Welcome Bogo
You're on the right track (pun intended) with the speed calcs.
TM ratimg alrady has ITV and DTV and includes starting post adjustment.
Here's their description . . .
https://www.trackmaster.com/articles/har/ratings
I prefer using the horses actual final time as the base for adjustments to create a speed rating.
I use these ITV's (all relative to 120 seconds)
Code:
Track Trailer Spd adj
ACES 10 5.7
BR 9 2.8
BTVA 9 3.7
CALX 10 5.0
DD 9 6.1
DTN 10 6.1
FHLD 9 2.6
FLMD 9 2.9
GEOD 10 4.8
GRVR 9 3.1
HAR 9 4.2
HAW 10 5.6
HOP 10 6.4
LEX 11 6.4
LON 8 1.5
M 11 6.4
MEA 10 5.1
MOH 11 6.5
MR 9 1.9
MVR 10 5.5
NFLD 9 4.6
NP 9 4.7
PCD 10 6.2
PHL 9 5.8
PPK 10 5.5
PRC 10 5.3
RCR 9 5.0
RIDC 9 4.1
SCD 10 6.2
STGA 9 3.9
TGDN 10 5.7
VD 10 5.9
WDB 11 5.9
YR 9 4.8
Good Luck with Harness races!
