Originally Posted by
eddie10
Can someone steer me in the rifgt direction. im looking for a FDR for 17.5 and 13.5, big track with 115ft straight
I can only tell you indoor carpet....used 17.5 on Mi3.5 with SP speedo (novak 17.5 and SP 17.5) FDR was 4.1-4.3 because it was a 80 footer x 50. Since your track and may be deeper...you can go as high as 3.9-4 range...check your motor temp for adjustment.
13.5 motor...4.5 to 4.7 range (my track is tighter, so I use 4.8-5 range)