Boss 302 Intake Manifold Install How To
The 2012 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 FRPP 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 & quickly. Scott & I were recapping after the install & 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 & 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 2011-2012 5.0L Mustang. And yes, it does fit with the Boss Intake just fine. A full install write up will be coming up soon on this Nitrous System.
First, remove your intake cover. This is done by simply pulling up on the cover & 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 & PCV tube, & 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 & 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, & on the drivers side, the brake booster vacuum tube. Remove those & set the brackets to the side & pull the vacuum tube free.
Once those are out of the way, grab 2 sets of pliers & 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 & set them to the side. Unplug all the fuel injector electrical connectors. Using a 3/8″ fuel & a/c line disconnect tool, disconnect the fuel feed line. Wrap the fitting with a rag to prevent gas from going everywhere. (its still a safe bet to have your safety goggles on) Remove the fuel rails from the car by gently pulling up & releasing the injectors from the intake, & 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, & 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 & 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 & more power!
Here is a better look at the 4 wiring harness retainers. Also, that is oil on Scott’s finger & there was more in the intake. Probably a good excuse to add an 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 retaining bolts in these pics. Admittedly, we got in a hurry & forgot to check the inlet opening sizes, but we’ll get that info for you soon.
Okay, stop staring at the intake & get ready to put it on. Set the fuel rails in to place on the Boss intake & 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 & 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 & affix them to the intake.
Slide in the 4 fuel rail retaining bolts & finger tighten those as well. Torque the 6 Intake bolts to 89in-lb using the following sequence.
Torque the 4 fuel rail retaining bolts to 89in-lb using the following sequence.
Plug in all the injector electrical connectors, connect the fuel supply line, & reinstall the foam sound deadeners. Set the booster vacuum tube in to place & reinstall both plastic heater hose brackets.
Re-attach the throttle body. Doesn’t that Nitrous Plate just look baller? Nitro Dave & the crew & 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 & it will go on kink free. Remember to have you 2 pair of pliers & 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. You 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 & it is plumbed a little differently. You can get the correct Boss hoses, purge valve & 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 & 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, & some hose clamps, we’d be in business & 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 & it will go on. Put on a clamp & tighten it down.
Remove the rubber insulators as they won’t be needed. Using a bolt, a flat washer, & a lock washer (the lock washer goes between the head of the bolt & 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 & re-connect the purge line.
Run the fuel/emission hose under the neck of the intake & 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 & 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 & 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, & don’t even bother trying to re-use your stock strut tower brace. We’ll be trying several different varieties & listing which ones fit in the description of the Boss Manifold.
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 you new custom tune in your Mustang & start it up. It will sound a little angry at first as she re-learns everything, but it’ll smooth right out & 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.
Late Model Restoration offers the intake by itself:
2011-2012 Mustang 5.0L Ford Racing Boss 302 Intake Manifold, M-9424-M50BR
or with the required custom tune:
2011-12 Mustang 5.0L Ford Racing Boss 302 Intake Manifold M-9424-M50BR With BBR Custom Tune
Image Source Courtesy of LateModelRestoration.com