The more I look at the VIII speed curves the more I think something doesn't look right.
VIII was a better performer all round compared to the IX at low alts, yet the speed curves don't reflect this.
If they are correct, apart from an increased climb I can't see why they bothered with the Merlin 66.
Spit VIII level speed at all up weight 7,770lbs @18lbs boost
Feet, Speed
0, 338
2800, 349
9,000, 374
12,000, 371
14000, 380
20200, 405
Seems like the whole curve needs moving up at least 10 mph.