gearbox
Project CARS and AMS2
Audi A1 Quattro Gearbox translation
by JDougNY
Version 1.1 - 2/13/2016 - Text revisions for PC2
Version 1.0 - 8/24/2015 - Initial Release for PC2
This translation can be used to understand any gearbox file, no matter the amount of gears contained within the file.
0x00-0x07 = common data for every GDF
0x08-0x0B = 66000000 (Little Endian) = 102 // (Decimal) Total byte length of entire file.
Can vary depending upon amount of primary and final gears you want to have.
0x0C-0x0F = 01000000 (Little Endian) = 1 // (Decimal) common data for every GDF
0x10-0x13 = BABA1010 // common data for every GDF
0x14-0x17 = 4A000000 (Little Endian) = 74 // (Decimal) Total # of bytes for gearbox/bevel/final data.
The byte count starts at address 0x1C and ends at the end of the file.
This value will vary based upon the amount of gears included in the file.
0x18-0x1B = 1C000000 (Little Endian)// common data for every GDF
Gear Ratios Data
0x1C-0x20 = 60 88 DE 24 0F // common data for every GDF.
Indicates the beginning of gear data.
Note
Each primary gear is flagged by this string of bytes 24 9D 58 F9 64 02.
After that flag, the 2 bytes following represent the 2 cogs, which in the old text form would read "ratio=(xx,xx)". Each byte is in hex and needs to be converted to decimal to get the correct cog value.
0x21-0x26 = 24 9D 58 F9 64 02 // Hex string for 1st gear
0x27 = 0E = 14 // (Decimal) 1st gear cog #1 (Driver)
0x28 = 3C = 60 // (Decimal) 1st gear cog #2 (Driven)
1st gear Ratio=(14,60) // 4.2857
0x29-0x2E = 24 9D 58 F9 64 02 // Hex string for 2nd gear
0x2F = 0C = 12 // (Decimal) 2nd gear cog #1 (Driver)
0x30 = 20 = 32 // (Decimal) 2nd gear cog #2 (Driven)
2nd gear Ratio=(12,32) // 2.6666
0x31-0x36 = 24 9D 58 F9 64 02 // Hex string for 3rd gear
0x37 = 1C = 28 // (Decimal) 3rd gear cog #1 (Driver)
0x38 = 35 = 53 // (Decimal) 3rd gear cog #2 (Driven)
3rd gear Ratio=(28,53) // 1.8928
0x39-0x3E = 24 9D 58 F9 64 02 // Hex string for 4th gear
0x3F = 12 = 18 // (Decimal) 4th gear cog #1 (Driver)
0x40 = 19 = 25 // (Decimal) 4th gear cog #2 (Driven)
4th gear Ratio=(18,25) // 1.3888
0x41-0x46 = 24 9D 58 F9 64 02 // Hex string for 5th gear
0x47 = 1F = 31 // (Decimal) 5th gear cog #1 (Driver)
0x48 = 22 = 34 // (Decimal) 5th gear cog #2 (Driven)
5th gear Ratio=(31,34) // 1.0967
0x49-0x4E = 24 9D 58 F9 64 02 // Hex string for 6th gear
0x4F = 22 = 34 // (Decimal) 6th gear cog #1 (Driver)
0x50 = 1F = 31 // (Decimal) 6th gear cog #2 (Driven)
6th gear Ratio=(34,31) // 0.9117
0x51-55 = E0 97 65 B7 AF // common data for every GDF.
Indicates the end of primary gear data. Begin Bevel data.
Final Drive Ratios
Note
The bevel is flagged by this string of bytes 24 3C 5B EF 62 02.
After that flag, the 2 bytes following represent the 2 cogs, which in the old text form
would read "bevel=(xx,xx)". Each byte is in hex and needs to be converted to
decimal to get the correct cog value.
0x56-0x5B = 24 3C 5B EF 62 02 // Hex string for bevel
0x5C = 01 = 1 // (Decimal) bevel cog #1 (Driver)
0x5D = 01 = 1 // (Decimal) bevel cog #2 (Driven)
bevel=(1,1)
Note
Final drive gear(s) is(are) flagged by this string of bytes 24 9D 58 F9 64 02.
After that flag, the 2 bytes following represent the 2 cogs, which in the old text form
would read "ratio=(xx,xx)". Each byte is in hex and needs to be converted to
decimal to get the correct cog value.
0x5E-0x63 = 24 9D 58 F9 64 02 // Hex string for final gear
0x64 = 17 = 23 // (Decimal) Final gear cog #1 (Driver)
0x65 = 47 = 71 // (Decimal) Final gear cog #2 (Driven)
Final gear ratio=(23,71) // 3.0869