Engineering gap, perhaps. Technology gap? It matters which J-10 version you mean. Prior to fall of the Shah they had assembled far more than F-5’s. And over the years they’ve imported quite a bit of modern multiaxis milling equipment, electronics masking equipment, foundry capacity, and so on. The military doesn’t look at them as hacks. Perhaps you don’t take them seriously enough to think with Russian backing they are fully capable of engineering a J-10 class fighter.

I know people would love to see what an F119 would do in a Delta Dagger body, but realistically your aircraft wasn’t even built for the speeds attained by the F-15. Removing the vertical tail and canards from F-106X doesn’t address the thermal issues.

And why wouldn’t something as small as the F-106X be sufficiently overpowered by an F100-229? The most fuel thirsty leg of the F-106 mission was the climb, which the F100 would have been a huge improvement over J75.

not sure if twin tailed f-5s count as a j-10 class fighter..

or maybe it does.

J-10 is not exactly a fifth generation fighter. Iran had the ability to build cars and planes, as well as quite a few heavy industry products. Don’t underestimate them. They are quite different than most any Middle Eastern country.

Hongdu is falling behind Chengdu and Shenyang. They are strategic assets, but China is anything but a strict union. Regional centers are all playing against one another jockeying for influence no different than MiG, Sukhoi, Yakovlev, Tupovlev, etc

Wouldn’t it be pandemonium if China opted to float a J-10A bid?

Welcome to 2003. J-20 is 21 meters long….

M88 doesn’t have much more thrust, though it’s smaller & lighter. Slightly more thrust, some saved weight, & better fuel economy. M53 (proposed for an upgraded Mirage F.1, as Too_cool said) offered a lot more thrust for about the same weight, in a slightly smaller package & saving some, but not as much, fuel. Much more potential performance increase than the M88, though it needed bigger intakes & other structural changes, & more fuel to allow use of the extra thrust without running dry. Didn’t sell.

M53 was already in the Mirage 2000, so an F1-M53 would have competed against an existing production line. An F.1 reboot powered by M88 is in a 33% lighter weight class. Fuel economy between M53 and M88 is actually quite different, with M88 a mizer in comparison. And the F.1 reboot would be slimmer than the original due to the huge volume (diameter and length) difference between M88 and 9K50.

The point of an F.1 reboot isn’t more M2K sales, it’s about cheapening the operations of all Dassault customers for both Rafale and F.1M88 with common logistics.

Wait, all this squabbling is whether J-20 is 68 feet or whether once upon a time people imagined it was 73 feet long? What a stupid discussion