Rear End Ratio
- Thread starter chiliman
- Start date
Tom Wesenberg
Well-known member
Lift only one rear wheel, then shift to high gear and count how many revs it takes on the crank handle to turn the wheel two turns.
Tom Endy
Well-known member
MAFCA recently sent the attached out to all newsletter editors as a tiny tip to include in their newsletters.
I use a similar method of determining an R&P ratio. However, I take the readings off the tire instead of the front pulley.
When explaining this process to someone I offer a hypothetical R&P ratio of 4.00:1 as part of the explanation. I mark a rear tire at 12 o'clock. I mark the front pulley at 12 o'clock. Pull the spark plugs and roll the car forward in high gear until the pulley goes around four times and stop back at 12 o'clock. If the R&P were a 4.0 the mark on the tire would be back at 12 o'clock. The other gear ratios would put the mark on the tire the same as in the diagram for the pulley shown in the article.
Tom Endy
I use a similar method of determining an R&P ratio. However, I take the readings off the tire instead of the front pulley.
When explaining this process to someone I offer a hypothetical R&P ratio of 4.00:1 as part of the explanation. I mark a rear tire at 12 o'clock. I mark the front pulley at 12 o'clock. Pull the spark plugs and roll the car forward in high gear until the pulley goes around four times and stop back at 12 o'clock. If the R&P were a 4.0 the mark on the tire would be back at 12 o'clock. The other gear ratios would put the mark on the tire the same as in the diagram for the pulley shown in the article.
Tom Endy