toilet internal trapway

what is standard size for a toilet trapway, i recently installed water saving toilet with a 1 7/8" trapway and want to make sure that i will not need 2 flushes everytime i use it. Any help at all would be greatly appreciated.

 

To be honest with you, it's not necessarily the diameter of the trap that makes it work. They used to say a tennis ball should pass through but that can't be true with a 1 7/8" trap. What really matters is how they put the water through that trap. I have a 1.6 gallon flush standard toilet that I just put in and it really works well. It replaced a 3.5 gallon model that did not work properly from day 1. (almost always had to flush twice.) I tweaked everything on that old toilet that could possibly make it flush better to no avail. The new one is called a Toto and I like it. I guess were not in Kansas anymore.

Ken