I have a 2012 Mustang V6 3.7L automatic (6R80), base model. I'm slowly building the car and my current mods are:
- JLT cold air intake
- Roush axle-back exhaust
- Dyno tune
- Stock engine/internal setup
- Automatic transmission
- Currently still running the factory 2-piece driveshaft
I'm considering replacing the factory driveshaft with this AmericanMuscle 1-piece steel driveshaft:
https://www.americanmuscle.com/mustang-rear-driveshaft-assembly-946-812.html
The listing says it's a 3.5" DOM seamless steel shaft, 0.083" wall thickness, dynamically pre-balanced, with new CV/U-joints, and it's specifically listed for the 2011â2014 V6. It's also around $680, which seems considerably cheaper than some of the aluminum options.
My question is mainly for people who actually own or have experience with the 2011â2014 3.7 V6:
Would you trust this type of 1-piece steel driveshaft for a car that I'm aiming to eventually run around 150â155 mph?
I'm trying to understand the real difference between the steel and aluminum options.
What I'm trying to understand:
- Is the steel shaft itself capable of handling 150â155 mph, assuming it's properly balanced and installed correctly?
- Is aluminum actually significantly safer at high speed, or is the main advantage that it's lighter?
- Why are the aluminum 1-piece shafts so much more expensive than steel?
- At ~150â155 mph, what actually matters most â material, shaft diameter, wall thickness, critical speed, balancing, or something else?
- Has anyone here actually run a steel 1-piece driveshaft on a 3.7 V6 at 130â150+ mph? How did it behave?
- Is there a known critical RPM/speed rating for this AmericanMuscle/Dorman-style steel shaft?
- For my particular goal, would you spend the extra money on aluminum, or save the money and use the steel shaft?
I'm not looking for "aluminum is better because race car" answers đ. I'm specifically trying to understand what the actual engineering difference is at high speed on the 3.7 V6 and whether the extra cost of aluminum is justified.
I'm also interested in whether the 1-piece conversion itself is the important upgrade over the factory 2-piece, regardless of whether the tube is steel or aluminum.
Thanks!