Top 5 Ford 4.6 Performance Improvements. The Ford 4.6 V8 engine was one of the most powerful engines in the Ford lineup for many years. It is capable of laying down some serious rubber, producing north of 300 horsepower and 300 lb-ft of torque in performance vehicles such as the Mustang GT and SVT Cobra. Ford also installed the engine in non-performance vehicles such as family sedans and SUVs. If you want to get a little more power out of your 4.6 V8, you’ve come to the right spot, because today we’re going over the top 5 Ford 4.6 performance modifications.
Whether you have an SVT Cobra or Bullitt Mustang, or simply want to add some power to your Expedition or Explorer, the Ford 4.6 is an excellent engine for modding. No matter what model you have, a few improvements can result in significant increases in horsepower and torque. We’ll look at the greatest mods for any Ford 4.6 owner, including those with supercharged SVT Cobras, in this article. We’re looking at functionality, cost, quality, and, most importantly, performance. Let’s get this party started.
Ford 4.6 Engine Specifications
From 1991 through 2014, Ford produced the 4.6 modular V8, which was used in nearly 20 distinct models across the Ford, Lincoln, and Mercury brands. The engine is a 4.6-liter V8 with an aluminum head and cast iron and aluminum blocks. The 4.6 Ford V8 is available in three configurations: 2-valve SOHC, 3-valve SOHC, and 4-valve DOHC. The 4-valve delivers by far the best performance of all of them (check the linked engine guide above for a full list of 4-valve 4.6 Ford vehicle applications).
The bore and stroke measurements are 3.55 in 3.54 in (90.2 mm 90.0 mm), giving it an almost completely square engine. Both the SOHC and DOHC engines have two different factory cylinder heads, as well as a Ford Performance cylinder head with enhanced flow characteristics that is available. Electronic fuel injection is used in all Ford 4.6 engines, while Variable Camshaft Timing is used in the 3-valve models (VCT).
Ford released the “Terminator” variant of the 4-valve engine from 2003 to 2004, which many consider to be one of the best Ford engines ever made. It generated 390 horsepower and 390 pound-feet of torque thanks to an Eaton M112 roots-type supercharger operating at 8 psi of boost. Even today, the Terminator 4.6 Ford Mustang is highly regarded, with examples regularly fetching more than $50,000 for well-maintained models.
Top 5 Ford 4.6 Performance Enhancements
Our top five Ford 4.6 performance enhancements are as follows:
- ECU Programming
- Fresh Air Intake
- Headers for Long-Tube Vehicles
- Underdrive and Blower Pulleys
- Upper Plenum and Throttle Body
These are by far the best Ford 4.6 performance enhancements, regardless of the 4.6 Ford V8 powered vehicle you drive. The first is ECU tuning. ECU tuning is one of the simplest, safest, and most cost-effective ways to increase the power of your vehicle. As we’ll see later, tweaking can result in gains of up to 30 horsepower. It can also assist compensate for other bolt-on modifications like as heads and intakes.
Following ECU tuning, we recommend making changes to enhance the quantity of airflow in and out of the engine. The simplest method to accomplish this is to upgrade the intake and exhaust. A cold air intake improvement will allow your engine to regularly take in cool air. Long-tube headers will be used to replace the heavy and inefficient cast-iron manifold with more efficient stainless steel pipes. Both will increase the horsepower and volume of your engine.
Following tune and ventilation, another very inexpensive change is to replace your supercharger and/or underdrive pulleys. If you have a Terminator 4.6 V8, increasing the blower pulley frees up a significant amount of horsepower and is a simple process. Underdrive pulleys also liberate up horsepower and are inexpensive and simple to install.
Finally, we recommend that the throttle body and upper plenum be upgraded. Apart from the air filter, these are by far the most restrictive parts of the intake system. Before attempting to increase power levels, they must be upgraded.
Let’s take a closer look at each of these Ford 4.6 performance enhancements.
1) Ford 4.6 Performance Enhancement: ECU Tuning
ECU Tuning ranks first on our list of the top 5 Ford 4.6 performance enhancements. The engine control unit (ECU) is the computer that fundamentally controls how your engine works. You can add a solid 10-20% gain in power over stock simply by tuning your ECU, and that’s without any hardware or bolt-on alterations.
To meet pollution requirements and ensure that their engines run as long as possible, most automobile manufacturers intentionally undertune their vehicles, even high-performance models like the SVT Cobra, to produce less horsepower and torque than they could otherwise. A qualified tuner may uncover part of this hidden horsepower through ECU tuning by adjusting variables like ignition timing, camshaft timing, air-to-fuel ratios, and boost pressure (if you have a supercharger equipped).
Furthermore, when bolt-on and hardware changes like as cold air intakes and long-tube headers are introduced, tuning can assist your engine run safely. Several bolt-ons alter engine airflow, which the ECU may fail to correct for. Although many of them claim to still have safe air-to-fuel ratios, the only way to be certain is to have your ECU calibrated.
To ensure that your engine is running healthy and ideally, your tuner may check for things like engine detonation (knock) or pre-ignition. Tuning also allows you to get more power out of your bolt-on and hardware upgrades.
ECU Tuning Ford 4.6 Performance Improvements
When it comes to tweaking the Ford 4.6 V8, you have a few alternatives. This is referred to as custom tuning or canned tuning. Custom tuning is the superior choice since it involves a tuner making modifications based on your individual automobile in your specific weather circumstances.
Canned tunes, on the other hand, are more like one-size-fits-all tunes designed to work for a single brand of car. They are car-specific, but they are less exact than bespoke tuning because they are not tailored to your individual vehicle and environmental conditions. Certainly, someone living in Florida and someone living in Seattle will have very different weather conditions. Hence, in order to fully optimize your vehicle for your mods and environment, you must go bespoke.
Bespoke tuning is best done using a dynamometer, which can be found at most local performance shops. E-tuning is another alternative, in which you communicate with a tuner by email. Nevertheless, unless you own a Mustang, finding a bespoke e-tuner will be difficult.
We recommend Unleashed Tuning and 5 Star Tuning for canned tuning. They are a middle ground between canned and bespoke tuning in that they provide personalized tunes but do not make particular modifications for your vehicle. These are not as accurate as a bespoke tune on a real dynamometer, but they come close.
Whether you use custom or canned tuning, you’ll need some sort of tuning hardware device to send the tune to your vehicle. The SCT and DiabloSport are two of the most popular. We strongly advise you to choose your preferred tuner first, and then purchase any tuning tools they propose. Remember that not all tuners use the same tuning devices.
2) Upgraded Ford 4.6 Cold Air Intake
A cold air intake is the next item on our list of the top 5 Ford 4.6 performance modifications. Cold air intakes are likely the most common and popular improvement for the 4.6 Ford. Cool air intakes function by rerouting the air intake filter away from the engine bay and towards the fenderwall. This enables them to absorb cooler and colder air. The cooler the air the more oxygen it has, which means your engine can create more power, get better gas mileage, and perform more efficiently.
Furthermore, cold air intakes typically feature larger air filters and tubing than factory intakes. This implies they can take in more air than stock, which is important if you want to increase power. Improved intakes also contribute extra sound to the engine, making it noisier. They also significantly improve the engine bay’s appearance, giving it a much more race-like appearance.
A ram air intake is another alternative, but these aren’t always ideal choices. Ram air intakes operate by directing incoming air along the shortest and least resistive channel possible. It normally does not bring in colder air, but it does remove constriction and boost flow.
While the standard intakes are normally adequate, adding bolt-ons such as long-tube headers can cause a limitation. A more free-flowing intake will improve throttle response, top-end power, and engine noise.
The Best Ford 4.6 Cold Air Intakes
Most 4.6 V8 powered Ford, Lincoln, and Mercury vehicles come standard with cool air intakes. The air filters are situated near the fenderwall, away from the engine area, where they can be exposed to relatively chilly air.
The goal of upgrading the cold air intake is to eliminate resistance, increase tube diameter, and move the filter further away from the engine bay. The stock air box is heavy, and the tubing is usually composed of cheap plastic and is relatively restricting. Improved intakes typically include an open air box, a panel filter replaced with a cone filter, and larger diameter and better pipework. Because of the reduced restriction, all of this equates to improved airflow.
Upgraded intakes can also be located closer to the fenderwall due to the usage of a cone filter rather than a panel filter. Though the improvement is slight, it does help to keep hot air from the engine bay at bay.
5 Star Tuning is our choice for Ford 4.6 cold air intakes. They sell intakes for a wide range of Ford 4.6-powered vehicles, including Crown Victorias, Mustangs, and E-series vans. The majority of them employ high-quality K&N air filters that are competitively priced.
Keep in mind that the Ford 4.6 engine employs a MAF-based airflow measurement system. Without getting too technical, this means that if you upgrade your intake, you will want to invest in specialized tuning. When acquiring and installing improved intakes, make sure you have a tuner in mind.
3) Long-tube Ford 4.6 Headers
Long-tube headers will be the third item on our list, following ECU tuning and cold air intakes. The Factory headers on the Ford 4.6 V8 are made of thick, restricting cast iron. As a result, they perform poorly in terms of ideal flow and are prone to cracking after repeated heat cycles. Upgrading your headers is a necessary for each build, no matter how minor. Because the Ford V8 has two cylinder banks, it also has two headers, one for each bank.
Long-tube headers are designed to replace the OEM exhaust manifold (also known as headers) all the way back to the mufflers. Aftermarket headers are typically made of T304 stainless steel, which is lighter than cast iron but extremely sturdy. They are also intended to provide the most efficient and least restricted flow possible. Long-tube headers also take the place of the factory catalytic converters, which are by far the most restrictive part of the exhaust system.
Long-tube headers function by lowering back pressure and enhancing exhaust scavenging. The reduced back pressure provides for improved exhaust flow. Exhaust gasses are eliminated faster and more clean air can enter the combustion chamber due to increased exhaust scavenging and less reversion. This results in greater and longer-lasting power.
Long-tube headers will surely increase exhaust volume significantly. As you may guess, the increased pipes and available cats amp up the sound of the Ford 4.6 V8.
Best Ford 4.6 long-tube header performance enhancements
When it comes to long-tube headers for a 4.6-powered Mustang or comparable vehicle, you have two choices: catted or catless. While catless systems create somewhat greater power, they are also non-compliant with emissions regulations and will fail inspection. We choose catted headers because the power differential is modest and they are more suitable for daily driving. They still flow well enough to achieve most power goals while significantly reducing the unpleasant catless exhaust odours.
You may have heard of short-tube or “shorty” heads, but we normally advise avoiding them as well. They just replace the very front of the exhaust manifold, before the cats, and offer little power. It’s long-tube or bust if you want to modify your exhaust.
Long-tube headers are manufactured by a variety of companies, so your best bet is to go for a respected brand like Magnaflow, Borla, Corsa, Kooks, or American Racing Headers. If you own a 4.6 Mustang and want to replace the long-tube headers, American Racing Headers has a few good options. They provide 2-, 3-, and 4-valve alternatives for any 4.6-powered Mustang. They have an excellent reputation in the market, and their headers are guaranteed to look and function superbly.
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4) Upgraded Ford 4.6 Blower and Underdrive Pulley
The pulleys on your Ford 4.6 V8 powered vehicle will be upgraded next. Depending on the model, you’ll need to replace your supercharger pulley or underdrive pulley (or both).
Supercharger (blower) pulleys increase the amount of boost produced by your supercharger. Mechanical drives, usually serpentine belts spun by the crankshaft, power superchargers. These belts are linked to pulleys, the size of which controls how fast the supercharger operates. The smaller the pulley, the faster the supercharger operates, and the more boost it produces. Higher boost equals more power, and blower pulleys can typically produce 30-40 wheel horsepower.
Underdrive pulleys increase horsepower in a similar but distinct manner. The accessory belt, which includes things like A/C, the water pump, and the alternator, is driven by the crankshaft pulley on many 4.6-powered Fords. The function of an underdrive pulley is to reduce parasitic drain from the engine’s auxiliary belt. It accomplishes this by slowing down the auxiliary belt, so reducing the amount of power required. Instead of wasting power on the accessory belt, it can be directed to the wheels.
Ford 4.6 Supercharger with Underdrive Pulleys at the Top
Steeda offers the best solutions for upgrading the supercharger and underdrive pulleys on your 4.6-powered Ford. And has a great reputation in the Ford and Mustang performance industries, and they’ve been around for a long time.
Steeda supercharger pulleys are available in two sizes: 3.10″ and 2.81″. The larger pulley results in a 1-2 psi boost pressure increase and a 25+ horsepower improvement. The smaller pulley results in a 4-5 psi boost pressure increase and a 60+ horsepower improvement. Critically, the smaller pulley will necessitate a smaller serpentine belt in order to maintain adequate tension.
The Steeda underdrive pulley claims to slow down the accessory belt by 25%, resulting in a 5-10 horsepower gain. Installing an underdrive pulley will also result in a 2-3 mpg boost.
Modifications to the Ford 4.6 Throttle Body and Upper Plenum
The throttle body and upper plenum are our final top 5 Ford 4.6 performance enhancements recommendation. Aside from the intake filter, the throttle body and upper plenum of the intake manifold are the most restrictive portions of the intake system. The throttle body is located between the intake manifold and the air intake. The upper plenum is the intake manifold’s highest point.
The factory throttle body is 65mm in diameter, which is slightly undersized for a 4.6 liter engine. Aftermarket throttle bodies are typically 5-10 mm larger than standard, allowing them to take in more air. Also, the manifold’s upper plenum is quite restrictive, thus porting it allows it to take in more air. Porting is the technique of smoothing the metal to improve airflow and reduce turbulence.
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The Accufab item is by far the best modification for the Ford 4.6 V8 throttle body and plenum. Accufab offers throttle body choices of 70 mm or 75 mm, representing 5 mm and 10 mm over stock. They will allow for more airflow, resulting in a boost of 5-8 horsepower.
The Accufab unit is available with or without the enhanced top plenum, which we suggest. The ported plenum will provide much improved airflow over stock, and if you’re replacing the throttle body, it’s a no-brainer to change the plenum as well. Unless you have a 4-valve 4.6 Ford V8, in which case it is not as severe.
Combined, you should get 10-15 horsepower boosts as well as an expanded power band.
Verdict on the Best Ford 4.6 Performance Improvements
Generally, the Ford 4.6 V8 is a relatively reliable engine that reacts well to modifications. Whether you have a naturally aspirated or supercharged Terminator Cobra, a few simple modifications can completely transform the engine.
To begin, we propose performing basic ECU tuning to obtain a healthy power gain without the need for any hardware or bolt-on changes. If ECU tuning isn’t enough, upgrading the cold air intake and long-tube headers is the next step. These are two of the most common mods, and they will significantly increase the power and volume of your Ford 4.6.
Following the ECU and intake/exhaust, you should investigate supercharger or underdrive pulleys. These are fairly inexpensive ways to enhance horsepower, especially the supercharger pulley. Finally, for Ford 4.6 performance modifications, we recommend getting a bigger throttle body and a ported upper plenum. They will add 5-15 horsepower to your engine and allow it to suck in some serious air.