Originally Posted by
svfetter
I would have to respectfully disagree with most of the above. I had a 2000 Expedition with the 5.4. After putting on a K/N CIA and a Gibson SS exhaust, you could feel a considerable difference in the seat of your pants. Not sure on the HP increase. Very glad I did it.
Well, the 5.4L and the new 5.0L are two different engines. The vehicles in question are completely different too. You're not comparing apples to apples.
My old school pushrod 5.0L engine in my '90 Mustang GT saw a considerable increase in HP when I pulled the OEM exhaust manifolds and bolted on a set of JBA shorty headers. However, if I were to do the same thing (pull the factory exhaust and bolt on a set of shorty headers) to a stock Gen 2 Lightning (which as you know has the S/C 5.4L modular engine) it wouldn't have made a hill of beans difference.
Two different engines, same modification, two different outcomes.
There is no performance gains to be had on the L until the engine is pushing A LOT MORE HP than stock. Only then will an exhaust upgrade help.
You can't compare your 2000 Expedition to a 2013 F150 with the new 5.0L engine.
Stewart
