Nascar Ratings

What is meant in Nascar that transmissions have to have a 1 to 1 ratio?

Could someone please explain what is meant in Nascar when they say tramsmissions have to have a 1 to 1 ratio. Please bear in mind I am only just getting into Nascar and don't have much experience with cars. Many thanks for any answers.

Public Comments

1. The RPM of the input shaft on the transmission must match the RPM of the output shaft on the transmission. Input rpm's would be determined by the rpm of the motor. Think of one to one as equal, like the transmission wasn't even there, motor connected directly to the drive shaft. Hope that helps! Peace!
2. the gear-box in the back can't be mismatched, take for example if ya have a car the little cogs around it are probably 30 to one or so.
3. Let me use a GM M20 manual shift transmission as an example. In a M20 manual transmission when you take off in first gear you have a gear ratio of "2.56 to 1" meaning the front of the transmission (the side bolted to the engine) turns 2.56 revolutions and the rear of the transmission turns only 1 revolution. When you shift to second the gear ratio changes to a "1.91 to 1" gear ratio which makes the car move even faster. That ratio means the front of the transmission turns 1.90 revolutions and the rear of the transmission turns 1 revolution. When you shift into third gear the gear ratio changes to a "1.48 to 1" gear ratio meaning the front of the transmission turns 1.48 revolutions and the rear of the transmission turns 1 revolution making the car go even faster. And finally when in 4th gear the M20 manual shift transmission has a "1 to 1" gear ratio meaning that both the front and rear of the transmission is turning the same amount of revolutions making the car go the fastest for a this particular transmission. Now cars that have transmissions with "overdrive" may have a fifth gear that may have a gear ratio more than a "1 to 1" ratio. A car with an overdrive may have a gear ratio of ".78 to 1" meaning the front of the transmission only turns .78 of a turn when the rear of the transmission turns 1 full revolution. http://www.nastyz28.com/chevy-manual-transmission-identification.php http://www.gearvendors.com/cg2wdt.html
4. the drive shaft turns the same R.P.M. as the engines crankshaft.