What will be 0-100 kmh time with 280 hp?

Thats a pretty pointless measurement especially now days. And way too many variables to say. Between 4.0-6.0seconds depending on entire setup. Better measurement is 60-130mph or 40-100mph. So tire, traction, launching are not variables.

Never dynoed but probably at 275whp on a dynojet.
With all season tires, and taking off from idle (no launching, or brake stalling) with a auto trans I’ve done 4.9sec. If i had a manual trans, with slicks, on the strip and clutch dump launched and tires hooked up I’d bet a 3.9 wouldn’t be out of the question. But not close to being real world applicable.

Hmmmm, in Poland we have a people making auto gearbox controller. Im thinking about first put an 8hp gearbox in my gt86 and then turbo it (order to make turbo later is important! :)) But I dont know how will gear ratios change this car and characteristic of fa20 n/a.
GT86 MT ratios according to Toyota Poland :P
1. – 3,626;
2. – 2,188;
3. – 1,541;
4. – 1,213;
5. – 1;
6. – 0,767
And 8hp ratios
1. - 4.6957
2. - 3.1304
3. - 2.1039
4. - 1.6667
5. - 1.2845
6. - 1.0000
7. - 0.8392
8. - 0.6667

What is that 8 speed transmission you are talking about?

Probably ZF 8HP

8HP 51 is in the new supra.

based on those ratios
8HP 70

Can hold unlimited power.

It will only make it better. Closer more aggressive gearing even better than the MTs. Literally no downside, besides cost of getting this done. You could pair it with a 3.7 or 3.9 FD if you want higher MPH per gear while still keeping the closeness of the gears. 6 usable gears instead of 4. Would be perfect, and future proof yourself for big power later.

I have been posting about this and wanting to do this in another auto thread for a while.

Just not sure how to go about doing it though.

If you can actually get this done it will be a game changer. You can pave the path, and myself and many others will copy you if you complete it.

Not sure how the 8 speed will interact with the gauge cluster gear selector?

That is a very nice transmission. But it is a bit overkill for FA20, imho.

Depends how much it costs and ho hard core someone wants to get. 6 usable gears with close gear ratio. Plus 2 overdrive gears for fuel economy. Aside from cost no downside if you can get it to work.

A built FA20 making 300+ft lbs with one of those would pair nicely.