May 2023

Pembrey prep

I have cleaned all ten tyres, and given the car a clean since it was covered in dust and grit from Lydden. Thats a dustpan full of rubber crumb off all ten tyres.


I've made changes to the traction control, to increase the torque reduction, by increasing the base gain value. I'll see if this makes any difference on the first practice run. I've also been successful in getting the Dash4pro to display "BIG" when I adjust the tyre sizes through the traction control multiplier switch on the steering wheel. It also says "WET" or "DRY" for the other two tyre choices.

I've also changed the config to increase the logging rate for Yaw Angle and wheelspin, since these were logging too slowly to allow a full diagnostics of the wheelspin.

Paint has been applied to the heave spring mechanism.

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FTD winner, Run off winner, two podiums, and a new class record at Lydden

The weekend went far better than I was anticipating, winning the first run off, with a time 1s below the existing class record, which turned out to be the fastest run of the day, bagging me my first FTD award of the year, and the first FTD for me at Lydden Hill.

I have reduced the points defecit to championship leader Pete Goulding, from 14pts to 7pts, and I am still in second place overall.

Friday

Arriving Friday afternoon, I bagged my usual spot in the paddock, and set the car up. Prior to leaving Leicester, I'd already fuelled the car, filled the air bottle, cleaned all the tyres etc, so that meant I had a relaxing afternoon, waiting for others to arrive. What was apparent when I arrived, was the amount of dust on the track, and in the paddock. One of the track staff was busy pressure washing the startline area, trying to clean it up. Clearly using the venue for rally-x, means, its always going to be a dirty track, but would it affect the grip levels on Saturday?

Saturday

Up bright and early, I moved the car behind the van and trailer, and got ready for scrutineering. Last year we discovered my seatbelts were out of date, and I broke the steering wheel on the first timed run, so with that in mind, I was quite happy to have the car checked, not expecting to find anything wrong. The scrutineer pointed out that my crash helmet expires at the end of 2023, then asked me to provide stickers with PUSH printed on them, next to the pair of blue push button battery isolator buttons. Er, ok. I got the label printer out, produced two labels, and promptly stuck them on the car. That was it, nothing serious, and a scrutineering sticker was provided and I was good to go.


Having walked the course on Friday, I walked it again with Pete Goulding, just to have another look at the lines. Practice was soon underway, and some of the drivers clearly needed it. One Porsche owner, decided to turn right on to the rally-x track, at Pilgrims, which brought out cheers and laughter from the onlookers. He promptly turned around and drove back towards the circuit, which then caused concern as another driver had set-off and was rapidly approaching the same piece of track that the Porsche was headed for. The ever alert marshals were soon waving red flags, and the Porsche headed back to the paddock, tail firmly between legs. A course car was then dispatched to cone off the entrance to the dirt section.


On to our first practice, I set a good time, and got used to the speeds and g forces. I had recovered from Manflu from the weekend before, but still had a very dry throat after the first run. No dramas for any of the BSC team, and we were then readying for the first timed runs. Again, my speeds improved as did my time, and I was on the large 300mm rears, which were producing some good grip, despite their age. I'd programmed the ECU to use the Intermediate Tyre size for the 300's, leaving the Wet and Dry tyres sizes programmed for the smaller 250mm rears. One thing I couldn't get working was the Dash4pro to display the word "INT" when I had the Intermediate tyres selected on the steering wheel. I'll try and sort this out in the garage at home, when there is more time to focus.


So on to the second timed run, which was the first run-off. I was back on the nine month old Ultrasofts, which I'd cleaned at home with the Greaves 3D heat gun, and I was fully focused on putting in a good run. I set off, got almost everything right, and the timing screen showed 66.13s, which was over 1.5s quicker than my T1 time, and over a second under the class reocord! Was it fast enough to win the run off though? Back in the paddock, the results were published very slowly, using a PDF based results system, so we had to discuss amongst ourselves what time we'd done, and it was apparent I was fastest, by over half a second to Smiley in second place. Once the results caught up, I realised I'd done it, and scored an extra bonus point for breaking the class record. 26 points, thank you very much.

Whilst checking the car, I noticed another one of the clear plastic sight gauges on the side of the gearbox had split, and was allowing engine oil to leak down the side of the gearbox. This happened before at Mallory Park when I was testing, and I'd bought an aluminium blanking plug off Mark Bailey, which I carried with me. So I quickly undid the pair of M6 fasteners, prised the Mygale part out the box, and pushed the blanking plug in, losing about 100cl of oil in the process. Warm engine oil gets everywhere when you spill even the tiniest amount, and I spent the next 5 minutes cleaning the mess from the diffuser. For this event I'd added an extra litre of oil to the sump tank, because I'd seen surge in the oil pressure at Blyton the previous weekend, and this obviously raised the oil level, cured the surge, but revealed the issue with the leaking sight gauge.

On to the third timed run, I was back on the 300mm rears, and set off at a good pace, but starting the 2nd lap, the rear end suddenly stepped out, and I had to get off the gas to catch her, but still recorded a 68s run, and it was just qualifying after all. I think I know the cause of the oversteer, it was me giving it full beans on 4 year old rubber, and the track surface changes camber quite rapidly, so I was just caught out. No harm done, and it got a reaction from the crowd of people watching :D

On the fourth and final timed run, which was the second run off, I was back on the 250mm pirellis, having cleaned them over lunch break, and I lined up behind the blue SBD DJ to take my run. The DJ set off, and I moved forward to the line to take my run. Sadly, one of the National B drivers was starting his second lap, when he tagged the steep kerbs on the apex of the corner, which launched the car in to the gravel, breaking the rear wishbones on both sides of the car.



This brought the red flags out, and I sat for 17 minutes, with the engine off, watching the recovery. When it was then my turn to start, I'd lost my focus, and did a low 67s run, which was only good enough for 2nd place, and 24 points. It was a quick run, but I didnt stick to my plan of which gear to use for the corners, and that cost me a few tenths. There was also oil down on the circuit, covered in cement powder, but you could definitely feel less grip in some parts of the track. Shame.

The next job was to load the car up, and wait for the prize giving, where I collected my trophy, and made a quick speech thanking everybody concerned. Then at 5:30pm after finishing loading all the gear back in to the van and trailer, I set off, arriving back in Leicester around 8:45pm.

Here is the video of my FTD run.

Final results

Total fuel used was 6.364 litres of 102RON, over a distance of 9.5 miles (5 runs).

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Results service

There is a mind boggling complex set of Google Spreadsheets that hold all the scores this year, written and managed by Simon Wallis, and they're excellent, accurate, and up to date, but, aren't exactly easy on the eye. So I've been developing a python program to scrape the results from the published Google Sheets, prettify them, and generate an html page with the more user-friendly results on. The Python code runs from a Raspberry Pi Zero, at home, and I can send it emails to turn the processing on and off, and also to change the configuration so it knows what web page to scrape, and the name of the web page to create. It was working up to a point at Blyton, but a bug stopped it on Sunday, which I think I've now cured. This page should be live on Saturday, so keep an eye on it and the results should appear as they're entered in to the Google Sheets. Fingers crossed.....

Graham's python BSC results scraper

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Four Podiums and a run off win at Blyton

Suffering from a very heavy cold all weekend, and sounding like a poor Barry White impressionist, with a horrible sore throat, I soldiered through the weekend at Blyton to win the first run off on Saturday, and finish third in the other three. Four podiums :D

Arriving at the circuit we were told no parking on the grass, so race cars had to be unloaded, before the trailers were then reversed on to the grass, whilst keeping the front wheels of the tow vehicles safe on the tarmac. It was a bit fraught unloading everything, and I'm glad I had my waterproof steel toe caps on, as the grass was a total bog all weekend, your race boots or trainers would have been soaked through in seconds. The weather remained pretty good all weekend, allowing for all ten timed runs to take place in the dry, until we came to pack up on Sunday afternoon when the heavens opened, and the T5 run was abandoned. The rain was quite refreshing after the heat though :D

Saturday (Eastern circuit)

I tried the heave spring on the practice run, with three packing spacers. One of my old Gopro Hero's was stuck on the rear of the engine cover, to film the operation of the spring, and I felt the car was quite bouncy. Watching the video showed that the spring was being compressed before any real speed had been reached, so I removed one packing spacer, and tried it again on the first timed run. Again, the car still felt like the spring was operating earlier than it needed to, and the video again showed that that was the case, it was being compressed before any significant downforce had been built up. So back in the paddock I removed a second spacer, and got myself ready for the first run off. Adjusting to the softer 1100lb springs was taking some getting used to, the car definitely felt like it had more grip, but the 2022 Avons were still not giving me the grip I needed to drive faster. For the run off I had the Pirelli Ultrasofts, now nine months old, fitted, and I lined up and gave it my all for the run off. And I won it, which was a great result. With the Pirellis' on the car, I was two seconds faster, that is the difference between the two brands.

I refitted the Avons and qualified easily for the fourth timed run, and then put the Pirellis' back on again for the second and final run off, but could only manage 3rd. It had been a long and busy day, and I was definitely suffering. After the fourth run, I put the 300mm wide Ultrasofts on the car. These are four years old, and I cleaned them using the Greaves 3D gun during the week which seemed to restore the surface back to a tacky and grippy finish. I had to alter the tyre circumference in the ECU to make sure the traction control didnt have a wobbly, and drove over to the start to take my fifth run. Setting off, the acceleration was quite good, and corner after corner I found more and more grip, on the Eastern circuit layout. Returning the pits, it wasnt my fastest run of the day, but neither was it my slowest, and the car felt fine, with no vibration or wobble from either of the rear tyres/rims. A useful test.

After the prize giving, the FTD went to Goulding but was slower than my 2022 record, I decided against going to the pub, and instead ordered pizzas using the Justeat app, and we all sat and ate in Simon Bainbridge's bus. Simon had had a huge crash during the afternoon, after losing body work and downforce, and he was out as the damage was too bad to let him continue. Steve Browns Empire Evo dropped a valve on the first practice run in the morning, and he was out. Possibly for the remainder of the year, while he licks his wounds and tries to decide whether to continue with the current car. Its rare that the Empire finishes an event, its not been the luckiest of cars to own/run.

Sunday (Outer circuit)

Sunday dawned cool and overcast for a second day, and soon everyone began preparing their cars for the outer circuit. I was still running the lower downforce configuration from Saturday, but would later increase the front and rear wings to try to get some more grip. I was again third in the first run off, and third again in the second run off in the afternoon, which was held in much higher temperatures than the morning. Indeed when I got home sunday evening and looked in the mirror, I was quite red from sunburn. In all it was another good, if not tiring, day. Whilst packing the cars away after the final runs, the heavens opened, and we had a very heavy downpour which was actually quite refreshing to stand in. I stayed for the awards, and collected my glass ware from the weekend, eventually arriving back in Leicester around 7.00pm

Conclusions: The heave spring was a great success, however I now need to tune the chassis to make the most from it, and am considering dropping to 950lbin springs at the rear, to see if that gives me even more grip. Grip is key this year, and me running a set of Avons and Pirellis is definitely hindering my performance. I wonder how we'll all cope next year. The automatic gearshift from 2nd to 3rd worked really well. Off the line my best start on Sunday was a 2.1 64ft, and I've got the ECU changing up at 6000rpm in both 1st and 2nd, as the engine runs lower boost in 1st and 2nd so it makes sense to get in to 3rd gear as quickly as possible. Coming out the wiggler on Saturday in 2nd, the car does of course change in to 3rd gear automatically as I accelerate, which took a little getting used to, but it certainly didnt hinder me.

This is a video taken from Sunday on the Outer circuit of the heave spring in operation.

Results

Total fuel used Saturday, 6.547 litres of 102RON over 9.6 miles (6 runs)
Total fuel used Sunday, 5.455 litres over 7.5 miles (5 runs)

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Oil filler cap revised

I've made a few minor changes to the oil filler cap, to allow it accomodate the 5mm thick o-ring and to improve its appearance. Two are on order with 3D People, delivery is expected next week.

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Setting up the heave spring

I had some setting up to do before I can run the heave spring. I had to determine the minimum length of the telescopic shaft, to ensure that it doesnt bind when the suspension is fully compressed. To do that the weight of the rear of the car is supported by the trolley jack, which allows the two spring platforms on the Intrax dampers to be fully undone, which removes any load from the springs when the car is placed back on its wheels. Rather than fitting the wheels, I placed wooden blocks below the ends of the rear wishbones, and then gently lowered the car back down until the dampers were fully compressed, sitting on their silicon bumpstops and packing spacers. Measuring the length of the dampers, they only close 20mm under full load, and this is reflected in the data that I have captured when the car has been driven, since all four dampers have a position sensor fitted which returns their displacement.

With the dampers compressed I then adjusted the length of the telescopic shaft, so that it still had some 5mm of compression left. I then locked the locking nuts on the two M8 rod ends, and marked the positions for reference. With the car then lifted back up by the trolley jack under the gearbox, I wound the spring platforms back again, and measured their lengths to ensure that the same preload was applied to both 1300lbin springs. Next I could remove the telescopt heave spring shaft and fit the BR38 black Penske rubber. With the car then lowered back on to the wooden blocks, I could add a few spacers next to the rubber spring, to force the spring to work earlier in the compression of the rear suspension. The spacers can be easily added or removed, and this provides fine tuning for the operation of the heave spring.

I have purchased all four grades of the Penske bump rubbers, so I can easily switch to a softer or harder rubber, if I dont feel that the heave spring is providing enough assistance. I have also ordered some Eibach 4inch long springs, in 1100lbin and 950lbin, which I will try at Blyton. The reason I've gone for shorter 4inch rather than 5inch springs is two fold. First the 4inch springs are obviously lighter, and I dont need the travel of a 5inch spring anyway, as the dampers compress less than an inch. Sadly Eibach dont sell 3inch springs, otherwise I'd have bought them in that length.
Here is a video showing some of the work in adjusting the heave spring to allow it to fit and operate safely.

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