Have one with identical looking flowers by the name of Brilliant. Gotta love these REALLY red hibiscus!

i have brilliant, they are close in color, but different in form and texture. hmm lets see...here is a shot of brilliant. they are almost the same color, but Tonga Wind has a velvety quality to the petals that brilliant doesn't have ( i didn't get that on camera). also brilliant blooms tend to not have overlapping petals like Tonga Wind does. and the stigma pads on brilliant tend to be longer and very spread out, while Tonga Wind seems to be shorter and more compact.