Gear Ratio Change

Thinking of changing rear gears? Make much difference?

125" altered,2160lbs with driver,Blown BBC,14-71,1600hp@ 7700rpm,Coan XST glide 1.80 first,Coan bolt togther converter,1-2 shift @ 8000 rpm,4.30 gear,34.5 M/T's on beadlocks.

Have ran 7.02@188 mph with combo but seems a little violent at the starting line so I thought the 4.10's might calm it down and MPH a bit better

 

Mac....sent you a PM

 

There are a lot of other variables....but here is my experience....Lencodrive automatic with 1.38 & 1.31 for a 1.80 low in the trans and a 3.89 in the rear - overall 1st gear was a 7.03....worked on most tracks...but was on the edge of getting loose and shaking. I bought new chassis in 2006 with a Top Loader and a 4.29 rear gear - transplanted the drivetrain from old car. Shook hard or spun every lap! The overall 1st gear was now a 7.75....just too much leverage! So we engaged the 2-3 unit and now run as a 1.38 X 4.29 (2 speed) and the overall 1st gear = 5.92...smooth as silk....60 foot is 9.60-1.00 range and we can run it down a dirt road....I know the clutch guys may have totally different ideas on gear ratio...but with a converter keeping the 1st gear ratio under 6:1 seems to be easier to get down most tracks...but we are mostly match racing and don't run national event tracks very often...hope this helps...