Hmm, hard to believe that there’s really no info on the 14 (nor is it on the “recommended” list for any of their current on road engines), but based on the numbers and because it is a “straighter” pipe compared to the curvier looking 41015-17 models, I’d venture to say that it’s the shortest of the 4, and thus, would highly favor top end over acceleration compared to the 16 - especially considering that the 16 is the happy balance between the 15 and 17.