Hello all,

What is the right gearing to use for the 1/8th mile?

I know that I should be at or near the rev limiter when I go through the trap but should I use 3, 4, or all 5 gears. What is quicker?

I know that with practice, I will get faster so I will need to change the overall ratio to to keep the rpm's where they need to be for the finish line.

I am in no way a professional in this area but my thinking is this:

The more you shift the more time you spend not at WOT. That is unless you have one of those electronic shifters that shift for you.

For an 1/8, I'd think you should be wound out in 2nd, or just shifted into 3rd. Practice short shifting to 3rd and let her pull.

I always ran stock ratio gears. Just a couple of feet off the line I could be hooked up and gone. Lower gears just made it easier to light the tire again in 3rd. Higher ratios killed the launch.


Sam
former All Harley Drag racer

Right now I am crossing the finish line at 92 mph @6500 rpm in 3rd. My Overall ratio is 3.64.
stock 883 ratio-4.07 and stock 1200 is 3.51 ( I changed the primary engine sprocket to the 1200's 38 tooth from a 34 tooth

I don't think any rubber mount could cross the trap in 2nd gear unless one plug wire was broke. I think my 2nd maxes out in the 60's. I couldn't gear it low enough to max 2nd across the finish and still get 1st gear off the starting line. I don't understand your statment.

Mikel, I'm with you, we had 300' drags here and I was topping 2nd there. With 360' more to go I'm sure the rev limiter would get a heck of a work out. I'd sure like to see what you'd get in the quarter, thats awful fast in an 1/8!

Mikel,
DAYUM! Never mind, I ran a 4 speed,etc.
If you're at redline in third, you might try short shiftin to 4th.
Any Sportster that winds that fast is hiding some torque.

Sam

the dyno sheet said that I have 80+ tq from 2200 rpm and 90+ tq from 2600 rpms. 80+ past my red line of 6500 rpms.


( I don't want to rev it any higher... to much wear and tear for a street motor)