Peter Carmichael Posted June 19, 2004 Share Posted June 19, 2004 Dave J summed it up as a great day's sport and I couldn't put it fairer. I seem to finally have the car handling well enough to take the challenge to Dave, even if the jammy sod does fall lucky in the last extra run of the day. My message is a clear: "if you want points you're going to have to work for them". Life needn't be as complicated as I make it, but... I ran my datalogging on all the runs today and something funny was going on. I know what it is like to "feel fast" and find yourself going slower - datalogging is normally very sobering in such situations, giving you nowhere to hide. Today, my last run felt fast. I overlaid it on my second practice run (which was a better time on the clock) and it clearly showed me picking up time throughout the run and particularly in the braking at the control tower. I compare it to my other timed runs and it shows the same thing. So this doesn't make sense - drive faster and receive a slower time. This is not a sour grapes post. I know the timing system can't be wrong, but it is making me look at the datalogging more closely. I suspect it is something to do with an inaccuracy between the recorded front wheel speed and my progress up the course. My trust in the datalogging is undermined for the time being. Link to comment Share on other sites More sharing options...
Mark Durrant Posted June 20, 2004 Share Posted June 20, 2004 Bad luck Peter but also congratulations on pushing Dave J so hard. I am at a loss to explain your anomaly with the data logging and would suggest that you should now concentrate on getting your big engine back in the car and take on the reigning champion on a level playing field. See you at Harewood Mark D Su77on Se7ens Link to comment Share on other sites More sharing options...
Jason Plato Posted June 20, 2004 Share Posted June 20, 2004 Ohh stop bloody moaning and coming up with all these lame excuses . There wasnt anything wrong with the timing My lame excuse - Yesterday was a bad day for me , I was 8/10ths off last years pace . I have since found that the rear arb mount was disconnected / very loose in the chassis mount . This may explain the snap oversteer I was experiencing . Speed through the trap was good at 116mph but the corners were a pain in the arse . As for level playing field ............ I hope I wont have to buy some A24 ACB's instead of my rock hard A48R's 😳 I was a good days sport .See you at loton Dave Link to comment Share on other sites More sharing options...
Bilbo Posted June 20, 2004 Share Posted June 20, 2004 Hi Peter "feel fast" and find yourself going slower I know the feeling well........ but in my case its using the wrong line or gear or set up and that makes me / the car work harder so it feels quicker. 😬 The opposites also true feel like is slower because its smoother and you get a better time. A question..... not having data logging how do you or did you compare the log with the break beam times 🤔 'Can you hear me running' ......... OH YES and its music to my ears 😬 😬 😬 1988 200 bhp, 146 ft lbs, 1700cc Cosworth BD? engineered by Roger King, on Weber's with Brooklands and Clamshell wings, Freestyle Motorsport suspension. Link to comment Share on other sites More sharing options...
KenEvans Posted June 21, 2004 Share Posted June 21, 2004 Apparently on one of Brodie's runs he took more than 6 seconds for the first 64 ft suggesting that he'd broken the beam prematurely or the timing had started prematurely. Anyway, I just thought I'd mention that. Ken Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 21, 2004 Author Share Posted June 21, 2004 I had that thought too. I did check the 0-64 ft time on the run in question and it was OK at 2.49s. I think I have the answer for the funny datalogging behaviour though. The runs have not been normalised for distance. Obviously I was driving a course of fixed distance, but my right front wheel (which has the speed sensor attached) might have taken more or fewer revolutions to cover the distance depending on lock-ups, cock-ups and wheel scrub. I think after I have normalised the distance it will show me exactly where I cocked up and drove slower. But blimey. The braking at the control tower was scary stuff. I will check later, 'cos I think I was only on the brakes for about a second, dropping from 106mph down to about 80 for turn in to the corner. The braking on my car is working very well at the moment, but my brain is finding it hard to keep up. My braking for the last corner as well was a matter of going well beyond my comfort zone. Link to comment Share on other sites More sharing options...
robmar Posted June 21, 2004 Share Posted June 21, 2004 excuse my total ignorance of data logging, but is this something that the GPS systems do/would not suffer from 🤔 Link to comment Share on other sites More sharing options...
Jason Plato Posted June 21, 2004 Share Posted June 21, 2004 But blimey. The braking at the control tower was scary stuff. I will check later, 'cos I think I was only on the brakes for about a second, dropping from 106mph down to about 80 for turn in to the corner. The braking on my car is working very well at the moment, but my brain is finding it hard to keep up. My braking for the last corner as well was a matter of going well beyond my comfort zone. ........... and it still wasnt quick enough Link to comment Share on other sites More sharing options...
KenEvans Posted June 21, 2004 Share Posted June 21, 2004 I don't know why you're ALL so slow on those list 1B tyres anyway Link to comment Share on other sites More sharing options...
Paul Ranson Posted June 21, 2004 Share Posted June 21, 2004 How are you establishing in and out markers? We use the 'hillclimb' version of the Stack and it puts a marker in when it first sees a wheel sensor pulse. So with the front wheel being 1.8m around that's quite a variance. I guess an ACB10 is smaller. Anyway if you're doing it manually you're likely to be less accurate, I'd have thought. You will probably enjoy practising your braking at Harewood, and they record about 5 sector times for normalising data logging to. The latter are very useful to show where you are slow wrt your classmates, and they cannot stop you seeing it.... Paul Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 21, 2004 Author Share Posted June 21, 2004 Steady now Jackson, that could be taken as unsportsmanlike gloating. Let's face it, any muppet can bury the throttle pedal and use the advantage of a powerful car. I've normalised the runs now and it shows up my *mistake* very clearly. First to answer Paul's question: I use the characteristic dip in the rpm curve that marks the engaging of the clutch. This is pretty reliable. I then place a lap marker at the 64ft point using the recorded 64ft time. I mark the end of the run using the recorded time. I generally do my run to run comparisons on the "64ft to finish" segment because the bit at zero speed at the start line confuses the distance-based calculations. So compared to last year, how did it go..? There was more grip off the start last year and the headwind on Saturday knocked about 4 mph off the speed at the trap. Now for the astonishing bit... I was braking 38m later at control tower, to good advantage. My momentary mis-selection of 6th gear instead of 4th lost me a bit but on the whole I was up on time by the exit of control tower. The cones were laid out a bit tighter this year for the following corner onto the straight, demanding a slower tighter turn (4th gear last year, 3rd gear this), resulting in reduced speed up the straight with the headwind taking its toll also. Then we come to my mistake... trying to repeat the advantage of the aggressive braking into the last corner. I completely misjudged the braking and was shedding far too much speed compared to the more successful approach of fade braking into the turn - indications are that this cost me about 0.4s. Now for the admission. On Saturday, I was taking the logs off the car after each run in order to plan improvements in my driving for the following run. Unfortunately, I didn't normalise the distance on these logs, so my comparisons were false (exactly what I was observing when I started this thread) and so I deceived myself into thinking that the aggressive braking for the last corner would gain me time. I fooled myself with my misuse of technology. Sahf London; every 1st Wednesday from 19:30 at The Duck just around the corner from Clapham Junction station Link to comment Share on other sites More sharing options...
Jason Plato Posted June 22, 2004 Share Posted June 22, 2004 Ohhhh now calm down you can see the little smilies and winks ...... My car is not that powerfull , you can see from my speeds across the line at curborough that I have similar to a SLR or R400 . Its nowhere near like the power of your 253 bhp "big engine" in 2002 . Ken is right - Class 5 was slow on Saturday , I was a huge 0.8 seconds off 2003 times . The class 4 runners were biting at class 5 heels !!! Dave Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 22, 2004 Author Share Posted June 22, 2004 Dave, I smilied you back. It's all in good spirit. Not got much power, eh? You don't know the meaning. Your 10mph advantage at the speed trap is obviously down to superior aerodynamics. Sahf London; every 1st Wednesday from 19:30 at The Duck just around the corner from Clapham Junction station Link to comment Share on other sites More sharing options...
Jason Plato Posted June 22, 2004 Share Posted June 22, 2004 If you look at Nick Addisons video you will see that my belts are undone and I'm ducking down behind the dash as we go through the trap . 😬 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now