The Guide to Upgrading the Downpipe on a Ford F-150 3.5 EcoBoost. If you read our guide to the 5 best mods for the 3.5 EcoBoost, you’ll notice that downpipes were at the top of the list as one of the best mods for the F-150. Because downpipes are the most restrictive component of the F150’s exhaust system, switching to a less restrictive downpipe can result in significant performance and power gains.
This guide will cover the advantages of upgrading your downpipes, the distinction between catless and high-flow catted downpipes, and the best downpipe brands for your Ford F150. While this guide is geared toward the F150, it applies to all Fords equipped with the 3.5 EcoBoost engine.
What Exactly is a Downpipe Ford EcoBoost F150 ?
Because turbochargers are relatively new to Ford trucks, we’ll provide a brief overview of what a downpipe is and why it’s a popular modification for turbo engines.
A downpipe is an exhaust system component that connects the turbocharger to the cat-back portion of the exhaust. Downpipes are specific to turbocharged engines, but they are similar to headers on naturally aspirated engines in that they are the first component of the exhaust system.
The downpipe houses the primary catalytic converter in most turbo engines, including the 3.5 EcoBoost. It is the most important and restrictive component of the exhaust system because it bolts directly to the turbo and houses the cat. Because all of the restriction is contained within the downpipe, adding a catback exhaust to your F150 usually does not result in a significant increase in power.
Because the restriction is in the downpipe and the downpipe is connected to the turbo, there is a lot of backpressure. The ability of the turbine wheels to spool is affected by backpressure because the pressure creates a restriction. You want the highest pre-turbo pressures and the lowest post-turbo pressures. The best way to reduce post-turbo pressure is to upgrade the downpipe.
Advantages of 3.5 Ecoboost Downpipe Upgrade
- Gains of 10 to 25 watts
- 10-25wtq increases
- Increased turbo spool and efficiency
- Backpressure is reduced.
- EGTs have been reduced (exhaust gas temps)
- Exhaust tone has become slightly louder.
The primary advantage of upgraded F150 downpipes is reduced backpressure in the exhaust system. Running no exhaust system after the turbo is the best exhaust for a turbo engine, but due to emissions, this isn’t always possible. However, because the downpipes contain the primary catalytic converters, they are the primary source of backpressure in the exhaust system.
When there is a greater pressure drop from pre- to post-turbo, turbochargers spool more efficiently. Because the catalytic converter is restrictive, post-turbo pressure is generated, reducing the turbocharger’s ability to spool. Reduced backpressure means less force against the turbo, allowing it to spool more easily and quickly. And a more efficient turbo is a more powerful turbo, which accounts for the majority of the power gains.
Furthermore, the benefit of downpipes is enhanced when combined with a tune and upgraded intake.
Differences in 3.5 EcoBoost Power Between Generations I and II
The bone stock Gen I 3.5 produces 365hp and 420lb-ft of torque, while the Gen II produces 375hp-450hp and 470-570lb-ft of torque.
The addition of port injection alongside direct injection is the primary difference that results in increased power levels. In addition, the turbine wheels have been made lighter, and an electronic wastegate has been installed. While the performance benefits of upgraded downpipes are similar for both generations of the 3.5 EcoBoost, the turbocharger upgrades on Gen II engines will result in slightly more power gains.
Catted vs. Catted F150 Downpipes
Catless or high-flow catted downpipes are the two options for upgraded downpipes. Catless downpipes, as the name implies, eliminate the catalytic converter entirely. Because the catalytic converter is the most restrictive component of the exhaust system, going catless reduces backpressure the most and provides slightly better power gains.
High-flow catted downpipes retain the catalytic converter but use a higher-flowing cat that still meets emissions standards. However, because they still have a cat, they will provide less power gains (around 5-8whp) than catless options. The tradeoff is that your car will remain legal and pass emissions testing.
While catted options produce less horsepower, the increased flow is still a significant improvement over the OEM downpipe. Given the recent emissions crackdowns, it’s best to stick with a catted option. We would only recommend the catless option for those looking to push serious power for track applications, usually in conjunction with an upgraded turbocharger setup.
The only other benefit of catless downpipes worth mentioning is the value for money. They are roughly half the price of the high-flow catted options because they are a hollow pipe without a cat.
Downpipes for 3.5 EcoBoost F150
Finding catless downpipes is becoming more difficult as a result of recent EPA emissions activity. The best way to find some is to search for used options on forums and marketplaces.
Furthermore, regulations differ from one state to the next. Catted downpipes are still illegal in some states, including California, so check your state and local regulations for downpipe upgrades. While most catalytic converters are EPA-approved, they may be illegal in some states.
1) Excellent Buy: 3.5 EcoBoost CVF Catted Downpipes
When it comes to 3.5 EcoBoost upgrades, CV Fabrication (CVF) is a relatively new company. They do, however, provide some high-quality products at reasonable prices. That goes for their F-150 downpipes for the 3.5L twin turbo V6 engine as well. Downpipes with 400 cell high-flow cats are available from CVF. T304 stainless steel downpipes with a 3″ diameter.
From top to bottom, this is an excellent choice. It’s a little more expensive than catless options at $750, but it’s a great deal for a high-flow catted downpipe. They provide a lifetime warranty on their high-quality products. There isn’t much more you can ask for from an F-150 3.5L downpipe upgrade, in our opinion.
Anyway, we like CVF so much that we spent some time getting to know them. Finally, we were able to obtain a 5% discount code (TUNINGPRO) for all of our readers. That brings the price down to $712.50, which is a great deal for high-quality stainless steel downpipes. If you insist on catted F-150 downpipes, there are options for all 2011-2020 F-150 3.5 EcoBoost models.
2) The AMS Performance F150 High-Flow Downpipe is a budget buster.
For the 3.5 EcoBoost F150, AMS offers a top-tier downpipe option. This is one of the most expensive and premium options on the market, priced at $1,800 and designed specifically for race and high power applications. The AMS downpipes offer the highest flow and most backpressure reduction in the market, thanks to 3′′ piping and a 25% increase in inlet surface area.
3) Catless Downpipes: aFe Power F150
aFe Power manufactures a 3′′ catless option for those looking for a catless option. These downpipes, which cost around $500, provide more flow and less backpressure than catted options. These downpipes, however, are made of aluminized steel rather than stainless steel. In wet climates, this causes these downpipes to wear down and rust faster than stainless steel options.
The only disadvantage of this downpipe is that it is catless, which makes it illegal. Furthermore, finding them for sale online is becoming increasingly difficult, as most performance parts providers are moving away from selling catless products online.
It’s worth noting that eBay has a plethora of catless downpipe options. If you go that route, make sure to double-check the piping fitment before purchasing. Catless exhaust systems are essentially hollow pipes, so going with a cheaper eBay option won’t harm your engine.
Summary of the F150 3.5 EcoBoost Downpipe
One of the best modifications for your F150 EcoBoost 3.5 is to upgrade the downpipe. Higher flowing downpipes will provide exceptional performance benefits through increased turbo efficiency, especially when combined with a tune and intake.
Catless options are slightly louder and provide 5-8whp more than high flow options. High flow catted options are currently legal in most states, with the exception of California and New York. There are no catless or catted options that will produce extremely loud exhaust notes. Unless you opt for a full cat-back system with downpipes, you should only expect minor sound improvements.
Overall, downpipes are a worthwhile upgrade for those looking to boost the performance of their 3.5 EcoBoost F150s.