jdback19

I was looking under my hood and noticed a couple things. Did Ford start putting round tube steel headers on these coyote motors? I was expecting a cast iron header but saw round tube steel. Also I noticed that they plastered "Cold air intake" on the intake box. But it seems like any other stock air box.

BrazenStang

Yes, those are factory headers for the coyote motor. That is why people typically go with long-tubes for these motors since ford did such a good job with the factory headers. There is little to gain from shorty headers. Not to mention the huge PITA for installation it is worth it to go straight to long tubes.

The Cold Air box from the factory does provide better airflow than any other generation stock airbox. Many guys are just tuning these cars and leaving the stock airbox. A new CAI will gain a few HP when tuned over the stock airbox, but nothing like it used to be. It is more of a visual mod.

jdback19

Good to know! I was scratching my head thinking somebody at the dealership put shorty headers on my car. Thanks for the info Brazen.

MustangVixenGT

Yeah they come pretty awesome from the factory.

jz78817

Coyote Mustangs have had headers since the 5.0 was introduced in 2011. The F-150 version of the motor still has cast manifolds. it's one part of why the 5.0 makes 420 hp in the Mustang but only 360 in the F-150.

MrSandman

The stock air box can pull in more air than can pass through the throttle body. It is overbuilt for a change. The Boss needs more air...and it has the exact same air box as a base GT. That should tell you something.

The fact that it is covered makes it better than most aftermarket designs. It sucks in air from the grill and not the engine bay. An open CAI is sucking in air that is hotter than the outside temp...not a good thing.

jz78817

yeah I giggle my dick off at all of those "cold air" intakes which pull air from underhood.

oh, and by the way, if you're using the stock airbox, open it up every once in a while and clear the leaves out from under the filter. Yes, they're there.

JIM5.0

Aftermarket shorty headers can help draw out a little more power, but only at a more focused and smaller RPM bandwidth than the stock headers.

The stock headers are tuned to the Coyote's exhaust valve opening and closing events to assist with scavenging and also to provide proper back pressure to prevent overscavenging. The overscavenging prevention is primarily there to meet emissions standards of preventing too much unburnt fuel from entering the exhaust system as well as promote fuel economy. But a beneficial side effect is also some power increase because that otherwise wasted unburnt fuel is pushed back into the cylinder to used to produce more power.

Now, for the Coyote stock air box flowing more air, I'm not too sure about that. Someone did a flowbench experiment between the Coyote air box and the decommissioned 4.6L air box. The our of production 4.6L air box flowed more air in their experiment. I cannot remember the exact numbers, but I think it was at least a 30CFM difference.