The Music Behind F150 Mid Pipes

Before we kick off and analyze the mid pipes available for each generation of F150 engines, it is important to discuss the difference between catted mid-pipes and off-road mid-pipes.

A catted mid-pipe is a y-pipe that, just like the OEM y-pipe, features inline catalytic converters. Catalytic converters are essential to emission compliance and are responsible for scrubbing the exhaust of particularly harmful emissions. Aftermarket catted y-pipes do use high flow converters that only slightly impede exhaust flow. It is important to note, however, that just because a mid-pipe has catalytic converters does not mean it carries CARB certification and may not be legal to use in all 50 states.

Off-road mid-pipes are the equivalent of straight pipes. They do not have any emission controlling catalytic converters at all and as such provide the absolute best flow rate but are nowhere near emissions compliant. Thus off-road mid pipes are only supposed to be used for non-road going F150 trucks. With ever stricter emissions regulations being put in place, availability of this type of mid-pipe is waning.

One other area to briefly consider is mid-pipe construction. Basically, any exhaust component is made from one of three materials (mid-pipes included). First we have aluminized steel, which is lightweight, fairly durable, and extremely cost effective. It is the choice material for nearly all OEM exhaust systems on the market.

Next up there is stainless steel, which comes in two variations: 409 and 304. The main difference between 409 and 304 grade stainless steel is the nickel and chromium content. Simply put, 304 grade stainless steel has a much higher concentration of nickel, chromium, and a lower concentration of iron, which makes it stronger and considerably more resistant to rust and corrosion. 409 grade stainless steel is the mid-tier option between aluminized steel and 304 stainless. It offers improved rust and corrosion resistance over aluminized steel but not to the same extent as 304 stainless. 

Performance mid-pipes configured for F150 pickup trucks equipped with a 5.0L Coyote V8 are available in two distinct flavors. The first option available is a completely redone y-pipe configuration mid-pipe. Aftermarket y-pipe configurations up the inlet diameter size to 3”, which accounts for a major boost in exhaust flow capacity. There is one caveat with the available aftermarket 5.0L V8 y-pipes – they are all designed and manufactured to connect with an aftermarket set of long tube headers. Thus, in order to reap the benefits of one of these y-pipes, you need to install it in conjunction with a set of long tube headers. Going this route however will yield major power and torque gains, easily in the neighborhood of 30 horsepower, and will also produce a deeper and raspier exhaust note. Using an upgraded mid-pipe like this alongside long tube headers will necessitate the ECU be reprogrammed in order to optimize engine performance.

The second option for 5.0L F150 owners is a more conservative approach. After the OEM y-pipe merges into a single outlet, an intermediate pipe with a resonator runs downstream to the muffler. Instead of changing the y-pipe, some manufacturers are marketing a mid-pipe that replaces this intermediate resonator pipe with a resonator delete pipe (straight pipe). Eliminating the resonator will decrease overall exhaust resistance and net a small gain in horsepower and torque. The exhaust note will also become louder and sound angrier with more rasp in the upper levels.

For maximum performance gains, logic would dictate combining option one and option two (i.e. long tube headers, 3” y-pipe, and resonator delete pipe), but of course this will also be the hardest on the bank account.

There is a strong offering of mid-pipes for EcoBoost F150s. Also manufactured in a y-pipe configuration, aftermarket mid-pipes for EcoBoost F150 pickups also see a bump in pipe size, enlargening the diameter up to 3”. This increase is pipe diameter is good for a 10-15 horsepower bump on its own but really comes into its own when playing with boost levels. If you plan to up the boost on your EcoBoost, the added capacity of a 3” mid-pipe is going to pay dividends at the top end of the power band.

In terms of sound, an aftermarket mid-pipe will deepen the pitch of the exhaust note. However, the most prominent auditory change comes via the increased turbo noise, which easily permeates the cabin with an intoxicating whoosh when standing on the go pedal.

Turning to an installation standpoint, EcoBoost F150 owners will be happy to know that an aftermarket mid-pipe has been designed to bolt to the factory turbo headers. And just like a 5.0L F150, a resonator delete pipe can be coupled with an upgraded 3” EcoBoost y-pipe to further recover a few extra horsepower.

The 4.6L and 5.4L Triton V8 series of engines were the choice powerplants of 1997-2010 F150s. Having been on the market for so long, it of course stands to reason the aftermarket has developed plenty of options in this time to upgrade their factory exhaust systems, and this is indeed the case.

An upgraded y-pipe is still the most frequently available type of mid-pipe for the Triton motors, made in either 2.5” or 3” diameters. The former matches the OEM mid-pipe size, but will feature high flow catalytic converters (or if an off-road version no converters at all) and subsequently will boost horsepower a small amount. A 3” mid-pipe takes these power and torque gains to the next level due to the increased flow capacity. On top of the better flow capacity, many of these aftermarket 3” y-pipes are configured to work with long tube headers, which both the 4.6L and 5.4L mod motors are highly responsive to.

Another unique option offered for the Triton motors is an x-pipe mid-pipe. An x-pipe produces a more aggressive, raspier sound and is used to create a true dual exhaust system. By providing a crossover for the exhaust pulses via an interconnected x, an x-pipe is said to better balance exhaust flow between the cylinder banks and therefore lower restriction.