[HR9121]

First thing I can tell you is that there is no manual to make it work it will just be what works best for your car. I have run as little as 4 tenths in my timer( yes my car is slow) but it works for me. You have to find something that works for your set up but I agree with supercomp that you'll probably be better off getting your ratio down some and making sure its accurate.
My second concern is your rear gear ratio. Have you made a 1/4 mile pass to know what rpms you'll be turning. If you think that you might be turning too hard you can also go on the stop later that will help a little with down track rpms. I don't go on the stop till 1.50 this also helps with getting more accurate 60' times. I can tell you also that a 6.90 will put me real close to 10.90 but this varies from car to car. The faster cars will be much slower at the 1/8 to hit the 10.90 because they are killing so much at the low end of the track. Good luck and enjoy yourself its alot of fun.