I used to live there (until I was 25) and remember very well the numerous times when I would go to the old track in the very early hours of the morning and do a few fast laps (including "le raidillon"). The section from the old Stavelot corner (the Southern curve on the above map) to the "la source" hairpin I used to do flat out, including Blanchimont, in a Flat-2 car [
] though I had a few hairy moments with an Opel Manta GTE...
In those days, before they enclosed the new track, when you got bored of doing the old one, you could literally drive down in front of the pits, take "le raidillon", go up Kemel to "les combes," get out of your car, move a flismy, unattached barrier, drive down the new section of the track to "le raccordement", where you would again move another flimsy barrier, and complete the lap via the "la source hairpin," and start again, this time with all the barriers opened [
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It might sound crazy today, but at 3:00 am in the Ardennes in the 80s', no other car was in sight, besides you friends'... and the law was too far away (in Spa and Malmedy) and did not bother anyway...
The problems started in the mid-to-late 80s' when people used the new section of the track the other way around (i.e. going up from "Raccordement" to "les Combes"), praticing their car control in the snow, hitting the armco once in a while. With their Belgian sense for the absurd, the law declared the new section "une route a sens interdit, dans les deux sens" (a one-way street, both ways, so you literally had two one-way panels, one at the bottom, one at the end of the section). The gendarmes also started to patrol the section. It did not stop enthusiasts to "faire le tour", but it was becoming dangerous to face the ominous white and orange fluo car coming up the track when you were going down the "double-left!"...