Gearing
 

Please help...Im was using a 30t pinion and 78t spur in my car running a Tekin 10.5 with boost and getting awesome speed...I entered a race and everyone was using the same 13.5 motor in Blinky mode but my car was much slower than theirs which looked like they were running 10.5. The thing is i was using the same gearing which i think was a bad thing....what gearing do you think I should have used in this case.?

Totally need more info. What car, what kind of track, tires and so on. There will be many factors to what gearing you need. If the track is flowing with few hard turns or very technical with many sharp turns. Is this a 1/10th scale TC or 12th scale pan car? What pitch gears are the ones you mentioned, 64 or 48? Give us some more info and we can prob get you headed in the right direction.

just like what jerz said, we need more info such as chassis model to figure the internal ratio. also running 10.5 boosted to 13.5 blinky is a big gap due to boosted chassis usually run high FDR. With any blinky class races, their FDR is usually lower compared with boosted counter parts. somewhere in the field of 4.5 to 5.0 FDR is what I would recommend for 13.5 blinky. there are a couple of websites out there such TQ Racing that have a FDR calculator. there are also a couple of phone apps that can perform the same thing. just make sure you know the chassis internal ratio.