(42S) Solvers: Automobiles
06-29-2019, 03:29 PM
Post: #1
 Eddie W. Shore Senior Member Posts: 1,079 Joined: Dec 2013
(42S) Solvers: Automobiles
Blog Entry: http://edspi31415.blogspot.com/2019/06/h...lvers.html

1. Displacement, Bore, Strokes (File: displacement.raw)
﻿
Code:
00 { 79-Byte Prgm } 01▸LBL "DISPMNT" 02 MVAR "DISPMNT" 03 MVAR "BORE" 04 MVAR "STROKE" 05 MVAR "#CYLIN" 06 PI 07 4 08 ÷ 09 RCL "BORE" 10 X↑2 11 × 12 RCL× "STROKE" 13 RCL× "#CYLIN" 14 RCL- "DISPMNT" 15 .END.

Variables:

(DISPM): displacement of the a cylinder (cubic inches)
(BORE): diameter of the cylinder (inches)
(STRO): distance traveled by the piston (inches)
(#CYLI): number of cylinders

Equation:

π/4 * bore^2 * stroke * #cylinders - displacement = 0

Example:

Bore = 4 in
Stroke = 3.5 in
4-cylinder engine

Result: Displacement = 175.9292 in^3

2. Gear Ratio, MPH, RPM (File: gearratio.raw)

Code:
00 { 74-Byte Prgm } 01▸LBL "GEARRTO" 02 MVAR "RPM" 03 MVAR "MPH" 04 MVAR "TIREDIA" 05 MVAR "GEARRAT" 06 PI 07 RCL× "RPM" 08 RCL× "TIREDIA" 09 RCL÷ "MPH" 10 1056 11 ÷ 12 RCL- "GEARRAT" 13 .END.

Variables:

(RPM): the tire's revolution per minute
(MPH): speed of the vehicle (miles/hour)
(TIREDI): diameter of the tire (inches)
(GEAR): gear ratio = transmission ratio * final drive ratio

Equation:

(RPM * π * tire_diameter) / (MPH * 1056) - gear_ratio = 0

Example:

RPM = 3,400 rpm
Tire Diameter = 28 in
Gear Ratio = 3.85

Result: MPH = 73.5635 mph

3. Quarter Mile Estimation: Elapsed Time, Car's Weight, Horsepower
(File: quartermile.raw)

Code:
00 { 52-Byte Prgm } 01 ▸ LBL "QRTMI" 02 MVAR "ET" 03 MVAR "WEIGHT" 04 MVAR "HP" 05 5.825 06 RCL "WEIGHT" 07 RCL÷ "HP" 08 3 09 1/X 10 Y↑X 11 × 12 RCL- "ET" 13 .END.

Variables:

(ET): elapsed time for the car to travel 1/4 mile (seconds)
(WEIG): weight of the car including passengers, drivers, fuel, and other items carried (pounds)
(HP): horsepower

Equation:

(weight/horsepower)^(1/3) * 5.825 - elapsed_time = 0

Note: MPH = (horsepower/weight)^(1/3) * 234 = 1363.05/elapsed_time

Example:

Weight: 3,540 lb
HP: 215 hp

Result:

ET: 14.8190
(MPH = 91.9802 mph, [SHIFT] (TOP.FCN) ( 1/X ) 1363.05 [ * ])

4. Tire Sizes (file name: tiresize.raw)

Code:
00 { 87-Byte Prgm } 01 ▸ LBL "TIRESZE" 02 MVAR "SECWDTH" 03 MVAR "RIMDIA" 04 MVAR "ASPECT" 05 MVAR "TIREDIA" 06 2 07 RCL× "SECWDTH" 08 RCL× "ASPECT" 09 2540 10 ÷ 11 RCL+ "RIMDIA" 12 RCL- "TIREDIA" 13 .END.

Variable:

(SECW): section width (millimeter)
(RIMDI): rim diameter (inches)
(ASEPC): aspect ratio
(TIREDI): tire diameter (inches)

On a side of a tire, we can get three of the four values by from a code that looks like this:

P235 / 75R17

P: passenger car (L for light trucks)
235: section width
75: aspect ratio
17: rim diameter

Equation:

(2 * section_width * aspect_ratio) / 2540 + rim_diameter - tire_diameter = 0

Example: Use the stats of the tire above to calculate tire diameter.

Result: 30.8780 in
 « Next Oldest | Next Newest »

User(s) browsing this thread: 1 Guest(s)