Originally Posted by
Chrisg23
Hey guy's, I could use some help.
I'm looking for a way to get the FDR close to 4.0:1. With the ring and pinion gear factored into my calculator, and the smallest spur AE offers(66) I will need a 41t pinion. On 48 pitch this cant be right. Can I change over to 64 pitch? Cause then the numbers may work. I'm confused.
I'm assuming you're running a TC3 or TC4 since mathematically your internal drive ratio turns out to be 2.5:1. And yes, that 41T pinion is correct with the 66T spur. If you want to stick with 48 pitch I've also used a 65T spurs from HPI. Currently, I've got a 88T 64P Kimbrough spur in my TC3. For a 4.0:1 FDR, I would need a 55T pinion. Good luck!