Llandow Test

On Friday we headed to Llandow for a bit of familiarisation with the circuit and some more seat time.  It was also an opportunity for Dave to get his first drive of the car.  We planned a 90 minute session in the morning and 90 minutes in the afternoon.  Each session was split into 6 stints, with each stint consisting of two 1.75 lap runs with a minute break between them.  I took the first stint to check everything was OK and laid down an 84 followed by a 75, which would have been enough for a top 5 overall and a class win had I made it to the last event there.  Not bad for my first two runs on the circuit, but the weather was better, so the results are not directly comparable.  We alternated stints all day, which allowed the car time to cool down, although the tyres were badly overheating with the temperature of the day and inadequate time to cool down.

Dave's first run was tentative as he got to grips with the direct steering, slicks, wings and a sequential dog 'box, all of which were new to him.  He picked up speed quickly and got progressively quicker through the morning, soon getting the hang of the extra grip, especially in the slower corners.

We were testing out WifiLapper as a new data logger during the test.  A wheel speed sensor and brake pedal sensor had been hooked up with the rest of the data coming from the phone's GPS and accelerometers.  Sadly, the phone's internal GPS is poor and the data was not good enough to be usable.  The wheel speed sensor didn't work as expected, but the brake pedal sensor worked flawlessly.  Unfortunately, the poor quality GPS and the broken wheel speed sensor means that whilst I can be certain when the brake pedal was pressed, I can't be certain where it happened, so it's not much use!  There's onboard video to review and hopefully data from the RacePak logger, although I've not found time to check yet.

In the afternoon, a worrying wobble surfaced, which led us to the top mount on the upright.  The brand new rosejoint had some play on each side and was allowing the front wheels to steer a few degrees without moving the steering wheel.  At the same time, the gear lever developed some slack, preventing clean changes.  The lever was because of a broken bolt, but with these two issues and just 30 minutes of the session left, we called it a day.  The car had completed the equivalent of 4.5 sprint events in just 2.5 hours with nothing more than a quick spanner check over lunch.  That was good news, but now there's data to debug, work to be done on the data logger and some fixing to be done.  This might be the right time to fit that paddleshift...

2012 August Curborough Sprint

It all started over a beer (don’t they all?) whilst celebrating a friend's birthday.  I said to Dave Greenslade that the MIRA event I’d entered had been cancelled and I was considering entering the Curborough event on the same day instead.  “Fancy it?” I said.  “Yeah, alright then” replied Dave.  It was on!  Entries in the post, we decided to enter a team in the teams event as well as individual class entries.  Neither of us had been there, so it was a bit of a punt.

I’d not driven the ADR since the Dick Mayo thanks to the drama of my tow car breaking down on the way to Clay Pigeon and putting me out of action for Llandow the following weekend too.  I’d also not tested the new steering setup that had been altered to get more lock for the tight corners after wider wheels had reduced lock to practically nil.  Curborough being tight, I was worried, but not as much as the fact that I had no wets.  Not knowing whether I could retain the wider wheels, I’d held off buying a second set for the wet tyres in case I had to change to different wheels and the forecast was horrendous!

I drove through rain on the way to the event and dark clouds loomed ominously.  The forecast showed rain coming later on, but nobody really knew when or how much.  Dave arrived in plenty of time (yes, really!) and we walked the course to see what we’d taken on.  Our summary was that the first left was completely flat (we didn’t bother walking down there) and it really was quite tight in places.  Maybe 4th gear at best down the straight.

Dave was out first in the Evo Half and came back in saying it was like an AutoSolo.  Both of us have done quite a few AutoSolos, so that sounded good to me.  He also said the first corner was not flat.  With less power and more grip, I didn’t think it’d be a problem for me.  He’d done a respectable 69 second run though!

I headed down for my first run.  By the time I’d got to the line, the temperature gauge was showing 103, which was giving me palpitations!  I took off from the line and snatched second before the first corner.  It’s not flat.  I took a big lift and dabbed the brakes into the second corner.  I drove slow and steady as I had no idea how much grip there was and whether I had enough lock to get round the corners.  I gave it a bit more on the second lap and recorded a mid-61.  My target for the day was sub-60 seconds, so I was happy to be so close after such a tentative run.

After second practice, both of us had improved.  Dave was in a commanding lead of the class, 1.5 seconds clear of David Pearce in his vastly more powerful Impreza.  I was 0.36 behind my nemesis, Clive “I always pull one out of the bag on the last run” Wooster.  With only 40 cars on the entry list and just 60-70 seconds per runner, we had time for the first timed run before lunch.  Black clouds were looming, so it was now or never.

Dave was doing well and pronounced he’d do a 65.  I was doubtful and said I’d buy him a pint if he managed it.  He did.  That put him fastest of all production cars, irrespective of engine capacity.  Not bad for a £1000 car that’s not even seen a sponge for years, let alone anything to make it go quickly!  I shall be very glad to buy him that pint at club night on Tuesday; a well deserved prize.  I also improved, getting down to a low 58 second run, just 0.04 off Clive’s time.  As the rain came down during the final few cars, that appeared to be the end of competition for the day.

The rain quickly let up and the track dried over the lunch break.  When battle resumed, Dave was able to get within a few tenths of his earlier time.  His closest challenger went 2 seconds faster, eclipsing Dave’s best and taking the top position.  I went 0.7 quicker, but Clive lopped off a second.  Two bridesmaids.  Or was it…

We were so far ahead of time, there was a third run.  Dave took to the track, but was unable to improve his time.  Second place was all he could muster from his pretty special time.  The only consolation was that he recorded a 2.09 to 64 feet and that the man who beat him had enough power to be 8mph quicker over the finish line, which probably made the difference.

It was all or nothing and, as thunder and lightening crackled and sparkled around us, I headed to the start line early to try and get a run in before it was too late.  Clive was glued to my rear wing.  For the first time ever, I did a burnout up to the line to warm the rear tyres.  I lopped 0.1 off my 64 foot time, so it was worth it!  Clive was 0.23 faster still.  I was scrappy, but not overly so.  Coming into the second lap, I missed my braking point into the tight right-hander and started writing a postcard to the apex.  The rest of the lap was good until the finish straight and I missed a gear.  I finally found the right cog, but the time was gone.  I crossed the line at 96mph compared to Clive’s 108mph.

I came back to the paddock where Dave was waiting and he said I’d gone quicker, beating Clive’s previous best by a few hundredths.  I cheered with excitement.  Could it be that I’d finally beaten Clive with a scrappy lap that I thought was rubbish?  No.  Clive had knocked 0.3 off his previous best and pipped me again.  I’m sure that without that missed apex and fluffed gear change, I’d have scalped him on my first ever visit to Curborough.

Watch out for a data debug coming up soon.

2012 Dick Mayo Sprint Data Debug

It's almost two weeks since the Dick Mayo Sprint and so it's time to have a look at the data and see what happened.  This, however, is a special data debug as Tom Arnold has provided data from his fastest run (68.73) in the Kawasaki ZX-12 powered Spire GTR to compare with mine (66.57).  The two times were set just a few minutes apart, so utterly comparable.  Tom's Spire is somewhat heavier (at least 100kg) than the ADR, although Tom's a few kilos lighter than me!  The engines should be of similar power and the frontal area won't be much different.  Tom's tyres are a harder compound, so mechanical grip is likely to be less.

Speed vs Time

So starting at the left, the most obvious point here is that Tom appears to accelerate quickly off the line before slowing down around 40mph.  The reason for this is that Tom's data comes from a rear wheel speed sensor, so this is actually wheelspin.  My data is from GPS, so wheelspin is not shown.  Our 64 foot times are actually within 0.01 seconds according to the official results from TSL.  So this means that Tom's data is actually shifted to the right, which explains why his trace looks slightly off for the rest of the run.

Accelerating up Avon Rise, the cars are very similar.  I'm first to lift off going over the rise with a small confidence lift.  Tom appears to be on the brakes soon after, whilst I'm on the throttle again.  At this point, I'm about 7mph quicker before we both get on the brakes in a similar fashion, Tom perhaps slightly later.  We carry similar speed at the apex, but Tom picks up the throttle earlier, yet doesn't get as good a drive off the corner.  This could be because of how early he was on the throttle or it could be because my car accelerates better at that speed.  It's actually because Quarry is borderline between 2nd and 3rd gear in the Spire.  Whilst 2nd gear would be faster accelerating, it'd require an upshift very quickly, which might not work out quicker - something to try, Tom!

Once into the power band, Tom starts to close in over about 90mph.  The slower exit from Quarry means he's 3mph slower down most of the straight and he brakes earlier into The Esses.  Despite the earlier braking, Tom carries more speed through the apex and gets on the throttle earlier.  This works well, especially as I miss a gear between The Esses and Old Paddock, but whilst I take Old Paddock completely flat, Tom's slowing down.  There's almost 10mph between us at Old Paddock and it takes the whole length of Hammerdown for Tom to recover that speed.  This clearly shows the straight line speed advantage of the Spire.

Into Tower, I'm slightly later on the brakes than Tom and brake less, resulting in a higher apex speed.  Tom's trace suggests he realised he braked too early and accelerated into the corner as the dip appeared immediately after braking and before a long period of acceleration.  The trace also shows Tom was on the throttle early and this is shown in the peak speed before Bobbies, which was about 2mph higher.  I was again slightly later on the brakes by about 5 metres and braked harder, but slowed to an apex speed 2mph slower, the reason for which isn't apparent until you see the video.  I missed the apex by a country mile as I struggled to slow the car for the corner!  It all evened out by the time we both crossed the line at 84mph.

I should mention that there will be no data debug from Clay Pigeon last week as I failed to make it to the event when the gearbox on my tow car failed.  The next entry on the blog might be entitled 100 reasons not to use Brunel Ford given their ironically titled Service department's ability so far.  Many thanks to Torbay Motor Club who kindly gave me a refund on my entry fee despite me pulling out by telephone after signing on had begun.  I didn't ask for it and the sentiment is appreciated!  Here's hoping I make it there one day...

2012 Dick Mayo Sprint

Two events in, I arrived at Castle Combe keen to continue my form and take another class win.  Sports Libre had been split into <1800cc, >1800cc and rally cars leaving four of us battling in the small engined cars with Colin Early on his own in the unlimited class and a solitary rally car.  Colin took part in the battle for the category win, comparing times with us after each run.

The car had been significantly upgraded since the last event with four new wheels, new tyres, new hubs, new wing element and everything else you've probably read about on this blog.  I was keen to improve on my 68 second run of 2011.  I took it easy in first practice as you would an installation lap.  I was surprised to get a 70.06 on that first lap and it showed promise for later on.  Clive and Colin both put in a 68 and Tom Arnold was only half a second behind me.  In second practice, I put a bit more effort in but was red flagged when Tom had a spin at Bobbies.  In my re-run, I was surprised to put in a 66.26, which was 0.9 clear of Colin and 1.66 clear of Clive.  I was confident I could go quicker in the afternoon and Clive was clearly worried.

In the first timed runs, I followed form and went slower than practice with a 67.67, whilst Clive went one hundredth quicker than I had done in practice and Colin trailed me by two tenths.  Tom, meanwhile, had broken the 70 second barrier for the first time.  It was looking like rain and the last run would decide the winner.  Any of us could win it and I wanted it to be me.  I set off and took Avon Rise faster than I've ever done before, made a good exit from Quarry, locked the rear going into The Esses (brake balance needs to go forwards), kept it pinned through Old Paddock and made a brave stab at Tower (still more bravery required) before fumbling the downshift into Bobbies and accelerating towards the finish in the wrong gear.  It felt good.  A 66.57 was the result and to add insult to injury, Clive followed me through the timing beam with a 65.54.  Second in class.  Colin was unable to improve, but Tom put in a 68.73 to lop about 4 seconds off his PB.  He must now be considered a contender in class.

A quick skim of the data suggests that the car's not really much quicker than before, but I'm getting to grips with the circuit, braking later and carrying more speed everywhere around the apex.  Most intriguingly, I've had a photo of the rear wing sent through by Scott Boulton, which clearly shows the wool tufts on the rear wing.  Whilst the ones on the flap are showing attached flow, the main plane is showing separation.  It's stalled, so I need to lessen the angle so it's working like a wing rather than a parachute as it must be at the moment!

Rear wing tuft test

Unfortunately, the car needs yet more work as the steering lock was inadequate at best.  The wider wheels contact the steering arms at half the lock it had before, so I've had to get the mounts machined to get more clearance.  Keeping a close eye on Ackerman, it's going at add 50% more steering angle, which should be enough for paddock manouvres and getting around Clay Pigeon Raceway on Sunday.

Keep an eye on the blog for a data debug including a comparison of data between the ADR and Tom's ever-improving Spire GTR.  Here's hoping he doesn't go any quicker!

Data Logger Upgrade

I've ordered myself a IOIO (pronounced yo-yo), which plugs into an Android phone to provide 48 inputs and outputs. £37 delivered is an absolute steal!  It's just a bare board, so will need a waterproof box to sit in.  I plan to use Tupperware!  I've got a few sensors that I can hook up to it; wheel speed, fuel level, brake pressure, dry sump oil level, header tank water level, water temperature, oil pressure and oil temperature.  I have also purchased a selection of potentiometers from Maplin to measure clutch pedal position, throttle position and steering angle.

I've also found WifiLapper to use with it.  It's a great piece of software that uses the phone's internal accelerometer, a Bluetooth GPS unit and the IOIO for collecting data.  It shows the current lap delta on the phone's screen (red for slow, green for fast), so you know how well you're doing at a glance.  Best of all, if you have your laptop on the pit wall, it'll upload the data as you whizz down the start/finish straight.  Of course, that's not much use in a sprint where most events are less than a lap.

The software isn't an analysis tool, so with my RacePak G2X collecting RPM and the phone collecting other data, I'll need to combine the two.  I could do that in Excel, but I'd much rather use a better tool.  I've found Dashware, which seems to do the job for about £30 ($50) and also synchronises with the video from the GoPro to create video with a nice data overlay.

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