Whether you’re just looking for some addition sound or you’re tuned and looking to increase power, an exhaust upgrade is one of the modifications for the 7.3 Powerstroke.
Only a handful of Ford’s 7.3 diesels came with emissions exhaust systems. This was mostly limited to the CARB versions of the F250 and F350 that were sold in California. Furthermore, they only had catalytic converters. The rest of the 7.3’s didn’t have everything which is great for performance as it significantly reduces exhaust backpressure, leading to a more efficient, powerful, and reliable turbocharger.
Despite already having a free-flowing exhaust system from the factory, there are still a lot of performance benefits to upgrading the 7.3 Powerstroke exhaust system. These benefits are especially amplified once you are running other modifications like a cold air intake and a tune.
This guide is going to cover exhaust upgrades: from downpipes to turbo-back systems and all the things you need to consider like exhaust diameter, mufflers, piping material, and more. First, let’s discuss the performance benefits of upgrading the 7.3 Powerstroke exhaust.
7.3 Powerstroke Exhaust Upgrade Benefits
- 5-15whp and 10-30wtq depending on tuning
- Increased exhaust sounds
- Reduced backpressure in the exhaust system
- Lower engine temps and EGTs
- Improved reliability and turbo efficiency
The benefits of an exhaust go beyond simply the power gains you get from it. First off, I would note that the power gains are going to be on the low end of that range if you aren’t tuned and running an intake. A bigger and better flowing exhaust system becomes more important once you are brining more air into the engine and running above stock boost levels on the turbo.
The secondary benefits of an exhaust are really reliability benefits. It will help keep engine and EGT temps down which is important for longevity. Additionally, tuning increases stress on the turbo by increasing boost levels and an exhaust will help reduce that stress by reducing backpressure. If you are tuned an exhaust will help improve the reliability of the turbo.
Considerations for Choosing an Exhaust
There are a lot of exhaust systems on the market for the 7.3 Powerstroke, both for the 1994-1998 models and the 1999+ models. An exhaust is really just a long, bent piece of metal. They’re not very hard to make, or expensive, which means you have lots of options across a ton of different price points.
Not all exhausts are made equal, though. We are going to discuss a few important things you’ll have to decide on when choosing an exhaust system.
Turbo-Back or Downpipe-Back
Since most of the 7.3’s didn’t come with emissions equipment, turbo-back systems are the most popular. As the name suggests, they bolt directly to the turbo and go all the back to the exhaust tip.
Now, there are also kits that go from the downpipe back, or from the catalytic converter and back, albeit they are less popular. To fully upgrade your exhaust you need a downpipe and everything behind it. If you have a cat and leave it in then you’ll need the downpipe and cat-back part of the exhaust.
Ultimately, we recommend a turbo-back setup as it has the best performance benefits.
Exhaust Diameter: 4″ or 5″
The second most important consideration is the exhaust sizing. The two most widely available systems are 4″ and 5″ systems. This refers to the diameter of the exhaust piping.
A 4″ system is going to reduce exhaust backpressure by about 80%. A 5″ system will reduce is even more. You’ll also typically see EGT reduction in the 150-200 degree range, with a 5″ system being on the higher end and a 4″ on the lower end.
4″ is probably the more popular option for 7.3 Powerstroke’s. There are benefits to a 5″ but it really isn’t completely necessary unless you have an upgraded turbo. A 5″ is probably going to run around $100-$200 more expensive which is why people stick to 4″ unless they need it bigger.
Our opinion: if an extra couple hundred bucks for a 5in doesn’t bother you then get the 5-inch. Otherwise, 4″ is all you need if you are on the stock turbo.
Stainless Steel vs. Aluminum
Budget exhaust systems are usually made of aluminum, and the premium options are stainless steel. Stainless steel holds up better over time and doesn’t rust like aluminum does.
I made the mistake of putting an aluminum exhaust on my 7.3 F350 which I drive in the Colorado area. It rusted and developed a hole in it which caused me to fail my emissions test, so I had to spend $150 getting it cut and welded just to pass my test.
Opinion: get the stainless steel if you can afford it. If you don’t live in an area where things rust then aluminum will be okay but it still has a limited lifespan.
Mufflers: Do You Want it Loud?
Some exhaust systems for the 7.3 Powerstroke have mufflers and some are completely straight piped. Mine is a straight pipe and it’s quite loud from outside the vehicle. Really a personal preference here, but ones with mufflers are going to be a bit quieter.
Muffler exhaust systems do have a little bit more backpressure and they won’t reduce EGTs as much. But the difference is honestly very minimal and on a tuned and lightly modified truck it is still an upgrade for performance.
Best 7.3 Powerstroke Exhaust Systems
Ultimately, my recommendation would be for a 5″ stainless steel, turbo-back exhaust system. Again, an exhaust is just bent metal so as long as it is constructed well and it fits every exhaust is going to offer very similar performance benefits.
With that being said, stick with a reputable manufacturer and you’ll end up with a great product. In my opinion, upgrading your exhaust system is more important than which actual exhaust you choose.
Here are the best brands on the market:
- Banks Monster Exhaust Systems
- Diamond Eye (good budget options)
- Magnaflow (good but overpriced)
My 7.3 F350 Exhaust Setup
While I don’t 100% recommend setting your exhaust up like I did mine, here is my setup and what I would do different next time.
I’ve got a 4″ turbo-back exhaust system (can’t remember if it is MBRP or what) that is aluminum. Also, most exhausts don’t come with an exhaust tip so I purchased a 5″ exhaust tip to mate up to the exhaust. I initially had a muffler, but the aluminum wore down after a few years leaving me with a hole in the muffler. So I had the muffler cut and straight piped (+$150) so that I could pass emissions. It’s now pretty darn loud but works great and keeps EGTs down.
I’m on the stock turbo so a 4″ is just fine with me. Really the only thing I would do differently is get a stainless steel system and go straight-pipe to have it hold-up better in the Colorado weather and perform better.