Did the upgrade sound chip for 3rd Rail come out?

I take it there isn't an answer yet from 3RD Rail. The Northern Pacific Zs sound "non-NP" with the hooter. Like to be able to upgrade it to "true" NP whistle sounds.

I realize this is an old post. 3rd Rail's Challenger sound/hooter whistle is Lionel's RS4 based on N&W articulateds. It's also what's in 3rd Rail's SP AM-2 cab forward. It ain't right, for sure, but at the time that's all Lionel would sell. You might contact Mike Reagan at Lionel and ask if you could swap your current sound chip for a generic RS4 steam loco that has a deeper-toned whistle, or if L would swap yours for a JLC Challenger sound chip or a Lionmaster Challenger sound chip (I think they're the same with steamboat whistle). The sound chip 3rd Rail used for its TMCC SP Mogul is a good one (4 yrs ago), has a really nice whistle better suited to a non-N&W engine. I don't believe there's an NP sound chip available. Check around on this forum or go on youtube for some videos that have been posted so you can hear different locos. 

Now that Sunset/3rd Rail is using ERR in all their 3-Rail models, there is a greater variety of whistles. 

Suggest you contact Scott Mann at Sunset/3rd Rail. (800) 373-7245