Some technical questions..

In general Diesel has a very low flamability, because it only builds flamable gases at temperatures about 55°C (For comparison: patrol -20°C) . That's why it dosen't ignite so easy in the exhaust system like patrol does. It is said you can put out a cigaret out in a diesel laugh. I never tested it.

In the VLN the noise ruels are extremly strikt, compared with other race series. Thats because the Nordschleife is situated in a nature protection area. And because of the hughe silencers, backfires are not seen realy often in the VLN even at petrol fueld cars.

on a "normal" VLN Weekend you have a "Einstellfahrt" on Friday, what is lika a practice, from 16-18 o'clock (or was it 15-17? olli?). the next weekend the Einstellfahrt is from 15:30-18:00. But it dont has a connection to the VLN, the Einstellfahrt ist from MH-Sportpromotion and you can drive with cars, wich arent driving in vln.
On Saturday you have a Quali from 8:30-10:00. But sometimes its from 8:00-9:30 (barbarossapreis) or from 9:00-10:30 (dunno the exact race, british single seater are driving too there).
Also on saturday you have the race from 12:00-16:00 mostly. On 6h Race its from 12:00-18:00 and on the Barbarossapreis the race starts at 11:30-15:30 cause there is a youngtimer race after the vln race. Normally the race where the british single seaters drive, starts about 12:30-16:30

Misan is the expert

The "Einstellfahrten" from MH Sportpromotions are from 16 till 18 o'clock Friday before the race. It is not part of the VLN race but nearly all the Teams uses it for Tests and Taxi drives.