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Donnington 29th June UPDATED 11th AUGUST with movies and analysis My second time at Donnington this year and another excellent BAT open pitlane day with top organistaion, hospitality and more track time that you can shake at stick at. The day was pretty smooth apart from a few stoppages in the morning (including a very badly injured Honda S2000 who went off through Schwartz curve). Previously the Superlight R seemed to have developed a bit of steering vibration, a sort of resonance at high speed but prior to the day I had everything checked over and the car was certainly safe and in a fit state to be driven with perhaps a slightly buckled wheel being the most logical cause. Also, since Cadwell, I had removed the windscreen, fitted the upright rearview mirror and installed a brand new set of semi-slick Avon ACB10's so I was pretty interested to find out what difference these two potential upgrades would make.
It was good to see a lot of the BAT regulars there. Plenty of Buzzez people and also usual addicts like elise S2 "TEE", David B. in his 280bhp Exige and of course Howard in his newly prepared Van Diemen Formula Ford. Howard purchased this supreme bit of kit sometime ago as a rolling chassis and then dropped a tuned Ford Zetec 205bhp engine in the back. An immense amount of work on his behalf the night before with suspension and dampers and the like meant that the car was ready by lunchtime. I have some good footage of the car and boy does it shift. Running on full slicks I imagine there is a fair bit left in the corners once Howard gets more used to the car (I was matching him for corner speed and I don't thing I should have been ) but on the straights, particularly past say 80mph this aerodynamic 450+/ton beast had some serious grunt and completely left me for dead... 135mph on the back straight, how does that sound ! The gearing he had was apparently for Thruxton, a very high speed track, and it certainly showed. Although it has a very tight powerband and just 4 gears it seemed that the only time the SLR was shifting any quicker was out of Redgate when he was probably caught in low revs. Later in the day he sorted the braking as well by adjusting the bias. The FF is a very viable trackday solution and although a high degree of tinkering is required, at such a small cost it makes a hell of a lot of sense.
A Lap Compared to last time I guess I was generally being a bit more aggressive going into the some of the bends and also attempting to be a bit braver charging out of redgate and through the Craners. I was low on sleep the preceeding week and after the long tiring drive up with helmet and no windscreen on the M1 my driving was initially quite edgy. The second session I took a step back to smooth everything out and ease myself back into a methodical rhythm. Out of Redgate, up into 3rd then flat in 4th I was still short shifting into 5th because the high revs (6-7K +) during the first right hander approaching the Craners make the car feel awkward. But I was holding onto most of 4th and then building up a fair bit more speed in 5th than I was last time. Keeping the car in 5th and easing slightly helped keep the car smooth. Not entirely sure of my speeds into the second left hander of Craners but they were probably around the 100-110mph mark. On one lap the car did a very slight dance through this bend but never anything too frightening. Old hairpin and Mcleans were pretty much the same as before except that Mcleans I made a mental note to turn in more over to the left of track and use more of the tarmac, and also never to turn in too early: later seems much better for me here. By the end of the day I had opted to keep the car in 4th on the charge up the small straight and this now seems preferable although at the next braking point the car is getting perilously close to the redline. Coppice was one of my main targets of the day and I really tried to increase my speed through here. The thing with Coppice is that when turning in not only does the front of the car feel as if it's lacking grip (but its not and its not understeering) but its hard to judge whether you will get round the bend or not. It looks narrower than it is but having said that on a few occasions I turned in too fast and had to back off to avoid going into the grass; the geometry of this bend is quite confusing. Nevertheless, judging by the pain from my neck muscles through Coppice I figured that I must have been doing something better than I was last time. I was expecting good things down the back straight with the car now de-screened. However it wasn't to be and although its possible that the car piled on the speed a bit quicker, the top speed didn't seem to be any better and certainly never near the 120mph mark. In fact, where the track crests slightly under the bridge the car seemed to actually pause momentarily and loose a bit of speed ! Unlike last time, I worked on braking a little bit as well. Braking for the chicane was late and hard and quite a few times I was at the limit, locking up just one wheel then easing back a touch. Similarly, my stopping distance for Redgate tumbled and in the SLR you really only need a moderate amount of braking here.
ACB10s These tyres are a nightmare on the road. Unless you are on the smoothest of tarmac the drive is completely spoilt by all manner of unwanted messages travelling through the car and also severe tramlining and camber-chasing. But for the circuit it was immediately obvious that they posess a lot more grip. Donnington has mainly faster bends and i'll be very interested to try the tyres out in tighter bends such as say Druids and Clearways but even so, the advantage is very clear. Whats more, they are really nice and progressive. Exiting Redgate I was often squeezing the power just enough to get the rear to slip out a bit and point the car back in a touch.. its all so controllable and feelsome.
GAIN Well looking at the video something has made me go a hell of a lot quicker. My speed down the back straight didn't seem any different but I know from the road that the lack of windscreen means faster acceleration . But perhaps more beacuse of the tyres and me knowing the car and the track a bit better, my laptimes came tumbling down by over 3 seconds. Of course I'm still well off the pace for my car and need to be on the limit more in some of the braking areas and some of the corners but with a clear run and when I was most alert and energetic just before lunch, I managed to be over 3 seconds quicker than last time. The main point of these days is of course having fun but its good to know that you're making some sort of progression as well. Now that I have got the footage in I can bring you the findings if you're interested. Judging 2 of my fastest laps from both 2002 Donnington trackdays and analysing them frame by frame the timings go something like this:
The table shows greater speed almost everywhere. All corners were between 0.16 and 0.36 seconds quicker apart from the hairpin before the straight where I was slower on this particular lap (due to a slow puncture on the offside rear). But biggest change of all was Craners and the back straight (the pit straight did not show any gain though because I had to lift off every lap for the noise meter). Through Craners I was close to a second quicker and the back straight well over half a second however, i seemed to loose time on the lap taken from the 29th in the braking for Old Hairpin... losing just under 3/10ths between the apex of Craners 2 and the turn in for Old Hairpin.
In the above movie you will see the lap from the 29th in the main large part of the screen with its time in the top RH corner. In the RH bottom corner is the old lap which starts at the same time so you can watch how much ground I lose to the faster lap on a cumulative basis. In the Top right hand portion of the screen I keep zeroing or time-matching the old lap at the start of the corners and some of the straights and then when the main faster lap reaches the end measurement point for a particular corner the small inset footage of the slower lap will flash white and then disappear when the car reaches the same point a few frames later. This gives a visual sense of the delay or extra time required by the slower lap to complete the corner or straight in question. Its very interesting seeing side by side just how much 3 seconds is in distance terms on a circuit - note when the 2 movies pass under the bridge, its a long long way... feels like an eternity !
MOVIES For details on my codecs, required software and filming equipment used click here. If you have the connestion speed, iWMV files are the preffered download.
Please note that timing, the use of laptiming equipment or data logging at general trackday events is strictly prohibited. The author calculates lap times AFTER such events purely as a by product of in-car filming. |
