Locost: Snetterton Damage Report

We made it to Snetterton; its official. I’m going to leave it until later to give you a run down of what it took to make my little red car trackday-ready. However, its fair to say the six weeks leading up to Snetterton left me feeling both physically and mentally achy.

Having just performed a two day fabrication marathon on Saturday and Sunday (Feburary the 11th/12th; for posterity), the car was sat on the trailer ready to go at 7pm. After a quick batch of takeaway pizza and beer we were ready for bed; we had a 5am start the next day to get to the track. “We” was myself and my younger brother Alex, who is now the official truckie for OgilvieRacingTM and second mechanic (he fit the passenger seat in the car the day before).

The two hour drive to Snetterton went without a hitch and we rolled in at about 7:40am, giving us 50 minutes to unload and sound check the car.

Sound Check

Every circuit has a different static noise level which your car must pass to be allowed on track. Snetterton’s static noise level sits at a deafening 105dB, which mean’t I was quietly confident the car would sneak in under the volume radar. While sitting in the cue waiting to be tested we both got quite giddy, as it dawned on us we were actually at a race track track and it was really happening. Hence the following terrifying selfie.

We were surrounded by Sevens of many shapes and sizes, Subarus, RGBs, Hatchbacks and a multitude of MX5s. The atmosphere was quietly buzzing as everyone was excited to be there and not taking themselves too seriously.

When our turn came around the operator asked us what type of engine we were running, I said “A 1300”, and he explained that we should bring the car up to 5000rpm and hold it there for the test. This was based on the car being at ~3/4 of its peak RPM, which was a fair guess as I was  planning to shift between 6500 and  7000rpm. Fortunately we breezed through with a reading of 100dB; even though I was running a weedy little motorbike exhaust can. This was our first achievement of the day.

Run 0 – Sighting Run
Data: None

Following the drivers briefing we were required to perform three sighting laps in a group of approximately 20 cars, to get a feel for the layout of circuit and any slippery bits. Given that it had snowed all weekend the track was very greasy and gave me a few surprises even at low speed. I was following a Porsche 911 , which was both gorgeous and  incredibly hard to keep up with at full chat! I took these laps to get used to the gearbox and pedal layout, having never driven the car for this period of time before. That said, it took to the track rather well and had a lot of front end grip.

Having completed my three laps I returned to the pits,.

Run 1 – A trip in the mud
Data: LOG022.TXT

Feeling confident, my brother and I jumped in and went for the first official
drive of the Locost at Snetterton; this didn’t last long. We did a slow out lap to
get a feel for the grip level and then started to push a little. The car felt good,
the gauges looked happy.

Coming into T6 (Oggies) on our first flying lap I over cooked it on the brakes, expecting
there to be a lot more grip than there was; doh! With a little steering angle the
rear would start to step out, and with less steering angle the front would plow on, giving me two options. Go off front-first, or off rear-first. I chose front.

Fortunately the car kept turning as it went into the mud and we were almost back on
track once we came to a stop. I slowly got the car back to the pits, thankfully without having to be rescued, and we were surprised to find that the car was not damaged at all. Just slightly sad looking. With an old towel in hand we were able to clean the car to an acceptable level and get ready for another crack at it.

About thirty seconds after we got into the garage my far-more-trackday-experienced-friend Dan rolled in covered in mud. He had also gone off at Oggies, which made me feel a lot better about my driving!

Run 2 – Before Lunch
Data: LOG023.TXT

Given how slippy the track was I made some setup adjustments before heading out again. I raised the Front Ride Height by 3mm at the front dampers (1.5 Turns, ~1.6 Wheel/Damper Motion Ratio giving +4.8mm Front Ride Height), which also happened to reduce the Front Static Camber (due to the camber change in bump) and raise the Front Roll Centre; each of these helping to stabilise the car. I also increased the front damping by two clicks to slow down the initial turn in response. The car was a little two reactive for me at this time of the day.

The car felt great following the changes I had made and gave just a touch of understeer, with on throttle rotation on exit thanks to the open differential.

I only managed four laps, including my in and out laps, as I could see a big drop in oil pressure on the gauge in T7 going onto the back straight and I wanted to make sure the car was okay. That said, I drove the car as fast as I could while I was on track; it appears all mechanical sympathy goes out of the window once your at speed!

Having checked the data over lunch it appeared that the engine temperatures were safe and the oil pressure never dropped below 20psi. That said the oil pressure was dropping off in right hand corners, from 40/50psi to 20psi, but never going to zero.

It was likely the engine was sucking some slightly thinner aerated oil in these corners. To be safe we topped up the sump to the maximum amount I’d designed for. In fast right hand corners the oil pressure stayed rock solid; Turn 3 (Palmer), Turn 4 (Hamilton) and Turn 8 (Brundle).

Run 3 – PM Brake Bias Forward
Data: LOG024.TXT

Before lunch I was struggling to trail braking into the T2 hairpin (Montreal) without some rear inside locking; especially as I released the clutch. I decided to move the brake bias 2% forward to help with this, which was ~2mm at the balance bar.

I went out again with Alex in the passenger seat, so setup wise it wasn’t going to be too representative, but it is plenty of fun with a passenger on board.

Unfortunately I had forgotten to put my helmet strap on! Being smart I did an Out/In lap and fixed my helmet in the pit-lane. This coincided with a red flag on track so we ended up sitting in the pit lane for a little while looking at a red flag (the data suggests almost 6 minutes). We noticed the engine getting properly hot at this point, and blowing a little steam, so we took it back into the garage to cool down.

I didn’t notice it at this point in the day, as I already had enough to think about , but the fan had failed; maybe even when we towed the car to the track on the trailer. The data showed very high pit lane engine temperatures all day, however the car had not sat still for long enough for this to be an issue; until this red flag.

Run 4/5 – Overheating!
Data: LOG025.TXT / LOG026.TXT

We went out for two short runs (two timed laps, three timed laps) but clearly the car wasn’t running right. Once we brought it back in and it was finally clear to me that it was overheating.

Once it had cooled down I opened the water cap and topped up the system, a lot; too much . Following the pit-lane incident in Run 3 the engine had spilled a lot of its water onto the pavement (I have no expansion tank) and was now running sub-optimally. There was still water in the head but the top pipe and the top of the radiator were completely empty. Flow across the thermostat would have been very slow indeed.

Fortunately I had dodged a bullet. The water was running clean and the oil was also clean; so no blown head gasket.

These runs did show an improvement in oil pressure in right hand corners, which was a relief. Topping up the sump had at least made a measurable difference.

Run 6 – Short Lived Glory
Data: LOG027.TXT

With the track having fully dried out, and my car back in tip top health, I went out for what would be my final run of the day; riding solo and at race weight with a little less than half a tank of fuel.

This fifteen minutes was what the day was all about. The track had gripped up nicely and the car was running the best it had all day. I kept pushing the braking points until I was starting to under rotate the front inside wheel and felt I had quickly found my limit.

The Nankang NS2R’s actually came in quite quickly, which was a surprise for a Medium compound tyre, and gave really good feedback. My lines were pretty lame and I was only pushing the kerbs on corner exit, but I was having a lot of fun and going faster each time around.

Coming into T4 (Agostini) on my fifth lap I felt a large front end vibration which suddenly disappeared. This was accompanied by some mid-corner understeer/weirdness and a general feeling of confusion. Once I limped around to T10 (Bomb Hole) I was flagged by the marshals to return to the pits. Upon my arrival the man in orange explained to me that I had broken my front splitter and it was waggling all over the place; fair enough!

At this point I parked the car and basked in my own smugness. I had experienced a small glimpse of all the fun that could be had doing track days and was relieved that I had made it this far. Of all things to break the splitter was the easiest to fix, but it would have to wait until the car was at home. This felt like the right time to pack up and call it a victory.

Final Thoughts

On paper, we didn’t have a hugely successful day. The car didn’t turn that many laps and suffered a few engine teething problems along way. However, that was never what this was about. The Locost has been the accumulation of almost ten years work, and started life in my young teenage mind going on fifteen years ago.

On Monday the 13th of February 2017 I achieved a life goal: I built and trackdayed my own little racecar; and I’m still buzzing about it! I have definitely caught the trackday bug it. A car like this, driven in a track environment  is a massive endorphin hit.

What really surprised me was how well the chassis handled on track. In the tight car park events that I am used too, it lacks rotation at a high steering angles and tends to plow on if you push it too hard. On track it eats up kerbs, rotates on demand on corner entry and, if your willing enough to use it, has great peak grip in the mid-corner. The small adjustments I made at the beginning of the day gave me a measurable change in handling, and the engineering knowledge I had learn’t in motorsport was both applicable and effective.

The Locost has always held a special place in my heart. Uncountable hours have been poured into it, however it hasn’t always been that usable. Now that I can drive it on track, I think I have fallen in love with it all over again.

Time for more trackdays, lots of development, and endless fun. Success.

 

Engineering Notes

Just a few bullet points about the car, which I will likely elaborate on in the future:

  • The engine was definitely down on power compared to where it could have been and is in need of a dyno session in the very near future. This was also reflected in poor drivability out of corners.
  • I am getting spikes in RPM from the ECU which suggests the ignition system needs more filtering/shielding. This tended to happen at the same engine speed each time, supporting my electrical noise theory. These could be felt as flat spots while driving and were obvious in the data.
  • The fan is dead, long live the fan; replace the fan.
  • The splitter needs supports back to the chassis at the forward edge; clearly.
  • Having to add so much front ride height to balance the car suggests the mechanical balance is too far rearward, and I need to get softer rear springs, stiffer front springs OR add a front anti-roll bar.
  • The GPS was broken on my datalogger all day and it needs to be torn down and investigated. This was also the case when I drove the car in the week, but I didn’t have time to fix it. It has been tested and known to work, so it was rather odd.
  • The car needs a water expansion tank. Badly.

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