Your RIOT can be custom ordered any way you want it. Stock I build them with between 1600cc-2332cc Dual Port VW Motors. These are very reliable and cost between $1995 to $6995 Turn Key. The RIOT is most popular with Dual IDF Weber Setup and I personally am Running a Garrett T3 Turbo Charger.
The VW Motor popular because 180 Horse to 500 Horsepower is easy to achieve, and it doesn’t require Running Cooling Lines and Radiators etc and Fabricating a rear engine cage. However we can easily install a Subaru Motor. A 4.0 Northstar or a Mazda Rotary Turbo, but for the money you will get more horsepower per dollar from the VW Motor.
We have worked out a deal to install Electrical Motors and Converters in the RIOT Car.