Muscle Mustangs & Fast FordsHow To Engine
Ice Box Intake Part 1
We improve intake flow on our '01 blown GT with a ported Bullitt intake and custom tuning
The 4.6-liter Modular engines have powered the Ford Mustang for eight years now, and surprisingly there are only two aftermarket intakes available (both of which are from Ford Racing). This should lead astute Mustangers to conclude either the stock manifolds are just that good, or an aftermarket intake is not a viable item for aftermarket manufacturers to produce. We think the answer lies somewhere in the middle.
Both models of the 4.6 engines feature intricate intake systems with manifolds that have relatively complicated designs, but shouldn't be a brick wall in this technically advanced era. Perhaps the aftermarket thinks Mustang owners don't buy parts. Well, we certainly know that is not the case.
The four-valve units are cast from aluminum and have long runners to supply air at high velocity throughout the entire rpm range. To accomplish this, air enters the manifold at the throttle body located on the passenger side of the engine. The airflow is fed to a large plenum area in the center/bottom of the intake. Air is pulled into the individual runners that begin in the valley between the heads and swoop up and over the top to meet the individual ports in the cylinder heads.
The two-valve manifold found on GTs also sports long-arc-shaped runners, but it is formed from plastic. On GT intakes air is fed through a smaller throttle body, and the intake opening is located at the top/center of the manifold. Airflow through the GT intake follows through long runners on the way to the cylinder heads. Both designs have provisions to mount the injectors and fuel rails, thermostat, EGR valve, vacuum lines, throttle body, and a few brackets, too.
As you can see, any aftermarket intake must have provisions for all these accessories, it must bolt up clean to the heads, and equally important, it must make more power than stock. If the intake can't meet these requirements, what is the point of installing it?
Fortunately, we've heard rumblings from aftermarket manufacturers who are up to the task and are tooling up to produce some wild intakes for both 2V and 4V engines. But as of right now, none is available. This leaves owners who want to boost performance with either the '01 Bullitt intake or the Ford Racing High Flow manifold kit (PN M-9424-E46) for 2V models or the Ford Racing 4V kit (PN M-9424-T46) designed from the FR500.
Bullitt Blast Performance enthusiasts know one way to increase power is to improve the airflow to the engine. If you own a 4.6 2V, it means installing an '01 Bullitt intake manifold. Unlike the plastic intakes found on all '96-present GT models, the '01 Bullitt manifold is cast aluminum which gives it some advantages--first, because it can be ported, and second, because if you run nitrous, there is a much smaller chance of blowing the thing into a million pieces should your engine encounter a dreaded nitrous backfire. Another attribute is the shorter, yet larger, runners. If there is a downside, it is the weight. The Bullitt intake weighs about 35 pounds, which is about twice the weight of the plastic one.
Our '01 project Stang happens to be sporting a Vortech V-2 SQ with a Vortech aftercooler, and horsepower is in the 360 range at the tires. Recently, we installed a free-flowing BBK exhaust, and while we could still turn up the boost (we're only running 10 psi), we decided to first give the 4.6 more flow via a better intake. And that means slipping a Bullitt intake in place of the stocker.
After scoring a new intake from our friends in Dearborn, we had the unit hogged-out by Extrude Hone for some extra potential. We then turned to the gang at JDM Engineering in Freehold, New Jersey, for the install. Jim D'Amore and crew were kind enough to stop working on those Lightnings and new Cobras to fit us in. Master tech Shaun Lacko and I got the project underway by disconnecting the battery and draining the coolant from the aftercooler and the engine cooling system. Meanwhile, Jim D'Amore placed a call to Joe Amato at Downs Ford in Tom's River to obtain the necessary parts to complete the swap.
While the manifold exchange is relatively simple, a host of parts must be relocated and/or changed over. In this, part one, we'll go as far as removing the original parts and to preparing the Bullitt manifold for duty. In part two we'll complete the install, then we'll hop in with D'Amore and tune this puppy for maximum power.