I’ve been a car enthusiast ever since I could drive. I love the feeling of controlling a powerful machine and making it truly my own. One of the best ways to customize a ride is with an aftermarket exhaust system that unleashes the engine’s potential. Flowmaster has long been one of the leaders when it comes to exhaust systems that optimize performance and sound. I recently upgraded my own vehicle with a Flowmaster single in, dual out (SIDO) exhaust and wanted to share my experience for anyone considering this type of set-up.
Picking the Perfect Flowmaster SIDO System
The first step was choosing the right Flowmaster SIDO system for my vehicle. Flowmaster makes these systems for a wide range of makes and models. I drive a 2015 Ford Mustang GT, so I needed to find the kit designed specifically for the 5.0L V8 engine in my Stang.
After browsing the options on the Flowmaster website and watching some YouTube videos of different systems on late model Mustangs, I decided to go with the Flowmaster American Thunder SIDO cat-back exhaust system. This system has 2.5″ pipes and Flowmaster’s Delta Flow mufflers that I knew would sound aggressive but not obnoxious.
Feel the Power Gains
One of the biggest benefits of upgrading your exhaust is increased horsepower and torque output. The stock exhaust on most vehicles is very restrictive. All of that piping creates backpressure that literally holds your engine back from making maximum power.
By upgrading to a less restrictive Flowmaster SIDO exhaust like the American Thunder, your engine can breathe better and get rid of spent gasses more efficiently. The smooth mandrel bent piping reduces turbulence allowing exhaust to flow freely.
I definitely noticed an improvement in acceleration right away after the install. My Mustang feels a lot quicker jumping off the line and has a lot more mid-range punch when getting on the throttle. Based on the dyno tests I’ve seen, installing this Flowmaster exhaust likely gave me 15-20 extra horsepower easily.
Aggressive Sound for Muscle Cars
While the added power is great, an aggressive exhaust note is probably the main reason most people upgrade their exhaust. There are few things I love more than rowing through the gears and hearing my Mustang come to life with a deep, rumbling V8 soundtrack.
The Flowmaster Delta Flow mufflers gave my Stang a true American muscle car sound. It has a nice burble at idle, and really roars when you get into the upper RPMs. The tone is strong but not obnoxiously loud or raspy.
I don’t mind turning heads and cracking a few windows when I drive by, but this system provides the perfect balance of loudness in my opinion. It’s got just enough volume to let people know I mean business, without being annoying on long highway drives.
Dual Exhaust Benefits
Most V6 and V8 performance cars come from the factory with dual exhaust systems featuring two pipes. Upgrading to a Flowmaster dual out maintains that stock setup.
The benefits of a dual exhaust include better scavenging as the two pipes work together to efficiently expel gasses in a timing that reduces backpressure. Aesthetically, dual pipes just look great filling up the rear valance.
The Flowmaster American Thunder follows my Mustang’s stock dual routing all the way back. The twin 2.5″ pipes fill out the rear nicely and emit that iconic muscle car rumble from both sides.
Challenging but Rewarding Install
I decided to tackle the Flowmaster install myself in my garage using basic hand tools. This exhaust system is built to be a direct bolt-on replacement for the stock components. However, getting to some of the bolts on a lowered car like mine proved quite challenging.
I ended up recruiting a buddy to help with maneuvering the pipes during the process. Having an extra set of hands made a big difference. All in all, expect a 2-3 hour install depending on your skill level and access to a lift.
The end result made the hassle worthwhile. Hearing the throaty idle and thunderous acceleration for the first time post-install put a huge smile on my face. The tone and performance of this Flowmaster SIDO are really like nothing else.
Bringing the Muscle Back
So if you drive a Mustang, Camaro, Challenger or other V8 performance car, I can’t recommend the Flowmaster single in, dual out exhaust enough. The difference in sound and power brings these modern muscle cars back to their roots.
My Mustang feels faster and more visceral with the Flowmaster system. The American Thunder strikes the perfect balance of aggressive tone without being overbearing. I’m amazed how such a simple bolt-on modification totally transformed the personality of my car.
Now I’m looking for any excuse I can to take it out on spirited backroad drives and listen to that glorious rumble. No more flying under the radar with the stock exhaust! So if you’re ready to unleash your V8, go check out the Flowmaster SIDO options. I promise you won’t regret it.
Quick Comparison to Similar Systems
I chose the Flowmaster for its reputation and sound based on the many YouTube clips I watched. However, there are some other major players in the SIDO exhaust game. Here’s a quick rundown on how Flowmaster compares to the competition:
Magnaflow – Known for deep tone but slightly raspy/nasally sound
MBRP – More budget-friendly option but can have drone issues
Corsa – Aggressive sound with exotic materials but very expensive
Borla – Quality brand but their tone was too raspy for my liking
For my money, I still think Flowmaster provides the best combination of sound, quality, and performance. The Flowmaster tone just screams American muscle and never seems to get old.
Exhaust 101 – SIDO versus Cat-Back
When upgrading your exhaust system, you’ll generally have two main options – cat-back or SIDO style:
Cat-back replaces everything from the catalytic converters back. This leaves the stock manifolds and downpipe in place.
SIDO (single in, dual out) also replaces from the cats back but adds an x-pipe that converges the pipes back into a single inlet.
Most people opt for cat-back since it’s the simplest, most affordable way to upgrade. But for maximum performance, a SIDO style like the Flowmaster I chose can help scavenge gasses more efficiently.
If you really want to unlock your engine’s potential, pairing a SIDO exhaust with long tube headers instead of the stock manifolds is an excellent combination. The long tubes combine with the Flowmaster SIDO to allow the most free-flowing exhaust path possible.
Worth the Investment
Upgrading your ride’s exhaust system isn’t the cheapest modification, but it’s one of the most rewarding. With a quality brand like Flowmaster, you pay for top-notch materials and engineering.
Expect to budget $800-1200 for a complete cat-back or SIDO system depending on your vehicle. Some higher end options with exotic metals like titanium can cost $2000 or more.
You could go with a cheaper no-name brand, but quality issues are common. I see too many fellow enthusiasts buying cheap eBay kits only to end up spending more money replacing it a year later.
Flowmaster exhausts are built to last when properly maintained. The sound and performance make them well worth the investment in my book. Just be sure to have some help or rent a lift if tackling the install yourself!
Sound Clips Speak for Themselves
I can write about the Flowmaster tone all day long, but nothing tells the story better than sound clips. Here are some of my favorite YouTube videos showcasing Flowmaster’s aggression and rumble:
Mustang GT Flowmaster American Thunder
Challenger R/T Flowmaster Outlaw Axle-Back
Camaro SS Flowmaster American Thunder
F-150 Raptor Flowmaster Outlaw SIDO
Listen to those burbles, growls and roars! No question Flowmaster exhausts make these American performance machines sound as mean as they look.
Professional Installation Recommended
As mentioned before, I was able to install my Flowmaster at home with some difficulty. But for many vehicles, getting professional help is probably smart.
Shops that specialize in exhaust work often have the right tools like on-car brake lathes to alter pipe bends for proper fitment. Plus they have vehicle lifts that make things much easier.
A competent shop should be able to install a Flowmaster SIDO system in 1-2 hours or less. Expect a labor charge around $200 give or take.
To me, that’s money well spent for proper installation and not ending up with leaks or clearance issues. Do your research to find a qualified local shop that knows how to handle performance exhaust work.
Daily Driven Thunder
I was admittedly worried that the Flowmaster would drone too much to enjoy as a daily driver. But surprisingly, its tone quiets down nicely at highway speeds.
Of course, you still hear that V8 rumble which I love. But it’s not so overbearing that long drives become fatiguing or annoying.
Having the MDS cylinder deactivation in my Mustang helps. At light cruise it drops to four cylinders which takes some edge off. But even under load, this system provides a great balance of aggressiveness and livability.
Maintaining Your Upgrade
Investing in a quality exhaust system means taking care of it properly. Be sure to avoid scraping over steep inclines if lowered like me. I’m also careful when loading things in the hatch to avoid dings.
It’s also important to re-tighten clamps after the first several heat cycles as the gaskets fully seat. I check mine periodically to avoid any exhaust leaks.
Cleaning tips depend on the exhaust material. Polished stainless can use metal polish. Coated systems like mine can be maintained with soap and water. Avoid abrasive cleaners than can scratch the finish.
And definitely clean up any road salt in winter which can lead to corrosion over time. With proper care, your Flowmaster will maintain its looks and performance for years of enjoyment.
Built for Customization
One great thing about Flowmaster exhausts is that they are designed to work with aftermarket headers if you want to take things further.
Adding a set of long-tube headers to my Flowmaster SIDO down the road is definitely on my wish list.
Many exhaust companies bend and flare their piping in ways that make compatibly with aftermarket headers tricky. The team at Flowmaster keeps their bends smooth and clearance in mind.
So you can feel confident investing in a Flowmaster knowing you’ll have flexibility down the road if you want to upgrade other components like headers, intake, or even a supercharger.
Where to Purchase for Your Ride
When it comes to buying a Flowmaster SIDO exhaust system, you’ve got a few good options:
- Directly from Flowmaster at FlowmasterMufflers.com
- Through major retailers like Summit Racing and Jegs
- From various online vendors like AmericanMuscle and CJ Pony Parts
- At local specialized exhaust shops or speed shops
Flowmaster only sells their products through authorized retailers, so purchasing directly from Flowmaster or one of their major online partners ensures you’re getting a genuine system.
Prices are usually very competitive across the board. Browsing retailers for promos and free shipping deals can save you a few bucks.
If purchasing locally, inspect the packaging closely and ask questions if you have any concerns about authenticity. Going straight to the source guarantees you get a genuine Flowmaster.
Unleash the Beast Within Your Ride
Whether you drive America’s favorite pony car, a modern muscle sedan, or even a burly truck or SUV, Flowmaster’s SIDO kits bring a bold, aggressive sound.
More importantly, they optimize the performance potential hiding within your engine. With the Flowmaster name backing the quality, they are exhaust upgrades built to last.
Hopefully my experience gives you a good idea of what to expect with a Flowmaster single in, dual out exhaust system. Now it’s time to unleash that rumbling beast under your own hood!
