Divided housing to divided manifold
 

I'm slowly getting my project together and will soon be looking to do a single turbo swap. I understand the benefits of using a twin scroll set up and I've been looking at the Turbonetics GT-K series turbos, more specifically the Billet GT-K 750 or 850. I am no expert on turbos and I welcome any information I can get. So my questions are:

1. Is the .81 ar ok for a street ported engine looking to put between 400 and 500 whp running e85 on the ground. (I read the compressor map illiterate threads and still have no idea what I'm looking at.)
2. If I were to use the Full Race divided turbo manifold would I have to buy a turbo with a divided flange?
3. Is there any way for me to know whether or not the turbo that I want will fit on the manifold that I get, without trial and error or first buying the turbo and sending it to the manifold manufacturer?

1. I would go with the next size up A/R. .81 is on the small side for a rotary and will induce excessive back pressure but slightly better spool.

2. A divided manifold should ideally be mated to a divided turbo.

3. Some of it is trial and error, unless you know someone with that exact combination. Why not go with something proven like a GTX3582 or BWs362/366? Myself, A-spec, and Turblown all make manifold/turbo combos that we know fit with proper runner length and wastegate placement.

The GTX3582 looks like a pretty good choice, water cooled, ball bearing CHRA but I would have to find my own turbine housing, which isnt a problem, but for about the same price and with a Turbonetics warranty I can have them make me a frankenturbo which also comes with a water cooled, ball bearing CHRA and a divided t4 turbine housing with a 4" v-band discharge. Either way, I think they both look good on paper. I wont do one of the BW turbos specifically because of the journal bearing thing. Yes they are much cheaper but I am a magnet for things that fail.

I dont mind having to send my turbo out to get a manifold made for it, I was just making sure that there wasn't an easier option that I overlooked.