venting a new bathroom (toilet)

[spetrucco]

Need to know if the following scenario is viable.
First floor bathroom with vanity, tub/shower and toilet.
I want to drain the shower and vanity togeather with a 2" line into the main waste line directly under the proposed bathroom in the basment. The main waste line runs horizontaly out to the sewer main. These lines will be vented with a 2" vent line. NO fixtures tie in to this vent except from this bathroom.
My real question is venting the toilet. I want to use a 3inch pipe to drain the toilet directly into the waste line. But I want to vent the toilet with a 2inch line verticaly in the wall for 8feet then run the vent on a 45degree angle for 40inches and tie it back in to the vent from the vanity/shower. Is this permissible?
Please see attached sketch for a better explanation.

Thanks in advance
Shawn

 

[Markts30]

The max distance from the trap weir to the vent on a 2" trap arm is 5'
It sounds like yours will be longer....