Originally posted by JonGordo8:
2.0" pipe for Zetec and duratec naturally aspired
2.25" for 3L

True duals will give you the most power for a dual setup, and probably biggest gains overall.


True duals on a Zetec would be pretty hard to accomplish being as it only has one cylinder bank.

2.25" single is ideal for the Zetec

Also 2.25" dual is too large for a 3L
Even a 100% VE NA 3L (read not possible) spinning to over 7500rpm would only need 13% more air flow volume then a similiarly hopped up 2.5L Only ~26% more than a stock SVT at 7000rpm.

2.25" duals is ~22% larger than 2" duals. That's a significant loss of exhaust velocity.
One needs to consider 2" duals already outflow a 2.5" single pipe by over 22% & 2.25" single pipe (stock SVT) by ~37%.

That's already quite a substancial increase in volume over stock. (sans 2" pos resonator) Though thanks to using smaller piping it retains or exceeds stock exhaust velocity.

Leave the 2.25" duals to the S/C engines.

2000 SVT #674 13.47 @ 102 - All Motor! It was not broke; Yet I fixed it anyway.