March 2019
29Mar
ECU Calibration Speed Sensor changes and front wing discovery
I've found out how to increase the responsiveness of the front wheel speed sensors. At the moment when I launch the car, it takes up to a second for the front speed sensors to start generating speed data, and it turns out to be a setting in the ECU that basically says the wheel has to complete a full revolution to produce a speed reading. Thanks to Stevie Turbo on the Syvecs forum for the hint. I've now set the front speed sensors to 1 which makes them produce speed data the instant either wheel starts turning. The video clip below shows front right sensor at the default value of 0, and the other at the new value of 1 and spinning both front wheels together, at the same rate, you can immediately see the difference. The flspeed shows a higher update interval. This should make for another improvement in the launch performance, and safety, because at Combe the car was almost at the 32ft marker before the ECU could determine what the undriven speed was. So it would hold the rpm at 3000rpm until it realised the undriven wheels were at the required speed to allow the rpm clamp to be raised.I fitted the front wing on the car in the garage, and with a GoPro camera resting on the wing, I flexed one end up and down to see if I could find out where the movement was that caused it to wobble so much. It turned out to be the pair of L brackets fitted to the top surface of the wing. The 4 bolts were all loctited, but the brackets were moving. So I removed the bolts, applied Loctite Blue 243, and a split washer, and tightened all four fasteners as tight as I could, and once the Loctite has cured, I'll refit the wing and repeat the test to see if the movement has gone.
28Mar
2019 Round 1 Castle Combe
Arriving on Friday afternoon, the first job was to walk the track, with Pete Goulding, Steve Miles and Steve Brown, the first time I’d done so at Castle Combe. Once notes were exchanged, we returned to the paddock and moved in to our paddock locations, and I unloaded all the tyres and tools from the van in to the trailer, so I could bed down for the night. In the morning, the car was unloaded, and I fitted the front wing and nose cone, and the shiny new Pirelli tyres, which were still wrapped in plastic. I was a little nervous about the noise check, I’d tested the sound pressure from the exhaust at home, using a calibrated sound meter, and it registered 109-111 dba. I really had nothing to worry about, the sound check showed a border line 106dba, and I had permission to run. I’d even acquired a silencer just in case, but that’s now safely stored in the van for a rainy day. The scrutineer didn’t appreciate I’d attached the FHR to the helmet though, and told me they are meant to be presented separately. Note taken.For Combe, the front wing was lowered to 21 degrees, and the rear 26, which gives a combined theoretical downforce of 475KG at 150mph. That was judged to be more than enough for Combe’s long sweeping bends.
First practice: I had reprogrammed the ECU with a new Launch and Traction Control configuration, but on the fresh Ultrasoft tyres, I really didn’t want to have another accident joining the circuit, so the first practice run saw me make a very cautious granny start, and a slow run around the circuit. I was worried that the new tyres wouldn’t grip from the word go, but after a few corners, I was pleasantly surprised by the traction.
First timed run: I made a more determined start, but getting the car off the line with the new light weight flywheel and twin clutch was proving tricky, but despite the slow start, I was soon up to speed, reaching 150mph on the 2nd lap on the approach to Avon Rise, but again, it wasn’t as competitive a run as I’d have liked. Disappointingly the new front wing was striking the ground over 140mph, so back in the paddock I raised the front ride height 6mm, to see if raising the wing would allow a higher top speed before it started moving.
Second timed run: I decided I had to try out the launch control, even though it was untested and the track leading on to the circuit was narrow, with barriers along the track on the left. Although the telemetry shows I backed out the throttle a fraction, the car just sat down and accelerated, with the rear wheels spinning at 20mph, the car rapidly picked up speed, as the engine revs were automatically raised as speed increased. I’m pleased to say, the ECU kept the car pointing in a straight line. My 64ft time of 2.55s was pleasing considering I’d not tried it before. The important thing for me was that the launch was safe!
I’d done enough on this run to qualify 10th for the Run Off’s, with a 123s run, and I was 7s quicker than my personal best from 2018. The front wing still wobbled, there was nothing else I could try, so I just had to ignore it during the run off’s and focus on my driving.
Run Off 1: At around 4:30pm we were sent to the start area, and after a short wait I lined up for my first go. Another great start, with a 64ft in 2.56S, and I was straight on the pace, recording a 121s run, again a 2 second improvement. Not as quick a time as I’d hoped for, but the new tyres inspired so much confidence, I felt safe, and my times were dropping.
A long break followed, after Heather Calder’s rear suspension collapsed during her first run off run, sadly the car had to be collected on a low loader and Heather and Colin scored no points. My next run was about 30 minutes after the first, and by then it was well after 5pm with the track and ambient temperature dropping all the time. Better for the engine, but not for traction.
Run Off 2: Again, the launch control worked well, though it was 2.60s this time, maybe it was the cooler tarmac, who knows. I threw the car in to the corners, getting braver all the time, and I recorded a 119.97s run, placing me 5th in the Run Off’s and a very strong 3rd overall in the championship. I had to lift on the approach to Avon Rise, at 149mph, which was like hitting a brick wall. The wing was really striking the ground very hard, and the titanium blocks underneath the end plates, were producing showers of sparks.
I thought I’d cured the wing issue, but it seems to have returned with the replacement wing and drop brackets. I didn’t want to risk damaging the wing, there was no point doing so anyway, it’s the first event of the year, with a long season ahead.
There were no other issues with the car. The 7.25” PowerTrain clutch worked great; the brakes were good with no leaks from the refreshed brake lines; the biggest revelation of the day, was the grip from the tyres. And after 5 runs at Combe, they still looked in great condition, with just a small crumb on the surface, but importantly, no need to clean them with the heat gun. The wheel speed sensors also all worked, launch control worked, and traction control worked really well too. I had it on the minimum setting for Dry tyre sizes for all five runs, and it just did its job, and kept the rear end planted on the exit from the chicanes. The gearbox worked well, with no missed gears or false neutrals. No oil leaks either; in fact, the only thing I had to do was add petrol during the day. The relocated exhaust is definitely louder when sitting in the car. I’ll have to try ear plugs at Anglesey to see if the loud sound can be silenced. It hurt my ears. The heat sensitive label on the top wishbone, which is closest to the exhaust, only reached 88C so at least I won’t have any issues with blowing exhaust over the top wishbone.
However, the signs are good for a great season this year. We’ll have to keep our eyes on the V8’s still, but the Pirelli tyres, and the extra point scored for beating records in the earlier timed runs, may produce a few unexpected results this year.
The next round is Anglesey on April 6th, where with more determination, the results should come again.
27Mar
360 degree video
This is a video taken using the Kodak Pixpro VR 360 camera. I'll raise it up for the next round so the footage is more useful.24Mar
A great result
5th in the Top 12 Run Off's and I took 11seconds off my PB from 2018, so a good solid start to the season. I'm joint 3rd overall in the championship and Anglesey is the next port of call in two weeks. There was nothing to do on the car, just add petrol and drive it, just how I like it. Even my new launch and traction control settings work, and the car is far safer departing the start line now, with everything nicely in control, and the ECU doing what I programmed it to. Very happy.13Mar
All ready for Combe
So with the car now finished, and ready for the first event, its time I stopped worrying about car-prep, and diagnosing faults (though I do enjoy doing that), and started focusing on my performance. So to that end, I'll be going over my notes from last year, watching some on-board footage, remembering the rise in performance as the year went on, and hopefully, I'll be in a good place when I line up for the first practice run. To that end, thats the last of the updates for now. Its time for some mental preparation.11Mar
Front wheel speed sensor fixed
The issue with the front left speed sensor was simply it had too large a gap to the trigger wheel, its meant to be < 2.5mm gap, but it was around 3mm so it worked some of the time. I've reduced the gap and its testing out OK now.10Mar
Speed sensor wiring
I've wired the rear sensors in to my X10 harness, and they both now work 100%, so no more issues there I hope. I'll see how it goes at Castle Combe, and may use connectors again, but if they work, I'll probably just leave them alone. Speaking of Combe, I've been told I will wear my championship number 9 on the car, so the entry list will be reissued in due course with the right numbering.9Mar
Combe finals
The entry list is out for Castle Combe Great Western Sprint, and the organisers have put me down as car 16, and Pete down as 15, even though we finished 9th and 11th in the BSC. We've both emailed the organisers to let them know their mistake. I wonder how that even happened?7Mar
Fault found
I've traced the wiring fault that caused the rear speed sensors to fail, its the 3 pin ITT mini-sureseal connectors which are playing up, so I'll remove them and wire the sensors directly in to my harness to the X10 expander, which will cure the issue permanently. The Driven Speed is set to the maximum speed from the rear axle, so that'll mean if a sensor does fail in the future, the axle still returns the driven speed, as I doubt both sensors would ever fail at the same time. I'll regularly check the ECU for errors from now on. I des****ed one sensor at Blyton when the CV bolts sheared, as the sensors are positioned just below the CV bolts, and the breakage meant the sensor was hit, shearing the end off.I've also found the source of the oil leak on Wednesday, it was the Mygale oil level indicator, which is a threaded clear perspex cap that screws in to the side of the sump on the gearbox. It had split, and was allowing engine oil to escape, quite a bit in fact. Just as well it didnt fail on a sprint when I'd have been pulling some serious lateral G. Oil would have gone everywhere! I'll either replace it, or swap the oil level indicator out for a blanking plate, which would mean it wouldnt happen again. It took me half an hour to clean the oil up, it was all over the gearbox and the diffuser. At first I thought the catch tank had overflowed, but both the gearbox and oil bottles were in fact empty, which made me have another look for the cause of the leak.
6Mar
Testing at Mallory
Testing went well, with a very wet but drying track, and just 3.5 hours, the time soon went by and I completed around 30 laps. Mechanically the car was perfect, with no issues. However, I've now got three wheel speed sensor faults, which hampered traction control testing, so I'll work on resolving those issues this week. Apart from that, it was great to get back behind the wheel again, and running on 3/4 power due to the lack of grip, the car performed really well, with huge grip from the Michelin tyres and the revised diffuser made a big difference. Brakes were good, the new clutch worked perfectly, the replaced suspension stood up to the tests, and the front wing just grounded out at 130mph, but thats because the Michelins are not as tall as the Pirelli's so the wing was running 10mm closer to the ground than was ideal. Not a issue. Shame I didnt get to sample the new supersofts, I'll have to leave that for Castle Combe in a fortnight.
3Mar
