I’ve ridden near those speeds (4:58, 199w NP, 189w average) at 6ft and 190lbs for a flat Ironman. I would guess there are some pretty solid aero gains to be had for you as well as getting closer to 85% FTP for a 70.3. I can guarantee that 60lbs off my body would earn me significant time, even without getting shorter. ;)

I’m also in agreement with the camp that 85% of FTP is achievable. I’m not going to argue about what FTP is or isn’t… but it’s definitely not 85% of 95% of a full gas 20 minute climb PR, so if you’re not fully realistic about that stuff, it’s possible that your 78% is actually close to the 85%. If not, those ~12w or so should be enough to get you close to <2:20 from your current stats. I believe 85% to be pretty achievable with a good run to follow for most athletes riding under 2:30 for a 70.3.

You on a recumbent bike!? Maybe power meter reading low

Good call. I was reading the original post and thinking, "This guy is probably doing too much of that non muscular endurance stuff."

For those who don't understand sarcasm, all endurance is muscular.

Not the person you're replying to but I'm 6ft 195lbs and best bike split is giving me a 2:34/35 for 200 watts on a course with some rolling hills for a not aero optimized position so that definitely seems within the ballpark.

There's lots of good advice from some very smart people in this thread. I would add Z3/HIM pace+ intervals to your long ride towards the end, i.e do 2-2.5 hours zone 2 then 3 to 6 by 10-30 minutes at 85% on short rest (couple of minutes). I'd start with 3x10 and build from there as your body/fitness allows. I'd also make two of your rides "hard rides." One ride works on CP/FTP with 20-50 minutes of total work, and then one ride that does some VO2/above FTP/CP work with maybe 5-15 minutes of total work right now. A little can go a long way.

Not a recumbent! In fact, my BestBikeSplit analysis has been fairly pedestrian as far as I’m aware, but consistent in several different race analyses, at ~0.245-0.255 CdA range, so I’m not even particularly aero in the grand scheme of things.

More recently, I was 26.4mph for a sprint distance at 275w average, 277w NP. That’s pretty consistent with the CdA from the full distance race as well, at ~0.240. However, for that one I had a couple major advantages, including staying aero essentially the entire time besides turns, and a small fit tweak to drop the front end ~1cm. I don’t have narrow shoulders or a particularly aero shaped body, but I have a decent aero shrug that I’m pretty good about getting into.

As for the power meter: I’ve had two different power meters and they’ve been close to each other. Effort also feels very similar on my road bike, which is a 3rd power meter. I’ve ridden them to very similar times at similar power outputs at the same race over a couple seasons. I would say I’ve just done a very good job of optimizing without spending crazy money or involving actual aero experts. No formal testing, either. I’d love to do it sometime, though! Sounds like maybe the OP should consider that. Alternatively, try what I’ve done so far and copy the things people who are fast do until something seems to click well. I try to copy the fastest guys I can with similar size to me and go from there to get comfortable. A couple times, I’ve seen that make a real and noticeable difference in how fast I go on my typical training rides. At this point, (for about a year) it’s mostly been small tweaks.

Coming to triathlon as a runner and being around runners and teams, you have to know or learn how to hurt. Watching age groupers for so many years, I don't know how many know how to hurt or put themselves in that position as they are preparing. Learned how to redline for 40KM to get as close to an hour and then gradually extended that for 70.3 after years. Get after it. Not in an asinine "no pain, no gain" way but turning the corner does require being uncomfortable.

Yeah fair point, should've said do more stuff at 70.3 race pace/85%.

yea i wanna see that file.

what is anything?