19/10/2004 12:57:32 Alan Brooke I've been looking at some of the data from the Donington trackday, and for those of you interested in what speeds your car might be reaching here's the evidence from mine. The attached graph shows speed against distance round the lap in feet. The traces show that the speeds at different points around the circuit vary widely, mostly due to traffic around the circuit. For example the blue and purple traces around the 8000foot mark are where I was catching people along the top straight. Headline figures: [list] [*]90mph through Craner (the flat bit on the graph around 2200feet). The vertical cursor is on the short blast towards the Old Hairpin [*]103.6mph along the top straight after the pause as someone moved to let me through. The speedo was showing >110….liar! [*]Peak cornering force 1.1G through Redgate (at end of start/finish straight), often around 1G through there, Old Hairpin, Macleans, and the first part of the chicane. [*]After changing from EBC red to Mintex1177 brake pads there is a detectable improvement in braking force compared with earlier runs, even with the ABS. [/list]Notice the speed onto the top straight (around 7000feet) is very consistent even though the mid-corner speed varies by around 12mph, being early on the throttle and accelerating out of corners makes you just as fast as a heroic corner entry and having to wait for grip before accelerating again. The car is standard engine-wise with the original air filter, throttle body and exhaust. The gearbox has altered ratios, I can use 3rd all the way along the top straight, and the chicane is OK in 2nd but at highish revs (the purple trace shows a 2nd to 3rd change about 80 yards after the apex). A receipt from Quaife came with the car so I assume it's one of their close ratio sets. The suspension has Trophy gas units (I believe) with spherical jointed Eibach dampers, and smaller flow restrictors in the front-rear pipes. Ride height is stupidly low (around 300mm instead of 368mm from wheel centre to the wheel arch) 2 1/2" inches lower than standard! Standard brake discs with Mintex1177 fronts and EBC green rears. Braided hoses all round, and a servo steady bracket. Hopelessly ungrippy NCT3's which didn't warm up at all. Al

19/10/2004 13:44:42 Rob Bell Really interesting Data there Alan! What data logger did you use - and is it a transferable unit? I'm amazed you can corner at 1.1G with NCT3 tyres - how accurate are the accelerometers? Not sure that I'd want to see a data logger trace for my laps - probably be hopelessly inconsistent due to driver inability! LOL ;)

19/10/2004 16:23:26 Alan Brooke That particular unit is work's Racelogic Vbox, as used by top gear and many magazines. The hardware is a box about 4" square and 1" deep, a similar sized battery, and a GPS aerial. My own logger is a race technology one, again a GPS unit but it needs a 12V feed and the fag lighter in the F is in a terrible location! >I'm amazed you can corner at 1.1G with NCT3 tyres - how accurate are the >accelerometers? Supposedly its all accurate..... I was seeing around a G quite consistently. The lateral acceleration plot isn't as neat and tidy as the speed one so I didn't bother posting it. Al

19/10/2004 18:08:56 Ralph Um, I thought that data loggers and timing of laps were not allowed on these trackdays... Ralph

19/10/2004 23:14:01 Paul Nothard [QUOTE=Ralph]Um, I thought that data loggers and timing of laps were not allowed on these trackdays... Ralph[/QUOTE] I'm sure is plot is from a different day where they are allowed. ;) ;) ;) A very interesting read Alan. Thanks for posting it. P.

20/10/2004 10:49:12 Rob Bell [QUOTE=Ralph]Um, I thought that data loggers and timing of laps were not allowed on these trackdays... Ralph[/QUOTE] You're not. We've been talking about organising an 'autotest day' where these kind of devices can be encouraged - a kind of 'test day' if you like. The question is 'where'? Bruntingthorpe perhaps? A 'proper' track would be nice though...

21/10/2004 06:53:45 FRY That is a very interesting data plot Alan, many thanks! :) I personally can not see the problem of logging data as long as you do not view it on the day to improve performance and check lap times. But rules are rules...:rolleyes: Where indeed Mr Bell.....I am guessing that this requires a whole new approach for MGoT. An AutoTest gets us around the requirement for racing licences then!?

21/10/2004 08:50:34 Rob Bell [QUOTE=FRY]Where indeed Mr Bell.....I am guessing that this requires a whole new approach for MGoT. An AutoTest gets us around the requirement for racing licences then!?[/QUOTE] Yes, exactly! :D We can apply for an MSA licence that'll permit timing. Most usually it is used for those who like to park in cone 'garages' at high speed (no racing licence required! ;) ), but it should cover public liability for testing with timing devices and data loggers etc. If you were wanting to test engine mods, then a test day could be a good adjunct to a rolling road session (like the MGoT day at G-Force earlier in the year). What would be useful to know is how much interest there is for this kind of activity? :confused:

22/10/2004 07:00:44 FRY Yes, count me as interested. :D I think the hardest decision is where in the UK to hold the event. From the tracks I have been on (Castle Combe, Cadwell Park - Full Mountain Circuit, Bedford Aerodrome GT and Donington), I would suggest Donington. Looking at the diagram of Bruntingthorpe and speaking to people who have been there, seems quite a simple layout. Of course, it may depend on who will allow us to run for a reasonable price.

22/10/2004 11:17:11 Rob Bell I agree a proper circuit would be best - but cost is a significant factor here. Perhaps we could tie in with the MGCC race series test days, and share track time/ separate sessions with those guys? In which case, we'd probably be looking at the National Silverstone circuit...

22/10/2004 13:23:37 Alan Brooke [b]timing vs. logging[/b] The logger doesn't provide any timing or speed information to the driver, it's purely a post event analysis tool. As such it doesn't transgress the trackday rules about timing - I checked with Dave first! Conducting performance logging could be an add-on to an event like the North Weald day. For those who are interested in a data plot of their personal performance on some of the tests. I believe a straight line acceleration run was one of the tests - you could have you very own 0-xx mph runs recorded accurately. Bruntingthorpe is a good venue for speed work, a 2 mile runway allows reasonable rates of progress. We needed to do 120mph each way through a speed trap at the mid point of the runway using a 3l Omega. For work, honest! It's very, very open. In fact there are only 5 bends in the whole place and one of those you don't need to slow down for. For a bigger version of the North Weald day, possibly with two or more tests layouts running at once it would be ideal. As well as the runway and peri track there are a couple of reasonable hard standing areas. If I remember correctly the hire cost is around £4k for a whole day's sole use. If you share the track then its something like £60 per hour but you can only go around one way. [url="http://www.multimap.com/map/browse.cgi?lat=52.4956&lon=-1.1176&scale=25000&icon=x"]http://www.multimap.com/map/browse.cgi?lat=52.4956&lon=-1.1176&scale=25000&icon=x[/url] The line of dots on the northern side are some of the parked cars awaiting delivery, as a result the northern loop is not accessible. For those doubting Thomas's who think NCT3's aren't very good..... The particular bit of the plot shown here is the end of the start/finish straight and into Redgate. The reading stays over 1G for about 40m so it isn't an instantaneous reading through a discrepancy in the data. The values through the first part of the chicane are similar but over a shorter distance.

22/10/2004 13:31:42 Rob Bell Just imagine how much better that would be if you used some decent tyres Alan ;) ;) ;) LOL Regarding Brunty, there is no reason why we could lay out our own course with cones to add a little more challenge to proceedings - but I guess it all depends on what kind of data one wanted to look at?

22/10/2004 14:09:22 mikejnunn "The logger doesn't provide any timing or speed information to the driver, it's purely a post event analysis tool. " That depends on what extra's you have attached to the box, as there are a range of multi display readouts to give you instant info whilst on track. :D I know because I've just checked out the race logic website, and also asked how much a Vbox lite II costs. £££££ :(

22/10/2004 16:47:30 Alan Brooke That's why I bought a Race Technology DL1 for myself!! The VBox belongs to work. At the Donington trackday a couple of years back I was running a set of borrowed Dunlop D01J's. Extremely grippy tyres that reward being leaned on with ever more grip, until it rains.... Then they're a right bugger 'cos they've absolutely no traction on wet grass. Al

23/10/2004 07:03:34 FRY Alan, they weren't my D01Js per chance optained with the car from the previous owner of my car were they!? :D I haven't made the chance to use them yet as a) requires a support vehicle to carry b) a support team to fit them ;) and c) going back onto road tyres could be a huge disappointment. However, they do make very much talked about coffee tables in the lounge (I am sure people are screaming at this bit).

23/10/2004 18:50:31 Alan Brooke They were a set of used ones that Malcolm Gammons loaned me, they were too worn to be legal for the Trophy race series so were surplus to requirements. He had been planning to use them for a two driver or non-championship race but was kind enough to let me use them. Are they legal in the speed championship, or do you have to stick with List 1A rubber? Al

25/10/2004 06:55:08 FRY Well, the are road legal (just) so technically, I think I can use them. Saying that, I have not looked at the subject too deeply. I get the feeling they need a lot of heat in them, something that you do not really get a chance to do in the speed champinship with only a mile to run at a time. Also, it means I have to move the coffee and biscuits :eek: I just use my standard road tyres. Rob Bell, being the "oracle" might be able to say more?! Over to you Rob if anything to add. [QUOTE=Alan Brooke]They were a set of used ones that Malcolm Gammons loaned me, they were too worn to be legal for the Trophy race series so were surplus to requirements. He had been planning to use them for a two driver or non-championship race but was kind enough to let me use them. Are they legal in the speed championship, or do you have to stick with List 1A rubber? Al[/QUOTE]

25/10/2004 10:30:21 Rob Bell They're "1B" tyres, so you'd instantly find yourself in the RGM class :( Similarly with roadlegal track tyres such as the new Toyo R888 that I'd like to try... Alan, looks as though tomorrow's S&R track day at Pembry is a "Test day" - so it looks as though the insurance has been sorted out regarding data logging/timing equipment. Something to consider for future occasions?