big enough? seems like a waste of effort to put that baby thing on a rotary engine, the turbine housing will also choke up your exhaust flow. it is barely a step up from the stock twins, if that gives you idea. the twins are also more responsive unless you are referring to a set of twin 25's which will work, if they come with the custom manifold/wastegate otherwise you are talking about having a full custom exhaust made which can be $$.
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