While the Eco Drake is similar to the older Drake 1.6 GPF and is offered in the standard height but is more efficient at 1.28 GPF?
If I were replacing an older toilet I'd go with the Drake 1.28gpf in Elongated and ADA height.
(Today, for the first time in over 6 months, I had to double flush my Drake 1.28gpf non-ADA elongated. Caught me by surprise. For me, the regular height Drake tends to urine spot more. ymmv. I guess I will have to always sit down from now on when urinating.)
If you can afford it, go with the Drake II 1.28gpf ADA elongated dual cyclone toilet. It's a piece of art, imo.
I looked at my original paperwork and it indicates:
"TOTO Drake CEFIONTECT Two Piece Elongated Toilet CST744SG, Cotton White Toilet - Product Part #: CST744SG#01"
So I can only conclude it has the C744SG bowl unless there is a stamp or mark on the part somewhere?
That said, are you saying it would necessitate replacing the bowl to convert to the 1.28 GPF?
Guess I was hoping the tank would only require some internal parts change... if so I won't bother investing in retrofitting it.
I think you got the best of both worlds - a regular height bowl and 1.6gpf. The ADA height bowl supposedly has a better flush/wash down because of the increased height; therefor, a 1.28gpf Drake should closely match it in bowl wash, I surmise.
I wouldn't change it. But I may want to move it to the children's or hallway water closet. I would then install the ADA in the master bathroom so that as I get older it would be easier to sit down and stand up. I'd install a Kohler slim seat on it (versus the Toto thick seat, although if truth be told the Toto seat is scalloped and deeper, so, I feel, it spreads one's cheeks and one's rectum while also lowering it, since the scallop extends past the foot pads (deeper). Not everyone may like the sensation, though, some may find it uncomfortable), and I would add a 1" thick rubber mat footstool if the height is a problem. Installing the Toto seat on the ADA should help lower one's rectum closer to the water line.
1.6gpf,
regular height:
https://terrylove.com/pdf/cst744eg-specs.pdf
Tank is a ST743S
The bowl is a 744E.
1.28gpf,
regular height:
https://terrylove.com/pdf/cst744eg-specs.pdf
The bowl is a 744E.
Therefore, going with a
Toto 528MP fill valve should decrease the 1.6gpf Drake down to 1.28gpf; provided you also change the flapper to the one in the 1.28gpf Drake (red).
Likewise,
1.6gpf,
ADA height:
https://terrylove.com/pdf/cst744sl.pdf
The bowl is 744EL.
1.28gfp,
ADA height:
https://terrylove.com/pdf/cst744el.pdf
The bowl is 744EL.
Therefore, going with a
Toto 528T fill valve should increase a 1.28gpf Drake to 1.6gpf, provided you also change the flapper to the one in the 1.6gpg Drake (pink).
The difference between the regular height elongated and the ADA height elongated is the water spot shape, the regular height having a diamond shaped water spot and the ADA height having an oval shaped water spot.
How has the CEFIONTECT worked for you?
[Question to Terry: I noticed that my 1.28gpf Drake has the chain on the left most hole on the rod and my 1.6gpf Drake has the chain connected to the right most hole. What would be the result of moving the 1.28gpf chain all the way to the rightmost rod hole and the 1.6gpf chain all the way to the leftmost rod hole? To me, it would suggest an increase in the flapper actuation angle at the rightmost hole and a decrease in the angle in the leftmost hole, and therefore should affect the amount of water draining, either increasing or decreasing it slightly.
Another variable is the slack in the chain, with the 1.28gpf having little slack and the 1.6gpf having a lot of slack. I take it that the position should be adjusted so that at the lever's lowest position (fully depressed) the flapper should be as open as possible without straining it (possibly leading to breakage.)
What is the purpose of the white "weight" on the 1.6gpf? Obviously it should affect the amount of time it is open, but that just begs the question as to why the 1.28gpf doesn't have it. (Uh, because it doesn't need it? The time duration is maximum without it?) I surmise that it works in tandem with the refill ratio.
Or is it the other way around? Since the rod is angled down into the water, the right most hole will NOT open the flapper as wide and therefore less water is flushed down? Could you elucidate on the engineering?]