FASTRAK-Minimum curve radius But what about the turnouts?

I have yet to have that issue with my O36.    It makes me curious, though, since the O-36 and the 1/4 curve match an O36 curve exactly.    Take away the 1/4 curve and it's a greater radius going thru the turnout.

I don't have an SD70ACEm but I  run my Lionel Century Club 773 Hudson, and MTH PRR E8 AA  thru O36 turnouts  all the time with little issue.

One thing:  I did find one of my O36 remote turnouts to have a badly uneven rail that was causing a  Railking PRR S2 turbine to rock when going thru.   This maybe something to check on your layout.  Just an idea.

I've had issues with the moving rail(s) encouraging a derailment.

I think there might be something wrong with the switch too. I have no problems going through O36 switches on my layout with an SD70ACE.  Is the engine itself derailing or one of the cars that it is pulling?  I have noticed that on some of the older cars I have, the couplers are fixed and I have to place a car that has one of the newer "independent" couplers right behind the engine to get a little extra travel.  With that setup I am even able to run a few engines rated for O54 minimum curves through my O36 Switches

Nick,

   Because I run a lot of Tin Plate Trains on my FasTrack layout, my smallest Switches (Turn Out) are 048, they accommodate all my Tin Plate O Gauge Engines and Tenders real well.  Remember also if you re going to run A Scale GG1 TMCC JLC Engine these Scale GG1's are built for 072 curves, nothing smaller, so the Turn Outs must be 072 also, of course I run the Scale GG1 on my outer most loops.  The bigger the Turn Out, the easier for the engines and enders to run thru them.

PCRR/Dave