Continual Improvement Using Circuit Tools

Now that I have telemetry being collected reliably and consistently, am able to over lay it on to video and can interrogate that data in a useful tool I thought it would be interesting to share what I’ve learned so far about my driving.

I’ve got data from 2 separate sessions at Bayford Meadows that I’ll use for this discussion. On the 4th July I recorded 29 laps while a week later on the 11th I recorded another 19. The weather was dry across both days and although one was a bit cloudy the temperatures and times were largely the same. My best lap across the 2 days was a 0:59.92s while on the second day is was a 1:00.25.

I also have some data from the 6th of June where I recorded at 0:59.82s. The weather on that day was very warm though so I don’t plan to refer to that data here. For this post I’ll primarily be working from the best lap of 1:00.25 – here’s the full lap.

I’ll compare this lap against the 6 sectors that Circuit Tools has setup for Bayford and see what I can learn about my driving.

Sector 1 – From the start line to entering Turn 2

Getting through turn 1 as quickly as possible is key to a lap at Bayford as it’s at the end of the longest straight and at the start of the 2nd longest. It’s also a fast corner so I need to carry as much speed through it as possible. It’s the corner I wanted to concentrate on the most in this sessionso that I could feel consistent through it. I’ve been told that it’s possible to take the corner flat out but this isn’t supported by my data.

My fastest trip through the sector was on lap 6 where I completed it in 10.76s. I recorded my quickest lap immediately afterwards where I was 0.12s slower through here. Through out the first 15 laps of the session I was consistently within 0.2s of this time – after that I tried to get through without braking and was consistently slower – by as much as 0.6s compared to my quickest time.

Sector 1

If I take one of the laps from the second half of the session I can see in the traces that keeping my foot on the gas on turn in forces a wider line through the corner. In the example above, the green line represents the lap where I lifted while the red line is the lap I didn’t. You can immediately see that in the green line the speed is much smoother and that by braking I can stay on the racing line and ultimately achieve a higher top speed down the straight. Without lifting, the extra friction of the Kart sliding through the turn slows it down a little but this happens later in the corner by which time it’s better to be accelerating. Although I ultimately end up on the same piece of tarmac by just lifting off the accelerator a little I’m able to carry more speed through the corner and get a slightly higher top speed – Circuit Tools records the difference as 1.3kph and 0.44s by the time I brake for Turn 2.

Sector 2 – From Turn 2 to entering Turn 3

Sector 2 is a short section which is predominately Turn 2, the exit of which governs your speed down the straight into the hairpin Turn3. My data tells me that the fastest way through this corner is to brake in a straight line, hard, just before the kerb on the right hand side ends. Stay in the middle of the track and turn in at the start of the kerb on the right for Turn 2. The slowest point is the apex of Turn 2, and then it’s foot down on the gas in the shallowest curve possible down the straight. The data I have shows I’m pretty consistent in this part of the track. In fact, 9 of the 18 laps I recorded on the 11th were with 0.2s of each other in this sector.

Sector 3 – Turn 3

This is the shortest sector on the track at at only 6 seconds is all about the braking and Kart control. Comparing my fastest and slowest times through this sector (a difference of 0.27s) I can see that braking early allows me to control the Kart and stay close to the kerb on the inside and then use all of the kerb on the outside. Braking later forces me to brake harder which takes me deeper into the corner, has a slower speed and sets me up to not use the full track. Being able to use the full track gives me a higher top speed approaching the braking point for Turn 4.

You can see the difference the two braking points give – in the red box I’m about 60cm away from the kerb.

Looking at the video would suggest that on my fastest lap there is more speed available – either from braking earlier (unlikely) or braking harder which will come with better control of the Kart to stay closer to the kerbs.

Sector 4 – From Turn 4 to entering Turn 9

The 4th sector covers the hairpin turn of Turn 4 (the slowest point on the track) and the fast Turn 5 and accompanying long straight.

Comparing my fastest and slowest trips through this sector it’s noticeable that I brake at exactly the same point. There’s a line in the tarmac that I use as a marker so it’s pretty easy to hit the same spot. On both laps, the slowest point is after I’ve exited the corner and from there I accelerate down the short straight.

You can see the result of the two different steering inputs from the angle and position of the Kart on the track

On the slower lap I can tell from comparing the video that I used to much steering input on the slower lap which scrubbed off to much speed in the corner. On the quicker lap I ran right out to the right hand side of the track and used all the kerb. By the time I slowed for Turn 6, the difference in top speeds was only 0.2kph but the delta in time was 0.25s

Sector 5 – From Turn 6 to entering Turn 9

Barring a couple of laps, all of my trips through this sector on the 11th were within 0.1s of one another which is pretty consistent! I hit my top speed about halfway between corner entry and the corner itself with the slowest point at the corner apex (which is late). I’m trying to brake gradually, with maximum force just before the apex. I try and apply the gas as smoothly as possible to keep the Kart balanced while it turns. To much braking, power or steering and it’ll run wide at the exit, ruin the laptime and leave me exposed to anyone behind.

Pretty consistent!

Once I’ve hit the apex, I’m on the gas and lining up all the apexes all the way around Turns 7 and 8 to get the best speed possible along the straight.

Sector 6 – From Turn 9 to the finish line

One of the advantages of being light is that a SuperPro Kart is still accelerating by the time I get to Turn 9. I keep my foot down and let friction slow the Kart for the corner. On both my fastest and slowest trips through the sector I arrived at the same speed (pretty consistent through the previous sector!) and braked for Turn 9 at exactly the same time – about a Karts length before the change in tarmac.

The point where I lost a lot of time – 0.25s what by using to much steering which slowed the Kart down. Looking at the stills below you can see the difference. On the quicker (green) lap the Kart is pointing at the corner exit while on the slower one it’s pointing at the pit exit and will require further steering to get it around. The angle of the faster lap gives me a longer, shallow curve on to the main straight and a higher top speed

Compare the direction the Kart is pointed at in the quicker (left) and slower (right) photos

Just look at the difference in time from that one corner…

Conclusions

If you’re suitable inclined, here’s the full session with overlaid data.

The full session

So what did I learn from this? Firstly that Circuit Tools is awesome – and it’s free!

  1. The quickest way around Turn 1 is by lifting off
  2. I’m really consistent through sector 5
  3. There’s a massive amount of time to be lost in Turn 10
  4. I can find more time in Turn 3
  5. Keeping flat and using all the track in Turn 5 has a big advantage

Next time I’m on track at Bayford I want to concentrate on Turns 3 and 5 as the data is telling me that’s where the biggest inconsistencies are.