1/4
Mile Data Normalization
Drag strip numbers depend on atmospheric conditions. In
order to be able to compare numbers from one outing to
the next it is necessary to normalize the ET and MPH to
standard conditions. Here are the equations to compensate
for temperature and barometric. Weather
Normalization
ETstd = ETraw * Cet
Cet = 0.9986 + 0.0095 * (Baro29.1)  0.0002556 * (Temp35.0)
MPHstd = MPHraw * Cmph
Cmph = 1.0003525  0.00975 * (Baro29.1) + 0.0002667
* (Temp35.0)
ETstd is normalized ET, ETraw is ET from time slip,
Cet is the ET normalization factor, MPHstd is normalized
MPH, MPHraw is MPH from time slip, Cmph is the MPH normalization
factor, Temp and Baro are temperature and barometric
at run time.
Though Relative Humidity is not included here, these
numbers are better than raw data.
Altitude
Normalization
BHPloss = (Elevation * 0.03) * BHPsealevel / 1000, or
3%HP loss per 1,000' elevation.
BHPloss = Brake HP measured at elevation,
Elevation = elevation above sea level in feet,
BHPsealevel = Break HP measured at sea level
HP calculation from 1/4 Mi Data
Crank HP can be calculated from 1/4 mile trap speed
and vehicle weight.
CHP = (MPH / 234)^3 * Weight
ET = 1357 / MPH
Injector Sizing & Fuel
Pressure
TPI fuel injectors are rated in lb/hr of steady fuel
flow at 43.5psi. In an L98 engine the maximum injector
duty cycle is 80%. Required injector size can be estimated
from Brake HP (BHP). Assume a Brake Specific Fuel Consumption
(BSFC) value of 0.50 for a TPI (the range
is 0.45 to 0.50 for normally aspirated engines). Then
injector size (Flow Rate) is given by:
Flow Rate = (BHP * BSFC) / (8 * 0.8)
Maximum fuel flow capacity can be adjusted with fuel
pressure as follows:
FuelFlow2 = FuelFlow1 * SQRT(Pressure2 / Pressure1).
Table
A shows full capacity fuel flow at various fuel pressure
values. The corresponding BHP values assume BSFC=0.50
(for TPI intake) and 80% fuel injector duty cycle.
Table A  Fuel Flow / BHP vs Fuel Pressure
Flow@43.5psi 
40
psi 
45
psi 
48
psi 
50
psi 
55
psi 
60
psi 
Comments 
19
lb/hr 
18.1
/ 232

19.2
/ 246

19.8
/ 254

20.3
/ 259

21.2
/ 272

22.2
/ 284

stock
LB9 
22
lb/hr 
21.0
/ 268

22.2
/ 285

23.0
/ 294

23.5
/ 300

24.6
/ 315

25.7
/ 329

stock
L98 
24
lb/hr 
22.9
/ 293

24.3
/ 311

25.1
/ 321

25.6
/ 327

26.8
/ 343

28.0
/ 359

Ford
SVO 
30
lb/hr 
28.6
/ 366 
30.3
/ 388 
31.1
/ 401 
32.0
/ 409 
33.5
/ 429 
35.0
/ 448 
NonOEM 
