Le Mans may be the go-to event when you think of sportscar races, but few can lay claim to as diverse a history as the Spa 24 Hours.
First held in 1924, the Belgian classic was for many years a fixture on the European Touring Car Championship calendar before fleetingly joining the World Endurance Championship calendar in 1981, as Tom Walkinshaw Racing pre-empted Mazda's triumph at Le Mans by 10 years with a rotary-engined Mazda RX-7, then returned to touring cars until 2001 when it transitioned to a GT race.
From the Brabham/Olofsson/Hattori Nissan victory by 21 laps in 1991, to the unusual sight of Jacques Villeneuve sharing a Mosler with Ho-Pin Tung in 2009 and Bernd Schneider winning for a second time in 2013 some 24 years after his first, the race has delivered plenty of unforgettable moments.
Ahead of this weekend's 70th running of the event, we polled a selection of five drivers for their favourite memories.
Before he was a multiple Le Mans winner with Audi, the Swiss was a persistent thorn in the side of the all-conquering Maserati MC12 at Spa. After a near-miss in 2006, he won the following year with a Carsport Corvette (above) after pressuring Eric van de Poele into a mistake in the closing stages.
"2006 was my very first 24-hour race at Spa, and also my first time in the Aston Martin. At night one of my team-mates had a little contact and after that we had too much toe-out, so the front tyres were wearing too hard, but the biggest issue we had was a broken exhaust, which meant we needed to run rich to cool everything down. This meant fuel consumption was too high, but it was the only way to make it.
"In the end it was close, but we didn't have a chance because our car was not 100%. I remember it was super-hot in the car and I was dehydrated in the morning because I was inexperienced at 24 hours, so I was not really drinking after my stints. I got cramps and I had to drink salt water! I was completely fucked after the race...
"I wouldn't say we were lucky in 2007; I think it was well deserved because we had the pace to win - and my driving time was 11 hours or something. The conditions were really tough - it was raining a lot through the night, just pissing down the whole time. There was a lot of aquaplaning and it was super-easy to do mistakes, but we did none.
"I was much, much faster than everyone else; my pace was sometimes three seconds faster per lap. We were one lap behind the [Michael] Bartels Maserati, knowing if we kept the pace high, we could unlap ourselves and go for the lead. So I overtook, was on the same lap and started catching up. Then van de Poele put himself into the gravel and after that we were leading. It definitely was one of my highlights, the feeling was amazing. It's a win I will never forget.
"The Corvette guys were so clever in their design - for every problem they had a solution. I remember in 2007 the right-rear rain light was failing and so we had to pit. The guy just changed the light, put the battery on and we were driving with a battery until the end. If you would have to change the whole light system, we would never have won. The GT1s were really amazing race cars; it was good fun."
The WRT team boss had a mixed history as a driver, only managing a solitary victory with a Larbre Viper in 2002 - despite losing a wheel - in 16 appearances before starting his own squad, which won in '11 and, memorably, in '14 (above).
"I started quite late, doing Formula Ford in England, and at that time my goal was to do endurance racing and to start the 24 Hours of Spa. I started with Audi in 1995, driving with Philippe Adams and Terry Moss. We blew up the engine 10 minutes before the end and Christian Abt in the other Audi pushed me to the finish line!
"In 1999 I was in the works [Rafanelli] BMW with Didier de Radigues and Marc Duez. The other car was Jenson Button, Tomas Enge and David Saelens. Jenson was very inexperienced; Enge and Saelens were doing Formula 3000 and Button was doing Formula 3 in England. He was just a nice young kid - he was not the big star he has become.
"Then we had a vapour-lock issue; the mounting was upside down and both cars had to retire after a few stints [Saelens made it back to the pits before he was knocked out by the fumes]. Button did not race, so I had a beer with him and his father. I have good memories from Jenson, but especially from John!
"I started racing the Viper in 2001 and the next year I remember during the night, it was David [Terrien] in the car and he lost a wheel. Luckily it was in the final sector. The same thing happened the year before to Larbre Competition when they won in '01! David was able to bring the car back, we had no damage and we were able to recover.
"It was such a nice feeling because the Spa 24 was the goal of my career - it's something I was waiting and hoping for since I was a kid. I prefer to fight for the win in 24 Hours of Spa than to fight for the win in GTE-Pro/Am at Le Mans - winning overall is really something special.
"I didn't have a full-season drive for 2004, so I was with GPC Giesse, running a Ferrari 575 (below), which had no go compared to the 550. Mika Salo was my first team-mate who never clutched to go down with the gears. I thought the car would never handle that, but after a few hours we were leading the race and we led all the way through to the morning.
"Then at lunchtime, the floor fell off so we had to pit and lost the lead. I can't remember how much we finished behind, but it was not much behind the 550 of BMS Scuderia Italia.
"In 2008 we were on pole with the Saleen before Steve Zacchia crashed in the warm-up. Actually I was not there, I was cutting my grass at home and being relaxed before the race when a friend called me to say, 'I'm standing in front of your car... You will not race.' I was a bit surprised!
"When we won in 2011, it was our second attempt with WRT so the team was much smaller. It's an incredible feeling when you are part of the team - there is much more work behind it, so much more hope. And from the human side, it's much bigger and nicer to have built that with other people. You feel you are part of all the discussions, resolving problems, all the emotion when you win. The drivers, everyone knows them, but all the guys who are building those wins are just as important.
"I would say 2014 was a more special win, because it was a super-dramatic comeback and my wife gave birth during the night between Wednesday and Thursday. My phone was off because the battery was gone and when I got to my office and charged it again, she just texted me, 'I am in hospital.' It was not planned like that...
"I stayed all night in hospital between the Wednesday and Thursday, did the qualifying, then went back after qualifying on Thursday to the hospital in Brussels, spent the night there, came back for Superpole on Friday, so going into the race I was already completely dead. The feeling of winning that race with seven seconds to the BMW was just a great feeling."
The swashbuckling Soper contributed to one of the most famous finishes in event history in 1992 with his late pass on the ailing Eric van de Poele, then became a two-time winner in '95.
"It was never a favourite event of mine. I don't like 24-hour races anyway, they're too much hard work! I love the build-up, but when you get in at 8am and you're totally shot, you know you've got another eight hours to go... The following week I was like a zombie. I've never done fitness training - I just relied on stamina, so it probably took more out of me than a colleague who did an hour in the gym every day. In 1992 I was irritated to get back in the car for the final stint.
"The Bigazzi team was great, but had this mentality - even if there were three wheels hanging off and a rod through the side - that they were going to win. I'd showered and changed and went over to say, 'I'm off', and team boss Gabriele Rafanelli said, 'No way, you're getting in the car. We can win this race. The leading Schnitzer BMW has to do another stop.' I'd heard that sort of thing before and we had a 'consultation' about it. He won and I lost. So I put my soaking-wet overalls back on.
"I wasn't that impressed and was convinced we weren't going to win, so when I got back in I was motivated and angry. I started driving the car like it was a sprint race - we were either going to win or the car wasn't going to finish. We were out of sync because I'd collided with a backmarker during the night, knocked the alignment out and had to pit. That little window and fuel the team put in then is, I believe, why we could win in the end without a splash-and-dash.
"[Race leader] Van de Poele had been in the Schnitzer car quite a long time. As I got him in view I started to pick up his pit board and I could see them telling him to limit his revs to save fuel. He was going quickly enough to win until they told him to slow and then he lost his rhythm. Once you've got someone in your sights, that does motivate you and I caught him.
"You never know when they're going to throw the chequered flag so I wasn't going to risk waiting behind him. He'd woken up a few corners before and blocked me into the Bus Stop, which I wasn't having so we touched. We were both scrabbling all over the kerbs and I came out ahead. Then he came back at me on the final lap, but I figured it was my race and we won by half a second.
"When we won with Schnitzer in 1995 it was a fairly easy race and we were always in contention. Once you win these sorts of races it seems easier to win them a second time. I never had a problem concentrating, it just wasn't as fulfilling as the first time. Jo Winkelhock's a very likeable guy and a very fast driver, so to have him in the car was good, and Peter Kox was good too, so it was a strong car."
The Monegasque proved his outright podium in 2002 with a GT2 Porsche was no fluke by winning overall in the rain-hit '03 event (above). After taking an early lead with a well-timed switch from slicks to wets, his unconventional fuel-saving tactics behind the safety car have since been written into Spa 24 folklore.
"When people talk about the race, everybody thinks about the difference in categories, N-GT versus GT1, David against Goliath. Thanks to Dunlop and our good traction, the Porsche was a rocket in the rain conditions and we were very close to GT1 lap times - I could overtake the Lister and I could follow some of the Vipers when we were five or six seconds slower in the dry.
"But what pops up in my mind is the human aspect, especially the tears from Norbert Singer. He won Le Mans 16 times as an engineer since 1970, so to see him crying at his first ever Spa 24 Hours win for Porsche, you think 'it's not possible'. But we did it. We just reacted at every single moment of the race without making mistakes and always making good choices, like the first stint when I could see the black clouds - we could already take the lead by just doing the right strategy.
"The next one is of course by Norbert Singer, under the safety car. I judged the barrier damage was massive, and Norbert also saw it - our garage was on the downhill part in front of the place where the crash was - and he said a sentence I will remember for the rest of my life. 'I don't want to see you coming back. Stay out, do whatever you want, but don't come back.' Then I drove almost three hours with one tank of fuel.
"You can't do it anymore, but I was passing in front of the race director, then going down to Eau Rouge I was leaving a gap big enough that when I turned off the engine at Les Combes, there would be nobody in front of me I could catch. We had an H-gearbox that was easy to put in neutral without damaging the gearbox, so I was switching off the lights, running without power steering.
"One time I even went close to Blanchimont, then just before the car was going to stop, I put the main switch on again, used the clutch and restarted the car. I did it for more than two hours, so it looked normal in front of the race director. That was clearly something that only happens once in your life - it's not like I was planning it!
"Another thing on the human side - Marc Lieb was doing Porsche Carrera Cup at Hockenheim on the same weekend and he was tired, so with Romain Dumas we did quite a bit in the night trying to relax Marc.
"The year before, in 2002, Romain did his first ever 24-hour race at Daytona as a Porsche works driver and we were capable of winning overall, but we had to change the front radiator after Romain had a contact with a car that was 40 laps down. I told him, 'You are lucky Bob Wollek is not here anymore because a mistake like that in your first 24-hour race, you are losing your job.'
"I'm sure if you ask him, he'll say those words were important for him because at Spa he did everything right. He was a class apart in the night and that got us the win also."
Starting out as the touring car era was coming to a close in 2000, the Finn has seen the race morph through GT1/GT2 and now GT3 guises, and broke through in 2015 to give Marc VDS a long-awaited first win after an early tyre gamble went sour.
"I've done the race 15 times now. I remember in 2002 I drove a Porsche 996 GT2, which had a small but very powerful turbo engine. I think at best we reached a top speed of over 300km/h on the Kemmel straight, but the downforce and all the electronic aids were apparently not invented yet, so it was hairy to drive!
"We always came so close in the first few years with Marc VDS. In 2012 we finished fourth because we had some starter issues. In '13 we had three cars, all of them ending with trouble. Nicky Catsburg was in my car when the battery died just passing the pits, then Maxime Martin's car had a fire extinguisher blow up and break some wires. This kind of stuff always happened to us at Spa.
"And then in '14 we finished second, but we had an ABS failure and finished seven seconds behind - you can't get closer than that. It was pretty frustrating, so it was like a dream come true to finally win it in '15.
"It's always a compliment when the team puts you a little bit too early on slicks in the full wet and says that you can manage it. I did my best, but in the end it cost us almost a lap or something like that. I was on the radio saying, 'When will I see these dry patches you mentioned half an hour ago? I'm just going backwards!'
"The good thing was because of that, we basically just threw away all caution and strategy and just went flat-out. It was actually pretty enjoyable - there's always the pressure of going fast but not making mistakes, but when you are coming from behind it doesn't really matter. It was all or nothing - that's how we approached more than half of the race.
"We were very fast on Sunday when the heat came up and we had the right set-up and tyre pressures for that. It just all played for us and was pretty cool!"