TM's GT5 Endurance reports: 14 August - Tsukuba 4-Hour

[Touring Mars]

Incident at Indianopolis

Circuit: Indianapolis Motor Speedway
Distance: 200 laps/500 miles

Car: Peugeot 908 HDi FAR - Team Peugeot Total '10
PP: 697 (770 BHP/930 kg)
Settings: Stock (Racing Hard tyres)
Driving Options: ABS = 1, TCS = 1, SFR - off,
Controller: DS3

Pit Strategy - 4 stops (end Lap 40/Lap 80/Lap 120/Lap 160)​

Part 1: Laps 0-40

Started off slowly, and fell to the back of the pack. Pack split into 8 leaders, 3 in a second pack, and me. After a few laps, however, I started to catch the 2nd pack, and stabilised the gap to the leaders, which peaked at +12.5 seconds. As I cleared the chasing group, I started to claw back time on the leaders at the rate of around 1 sec per lap. I took the lead around lap 30 and decided upon a 4 stop strategy, noticing that my tyres would last about 40 laps... the tyres were nearly done as I pitted for the first time, and I came back out, ready for my second stint...

Part 2: Laps 41-80

Set a lap record of 42.4xx s on lap 43, which was to be my fastest lap of the race... but for good reason. I was putting in steady low 43.xxx lap times and pulling out a sizable lead. It was not until around lap 70 that I started to notice that my tyres were looking dodgy, so I backed off a bit... still, my in-lap was nearly a disaster as the right rear tyre was all but gone, and I was struggling to take the last corner into the pit. I made it OK though, and embarked on the next section with the same attitude - try to put in as many hotlaps as possible and build the gap...

Part 3: Laps 81-120

By the latter part of the third stint, I was lapping my nearest rivals, and peaked at a gap that must have been around 50 s. I didn't beat my lap record, but I was putting in consistent high 42s, and low 43s, a blistering pace... too fast, infact... it began to dawn on me that I would struggle to make the lap 120 pit window (and hence maintain my essential 4 stop strategy, a pit stop costing around 85-90 seconds each), and sure enough, as I started lap 120 (my in-lap), the right rear died and I spun the car... I hobbled back to the pits, but not before spinning again in the second pair of corners. All in all, my lead was cut to just 12 seconds, and I knew I couldn't afford another in-lap like that So now, I had to go fast enough in part 4 to stay ahead, but slow enough to keep the tyres alive...

Part 4: Laps 121-160

I set a pace of steady 44.5xx's, in order to ensure that I kept my tyres alive until the pit stop at the end of lap 160. The gap shuffled around a bit, but I kept it at around the 12 s mark for the most part, but as the tyres faded again, my lead was down to just 8 s as I reached the pit for the last time. I figured that I'd done enough, but the in-lap was sketchy too, as yet again the right rear was almost done. But, after the pit stops shook out, I was still leading by 8 s...

Part 5: Finale

The strategy of 4 stops turned out to be critical, as my lead was very slender heading into the final section of the race. But, my 44.5xx's were not quite enough to keep the gap comfortable, and I found myself putting in 44.0xx's to maintain the gap. My fuel and tyre situations looked too close to call, and my lead was dropping slowly but surely... by end of the penultimate lap, my lead was just 4.4 seconds... I took the first two corners fine, but I could feel that familiar sliding that meant that the rear right was about to go... I could see (what I thought was) my nearest rival, bearing down on me, and as I entered the last two corners, I knew that I needed more than to just hold my nerve, but to hope that the rear right didn't give up on me too... but, to my amazement, the gap was now reading - 24.2 seconds... what happened?! Luckily for me, it seems that the 2nd place car had lost it on the last lap... but my joy was (very) short lived. Just a few seconds after that final split reading, and my rear right tyre went, and I spun out on the last turn Desperately, I slowly accelerated and just hoped that the chasing pack were further back than I thought, and then disaster... I spun the car on the straight, just seconds from the finish line... it felt like one of those nightmares when you are trying to run, but can't. Two cars sped past me in a blinding flash, but to my sheer amazement, I was still in 1st place! My rival, Schaefer, must indeed have gone over the tyre cliff just as I had! I crawled over the line, and Schaefer was nowhere to be seen.

Epilogue

An incredible final lap and arguably the most sickening and most exciting race of my GT5 career thus far (and hence why I am telling you about it!)

Result

1st. GTP_Mars - Peugeot 908 HDi FAR Team Peugeot Total '10 (PP 697) - 2"35'16.xxx
2nd. F. Schaefer - Audi R8 Race Car '01 (PP 705) - no time recorded
3rd. D. Lawson - Audi R8 Race Car Playstation Team Oreca (PP 702)

 

[DK]

Were you on Pirellis? (j/k)

 

[Touring Mars]

Laguna Seca 200 Miles

Circuit: err, Laguna Seca
Distance: 90 laps/200 miles

Car: Chevrolet Camaro SS '10
PP: 441
Settings: Stock except Power Limiter set to 75% (Sports Hard tyres)
Driving Options: ABS = 1, TCS = 1, SFR - off,
Controller: DS3

Planned Pit Strategy - 3 stops (Laps 23, 46 and 69)
Actual Pit Strategy - 4 stops (Lap 20, Lap 38, Lap 56, Lap 73)​

Prologue

Stock, the Camaro SS '10 is too much for this race, even though the fastest AI car is the same... after some testing, I settled on 75%, knowing that this would probably be enough for a win, but a potentially interesting race...

Part 1: Laps 0-20

I had taken the lead by the start of Lap 3 and was comfortably building a lead by 1-2 secs per lap until around Lap 12, by which point I was over 20 s ahead. I figured that the car may be too much for this race, and considered quitting, but I decided to keep it going, since I could see that my planned tyre strategy (3 stops/23 lap stints) was not going to work...

As I continued, the lead started to come down - the other Camaro must have cleared the field and was starting to gain... as my tyres started to struggle, I began to realise that the race was on... I held out until Lap 20, and my lead was cut to just 8 seconds, before I pitted - I should have come in earlier, as I realised that running the 3 stop strategy was a bad idea!

Part 2: Laps 21-38

With the leader a good 25 seconds infront, and lapping at pretty much the same rate as me, I began to fear that he was on a 2 stop strategy, or even worse, a single stop. At this point, I really began to wonder how I could win...

But, with less fuel, and fresher tyres, I started to pump in some good times - low 1.41's and into the high 1.40's, and I started to eat into the other Camaro's lead. I pit again on Lap 38, consistent with my newly adopted strategy of 4 stopping. I emerged back in 3rd, and with still no sign of my main opponent pitting, I figured that I needed to get the hammer down in the hope of countering a possible 1-stop strategy....

Parts 3+4: Laps 39-56, 57-73

I was now comfortably putting in consistent 1.40's and low 1.41's, and the gap to the leader was now pretty short, but I still faced the prospect of two more stops, while the leader might only have one stop... but on Lap 41, he pitted, and I emerged with a very comfortable 40 s lead.

At this point, I figured that my tyre strategy coupled with some decent laps times, would be enough to win me the race, based on the assumption that the leader would pit again at around lap 80-82. I pit again, and emerged just behind the leader, but now with only one stop left, and with fresh tyres, I felt confident of the win.

Part 4: Finale

I pit for the last time with a decent lead of around 10 seconds, and as expected, my nearest rival did indeed have to pit again - albeit for a quick stop, and I lead by around 30 s with no more stops to go. I could afford to take it quite easy for the last stint, and the other Camaro made some gains, but ultimately finished +27 secs behind.

Epilogue

Not as comfortable as I had anticipated, but the car was more than enough at the end of the day. 4-stops worked out well in the end, even though my main opponent only stopped twice. 75% of the engine power was enough for a comfortable 27 s win, while 65 % looked like a struggle, so perhaps another go at 70% would provide a very tight race...

Result

1st: GTP_Mars - Camaro SS '10 (75 % engine power) :- 2"35'53.xxx
2nd: F. Carpentier - Camaro SS ' 10 :- + 27 s
3rd: S. Rogers - Corvette Z06 C5 '00 :- + ?

My best lap: Lap 60 - 1:40.189

 

[Aqua F1]

Very nice 👍. Although I managed a 1 stop strategy on the Laguna Seca 200 , my tyres were pretty dead though, my pace went 1 second a lap slower for 5 laps until my stops.

EDIT: Can't remember the car name

 

[bonobo4]

Sorry for reviving a dead thread, but great reports!

 

[Touring Mars]

Thanks bonobo4 👍

Roadster 4-Hour Race at Tsukuba

Circuit: Tsukuba
Distance: 201 laps (4 hours)

Car: Mazda Eunos Roadster (NA Special Package) '89
Settings: Sports Hard tyres
Driving Options: ABS = 1, TCS = 1, SFR - off,
Controller: DS3

Planned Pit Strategy - 4 stops (40 lap intervals)
Actual Pit Strategy - 5 stops (Lap 40, Lap 80, Lap 110, Lap 140 and Lap 170)​

---

Introduction

For this race, I decided to try and make it as close a race as possible, so I used much the same settings as suggested by Hun200kmh. In addition, I installed a twin-plate clutch and semi-racing flywheel. Traction control was set to 1, and ABS was set to 1. Controller sensitivity was set to 2, and manual gears were used (DS3). All other aids were switched off. After the race, I decided to log the laptimes and take a closer look at the race, from the perspective of both myself, and my nearest rival. It's a shame that the race data is not available to export directly, since looking at the data from the race can give you alot more of an insight into what actually happened, and casts new light on some of the decisions you make during the race... Anyway, for the fun of it, here is a slightly more 'scientific' approach to the race report

Race Results

Figure 1 shows the result of the lap time logging across the whole four hour endurance race for me (Mars, Mazda Eunos Roadster (NA Special Package) '89) and the fastest A.I. competitor (I. Burch, Mazda MX-5 1800 RS (NB, J)). The graph shows several spikes, each indicating a pit stop. I undertook five pit stops, at laps 40, 80, 110, 140 and 170, while Burch undertook just one stop, at Lap 116. The race would eventually last for 201 laps. Initially, I had set out on a four stop strategy, but after the second stop, it became clear that a 5 stop strategy would be quicker, hence the stints were shortened to 30 laps rather than 40. The peak at Lap 80 in the Mars trace indicates that the second stop took longer than the others. This was a result of the Tsukuba ‘pit glitch’, a bug that results from an over-zealous entry into the pit lane, causing the pit dialogue box and pit crew to disappear. As a result, the maximum fuel load is automatically applied, and the pit stop lasts longer, in this case, 14 seconds longer than the other stops. (Of course, if the pit glitch happens later in the race, the penalty is much worse, as it will add the maximum amount of fuel).

Figure 1. Lap time comparison between Mars and Burch. Mars made five stops, while the fastest A.I. car (I. Burch/purple) made just one.​

Figure 2 shows the gap between the two main competitors. In the red trace (me), there are two notable regions, between laps 31-40 and laps 71-80. In both of these ten lap periods, the gap reverses a generally downward trend and starts to go in Burch's favour. This was due to the fact that the tyres were wearing out and lap times started to fall beneath the A.I. level. For this reason, it was decided to switch from a four stop strategy to a five stop, with 30 lap stints being used for the remainder of the race. Since a pit stop (without the pit glitch) was costing about 23-24 seconds, it was estimated that three stops save about 5-10 seconds, based on the assumption that running 40 lap stints was costing about a second a lap for the final ten laps of those stints.

Despite falling considerably behind in the middle of the race, I had anticipated Burch's stop and had concluded that short (30 lap) stints would produce enough quick laps (in the low 1'10's) sufficient to overturn the deficit. Unfortunately, my penultimate stint only resulted in me holding a very small lead over Burch (of approx. 1 s), and Burch took a 25 s lead after I made my final stop at Lap 170. With approx. 25 laps of the race remaining, I was still 25 s adrift, and needed to lap atleast 1 s per lap faster than Burch. Initially, this didn’t appear to be happening, but Burch neared traffic and his lap times started to fall...

Figure 2. The gap between Mars and Burch during the entire race.
While I started off infront and built a lead over Burch, Burch would benefit greatly from a one-stop strategy as opposed to Mars’ five stop strategy.​

Figure 3 shows the race position for myself and Burch throughout the race. Burch spent a total of 106 laps in the lead of the race, and I led for 45. Both drivers led for some part of the 201st and final lap. As we both crossed the line at the end of Lap 200, Burch led by just 0.6 s. However, there was still 11 seconds left on the race timer, and so the race would go to a crucial 201st lap. I finally took the lead at the 2nd hairpin with the race timer already at zero and the four hour mark passed... I held on to record a victory of just 1.1 s over Burch...

Figure 3. Race position for Mars and Burch throughout the race.
Burch led the race for 106 laps in total, and Mars for 45. Mars took the lead on the 201st and final lap to record a victory of 1.1 seconds.​

Epilogue

Despite leading for most of the race, and holding the largest lead (52.143 s) of the pair, Burch (Mazda MX-5 1800 RS (NB, J) was pipped to the win by just 1.1 seconds after a race lasting 4”01’01.370. The fastest lap of the race was set by I. Burch at 1’09.560. My fastest lap was 1’09.619. Of the runners-up, the slowest ‘best lap’ was set by the 7th placed car, which could only manage a 1’11.473 and finished some three laps behind the leading pair. Of all the 12 runners in the race, all were lapped at least once by the eventual winner, except for I. Burch. I. Burch’s average lap time throughout the race was 1’11.950, while my average was 1’11.947. Excluding Lap 1 and in/out laps, Burch’s average ‘outlap’ time was 1’11.653, while mine was ~ 0.5 s per lap quicker with an outlap average of 1’11.173. This equated to 95 seconds advantage, whereas the four additional pit stops cost me almost exactly the same amount of time. My most consistent phase was a period of 24 consecutive laps within a 1.0 second window (laps 172-195), and I would have won the Human Stopwatch trophy on 9 separate occasions during the race, including one five lap spell (laps 183-187) within a 0.2 second time interval.

Conclusion

It's clear that there were some key moments and decisions during the race that drastically affected the outcome. The first, and most significant, was the decision to switch from a four stop strategy to a five stop. The falling lap times and gaps during laps 31-40 and 71-80 strongly indicated that 1’12 laps were insufficient, and that the A.I. was capable of 1’11’s for the majority of the race. The pit glitch cost me approx. 14 seconds, but this was avoided in later stops by braking early and staying in 3rd gear on the pit entry. I managed to run the entire race with only three laps in the 1’13s, while Burch had one lap in the 1’15s (lap 132), and a poor lap on lap 196 near the end of 1’13.989 brought the gap down from 7.1 s to just 4.3 s with only a few laps left. Perhaps without this single poor lap, Burch would have won the race...

Results

1st: GTP_Mars - Mazda Eunos Roadster (NA Special Package) '89 - 4”01’01.370
2nd: I. Burch - Mazda MX-5 1800 RS (NB, J) - + 1.144 s
3rd-12th: Lapped

Lap record: I. Burch: 1"09.560
My best lap: 1"09.619

 

[bonobo4]

They don't get much closer than this! Just so you know, in my A-Spec 1000km Suzuka Race, it lasted 6:23 and I won by just 35s, whicxh is nowhere near as close a race as yours. Even Famine's 4 Hour Nurburgring win of just 8s is still not as close as yours. Great race/report and I like the "scientific approach".

 

[Touring Mars]

They don't get much closer than this! Just so you know, in my A-Spec 1000km Suzuka Race, it lasted 6:23 and I won by just 35s, whicxh is nowhere near as close a race as yours. Even Famine's 4 Hour Nurburgring win of just 8s is still not as close as yours. Great race/report and I like the "scientific approach".

The Nurb 4 Hr and the Suzuka race are next on my list of priorities... Famine's thread is a great resource, and I'll probably use a set up as reported in there 👍

I didn't think this race would be even remotely as close as this, but Hun200kmh did infact lose the race by 14 s - although he had ABS off. I blame the four stop strategy though

It's interesting to note that Hun200kmh was hitting 1'08's, whereas I only scored a handful of laps under 1'10... and yet, I won by 1s and he lost by 14. I think it actually may have come down to the fact that, although we both got the dreaded Tsukuba pit glitch once in the race, it happened to me sufficiently early on, so it didn't cost me too much time (I estimated about 14 seconds extra), while for Hun200kmh, it probably cost him alot more than that.

Anyway, thanks again for stopping by 👍

 

[Aqua F1]

Wow, I would of been sweating in the final laps!