KevinA 695 Report post Posted October 3, 2017 Best lap but could have been quicker without the sloppy oversteer moment. www.youtube.com/watch?v=g1cKL33cjTw&t=5s&pbjreload=10 8 shiftspark, surrey86, Lauren and 5 others reacted to this Share this post Link to post Share on other sites
Cerastes 204 Report post Posted October 3, 2017 Good stuff. Looks fun and looked really slippery and really bumpy too, camera was shaking a lot. Share this post Link to post Share on other sites
Lauren 2259 Report post Posted October 3, 2017 That is really interesting to see. Amazing in respect of getting into a big slide into Charlies 1 that you still got the time you did. Also interesting that you are in 4th into Coppice. I was at the top of 4th, my gearing allowing 10mph more, yet I was taking Charlies 1 & 2 in 4th with not a lot of braking on the turn into Charlies 1. You look to be around 91mph on the turn into Coppice, yet I know I was over 100mph. I think I had a bit more sliding around in general managing oversteer in pretty much all the corners, though I didn't have any moments than were more than an 8th of a turn of opposite lock, though I was pretty much always in a constant drift, especially through Charlies 1 & 2 and of course Chris Curve. I suppose it's bloody hard to see 65/100ths of a second over an entire lap! Well done though. Sorry for almost making you kill yourself. Share this post Link to post Share on other sites
KevinA 695 Report post Posted October 3, 2017 Yep I changed complete strategy for the last lap, both gears and entry speeds. Guess it shows the Speedo doesn't tell all of the story, would have loved one more lap to clean it up but that had to do. 2 Ade and Lauren reacted to this Share this post Link to post Share on other sites
surrey86 352 Report post Posted October 3, 2017 Haha that looked pretty loose there, kept the rest of the lap together well considering there must have been a blip in the sphincter department. Great video. 1 KevinA reacted to this Share this post Link to post Share on other sites
thetyrant 30 Report post Posted October 4, 2017 That's impressive and well saved at Charlies! Ian Share this post Link to post Share on other sites
Lowe 191 Report post Posted October 4, 2017 Props to all of you that do this. Waaaaaay bigger balls than me Share this post Link to post Share on other sites
nerdstrike 186 Report post Posted October 4, 2017 That was exciting! Cadwell looks narrow - I don't think I could bring myself to commit 100% round there, even if it wasn't moist. Share this post Link to post Share on other sites
Mike 458 Report post Posted October 4, 2017 Well saved Kev and congrats on another win 1 Ade reacted to this Share this post Link to post Share on other sites
Mike@TD.co.uk 467 Report post Posted October 4, 2017 Well done Kev, Tomas & Lauren, sounded like an exciting day! 2 KevinA and Lauren reacted to this Share this post Link to post Share on other sites
Ade 517 Report post Posted October 4, 2017 @KevinA well done chap. Also 235/40/18 will be going 3mph faster at a ton indicted than the stock size wheels. Share this post Link to post Share on other sites
GraemeI 41 Report post Posted October 4, 2017 I nearly c****ed myself watching that moment, never mind being there! Nicely held Kevin! I was way slower through all the corners compared to you, some as much as 20mph less!!! What doesn't make sense it that I somehow had similar speed at the end of the straights which seems odd? 1 Lowe reacted to this Share this post Link to post Share on other sites
Lauren 2259 Report post Posted October 4, 2017 To be fair Graeme, your speed down the straights is a bit less than Kev's. It's your corner entry speed and the speed you carry through the corners which is costing you a bit. You will get up to a similar speed on the run down to Coppice. I noticed that your speed coming up to Park though was around 10mph leess on what Kev and I were doing. I had problems with traction through Chris Curve, I was in a constant drift which looked pretty but was costing me time. Share this post Link to post Share on other sites
GraemeI 41 Report post Posted October 4, 2017 I would love to see your video for comparison Lauren - I always have things to learn It's worth noting I was looking at speedo speed as the app has GPS lag so doesn't read the speed correctly. Based on the speedo, I had 2mph on Kevin before I braked like a baby into Coppice! I then had 10-15mph less into Charlies 1 as a result. Even after the 'moment', he had more speed than I did !! Kevin was still carrying 10mph more than me out of Charlies 2, but I only had 1mph less into Park (110 vs 109). Through the Gooseneck, he was 17mph faster than I was on the way in and 20mph faster on the way out as I again lost my adulthood! He was around 10mph faster before braking into Mansfield, and then about 5mph faster through the apex, but we were neck and neck at 86mph through the finish line. Doesn't that suggest I was accelerating a little quicker, or are there other things at play here? Like maybe his speedo is under-reading by a lot more Share this post Link to post Share on other sites
Lauren 2259 Report post Posted October 4, 2017 I don't really bother with doing vids, Graeme. Kev has a shorter final drive so his acceleration will be quicker and he has more power with a remap and his manifold and all that stuff. I think the way the car gains speed as it gets over 100mph slows quite a lot and the run when you get into 5th as you go up towards Park seems to take an age to add more speed. I was seeing 110mph on my speedo before braking for park. I was turning into Coppice though at 164km/h (I only use km/h), so that's a bit over 100mph. Speedos always over-read but if his overall tyre diameter makes it under-read than that would explain it, but it's more likely given the way in which speedo over reading errors increase with speed, that perhaps is speedo is a bit more accurrate and that is what is giving a lower apparent reading. I use 8" rims with stock tyre sizes so I guess my speedo will over read a bit more than a stock car, not by much though. All this probably means that mine and Kev's entry speeds are very similar. Difficult to know though as I have no evidence of my runs. Share this post Link to post Share on other sites
GraemeI 41 Report post Posted October 4, 2017 All good learning for me - thank you My tyres have a slightly larger diameter than stock, so mine is fairly close, but likely still over reading. Kev has slightly larger diameter again, so probably closer to actual speed. Just out of interest, why do you use km/h? It's taken me 2 decades to convert from km/h to mph - lol The main thing I was trying to work out was how I seemed to pick up more speed than Kevin did across the same distance. For example I picked up at least 7mph more between Charlies 2 and Park and 5mph more from Mansfield exit to the finish line. For example I just touched 109mph at Park (I was still in 4th before braking, so nearly on the limiter!) after doing only 63mph at the apex, . Kev was at 110 by Park, like you were, (but he also braked later than I did by probably 25-40m!) Kev was at the apex of Charlies 2 at 70 something mph, so I was a minimum of 7mph down at that point. Sorry for all this going on, but I like to analyse things so I can work out what I can do better in future. Just tell me to zip it if you've had enough! Share this post Link to post Share on other sites
Lauren 2259 Report post Posted October 4, 2017 Do you think it has anything to do with the tyres you were running? Might help a bit, but probably not that much. I've had a lot of imports so got used to km/h, it's an actually defined scale and a finer scale, I just prefer it. I also blame the daft teachers I had in the 70's and 80's that taught metric but didn't understand it. I've realised I understand metric perfectly well, but I still don't miles. I mean how long is a furlong? Terribly stupid system the imperial way was. It's hard to know, unless you can put the two vids together with telemetry to compare, you're never really going to know. I do wonder though if it's the slowing of acceleration as you go faster and faster that means even if you come out of the previous corner (Charlies 2) with a 7mph deficit both cars will accelerate to 100mph fairly quickly, but then it really slows and the hill definitely doesn't help. I generally change up to 5th at that point. 1 GraemeI reacted to this Share this post Link to post Share on other sites
KevinA 695 Report post Posted October 4, 2017 The FD conversation, somewhere there was a chart showing 0 to top speed through the gears on OEM final drive and a 4.67 that I run. Interestingly the 4.67 looses out in many areas to stock and gains in many less, I don't really worry too much and it is coming out anyway. Glad you enjoyed yourself Graeme and hope to see you again soon. Kev 2 Ade and GraemeI reacted to this Share this post Link to post Share on other sites
Lauren 2259 Report post Posted October 4, 2017 Yes, that's a fair point, Kev. Having tried the shorter final drive in your car (well Debbie's) I wasn't really getting the advantage of it. But yes, it's snakes and ladders really. Still, at least you'll get rid of the diff whine. Share this post Link to post Share on other sites
KevinA 695 Report post Posted October 4, 2017 And nobody has mentioned the amount of extra gear changes during the lap, including the one just before the finish line. Anybody care to calculate the lost time from this ? Share this post Link to post Share on other sites
Cerastes 204 Report post Posted October 4, 2017 6 hours ago, GraemeI said: I nearly c****ed myself watching that moment, never mind being there! Nicely held Kevin! I was way slower through all the corners compared to you, some as much as 20mph less!!! What doesn't make sense it that I somehow had similar speed at the end of the straights which seems odd? I had the exact same thing happen to me when I was at kendrew. He was so much faster in the corners (because it was my first ever track session so it was all new to me); but at the end of the straight my speed was very similar. Share this post Link to post Share on other sites
GraemeI 41 Report post Posted October 4, 2017 Firstly I would like to say that I did enjoy myself immensely, so thank you all for making me feel so welcome and helping me out so much! I knew there would be a reason somewhere, so there's a couple to start with!! Extra gear changes definitely would not help, but didn't think they would take that much speed out!? The FD will definitely make a difference, but as you said Kevin, it's only 500rpm? I would be curious to see acceleration figures side by side. I do find this very interesting! Totally understand what you mean about the metric system Lauren - I grew up with it, and then had to try work out the imperial one, so definitely confusing. I also see you're back on the tyre horse again Not sure that would have made a difference in the dry on the straight, but I like your persistence - lol (and for what it's worth, totally agree with your reasons). Just think though - next year, you can get some too, and I will still be right at the back of the pack! Share this post Link to post Share on other sites
GraemeI 41 Report post Posted October 4, 2017 1 minute ago, Cerastes said: I had the exact same thing happen to me when I was at kendrew. He was so much faster in the corners (because it was my first ever track session so it was all new to me); but at the end of the straight my speed was very similar. Very interesting, thank you for adding that. Kevin - looks like you need to dump the swing and jump on the roundabout - or the other way round 1 KevinA reacted to this Share this post Link to post Share on other sites
Foulsmell 120 Report post Posted October 5, 2017 The FD conversation, somewhere there was a chart showing 0 to top speed through the gears on OEM final drive and a 4.67 that I run. Interestingly the 4.67 looses out in many areas to stock and gains in many less, I don't really worry too much and it is coming out anyway. Glad you enjoyed yourself Graeme and hope to see you again soon. Kev Was it this? I was interested in this, so I did a few calculations of acceleration over various speed ranges for the different final drives. There are a couple of simplifying assumptons: no wheel slip, all tractive effort is used to accelerate the car, car mass of 1240 kg, shift times are 0.5s. 58b47f66de282_GT86Acceleration.thumb.png.280e3bf7cfc1f3ff381a6a925f30c634.png There's a lot less in it than I expected, across a variety of acceleration scenarios. Something I didn't graph that's interesting is that the fastest setup for a 40-80 pull is 4.1 final drive as you can do it in third. It;s very slightly faster than a 5.1 FD in fourth over those speeds. 1 KevinA reacted to this Share this post Link to post Share on other sites
Foulsmell 120 Report post Posted October 5, 2017 Found this which may be of interest. It relates to the 4.88 FD but give a better indication than a bar chart I think. 1 Ade reacted to this Share this post Link to post Share on other sites
