A German outfit has built an EV RV with a 3-rotor range extender (& power source and power plant for the RV once parked) and it's not from Mazda. This will be a great engine to explore for a future RX-8 upgrade.

https://jalopnik.com/this-electric-r...end-1847652524

 

Look at this gem:

 

How dod you conclude it will make a great RX8 engine?

 

3 rotors is better than 2 rotors. Duh!

 

0Well, there is no guarantee that it will work well outside of the range extender application.

The reason being, most ICE-only vehicles need a lot of variable/adjustable mechanisms to perform well. Continuously phasing VVT is standard in pretty much every car you buy nowadays(even the pushrod V8 in my Camaro has it). VVL is common, with both discrete(Honda's VTEC) and continuous(BMW's Valvetronic and Fiat's Multiair) bring available. There are also variable-length intakes, all with the goal to get the maximum area under the power curve.

That's why the RX-8 intake is very complex with the stepped intake port opening and variable-length intake. NA engines especially are sensitive to that. With turbos, the intake side doesn't have to be as complex, but you would have to work on the exhaust side and tuning if you want to have reasonable responses.

Range extenders, or even some hybrid engines, can be pretty simple. Just optimize your engine for a narrow band and let the electric motor take care of the rest, so unless you can swap the whole system into an RX-8 with the electric motors, this won't yield the performance you think it might.

 

It was mostly a rhetorical question, because that was pretty much the answer I was expecting