<!-- e46 Gear Ratio by Sam C. www.bokchoys.com -->
<!-- Begin
function compute(form) {
pi = 3.14159265358979;
mm_to_inch = 0.0393700787;
inch_in_mile = 63360.0;
var twidth = form.tire_width.value * 1;
var taspect = form.tire_aspect.value * 0.01;
var wheelsize = form.wheel_size.value * 1; 
var cruising_mph = form.mph.value * 1; 
circumference = pi * ((twidth * taspect * 2 * mm_to_inch) + wheelsize);
var g1 = form.gear1.value * 1;
var g2 = form.gear2.value * 1;
var g3 = form.gear3.value * 1;
var g4 = form.gear4.value * 1;
var g5 = form.gear5.value * 1;
var g6 = form.gear6.value * 1;
var fdrive = form.final_drive.value * 1;
var rpm_redline = form.redline.value * 1;

max_gear1 = circumference*rpm_redline*60/g1/fdrive/inch_in_mile; 
max_gear2 = circumference*rpm_redline*60/g2/fdrive/inch_in_mile;
max_gear3 = circumference*rpm_redline*60/g3/fdrive/inch_in_mile;
max_gear4 = circumference*rpm_redline*60/g4/fdrive/inch_in_mile;
max_gear5 = circumference*rpm_redline*60/g5/fdrive/inch_in_mile;
max_gear6 = circumference*rpm_redline*60/g6/fdrive/inch_in_mile;

max_gear1 = twoDecs(max_gear1);
max_gear2 = twoDecs(max_gear2);
max_gear3 = twoDecs(max_gear3);
max_gear4 = twoDecs(max_gear4);
max_gear5 = twoDecs(max_gear5);
max_gear6 = twoDecs(max_gear6);

gear1_rpm = cruising_mph/circumference/60*g1*fdrive*inch_in_mile;
gear2_rpm = cruising_mph/circumference/60*g2*fdrive*inch_in_mile;
gear3_rpm = cruising_mph/circumference/60*g3*fdrive*inch_in_mile;
gear4_rpm = cruising_mph/circumference/60*g4*fdrive*inch_in_mile;
gear5_rpm = cruising_mph/circumference/60*g5*fdrive*inch_in_mile;
gear6_rpm = cruising_mph/circumference/60*g6*fdrive*inch_in_mile;


if (g6 != '') {
form.crusing_RPM.value = eval(Math.round(gear6_rpm));}
  else {
    if (g5 != '') {
    form.crusing_RPM.value = eval(Math.round(gear5_rpm));}

  else {
    if (g4 != '') {
    form.crusing_RPM.value = eval(Math.round(gear4_rpm));}

  else {
    if (g3 != '') {
    form.crusing_RPM.value = eval(Math.round(gear3_rpm));}

  else {
    if (g2 != '') {
    form.crusing_RPM.value = eval(Math.round(gear2_rpm));}

  else {
    if (g1 != '') {
    form.crusing_RPM.value = eval(Math.round(gear1_rpm));}
    }}}}}

if (g1 != '') {
form.mph_max_gear1.value = max_gear1;
}
else {
	form.mph_max_gear1.value = '';
}
if (g2 != '') {
form.mph_max_gear2.value = max_gear2;
}
else {
	form.mph_max_gear2.value = '';
}
if (g3 != '') {
form.mph_max_gear3.value = max_gear3;
}
else {
	form.mph_max_gear3.value = '';
}
if (g4 != '') {
form.mph_max_gear4.value = max_gear4;
}
else {
	form.mph_max_gear4.value = '';
}
if (g5 != '') {
form.mph_max_gear5.value = max_gear5;
}
else {
	form.mph_max_gear5.value = '';
}
if (g6 != '') {
form.mph_max_gear6.value = max_gear6;
}
else {
	form.mph_max_gear6.value = '';
}

}
function twoDecs(item) {
return eval(Math.round(item * 100) * .01);
}