Driver debrief

LisboaKart, Pontinha · kart 19 · 21 October 2026, 16:12–16:47 · 45 laps with GPS, laps 3–47 · fourth session with GPS in kart 19

Your first laps in the 42s: 42.955s on lap 27 and 42.958s on lap 37, 0.707s under kart 19's best from 16 October. Not two lucky laps: the fastest five came down 0.755s and the median lap 0.716s, to 43.377s against 44.093s alone on 16 Oct. The kart had new front tyres and the air was about nine degrees cooler, and the time came from almost the whole lap, on the same route at higher speed — the pattern more grip and more power would give. The one place your route changed is S6, the long complex, last session's target: met, 8.429s against 8.50s.

Laps 1 and 2 have no GPS — you stopped on lap 2 to watch the logger find its satellites — and section 8, at the bottom, covers that and the rest of the recording; none of it changes anything above it.

Best lap

42.955

lap 27; 16 Oct: 43.662s

Fastest 5 avg

43.027

16 Oct: 43.782s

Median lap

43.377

43 clean laps; 16 Oct alone: 44.093s

Spread, last 23 laps

0.188s

16 Oct's last 23: 0.199s

1 · The circuit, and what the section numbers mean

Every section number on this page refers to this map: 4 September's sections, as on the earlier pages. Blue badges are corners, grey are straights, and the yellow ticks are the gates every lap is timed through. Numbering runs the way you drive it, from the start/finish marker.

Aerial imagery: Esri, Maxar, Earthstar Geographics and the GIS User Community. User visual calibration — provisional best visual fit: Esri imagery moved 3.356 m west, 1.854 m north. GPS coordinates and timing are unchanged; this is a subjective display alignment.

You worked on three passages: the corners before and after the start/finish straight, and the slightly longer complex. On this map, as I read your description, those are S12 (572–610 m) into the straight, S2 (44–104 m) out of it, and S6 (229–333 m), the long complex — last session's target.

2 · The session as it ran

Kart 19 again, with new front tyres — fitted a couple of days before, by your account, and you believe only the fronts — and pressures set just before you went out. The track was yours throughout. On lap 2 you stopped for about a minute, so its 1:45.711 holds the stop, and everything below starts at lap 3. On lap 38 you went off, and lap 39 ran on tyres still dirty from it; both are left out wherever this page says “clean laps”.

Measure	4 Sep, solo	8 Sep	16 Oct, alone	21 Oct, clean	vs 16 Oct
Best lap	43.940s	43.731s	43.662s	42.955s	−0.707s
Fastest five	44.072s	43.787s	43.782s	43.027s	−0.755s
Fastest ten	44.169s	43.874s	43.862s	43.126s	−0.736s
Median lap	44.336s	44.264s	44.093s	43.377s	−0.716s
Mean lap	44.399s	44.446s	44.116s	43.461s	−0.656s
Spread, all laps	0.300s	0.785s	0.247s	0.326s	+0.079s
Spread, laps under 45.5s	0.300s	0.328s	0.247s	0.326s	+0.079s

All four in kart 19, alone on track. 4 Sep: its last 21 laps, at 29–30 °C. 8 Sep: its 47 flying laps, at about 25–27 °C. 16 Oct: laps 18–47, after the slower karts had gone, at 28–30 °C. 21 Oct: the 43 clean laps from 3 to 47, at 19–20 °C. Grey differences are within 0.02s either way.

Measured Your quickest session in kart 19, by three quarters of a second. Best 42.955s, fastest five 43.027s, fastest ten 43.126s, against 43.662s, 43.782s and 43.862s on 16 Oct. 2 laps under 43 s, 27 under 43.5 s and 40 of the 45 from lap 3 under 44 s, where 16 Oct alone had 10 of 30. Best ten in a row: 43.252s, laps 23–32, against 44.041s (laps 30–39) on 16 Oct. It is also the quickest session in the log: kart 28's 7 Oct figures, the best until today, are 0.21–0.28s slower.

Measured The typical lap moved as far as the best. Median 43.377s over the 43 clean laps, against 44.093s alone on 16 Oct, 44.264s on 8 Sep and 44.336s on 4 Sep's solo laps: 0.716s, as against 0.755s on the fastest five.

Measured Quicker as the session went on, and by the end as steady as 16 Oct. The clean laps 3–22 had a median of 43.575s with a 0.325s spread; from lap 23 — where the best ten in a row begins — the 23 clean laps had a median of 43.279s and a 0.188s spread, against 0.199s over 16 Oct's last 23 laps (25–47). Over all 43 clean laps the spread is 0.326s against 0.247s alone on 16 Oct: the early laps. The 0.295s step is spread over the lap: 11 of 13 sections got quicker, none by more than 0.067s.

Measured The off cost about 3.9 s, the lap after it 0.79 s, each against the clean median. Lap 38 (47.239s) lost its time in S9–S12, 415–610 m. Its trace leaves the usual line at 421 m, runs up to 4.3 m to the left of it through S9 and S10, then 6.5 m to the right at 511 m, early in S11, and is back within 2 m of it by 535 m, apart from up to 2.6 m to the left in S12; its slowest point over the stretch is 38 km/h, against the clean laps' 45 km/h. Before it, the lap was on pace — 0.24s quicker than usual through S6. Lap 39 (44.170s), on the tyres the off had dirtied, lost a little almost everywhere, most in S2 +0.21s, S12 +0.19s and S4 +0.14s; lap 40 was back to 43.241s.

Conditions New front tyres, and the coolest air in the log. Air 20.4 °C at 16:00 and 19.3 °C at 17:00, cloud 0%, humidity 34–39%, wind 16 km/h from the north gusting 38–39, no rain for fifteen days: about nine degrees cooler than 16 Oct. Kart 19's three earlier GPS days, at 25–30 °C, gave fastest fives within 0.20 s of each other, but your own progress runs through them, so they cannot show how much heat matters; none was cooler than about 25 °C, and no earlier session is recorded as on new tyres. Tyres and air changed together, so this page cannot divide the gain between them. The weather is a model grid point a few kilometres away, and air temperature is not track temperature.

3 · Kart 19 over time

Every session in the log, from the printed sheets: the fastest five laps, which an out-lap, a stop or an off barely moves.

Session	Kart	Best	Fastest five	Fastest ten
11 Aug	19	45.644s	45.941s	46.241s
14 Aug	19	45.043s	45.128s	45.249s
18 Aug	19	45.046s	45.125s	45.190s
20 Aug	19	44.725s	45.094s	45.169s
28 Aug	21	44.885s	44.977s	45.030s
4 Sep	19	43.873s	43.980s	44.073s
8 Sep	19	43.731s	43.787s	43.874s
7 Oct	28	43.239s	43.286s	43.337s
16 Oct	19	43.662s	43.782s	43.862s
21 Oct	19	42.955s	43.027s	43.126s

Measured The plateau is broken. In kart 19 the fastest five had run 43.980s (4 Sep), 43.787s (8 Sep) and 43.782s (16 Oct); today it is 43.027s, 0.755s in one step.

Context Where that sits at this track. The 270cc records board starts at 41.625s; tenth place is 42.157s, 0.798s quicker than your best. The track's kart list rates kart 19 P3, the best rating on it (P3–P8).

4 · Where the time came from

Each of the 13 sections, with every lap slid into 4 September's positional frame first and timed through the same gates (section 8 has the method): this session's 43 clean laps against 16 October's laps alone and 8 September's, all in kart 19. Down and blue is quicker; grey is within 0.02s either way.

Sec	Type	Distance	8 Sep	16 Oct alone	21 Oct	vs 16 Oct	vs 8 Sep	Slowest Δkm/h	Top Δkm/h	Route Δ
S1	straight	0–44 m	2.554s	2.588s	2.585s	−0.003s	+0.030s	−0.8	+0.8	0 m
S2	corner	44–104 m	5.153s	5.081s	4.994s	−0.087s	−0.160s	+1.4	−1.1	0 m
S3	straight	104–146 m	2.797s	2.853s	2.796s	−0.057s	−0.001s	+0.9	+0.9	0 m
S4	corner	146–192 m	2.889s	2.753s	2.766s	+0.013s	−0.124s	+1.0	+1.4	+0.1 m
S5	straight	192–229 m	2.294s	2.226s	2.227s	+0.001s	−0.068s	−0.8	0	+0.1 m
S6	corner	229–333 m	8.793s	8.584s	8.429s	−0.155s	−0.364s	+1.0	−0.9	−1.9 m
S7	straight	333–364 m	2.276s	2.332s	2.286s	−0.046s	+0.010s	+0.8	+0.8	0 m
S8	corner	364–415 m	3.257s	3.252s	3.149s	−0.104s	−0.108s	+0.8	+2.0	−0.6 m
S9	straight	415–463 m	2.902s	2.971s	2.906s	−0.066s	+0.004s	+0.2	+0.7	−0.1 m
S10	corner	463–497 m	1.976s	2.012s	1.982s	−0.030s	+0.006s	+1.5	0	0 m
S11	straight	497–572 m	4.341s	4.305s	4.216s	−0.088s	−0.125s	+0.5	+0.8	−0.3 m
S12	corner	572–610 m	2.839s	2.885s	2.808s	−0.077s	−0.031s	−0.3	+0.8	−0.2 m
S13	straight	610–641 m	2.143s	2.212s	2.168s	−0.044s	+0.025s	+0.9	+0.8	−0.1 m

Section medians. Speed and route changes are 21 Oct against 16 Oct alone. “Slowest” is the lowest speed in the section; “Top” the highest, which on a straight is near its end and in a corner often its entry.

Measured 7 of 13 sections quicker beyond the noise floor, none slower. Against 16 Oct alone, 7 sections are quicker by more than 0.05s — most in S6 −0.155s, S8 −0.104s, S11 −0.088s and S2 −0.087s — and 3 more by 0.03–0.05s, inside the noise. The other three, S1, S4 and S5, are unchanged, within 0.02s either way. The sections add up to −0.744s; the median lap through the gates is 43.367s against 44.084s. Against 8 Sep they add up to −0.905s.

Measured The same route, taken faster. Outside S6, no section's route changed by more than 0.6 m. In 5 of 6 corners the slowest point is 0.8–1.5 km/h faster; S12's is unchanged (−0.3 km/h). On 6 of 7 straights the top speed is 0.7–0.9 km/h higher, the long straight S11 included (68.8 against 68.0 km/h); S5's is unchanged (0 km/h).

Supported interpretation More speed at the slowest point of nearly every corner and at the end of nearly every straight, on an unchanged route: that is the pattern more front grip and more power would give, and new front tyres and nine degrees cooler, denser air could each supply one or both. A change of driving would more likely show as a new route, or as time gained in a few places, and the only such place is S6. With no RPM, throttle or brake channel this is a reading of speed traces, not a measurement of the engine or your feet.

5 · Your three passages, and the S6 target

Measured S6: target met, on the shorter route. The target was an S6 median of 8.50s over at least 10 laps, from 8.584s, with S7 no slower than 2.332s. Over 43 clean laps it is 8.429s, and S7 2.286s. The route through it is 1.9 m shorter than on 16 Oct (104.8 → 102.9 m) — the route 16 Oct's quickest quarter of passes took (103.1 m), now on a typical lap — with the slowest point 1.0 km/h faster. At 0.155s it is the largest gain on the lap.

Measured And S6 has settled. On 16 Oct, route and time through it went closely together (correlation 0.81) and its quickest and slowest quarters were 2.4 m apart in route; today 0.56 and 1.1 m. The passes now mostly take the shorter way.

Measured S2 and S12: quicker on the same route. S2 is 0.087s quicker (route 0 m, slowest point +1.4 km/h); S12 0.077s (route −0.2 m, slowest point −0.3 km/h; the figure below shows where). Together the three passages gained 0.319s: 1.9% of the time spent in them, against 1.5% over the rest of the lap — 0.06s more than the rest of the lap's rate would have given.

Supported interpretation The passages you worked on gained a little more than the rest of the lap, by about one noise floor. That fits the work having paid, but it is not enough to credit it over the tyres and the air. The clearer part is S6's route: with the same tyres and air, every other route stayed within 0.6 m, so its 1.9 m is most likely your driving.

Three corners drawn, each the same way: blue is the quicker way through, here today, and orange the slower, 16 October alone. Beside each map, the time gap shows where the quicker line gains, and the speed and line traces show how; under it, a short list says why, stretch by stretch.

S6 · 229–333 m · corner quicker by 0.155s

Quicker — 21 Oct: 8.429sSlower — 16 Oct alone: 8.584s

Overall: 0.155s quicker, on a route 1.9 m shorter (104.8 → 102.9 m), with the slowest point 1.0 km/h faster (38.8 → 39.8 km/h).
entry → A (0–32 m): gains 0.16s. The quicker line is 1.9 m shorter, the same speed and up to 1.4 m tighter at 16 m.
A → B (32–78 m): gives back 0.12s. The quicker line is the same distance and 0.9 km/h slower on average.
B → exit (78–104 m): gains 0.12s. The quicker line is the same distance and 1.3 km/h faster on average.

Each line is the median of its set at every 2 m of the 4 September lap — 43 and 30 laps — after the slide into one frame. The time gap falls where the quicker line pulls ahead; circled letters mark where it turns, at the same places on the map and the charts, and the numbers along the map's edge are metres into the section. The line chart is blank where the track runs straight and neither side is the inside. Routes within 1.1 m and lines within 0.6 m of each other are called the same: the resolution set out in section 8.

S2 · 44–104 m · corner quicker by 0.087s

Quicker — 21 Oct: 4.994sSlower — 16 Oct alone: 5.081s

Overall: 0.087s quicker, on the same route, with the slowest point 1.4 km/h faster (36.6 → 38.0 km/h).
entry → exit (0–60 m): gains 0.09s. The quicker line is the same distance and 1.0 km/h faster on average.

S12 · 572–610 m · corner quicker by 0.077s

Quicker — 21 Oct: 2.808sSlower — 16 Oct alone: 2.885s

Overall: 0.077s quicker, on the same route, with the slowest point 0.3 km/h slower (45.2 → 45.0 km/h).
entry → exit (0–38 m): gains 0.08s. The quicker line is the same distance and 0.8 km/h faster on average.

6 · Where the remaining time is

The 43 clean laps: the median through each section against the fastest pass recorded there.

Measured The median-to-best gaps sum to 1.07s. The largest are S2 (0.154s), S6 (0.149s) and S12 (0.102s) — your three passages — holding 38% of the total; S2 and S6 are level within the noise. The fastest section times add up to 42.241s against an actual best circuit of 42.939s. Each “best” is the quickest of 43 passes that each carry a few hundredths of slide error, so these rank the sections; they do not promise the time.

Measured In S2 the shorter way is the quicker way. Route and time through S2 go together more closely than anywhere else on the lap (correlation 0.82; next is S12 at 0.70). The quickest quarter of passes, 10 laps, took 4.903s on a route 1.7 m shorter than the slowest quarter's 5.112s, 1.8 km/h faster at the slowest point, and lost nothing after it: S3 took 2.799s after the quick passes against 2.802s.

S2 drawn the same way: blue, today's quickest quarter of passes; orange, today's slowest quarter; the pale dashed line 16 October alone, for reference.

S2 · 44–104 m · corner quicker by 0.209s

Quicker — 21 Oct, quickest quarter: 4.903sSlower — 21 Oct, slowest quarter: 5.112s16 Oct alone: 5.081s

Overall: 0.209s quicker, on a route 1.7 m shorter (59.5 → 57.8 m), with the slowest point 1.8 km/h faster (37.1 → 38.9 km/h).
entry → exit (0–60 m): gains 0.21s. The quicker line is 1.7 m shorter, 0.5 km/h faster on average and up to 0.7 m tighter at 30 m.

Each line is the median of its set at every 2 m of the 4 September lap — 10 and 10 laps — after the slide into one frame. The time gap falls where the quicker line pulls ahead; circled letters mark where it turns, at the same places on the map and the charts, and the numbers along the map's edge are metres into the section. The line chart is blank where the track runs straight and neither side is the inside. Routes within 1.1 m and lines within 0.6 m of each other are called the same: the resolution set out in section 8.

7 · Findings, and the next session

Your quickest session in kart 19, by three quarters of a second. Best 42.955s, your first laps under 43 s; fastest five 43.027s against 43.782s.
Almost the whole lap moved, on the same route outside S6. 7 of 13 sections quicker beyond the noise and none slower, faster through nearly every corner and down nearly every straight: the pattern new front tyres and cooler air would give.
S6 target met, on the shorter route. 8.429s against 8.50s, the one place your route changed, and now the settled way through.
S2 is the clearest next target. Level with S6 for the largest gap, and the closest link between route and time on the lap.

One experiment for the next session in kart 19: S2, the corner out of the start/finish straight, 44–104 m.

The change: Drive S2 the way today's quickest quarter of passes did: the shorter route, 1.7 m less, and the extra 1.8 km/h at its slowest point that comes with it. Keep the exit onto S3, and keep S6 as it is now.
Why there: It is one of your three passages, level with S6 for the largest median-to-best gap (0.154s against 0.149s), and the corner where route and time go together most closely (0.82). Your quickest quarter took 4.903s; the median was 4.994s.
The measure: S2's median over at least 10 clean laps, in this page's frame: target 4.93s, from 4.994s, with S3 no slower than 2.796s. Change nothing else, stay in kart 19, and compare with this session: the tyres will be older and the air may be warmer.
If it fails: If S2's route shortens and its time does not follow, the limit is the exit, and the next page compares the speed out of it pass by pass.

8 · Technical notes

Measured One recording, from lap 3 on.

Recording	Sheet laps	Began	Began before the line	First crossing	Line crossings it counted	GPS fixes	Gates vs sheet, median / worst
`a_0009`	3–47	16:14:43	68 m	8.1 s, 52 km/h	46 of 46	50,487	22 / 86 ms

The gates found every lap from 3 to 47 and agree with the sheet to a median of 22 ms, 86 ms at worst (lap 8).

Measured The logger started on lap 2, then counted the true line throughout. Laps 1 and 2 up to the stop are on the sheet only: nothing was recorded. a_0009 begins at 16:14:43 with the kart at 9 km/h, 58 m from the stored start/finish point (30.2 m south, 49.1 m east) and within 6 m of where the logger was restarted on 16 Oct; it crosses the line 8.1s later at 52 km/h. Its 47 lap records are a part-lap to the line, laps 3–47 to a median of 22 ms of the sheet (85 ms at worst), and the in-lap. The 46 that end inside the recording — all but the in-lap — end on the straight, a median 0.3 m from the stored point. The stop cost about 62s of track time.

Reading, not measured Why the start was late. The device listing gives the logger's start condition as speed, and speed comes from GPS; a receiver still without a fix would show no speed, so nothing would start. That fits what you saw on the stop — the signal going from weak to strong — and the recording starting as you pulled away. On 16 Oct the restart was at the same spot.

Measured The sheet reconciles, and its session stamp is the clock start. The 47 transcribed laps average 44.9320s against a printed 44.932s and sum to 2111.805s; the printed total is 2115.511s, 3.706s more, so the clock started 3.706s before lap 1 began — as on 28 August and 7 October, and the other way from 16 Oct. GPS puts 1960.1s between the start of lap 3 and the end of lap 47, against 1960.2s of listed laps. Lap 3 began at 16:14:51; counting back laps 1 and 2 puts lap 1's start at 16:12:19 and the clock start at 16:12:16, within 2 s of the sheet's “session date” stamp, 16:12:14. Its track-time stamp, 16:11:50, is 24s earlier. On 16 Oct the track-time stamp was about 25 minutes and the session-date stamp about 20 minutes earlier than the GPS clock.

Method One frame, fixed gates. Every lap is timed through 4 September's 13 section starts, a point on the ground and a direction of travel each, after its trace has been slid east and north — no rotation, no stretch — until its sideways position at the gates best matches 4 September's solo laps.

Session	Recording	Laps	Typical slide needed	Size	Range across laps
4 September	`a_0002`	46	0.0 m north, 0.3 m west	0.3 m	0.2–1.3 m
8 September	`a_0003`	47	1.9 m south, 0.3 m west	1.9 m	0.8–3.9 m
16 October	`a_0008`	30	1.6 m south, 2.2 m east	2.8 m	1.8–3.6 m
21 October	`a_0009`	45	0.1 m south, 1.5 m east	1.5 m	0.8–3.1 m

Sliding each recording as one block instead of lap by lap moves no section median by more than 0.033s, and differences below about 0.05s are treated as nothing. After sliding, the three earlier days' typical lines sit within 0.6 m of each other at every gate, and their routes through every section but S6 agree to within 1.1 m: the resolution of anything said about lines and routes here. Today's routes stay within it everywhere but S6.

Measured A clean recording, and still no engine data. 50,487 GPS fixes at nominal 25 Hz over 33.7 minutes and 29.5 km, none lost to the stock parser's guard. Satellites used ranged 9–16, most often 14; the receiver's accuracy estimate had a median of 68 cm (59–83 cm). RPM recorded zero throughout, for the fifth session running, and the logger has no brake or throttle channel.