[chrisguyw]

As it turns out, at the moment I only have one option, a 30t crown., so I'll give that a try.

I did. It's academic, as it doesn't fit.

As your track is twisty with shortish straights, trying the 30T Crown is very worthwhile.............especially with magnets, as the motor will spin up more readily and therefore run a touch cooler,...both good things !!

I am assuming that the increased dia. of the 30T Crown, interferes/rubs on the inside of the rear cowling or interior tray of you Nissan ???.........given that the 30T is not a ton larger than the 28T, you should be able to grind/file/sand a bit away to provide clearance.

Before you do this, it may be worthwhile to insert a thin spacer between the rear chassis plate and body post to achieve clearance.........this will let you know if the gear change makes a positive difference, before you start filing/sanding.

Cheers
Chris Walker

PS If you do like the difference that the gear change makes,.....and do not wish to do any body filing, you could always go to an 8T pinion (5.5mm dia.) and use your 28T Crown. This will give a a slight increase in numeric value vs your 9T x 30T (3.5 vs. 3.3), but, for your track. I do not think this will be problematic by any stretch.



Cheers
Chris Walker