I got a stock motor with Turbonetics ST kit.

When I was running the reflash I was at ~850-900rpm idle and sometimes it would stumble. Apparently this was a common problem with the reflash on the TN kits. I just got tuned with uprev and my tuner dropped the idle to stock...650rpm idle. It idles fine. Throwout bearing noise is a lot more apparent but it seems to run very smooth. I asked him about the idle but he said there's no reason for me to have been idling at 850-900rpm.

Was there a particular reason the TN reflash was running at 850-900rpm idle?

 

On stock motor... stock idle rpm is ok assuming the other components are able to idle there (cams, injectors etc). Some built engines will require an idle bump to increase oil pressure at idle depending how it was built / intended for.

 

My stock block turbo car (with Haltech) is very happy idline at 650rpm. It has been like that for a couple of years now.