October 13th

Snetterton circuitIt's a couple of days after the race weekend at Snetterton and a fine time was had by all. What follows is essentially the report that I posted to the cam7 mailing list earlier in the week.

Qualifying

We got up early, although not as early as on other occasions, and drove to Snetterton. The place was heaving with cars as this was a pretty big meeting. I went through all the preliminaries and in the first-time drivers' briefing met a new RGBer. Neil Constable-Berry has bought a car raced last year by someone. Looked to be a really nicely put together yellow Fury with a Blackbird engine. Hence, he's in class A. I introduced him to a few people so that he knows a bit more about what's going on. He seems like me in my first race in that he's pretty much at sea at the moment.

After scrutineering (it's amazing how much less worrying that is these days) we finally got out for qualifying at about noon. To cut a long story short it was really rather frenetic. I didn't feel that I got anywhere really and the times were rather worse than when I was testing a couple of weeks ago. Fastest lap was 1:23.40, 24th on the grid and 13th in class. The grid was 31 in all with Judi bringing up the rear having done one lap before losing it big time at Coram and smacking rearwards into the barriers by the Russell marshalls' post. (I still can't quite figure that out.) There then followed a long fettling session putting the bodywork back together with tank tale and GRP with *lots* of catalyst in it. Did I mention it was cold?

Interestingly, from the data logger, the effect of the wind was that the fastest times were on the Senna straight rather than the Revett straight, where you'd exit it to be faster. On my fastest lap the maximum speed down Revett was a measly 111.4 mph; on the Senna straight it was 113.7. At least, that's the fastest lap according to the datalogger, it doesn't quite match the fastest lap according to the official times, probably because the actual timing sensor is at a different point on the track from where I've placed the GPS track marker in the Race Technology analysis software.

I was actually placed one place further up the grid for the second race (based on the second fastest lap in qualifying).

I didn't manage to engineer myself anything like a clear lap on qualifying, and the car jumped out of gear on *every* trip down the Revett straight. I really need to have a look at the internals of the engine I think. I did think that my last lap was going to be the best (it's the one that the logger reckons was the fastest) but Jonathan Wright got in the way on the trip down from Coram to Russell. (He's a quick class A bod we sort of get in each other's way a bit on the run down to the Russell chicane.

The ADRs actually turned up for this race but acquitted themselves very poorly. Warwick Barnes just trundled round slowly getting in everyone's way (including Judi, I think) and Mark Falco's car never even made it. Apparently his gear change didn't work, the engine didn't work and, anyway, the gear change was the wrong way round. (Yes, I know, in a rational world these things would have been fixed before this....) The semi-official RGB race report later on commented that it was like Grolsch advert on the TV at the moment: "Schhhhhhhhtop…these cars aren’t ready yet, they need more time!".

Race 1

Leaving Russell Bend (Thanks to Nick Quill for the photo.)By the time our race came around, at about 5pm, now it was really cold and quite dark. However, the rain held off although it did spit just a little bit. I never did get any better tyres and I was worrying a bit at one point.

On the way to the grid I, for the first time ever, did a couple of practice near starts. (That is, I span the rear wheels.) I don't know if that helped but when the lights went out I got a really good start and zoomed up the outside of quite a few people. I was on the outside for Riches and I really fancied my chance of driving round the outside of Doug who freely admits to starting badly. I know he would just have driven past me on the straight (his is a car like Tim Harmer's) but it would have been fun. However, as I was going past I noticed his car start to rotate on the road in an alarming way. Discretion being the better part of things I took to the grass whereupon the world revolved in the way you'd expect. I finally got it pointing in the right direction but rejoined dead last. However, quite a number of cars didn't get back on at all. Phil had had a big coming together (enough to break his bottom wishbone and shear the 1/2" of a ball joint stud) and was parked at the back of the Sear marshall's post. There were quite a few other cars around.

So, not surprisingly, the race was red-flagged pretty quickly and we went back around to the start.

The next time I got an even better start, even though the grid was a bit tense after the previous start had been aborted with a couple of seconds to go when some car at the front stalled. I was on the left of the grid and zooming along and suddenly noticed a sort of parting of red sea in front and frantic yellow flag waving. After the Israelites had lined up I saw Jonathan's Megabusa right in front of me, completely stationary. As Chris Seaman said later, "adrenalin is brown", and I took to the grass again, there being no space to the right, and skittered past and got back on the track. My feeling was that I was doing at least 150mph at this point but the data logger reckons I was up to 52.29 mph before I slowed. Colin Chapman later on congratulated me for keeping the car in a straight line but it wasn't too difficult.

With that out of the way I set off in pursuit, although I don't think I'd made it down to last this time. Having looked at the logs I think I must have overtaken Nick Joyce and Richard Carter before setting off in pursuit of Colin. Ever since I started this lark I've been creeping up on Colin and I've been threatening him with beating him fair and square eventually. Finally, this time I seemed to have a chance and over a series of laps reeled him in until what I think was probably lap 5 when I did my fastest lap of 1:23.4. I came out of Sear obviously a bit faster than him and, much to my surprise, just outdragged him although with a bit of support from the tow. I thought I was going to have to include a little bit of outbraking in the manoeuvre by dint of the Matthew Burrows (a Caterham racer friend) patent Esses line but I actually got past before we got into the braking area.

After that Colin just sat 0.5 to 1 second behind me. It's clear from the logs that I did slow down after lap 5. Lap 7 in particular was 1.43 seconds slower. There was a little bit of traffic though as both Colin and I had to lap Judi through the chicane which was quite entertaining. Tim Harmer lapped both of us just after that too. Unfortunately, the race was eventually red-flagged caused by, I think, Paul Haynes' car failing just after Sear. Unfortunately, the clutch had failed meaning that the marshalls couldn't move it. Paul had just lubricated Extreme Engines palm with £2500 for an engine rebuild so he was a bit cheesed off. Unfortunately, when the clutch fails in a bike-engined car then it's almost certain to lunch the starter too as a spin tends to reverse the engine and that has the effect, due to the way the starter connection works, of revving the starter motor to 200,000 rpm.

So, a race ruined by grass-tracking but nonetheless fun for actually including some real racing action for the first time ever.

Oh, and I beat Colin.... :-)

Mark Falco's ADR didn't make this race, although Warwick Barnes' car did. This one only did 1 lap though and spun on the Revett straight into the corner board and then the barriers. It had done a lot of damage too. I thought at the time that it looked like a problem caused by rearward brake bias and talking to Judi the following day (she was being held up by Warwick, even though Judi's fastest lap was just a 1:36) he just spun in a straight line just about in the Esses braking zone. That does sound like brake bias to me and it sounds really stupid to bring a car to a race without doing any sort of testing at all.

Race 2

Glued to the back of Colin and Ian (Thanks to Nick Quill for the photo.)Another cold and windy day but at least there was a little bit of sunshine today. Our race was just after lunch and we'd get the luxury of a green flag lap this time!

I made a good start again and passed a couple of people in the run down to Riches. I've realised that I need to approach the first corner a lot differently. I got past Tim Evans easily on the start but then as I was out to the left he just outbraked me on the way into Riches.

To be honest I can't really remember what happend too well after this. I know I managed to get past 2 or 3 other people but then I got stuck behind Colin (I think he must also have outbraked me into the first corner) and Ian Fletcher. The photo just above is of the three of us heading into Russell. This was pretty much a re-run of Oulton where Colin, Charlie Gregory and I spent the entire race trying to get past Ian whose V-twin engined car runs out of puff at speed but grunts away from corners really effectively. He hadn't been in the race 1 as he had driven home to get his spare engine and was fitting it in the paddock. Apparently his other engine had overheated to the extent of actually melting the (aluminium) clutch cover.

A couple of laps later and Colin tried a demon outbraking stunt at Riches and just disappears off onto the green stuff. He was obviously trying to emulate Louis Scott from Saturday who had gone waaaay off into the cornfield and just sat there watching me and Colin dice round for the whole race. I was momentarily fazed by watching Colin skitter off and thought I was going to join him for a moment but I gathered it up and set off after Ian. At some point Neil came up behind the two of us. By this time he'd clearly worked out how to drive the car and he just drove past the two of us down Revett, the 'bird engine working well. Next lap, though, I managed to pass Ian. Again, I got out of Sear quickly (I just *might* have been some considerable distance beyond the white line there...:-) and got past him on Revett again. I set off after Neil but without much hope as his car was clearly a lot quicker in a staight line. I was loads quicker than him through the Esses/Bombhole/Coram complex but didn't had the balls to try outbraking him into the chicane. However, just seeing me there must have fazed him as he spun leaving the chicane and I passed him.

However. next lap around and Mark Falco's ADR is parked at the exit of Russell facing the wrong way; lots of yellow flags. A short while later and the flags go red and we trundle back to the start. After some faffing around they reform the grid on the basis of where we were on some long-forgetten lap. The end result of this was that both Ian and Neil were back in front of me. The restart was a poor start for me and I was right in the thick of it at the first corner. I did have a little go at Gordon Milner, who is normally miles up the road, but didn't really get close enough and on the run down Revett he pulled away. I did a carbon copy overtaking move on Ian and was following Neil, again, I think, when I had a rather spectacular bit of running wide at the exit of the chicane. The assembled spectators were treated to me trying to reach escape velocity in the Fury but I did demonstrate that no, Furies don't fly. I only narrowly missed the end of the pit wall but then set off again. That lap was a 1:26...:-(

However it was all to no avail as the wretched chequered flag appeared.

That is, the race was ruined by the ADR which turned up completely unprepared, in a state that means it isn't championship eligible anyway. It wasn't only me that was cheesed off. Oh well.

All the same, I was 17th overall, 9th in class and I beat Colin again. I was 4 seconds clear of him at the end of this 4 lap sprint, with a fastest lap a second quicker than him. I now need a new target...although I think he might well have me in his sights now....

Data logs

Best lapAfter I got back I had some time to look at the datalogs and see what could be gleaned from them. I'm still an amateur at this but there are some interesting things. The graph shown here (note that you can click on it to see it in a larger form) shows some of the data from what was my best lap all weekend.

The two datasets at the top are the lateral and longitudinal acceleration. You can quite easily see the Snetterton bends in the lateral curve. That is, the lumps at the top are Riches, Sear, the second Esse, Bombhole, Coram and the in turn into the chicane. The other two corners are lefts and are dips rather than rises in the trace.

The curve in the middle shows the yaw rate of the car: how fast it's turning. The jaggy one at the bottom is the throttle position. The final, upwards trending, trace shows the cumulative difference on this lap from a "best possible" lap made from sticking together the best sectors of all the laps over the weekend. That is, this curve shows that even on this best lap that if you take all the "best bits" that I had actually driven then I would have lapped 1.6 seconds quicker in a time of 1:21.5. That would have put me 16th on the grid instead of the 24th I actually managed. As this is a "lap" that I actually drove it makes you think.

Other interesting things on this log are:

  • I went all the way around Coram pulling just over 1g lateral. This is apparently what you would expect to get to on tyres like the A048. It's quite easy to get higher accelerations but only for very short periods of time.
  • The Bombhole looks exciting! That corner is effectively banked (really the inner half just has a more extreme camber) and consequently the peak of nearly 1.5g is not surprising. I wonder, though, whether it couldn't be a bit "fatter". Possibly not, as the narrowness of the "banked" bit means that you can't really adopt a proper racing line around the corner.
  • I seem to have had a bit of a moment around Riches. As the lateral acceleration (and the yaw rate) is higher at the beginning of the turn it would tend to indicate that I had turned in too late. At least I think it might be so, I'm hardly an expert at reading these things. However, this lap is actually the fastest in the sector that includes this part of the track, so something must have been right.
  • You can see where the car jumped out of gear on the Revett straight. There's a frenzy of min-max throttle movements as I got it back in gear, along with a big hole in the longitudinal acceleration curve. In fact, this hole is about 1.7 seconds long during which time the car actually slowed down which is not good.

Best lap in race 1Here's another one from my best lap in race 1, when I was chasing Colin. In fact, this is probably the lap when I passed him. For this log I've replaced the yaw rate trace by that showing the speed, as derived from the GPS receiver.

You can see here that this lap is actually the fastest for the second sector as the time slip trace is horizontal for that part of the track that includes the Revett straight. This is where I passed Colin and I remember having a bit of a moment just after I left the Esses. You can see this quite clearly on the traces, especially the fact that the speed is pretty much constant there which is usually a bad sign for a race car.

Friction circleFinally, this thing isn't a Rorschach ink blot designed to see if you're bonkers. It's a trace of the friction circle for the final 4 lap sprint of race 2. A friction circle essentially shows how well the tyres are being used in that it represents a circle with longitudinal acceleration in the upward axis and lateral acceleration in the horizontal axis.

So, the cluster of blobs over on the right hand side represent all the right hand corners at Snetterton. The cluster on the far left are all the exit turn of Russell. The cluster at the south-west are trail-braking into the Esses.

The spike at the top is pure straight line acceleration which means either the Senna or Revett straights.

What's odd, at least I think it's odd, is the huge blob in the middle with represents not very much going on. In general a race car is supposed to be accelerating or braking as hard as possible all the time. That ought to mean that there's nothing in the middle. What isn't clear is whether the blob is caused by moving from full acceleration to full braking in a straight line or whether it just represents hanging around. It's clear that a lot of it does come from the former but I have a feeling that my bad habit of not being able to force my right foot to stay on the loud pedal accounts for some of this.

Hmm, I need to think harder about this.

October 16th

Starting at Oulton ParkFame at last! I was reading the latest 750 Motor Club magazine and realised that in the photo of the RGB meeting at Oulton Park you can just about see me! I've helpfully pointed out where I am in the photo as I'm not totally obvious!

New, old, wheelsI've been looking for some more wheels for the car for a while now, as next year, at least, I'm going to need to be able to have another set of tyres. Even though we run the control Yokohamas it would be interesting to at least be able to try experimenting with a different set.

Eventually I found a chap who was selling a set of old Ford RS wheels just like the existing ones and on Tuesday I drove up to Staffordshire and picked them up. I got the old tyres—a fairly rag-bag selection—taken off them a couple of days ago and today I cleaned them up. I was originally intending to get some wheel lacquer and paint them but I've come to the conclusion that they're good enough as they are.

So, I'll get some new tyres as soon as I can. One problem with this is that I've got nowhere to carry them. It is possible to buy a tyre rack for the trailer and I'll either buy one of those, or make something myself that does the same thing.

The same worn tyreI also had a careful look at the existing tyres. The left front is, of course, now worn rather more. However, changing the camber settings has definitely affected what the tyres look like. This one, the left front again, has lost the chamfer that it had on the outside edge and it's more worn on the inside shoulder than it was. Of course, I really need to do some more testing and take some more tyre temperatures to get a decent handle on what's going on.

It was clear at the race, though, that I am suffering from understeer in many situations. Some of this is definitely down to muppetry on my part but I'll keep fiddling with the front suspension settings to see if I can get a bit more bite. I found at the race that on a couple of occasions if I was back on the power in a corner and starting to understeer then I could improve things slightly by provoking a bit of lift-off oversteer to get both ends of the car working together a bit better. I could change the settings, perhaps making the rear end stiffer, to provoke more oversteer but that's always seemed an odd way to set a car up to me. So, for now I'll concentrate on trying to dial out a bit more of the understeer.

October 17th

A place to stick the antennaThe logger data from the Snetterton race showed that teh GPS accuracy wasn't what it could have been and one possibility is the position of the antenna. I suppose the best place would be on top of the roll cage but I'm a bit concerned about the magnetically attached antenna being blown off there. So, as the next stage of testing it I attached this small piece of steel to the rear tub. At least this is outside the grounded bucket that is really the rest of the car so it should allow the antenna to see the horizon more effectively.

I did a bit more tweaking of the front suspention camber, efffectively making the setting 1° more negative than the original recommendation. Not sure when this is going to have an effect though. If I don't go to Mallory then the car probably won't turn a wheel until something like February. I also have to go through the process of renewing my licence which is going to be a bit more difficult for me as over-50s need to get re-medicalled. Sigh...

Gearchange moved?One other intriguing little issue is that I noticed that the hole through which the gearchange lever pokes out was getting bashed up at the back, as if the lever was hitting it all the time. This is odd as when I first put it in it was miles clear and the only thing I can think of is that the cable has stretched slightly. I wonder if this is why the engine keep jumping out of gear? If I wasn't managing to engage the gear properly then it might explain all the problems.

Anyway, I relieved the hole in the transmission tunnel cover plate slightly. Unfortunately, I can't compensate for any stretch in the cable as it's already at maximum adjustment. The long term plan was always to modify the gearlever slightly and as I now want to make a column mounted paddle(-like) change I won't bother for now.

October 22nd

I decided after all to go to the Mallory Park race. Problem is, the weather forecast is not too good and I really need to do something about the tyres. And in particular the rather worn front left. So, I'll probably go to George Polley's tomorrow and buy some new ones to go on the new wheels above. I don't have any way of taking both sets of wheels and tyres to a race though so I shall just have to put the new ones on before we go.

I noticed on the Bikecars site today that Gordon Milner, one of the class C front runners, is agitating for more class C grids next year. I doubt he'll succeed as it would make class A/B less interesting. I can see his point though, as he would be up for winning. Doesn't seem to affect me though....

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