Real example of Tabata on cycle Wattbike

So there is the theory : 8 bouts of 20s at 170% of VO2 max with 10s rest for the Tabata protocol.

On a Wattbike, I can do:

- test of 3mn: (http://www.wattbikeranking.com/ranking?c=4)

Position	Name	Age	Sex	Club/University	Nationality	Distance	Average Power	Date

29

Cedric Beltrame

37

Male

-

French

2368m

390

08/10/2011

- test 30mn

52

Cedric Beltrame

37

Male

-

French

21505m

302

14/01/2012

When I train for intervals 3mn/3mn, I usually cycle at 320 Watts for the hard intervals.
My power to weight ratio is 390/86=4.47 W/Kg.

So what about for Tabata?

The RPM is 90-100, level of resistane is 8-9 on the Wattbike, and intervals are cycled around this intensity : 460-440-420-400-400-380-380-390 = average of 408.75 watts

I think it is very hard to apply a constant 170% of VO2max or equivalent.

Watts avrg	% VO2max	duration	watts @vo2max
390	120%	3 mn	325
302	92%	30 mn	328.26
320	100%	3x 3 mn	320

Based on the 3 mentioned training (max 3mn, max 30mn, 3x3 intervals) I evaluate my power output at Vo2max on the bike around 325 Watts.
That will require 325*1.7 = 552.5 Watts for each interval!

I'm far from it, with an average of 408.75 watts which is in this case roughly 125% of the power output at Vo2max.

So although it is probably highly beneficial, it is a HIIT training rather than a pure Tabata. Unless my calculations are incorrect?