Re-locating toilet drain

Re-locating toilet drain - added diagram

Hello all! Been a lurker here for a while now and there is a lot of good info here! Just a little about myself...I'm an industrial electrician by trade and mechanic/consumer electronics repairer on the side (hobby mostly), so plumbing isn't completely my forte! This leads me to my questions.

First, we will be finising our basement, and the builders of the home ran the master WC on it's own drain along with the tub and sink. This is in the middle of a planned hallway, so I want to tie the WC and sinks into the main 3" tree. Currently, the guest WC, tub, and sink, is plumbed into the main line with a san tee with a left and right 2" inlet.


I was wondering if I should give the Master WC it's own san tee below the master tie-in with another left and right inlet (pic shows same orientation, but it will be about 90deg off),


or use a back-to-back fixture for the WC's then plumb the sinks and showers on a couple of double sanitary tees?


Also, the master sink and tub are plumbed just like the guest setup: WC sanitary tee with left and right inlets, with the sink and tub using it's own inlet. When I move these to the new location,

can I join the sink and tub into one line or do I need to run them separately to the new location?

If I can join them into a single line, it will be a horizontal run, so I should use a wye or combo, correct?

Finally, what is the maximum number of turns between trap and main drain line? I saw 135 deg max for trap to vent on this board, but not the other way.

Be as harsh or gentle as needed!

Thanks in advance!

Alex

(Yes, the orange in the pics on the 3" horizontal line is silicone sealant...leaky joint!)

WE would have to draw your system using your description to even start to answer HOW you could do the piping, and that would be very tedious and we would probably get it wrong anyway. There is no limit to the turns between a fixture and its connection to a main, BUT, you do need cleanouts anytime it turns more than 90 degrees. The 135 degrees between the trap and vent is a "Variance" so you would not need a cleanout in that line.

You can't place the second bathroom set below the other unless you separately vent the fixtures.
Flush the upper toilet will pull water from the lower set.

Ugh, so, all other drains aside, if I plumbed the wc's back to back using a double fixture, I'd still run into the suction problem? I forgot to mention that main 3" line in the pic is vented, so I don't know if that makes any difference. I wish I had one of those nifty 3d piping programs that everyone seems to be using here. My Microsoft Paint-manship is horrible! I'll draw a diagram and post it when I get it done.

Also, sorry to get off topic, but are the avatar pics randomly generated? I'm a little spooked since I own a shelby cobra replica, lol.

Here is a drawing of the current layout



The master vent line is 1.5 or 2 inch and ties into the main vent in the attic. I would really like to move all of the master plumbing over to where the guest stuff is plumbed. The other option, which I want to avoid, is tearing up the floor and moving the pipes over against the wall. Hope this helps some!