I think it was @geraldjust that pointed out that the crank position sensor and reluctor wheel are the same type as the 17+ cars. So a full swap doesn't look like too much work for those years. It looks like cam positioning also plays nice with the 17+ car.

The article does say that they initially got it running "by replacing and re-pulling the crank angle sensor wiring and several harnesses", but not much more detail than that.

It's hard to say for sure what they did. The translation loses some things. They may have just had to swap plugs or something for the sensors.

I guess I shouldn't say easy either, less hard would be more appropriate.

Maybe wait until some company like Haltech do a wire/sensor adapter so it can be plug n play

I don't think Haltech, but somebody will no doubt make a kit. It's going to be a bit more difficult on the pre facelift cars.

Because they started from the Zenki 86, they have to replace some harnesses and sensors. If started from the Kouki, those are not hurdles.

A few parts of the article suggest that they had already swapped to a Kouki engine and ECU:

"After successful start of the late model engine in the first half..."

"...the ZN6 of the first period can be started with a late model engine..."

"From the start of the late model the other day, we succeeded in starting the FA24 by replacing and re-pulling the crank angle sensor wiring and several harnesses."

It appears from that info (and another post a couple before that one in the site's journal confirms it) that they had already done the work of swapping to a Kouki motor and ECU, so maybe some further changes were needed.

Might be a bit of a dumb question, but how much hp can one extract from a well-tuned FA20 (headers, intake, possibly cams, E85, etc.)?

My mechanic (who works almost exclusively on 86s) claims to have seen as much as 250hp from an NA FA20, with what I'd expect to be a much lower budget than a complete FA24 swap. Makes one wonder whether those extra 14hp are worth the money, although other variables like torque and further modding potential have to be taken into consideration.

Wheel HP or crank HP?

The most I have ever seen on a dyno with a baseline is like 212whp. With no baseline the final number is always going to be suspect. Could have been making 238 stock and 250 modded. So when you look at the delta, not that impressive, even though the final number is big. Guys with low boost FI kits are only making 250-260.

Was thinking crank hp, based on around 195 stock crank hp so about +45whp.

Any idea of the weight difference between FA24 & 20? I'd guess it's negligible.

Yeah 250 crank isn’t an unrealistic number. 212/250=.848. So 15ish% drivetrain loss is realistic in that scenario.

Still i m not understanding how doable is this swap, fa24 short block into restyling fa20 with fa20 heads?
Did someone here figure out what s really needed?

Reviving this thread, it looks like there are a few shops in the US that either have it working or are working on it. I know of at least one that's offering the swap, which involves an FA24 short block and FA20 heads, but that's the extent of my information.

No one willing to talk about the fa24 spinning bearings at lower mileages than the fa20?

It would suck to replace a spun bearing 1st gen with a new second gen then pop the hybrid on your first track day.