Yup. That’s a good CdA.
The ratio of watts/CdA has to be about 1000, so if your CdA were 0.25, you’d need to produce 250 watts. If your CdA were 0.20, you’d only need to produce 200 watts.
Note that the red dotted lines don’t exactly line up with the black dotted lines so 1000 watts/m^2 is close but if you really really need to know you have to do the arithmetic (or else go to someone like Jim).
Yup. That’s why the fastest times in the UK are generally on “dual-carriage” roads (what we in the US would call “on the shoulder of a highway”). Their “effective CdA” on a dual-carriage can be way south of 0.17 m^2, depending on traffic. For example, look at the old times on the V718 route – that route is now no longer allowed.
Certain TT courses only! I’ve done more than my fair share of sporting TTs and road races on UK roads that are far from smooth. At a recent race briefing the organiser described one section as “frankly f***ing disgraceful”
I am not disparaging that if you read any of my posts correctly. In fact I’ve said almost exactly that. DC’s result in unrealisticly low CdA numbers because of less power needed to move at speed on them. I am pointing out however that in the likes of @jdman example on a non DC course, that folk have worked very hard on improving their CdA etc by other means. So whilst a DC is significant its not the whole reason they have achieved significant results.
CdA is king as the guy who did my bike fit on Monday said (George Fox - one of the best of the UK TT riders)…so hopefully next year I will go quicker for the same power as I don’t think any new Watts are going to appear this winter. Although I will be riding my TT bike more on the turbo to close my road vs TT bike FTP. The best examples are some of the v quick lady racers in UK TT - they don’t put out huge power but their position is so dialled they can produce some amazing results. 
100%, seeing as how we are fairly similar for height and weight there should not be a great difference as far as ability to get aero outside of biomechanical issues ( which i have more than most between past hip and shoulder injuries )
I worked with a great fitter and slowly played with all the little things to optimize as well ( as per my description )
Part of it will come down to conditions too, road or environmental. there is a good reason hour veledrome records tend to do well at high elevations, low pressure system, warm and humid 
I’d be interested in seeing your setup, position and see if there is any low hanging fruit.
You have a ton of low-hanging aero fruit to harvest here. You are on an Endurance road bike, which has a short reach and tall stack. Not good for aero.
Add in skinsuit, aero helmet (even if only an aero road helmet), etc.
You can easily save minutes without upping your power at all.
If you can post a side picture (taken level with you) on your aero bars, you can get a lot of good feedback re: your position.
Out of curiosity, what did you run off 2:19 bike @Power13?
What training plan do you follow for a 100mi TT @Majoeric? Do you just do the 40km TT and add longer rides? Or does plan builder work out what is needed off an A event TT of 4hrs?
I quit using TR awhile ago because I felt it prescribed too much high intensity for me. I now do my own thing that usually consist of longer intervals (20-60 mins) around sweet spot or just below and lots of z2-z3.
Naturally I have a higher anaerobic capacity vs aerobic so working on the aerobic engine is a priority.
Randomly I will just feel like knocking out longer miles on my TT bike and when I do, I usually like to go faster compared to just noodling.
I ran 1:41….but probably started out too fast on the run. Ran the first half at about a 7:30 pace and faded a bit on the way back in. But still beat my target pace (8:00 / mile) and was my fastest run split for a 70.3, only 2’ off my standalone HM PR.
Final time was 4:47, and I PR’d by 12 min, 5th place AG (50-54)
If you are anything like me, it is damn near impossible to not ride faster on a TT bike….it just makes you want to go harder! 
Was really hard to train for my IM races at prescribed power levels on my TT bike!! 
On full TT setup, 220-230W. (100m TT was 260W for 3:50 or 26mph. 10’ over 160km = 30-40W)
On RB, mudguards, Hunt 4 season wheels, winter long sleeve top, gloves, normal helmet, cotton socks… 333W lol
Both using Assiomas
180cm
83kg
Watts/drag is king. There are four main buckets to drag losses: aero, mechanical, potential energy, kinetic energy. Maximize the numerator as best you can; minimize the denominator as best you can.
well yes even with great CdA the athlete with the best power wins - and as you say there is all the tyre rolling resistance, drive chain stuff, chain waxing, single big front rings for chain line efficiency…the sport is great for tech and er expensive! 
258w for 33kph here (199cm tall, 76kg).
Being tall sucks.
I get aero and mechanical drag loss but, I’m blanking on what potential and kinetic drag loss are? Help?
That is absolutely not true…I ride with a bunch of guys who have WAY higher FTP (both in raw numbers and w/kg) and I routinely put the sword to them on our group rides. Sure, if I go to the line with them, they can get around me (but not always), but they usually aren’t there. 
about 260-270 on a road bike with TT bars
Potential energy refers to climbing and descending, kinetic refers to accelerations and decelerations. We know that weight matters for both; in addition, even if the route is known and everyone has to follow it, some riders take wider turns, or decelerate through braking and then have to accelerate out of the turns, so they waste energy both by unnecessary braking and then waste energy by trying to make up for it by aggressively accelerating. When you examine differences in acceleration/deceleration, and where they spend their energy, you get a sense for how wasteful some riders are.