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How To Install A Mustang Boss Intake Manifold

Created by Jeff Jimenez
Last Updated 9/2/2020

Don't miss our step by step installation article on the Ford Racing Boss 302 Intake Manifold! This is one of the easiest ways to add some serious performance to your 5.0L coyote engine!

Viewing this install and using the information shared is subject to the terms set forth here - View the LMR Install Instructions Disclaimer.

FOLLOW: mustang , 10 14 mustang , s197 , installation , tech , ford racing , air fuel , intake , engine

The Boss 302 Intake Manifold has been THE talk of the town since it was first spotted in the photos released by FoMoCo. Then we got another dose of it in the Ford Racing catalog wearing part # M-9424-M50BR. Then came all of the controversy on the interwebs all over the forums over availability. Well, all BS aside, we have them in the warehouse; we put one on a car. Scott's Race Red Brembo Package 2011 5.0L Mustang GT to be exact. Surprisingly, despite how it looks initially, it really went quite smoothly and quickly. Scott & I were recapping after the install and we both agreed that putting this intake on a 5.0L Coyote was vastly simpler than installing an intake on a venerable pushrod 5-oh. Enough of the appetizer, lets get to the meat and potatoes!

Oh, on a side note, you'll be getting several first looks at the all new Nitrous Outlet Plate Kit Nitrous System designed specifically for 2011-2014 5.0L Mustangs. And yes, it does fit with the Boss Intake just fine.

First, remove your intake cover. This is done by simply pulling up on the cover and unsnapping it.

Second, remove your inlet tube. This Mustang was already equipped with a Steeda CAI, so we simply loosened a couple of clamps, disconnected the sound tube and PCV tube, and pulled it free of the car. Just to get the PCV tube out of the way, we removed it from the valve cover as well.


We then removed the breather tube that runs from the RH valve cover to the intake manifold.


After that, we pulled the throttle body loose and let it hang out of the way. You can fully remove it from the car, but because of the nitrous system on this one, we just let it hang out because it looked comfortable.


Next, we pulled the purge valve off of the intake. This is the part that requires all the Boss specific stuff to properly locate. Well, at least that is what was being said. No says I. We'll cover the cheap fix here in a bit.


On each side of the intake you'll see 2 nuts holding down plastic brackets, and on the driver’s side, the brake booster vacuum tube. Remove those and set the brackets to the side and pull the vacuum tube free.


Once those are out of the way, grab 2 sets of pliers and a friend to remove the booster vacuum hose from the intake manifold. The 2 clamps are connected with a metal strap, so they don't move independently.


Then you can remove the foam sound deadener from both sides of the fuel rails.


Now, remove the 4 fuel rail retaining bolts and set them to the side. Unplug all the fuel injector electrical connectors. Using a 3/8" fuel and a disconnect tool, disconnect the fuel feed line. Wrap the fitting with a rag to prevent gas from going everywhere. (it’s still a safe bet to have your safety goggles on) Remove the fuel rails from the car by gently pulling up and releasing the injectors from the intake, and set them to the side.


You are now left with 6 bolts holding the intake to the heads, 3 on each side. They are located front corner, dead center, and rear corner. Fully loosen all 6 of these. They will not come out of the intake, so don't spend too much time trying. Once you're done with that, lift up on the manifold and slide it forward slightly. On the very back there are 4 wiring harness retainers that need to be pulled free from the intake.


Pull that stock intake out of the way to make room for better looks and more power!


Here is a better look at the 4 wiring harness retainers. Also, that is oil on Scott's finger and there was more in the intake. Probably a good excuse to add a Mustang oil separator.


Compared side by side, you'd pick the Boss 302 Intake all day long based on looks alone! You can also see the locations of the Admittedly, we got in a hurry and forgot to check the inlet opening sizes, but we'll get that info for you soon.


Okay, stop staring at the intake and get ready to put it on. Set the fuel rails in to place on the Boss intake and engage the injectors in to their respective ports. As you can see, the stock fuel rails clear just fine. This also illustrates the vast difference in the intakes, as the front crossover tube used to be above the throttle body!


The new intake comes with gaskets already installed, so all you have to do is set the Boss Intake on the heads and finger tighten the 6 retaining bolts. At the back of the intake, only the outer 2 of the 4 wiring harness retainers have a spot to attach, go ahead and affix them to the intake.


Slide in the 4 fuel rail retaining bolts and finger tighten those as well. Torque the 6 Intake bolts to 89in-lb using the following sequence.

Intake Bolt Pattern

Torque the 4 fuel rail retaining bolts to 89in-lb using the following sequence.

Fuel Rail Bolt Pattern

Plug in all the injector electrical connectors, connect the fuel supply line and reinstall the foam sound deadeners. Set the booster vacuum tube in to place and reinstall both plastic heater hose brackets.


Re-attach the throttle body. Doesn't that Nitrous Plate just look baller? Nitro Dave and the crew and Nitrous Outlet take their nitrous seriously.


In its stock orientation, the brake booster hose won't want to cooperate when trying to attach it to the Boss Intake.


Twist it around like so and it will go on kink free. Remember to have you 2 pair of pliers and a friend ready for this step.


Re-attach the breather tube. See that loose connector hanging there in the breeze? That is for your purge valve, which we'll cover next.


The purge valve. Its purpose is to vent fuel tank vapor in to the intake manifold during certain operating conditions. All we've seen on the 'net so far is that one company left it dangling. Well, that is an option. Your car does not need it to run. However, in my experience, this will cause the check engine light to illuminate. On the stock intake, the purge valve attached directly to the intake behind the throttle body. On the 2012 Boss 302, the purge valve is located on the driver side rear of the intake and it is plumbed a little differently. You can get the correct Boss hoses, purge valve and bracket for just under $200 when they are available but they are not currently available. Plus, you'll still have to lengthen your wiring harness to reach the new purge valve on the other side of the motor. While this is the most correct way to complete the install, it didn't help us at all right now. So good old southern ingenuity kicked in and we determined that if we made a run to the parts store to acquire an M8x1.25 bolt with some washers, 2 feet of fuel/emissions hose, and some hose clamps, we'd be in business and functioning as intended. So here is our fix. Is it ideal, no, but there is nothing wrong with it either. It gets the job done for now until something new comes about.

Squeeze on the 3/8" fuel/emisson hose. It is a tight fit, but apply a little lube and it will go on. Put on a clamp andtighten it down.


Remove the rubber insulators as they won't be needed. Using a bolt, a flat washer, and a lock washer (the lock washer goes between the head of the bolt and the flat washer) attach the purge valve to the engine block. It was kind of hard to get a good pic of this, but hopefully you get the gist. Plug the electrical connector back in and re-connect the purge line.


Run the fuel/emission hose under the neck of the intake and connect it to the remaining open port on the driver side of the intake, clamping the connection.


It has been widely reported that the Steeda cold air intake will not fit with the Boss 302 manifold, but I'm happy to report that it darn sure will. Now don't get me wrong, it's not a slide it on and done type of deal, but you can make it fit. We didn't even cut anything. Yes, there is a .75" nitrous plate installed on this car, but I can't help but think that only made the fitment a bit more difficult, if anything. Take your time and have an extra set of hands around to help tighten clamps or hold the intake in place. Supposedly the JLT CAI fits a little better, we'll be finding out for sure soon.


Oh, and don’t even bother trying to re-use your stock strut tower brace. We'll be trying several different varieties and listing which ones fit in the description of the Boss Manifold.


EDIT: We now have the 2010 Track pack slash 2012 Boss 302 Strut Tower Brace set up and shipping daily!

How To Install A Boss Intake Manifold (Ford Racing 11-14 Mustang GT) - Intake

Because of the difference in airflow this intake provides, a custom tune will be necessary. We do have the required tune available as we speak, so no worries there! Load your new custom tune in your Mustang and start it up. It will sound a little angry at first as she re-learns everything, but it'll smooth right out and you’ll be on the road enjoying your newfound power! Speaking of power, we we're unable to get to the dyno, but we'll be posting #s as soon as we have the ability to do so.

We offer the intake by itself:

2011-2012 Mustang 5.0L Ford Racing Boss 302 Intake Manifold, M-9424-M50BR


Don't forget to paint your coil covers, or replace them with the Blue FRPP Coil Covers to complete the Boss 302 appearance!