Finish this Equation :)

Peak HP = 272 @ 5800

Tire OD" = 26 inches

Final Drive = 3.73:1

1/4 Mile = 15,840 inches

Circumference of a 26" diameter tire = 81.68"

Tire revolves 193.92 turns down the quater mile

193.93 tire revolutions * 3.73 final gear (1:1 tranny) = ~ 723.32 engine revolutions to complete the race.

Questions:

Is there any method to calculate distance of travel per gear selected (IE: TH350, "seamless shifts")?

Is there any formula to estimate acceleration (time) of the car in
each gear knowing weight, gear ratios and horsepower/tq curves
of the engine (assuming 100% efficient tranny, no tire slip, etc)?

Possibly "tractive force"? You might could use that for a comparison.

If you try and manipulate simply physics formulas, you will not get accurate results with a simple equation. All of those take acceleration to be constant. Do you know calculus?


Is there any method to calculate distance of travel per gear selected (IE: TH350, "seamless shifts")?

You're trying to figure out how far you can go in first gear if you take off at WOT? Is that correct? I'm not sure why, but it seems like it would be more useful to know how fast you could go in each gear.

If you tell us exactly what you're looking for we may be able to help further.

Ben T.

Just wondering if there is a calculation to determine approximate
tire size and final gear ratio when setting up for quarter mile.

I'm hoping there is a method to correlate peak HP RPM, tire size
and gearing.

I don't know much Calculus (College level Electronics) ...my Physics is highschool level.

I might understand some of the mathematics if there was an
example, or link given.

Thanks for the reply.

What's the weight of the vehicle in question and how much power does it make? What transmission?


Ben T.

Originally posted by Zero_to_69
Questions:

Is there any method to calculate distance of travel per gear selected (IE: TH350, "seamless shifts")?

Is there any formula to estimate acceleration (time) of the car in
each gear knowing weight, gear ratios and horsepower/tq curves
of the engine (assuming 100% efficient tranny, no tire slip, etc)?

There are a number of drag racing simulators that wil do what you want. I use an old one from Performance Trends (DOS based!) that gives everything you wanted and more. Aero and friction drag, wheel/tire inertia and driveline efficiency are all figured in. Out put can be in feet travelled, mph or seconds.

You can input engine dyno curves, barometric info, traction of the tires, torque converter stall, etc.

The math is quite sophisticated, but it's already been done for you.

Try the demo in this one:

http://performancetrends.com/Drag%20Racing%20Analyzer.htm

Zero_to_69,

http://www.maxracesoftware.com/prod02.htm

http://www.maxracesoftware.com/prod03.htm

http://www.maxracesoftware.com/products.htm




links to DragRacing software to predict ET or HP/TQ


http://www.maxracesoftware.com/prod02.htm
will also calculate HP and Torque from ET times
the reverse

Nice programs!

I'll check them out guys.

Is there any formula to estimate acceleration (time) of the car in
each gear knowing weight, gear ratios and horsepower/tq curves
of the engine (assuming 100% efficient tranny, no tire slip, etc)?
=====================================

you would have to use the "Tractive Force" equation StudyTime mentioned..then iterate in small time steps for instantaneous acceleration from changing variable's values in Tractive Force


reverse method ;
from popular advertized data like
0 -to 60 mph times
you could get average GForce
then work out Force from that

example=>

0 -to- 60 MPH in one second ...in a 3000 lbs car

GForce = ( 60_MPH / 1_second ) * .045585462

Tractive_Force = GForce * Car_Lbs

Tractive_Force = 2.73512772 * 3000

Tractive_Force = 8205.4