Racing a standard 12 A engine RX7 class, does anyone know what the ultimate primary pipe length should be?

I understand the longer the better.

Has anyone running the 2 primarys to their own muffler, i.e no collector box, twin pipe system?

Is there an ulitmate primary pipe diameter?

Remember this is a standard ported engine.

the racing beat long system collects over the rear axle, and uses 2 x 1.75" id pipe, into a full 2" after the collection. thats a great starting place



mike