Paul, wye turnouts are different; the frog number isn't the amount of diversion from the through route like it is in conventional turnouts. Wye turnouts' frog # is the sum of the diversion BETWEEN the two routes...so it's really like a #8...except two of them back-to-back, sharing the same frog.I'm using Anyrail to design my new layout. I'm using the #5 Peco turnouts from my first crack at this and I know my 60' cars and SD40-2s run well on them.
Problem is that in the Anyrail track library there is only a Peco #4 wye (code 83). A quick google search suggests no other size exists. Will this equipment be alright on a #4?
BUT...Peco did something a little different with their #4 Wye using a somewhat smaller radius to get a shorter turnout:
Read this thread...it's worth the trouble:
At Fast Tracks, the place where you can learn to make your own turnouts, they have an extensive library of templates...printable ones.
Click on the 'download' icon and when it loads, you'll see, if you imagineer a through route instead of the other diverging route, that a #4 is really half of a #8 on each side.