer that I'd pay him £25,000 if I put
my video on the web. Oh well... Unfortunately there was some contact and they red-flagged the session later in
the lap so we re-formed on the grid.
The next start was pretty similar and again someone fell off at Paddock but this time he went out of his way to get the car a long way off the circuit so as to avoid another red flag.
The race went so-so although I essentially seemed to go backwards, eventually finishing 17th. However, I did have a race long battle with one car, the black Westfield that's at the far right of the grid. What's more, I actually overtook him on a couple of occasions under braking, the first time I've ever managed to do that. However, my race craft is seriously suspect. On a couple of occasions when battling with him I let other cars past. I need to get rather more aware of these things. It may be that I should buy a better rear mirror actually. A couple of people race with panoramic view rear mirrors which might be better.
I also really need to get some sort of tuition, something I've been meaning to do for quite some time.
So, a reasonably successful weekend. However, I need to start moving forward again somehow.
