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Drag car gear ratios/motor starting choice w/ 1-5/16" rear tires

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#1 mike1972chev


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Posted 18 February 2018 - 11:17 AM

Hello,me again :)


More newbie questions here ..  I am getting ready to place another order for some other projects and wanting to buy some "starter gear ratios " for my drag car project. I see Sonic lightened gears are what I am seeing used.

I dont even have a motor yet ,but will be getting a good powered motor for it. Will be spending a few tall dollars on one,but am not sure what??? I AM NOT trying to set a world's record with a drag car,but just want a FAST machine to own and play with. 


Things about the car known at this time:


4" in wheelbase brass chassis with a WRP brass motor bracket for tall tires and 4" in wheelie bars. Chassis is built to be lightened up as much as ever needed.


Lexan body.


1 5/16 tall rears 


Where would I start with a crown gear and a pinion gear???? (NEED GEAR RATIOS !!!!)


If more info is needed or any suggestions, feel free to "chime in".  ;)

Michael J. Boruff

#2 Samiam


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Posted 18 February 2018 - 11:40 AM

NO! Get the regular gears. More robust. And get the long pinions. Won't have to move it when changing crowns.


I use a small amount of fine valve lapping compound to break in the gears. Smooth as silk afterwards. Just clean off real good.


Sorry I can't help with ratios. I don't race. Just a few play cars.

Sam Levitch
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#3 Ramcatlarry


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Posted 18 February 2018 - 01:27 PM

Motor tends to determine gear ratio.  A grp 12, S16, or other motors have vastly different RPM ranges.

Larry D. Kelley, MA
retired raceway owner... (for now)
race directing around Chicago-land


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