Loss of torque with 4" exhaust?

[fulloutpwr]

Im going to second the fuel filter... I had the same kind of thing happened after my 4" install... changed fuel filter, BAM! feels good. more air in, more air out... needs fuel also... cant get fuel = slower.

[Ramsmoker]

As with any engine there is a balance of mod's to do to reach that balance. So I would look at the intake next and like a gasser with these mods, more fuel. You will see a drop in mileage now also. I always recommend setting a goal for power and match up a tune to your parts.