Our 2018 Mustang Gets Supernatural Drivetrain Upgrades

Imagine, if you will, a comic book hero that either currently possesses or will possess superpowers in the future. These powers obviously have to be controlled through the use of self-restraint or external factors to avoid wreaking havoc. A good example of this can be found in the X-men series with Cyclops and his powerful beams of energy that erupt when his eyes open. The only way to prevent him from destroying everything within sight, is with the use of a ruby quartz visor. While keeping his eyes closed is one method to prevent destruction, it is a band-aid solution that brings extreme risk to those around him. We’re facing a similar problem with our S550 Mustang named Project Magneto.

Our Ruby Quartz Visor

In case you’ve been absent from the Ford Muscle pages, Project Magneto is our 2018 Ford Mustang that sports a Gen-3 Coyote engine. The 5.0-liter pushes 460 horsepower towards the rear, a figure that I am confident we will be doubling in the future. However, the horsepower number is not what concerns us, but rather the medium of motorsport in which we have chosen to utilize these ponies.

You see, our aim with Project Magneto is to get 1,320 feet away from the starting line as fast as possible. Unfortunately that means a lot of shock on the drivetrain at launch. Even at factory power levels this was a concern to us. However, we had just elevated our build with RC Components’ wheels wrapped in Mickey Thompson drag radials and installed a slew of Steeda suspension. The next weak link was surely going to be found in our drivetrain. We had to look for a ruby quartz visor of our own to keep our Mustang from blasting the track with drivetrain debris.

Avoid Getting Shafted 

Naturally, the ultimate goal of upgrading the driveshaft is to increase performance and avoid breakage, but with modern engineering the factory units are starting to build a case for staying stock. So, it was not surprising that we found testimonials from the online peanut gallery stating the S550 Mustang’s factory two-piece driveshaft could handle the stresses of drag racing, despite lacking any MPH or torque ratings. Unfortunately, the risk of a night ruined based on internet rumors just doesn’t appeal to us. Combine that risk with towing cost and downtime, and we had sold ourselves on seeking out an aftermarket alternative.

S550 Mustang

Although a two-piece unit might have abilities to help prevent driveshaft bending at high RPM, the new QA1 driveshaft is built with the ability to handle both high RPM and still have the strength needed for hard launches on sticky surfaces.

While gravitating away from the stock driveshaft made sense, we had to find an aftermarket driveshaft that also made a compelling case for its price point. We decided to revisit the idea of a QA1 carbon-fiber driveshaft, similar to what we found when we were building Project Apex, our 2001 Cobra, aimed at road racing. However, Project Apex’s decision was made based on removing rotational weight, as the 4.6-liter was naturally aspirated. This time around, the reduction in weight is an added bonus associated with quicker acceleration, but our ultimate goal centers around strength.

The carbon fiber may be eye-catching, but it's the attention to detail on the ends of the shaft that stand out to us. The install process was extremely easy and after making sure our driveshaft bolts were properly torqued down, we had zero fear of a driveshaft failure.

There are two main factors that dictate the performance aspect of an aftermarket driveshaft: vehicle speed and torque capacity. High-RPM stability has to do with balancing and length of the shaft, while strength is needed to handle a hard launch. The QA1 REV series carbon-fiber driveshaft checked both these boxes, as the shaft is balanced as an assembly, without the use of welded or bonded weights, making it a more precise and reliable balance. Strength is put into perspective with QA1’s 1,500 horsepower and 1,000 lb-ft torque ratings. These manufacturing processes and power figures provided by QA1 easily meet the needs of our S550 Mustang GT.

Have Your Cake And Eat It 

With the driveshaft figured out, it was time to move down the line towards the rearend. While the internet made bold claims about the factory driveshaft’s strength and abilities, it did not hold back from detailing the weakness found when launching a vehicle equipped with an aluminum rear differential housing. Our joy of owning a Mustang with the incredibly potent 10R80 transmission, a main reason why we purchased this 2018 model, was quickly diffused after realizing we either had to replace it with an iron housing found in the manual transmission Mustang or brace the aluminum one.

The internet statements were mirrored by the advice given by Chris Cervenka, Steeda’s director of marketing. “The combination of adding more power, shocking the driveline, and the 10R80 transmission’s high ratio first gear, means we either recommend switching to an iron differential housing or running our Hardcore IRS differential support brackets,” Cervenka explains. “The support brackets are rated as Hardcore and will increase Noise, vibration, and harshness (NVH), but will strengthen the differential housing.”

Our 2018 Mustang GT came equipped with an aluminum rear differential housing. It wasn’t the end of the world to us, as Steeda makes the rear differential support brackets. We were able to save funds and weight when compared to going with an iron housing.

Price aside, the weight of the iron differential compared to adding strength to the aluminum housing made the choice to brace the factory one a no-brainer. We could retain our 20-pound-lighter aluminum housing, reduce the risk of front ear failure, and further reduce wheel hop and lateral movement of the rear differential. The classic proverb of not being able to have your cake and eat it too proved to be a myth by way of Steeda!

Spline Deep In Axle-ology

The job of transmitting power from the drivetrain to the tires is a mechanically simple one, the friction of the tires sticking to the pavement, propels the vehicle forward, while the whole Newton’s Third Law thing results in a force that can cause the axle shafts to twist. If the material used in the axle can’t handle that force, breakage can occur. We once again found ourselves debating whether to risk it with the factory axles or provide the car with products to keep us safe on the track and prevent future issues. We consulted with Lee Mejia of The Driveshaft Shop to discuss his take on S550 Mustang axles.

S550 Mustang

The Driveshaft Shop axles look very similar to OEM, with each containing no bolts and a clean design. However, there is a key difference in materials used with The Driveshaft Shop utilizing 300M steel for the bars and spline pieces and chromoly for the CV internals.

“Factory axles are made using OEM-quality materials and components. They’re designed with longevity and a lack of NVH in mind, but once you start launching the car, you’ll find the weak points,” Mejia explains. “The S550 Mustang Pro Level axles from The Driveshaft Shop are a direct-fit style that require no modifications to be installed. They plug into the differential and hub like the stock ones, but we make them out of 300M with chromoly internals.”

“We’ve found the best of both worlds approach works best. The parts that need to withstand the shock load, such as the splined sections that insert into the differential or hub and the axle bar itself, require a material like 300M,” Mejia details. “Then we have the hardness and increased wear properties found with Chromoly inside the CV, where it will not benefit from a harder material like the 300M.”

Both OEM and The Driveshaft Shop axles install into the hub and differential the same as each other with no modifications needed. This makes the task of installing our new axles a very simple procedure.

This means the axle’s torsional capability, especially under a high grip launch situation, has the ability to twist under load and have more flexibility in it than the stock axles. This should not only help reduce axle chatter that could produce wheel hop, but also gives it a strength rating of 2,000 horsepower!

Drivetrain Contained

Now that we’ve addressed our driveshaft, differential housing, and axles, we can say that our immediate fears of driveline failure have been laid to rest. While Ford built a fantastic product with its S550 Mustang platform, our build morphed itself from conservatism and spirited driving into one of horsepower greed and out-launching the competition in the opposing lane.

After the one-two punch of upgrades with wheels and suspension, we thought our driveline was soon to be knocked out. However, with this round of upgrades, we’re looking to knock out some killer timeslips instead. Stay tuned, as the next round of Project Magneto will be prepping for more power!

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About the author

James Elkins

Born into a household of motorsport lovers, James learned that wrenching takes priority over broken skin and damaged nerves. Passions include fixing previous owners’ mistakes, writing, and driving.
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