The V8 Owners Forum -

I'm building a custom trumpet base for 3.9 rover, with the aim of running it on an engine producing between 250 or 300 hp.

Is it worth using bigger trumpets for what they cost (199 quid plus vat so far) or shall i bung the standard ones in?

Bigger ones also present the problem of me having the trumpet base machined so they are at an angle to squeeze them all in.

If I had £200 +Vat to spend on tuning a RV8 I would spend it on new heads, valve train, bottom end, ECU in that order, once I had spent every penny improving the above only then I would spend money on the manifold, port match the thing first (without opening it all the out to the gasket). Trumpets last of all, you won't see any difference from this mod until all the others are Maxed out .
Best of luck
Mike