the problem i have with duals on an I4 is this, unless the Y joint is engineered and placed in the proper place, it will actually increase backpressure due to turbulence(sp?) of the exhaust gasses which causes loss of exhaust gas velocity induced by the split.

it is a myth that any engine needs backpressure to run. if this were the case we would all be sporting .5" exhaust piping, not shelling out the dough for a performance cat-back exhause or whatever. the reason too big of a diameter exhaust piping will cause loss of horsepower is not because of lack of backpressure, but the extra surface area of the piping causes the exhaust gasses to cool. this slows the exhaust gas velocity and causes backpressure.

in short.... duals on an I4 are teh :ghey: