The number of shrapnel materials. There are different types of shrapnel materials: noncars/ghostparts/shards. Shards are probably only used in texturechange.
Noncars: (After the impact, noncar model(s) appear and starts flying and moving around, physics file needed in data/noncars) 
1	// Shrapnel count
Noncars	// Shrapnel type
0,0	// Min, max towards you speed
0.6	// Impactee velocity factor
0	// Random velocity (max)
30	// Random up velocity (max)
0	// Random normal velocity (max)
2.0	// Random spin rate (max)
		
	actorbased	   // How the shrapnel bits are initially placed in the world
	-1,-1		   // Min , Max number of shrapnel bits to be used. -1,-1 = use each bit once.
	100		   // Chance of fire/smoke as percentages
	1		   // Number of fires/smoke columns
	0,0		   // Min,Max smokiness (0=fire, 1=black smoke, 2=grey smoke, 3=white smoke)
	&petpump.act  	   // Shrapnel material in track's folder. (ACT, MAT & DAT must be in the folder) 
	1		   // Number of separate actors in file
	&petpump.act 	   // Actor name
	99petpump.txt	   // Non-car text file to use for the above actor
Ghostparts: (These appear flying again, but go through the ground and disappear after couple of seconds. 
1		// Shrapnel count
Ghostparts	// Shrapnel type
0,0		// Min, max towards you speed
0.8		// Impactee velocity factor
4		// Random velocity (max)
25		// Random up velocity (max)
0		// Random normal velocity (max)
40		// Random spin rate (max)
actorbased	// How the shrapnel bits are initially placed in the world
3 , 4		// Min time, Max time before the shrapnel bits vanish
-1		// Count (Write -1 to these two to use every bit in shrapnel material exactly once)
-1		// Count
Smashparts.act	// Shrapnel material (in track's folder again, ACT, MAT & DAT must be there)
Shards: (The texture will be divided into shards, which drop through the ground and vanish) 
1			// Shrapnel count
Shards			// Shrapnel type
0,18			// Min, max towards you speed
0.3			// Impactee velocity factor
0.5			// Random velocity (max)
0			// Random up velocity (max)
0			// Random normal velocity (max)
15.0			// Random spin rate (max)
1.5,2.5			// Min time, Max time before vanishing
.4			// Min cut length
0			// Flags
R\25GL5			// Shrapnel material in track's folder, some .MAT file.