Steel Flywheel vs. Aluminum Flywheel? How to Decide

December 4, 2015

Here at Astro Performance Warehouse, we enjoy receiving questions about our products from our customers. We are always happy to help a customer better understand the functions and features of our products.

For today’s blog post, we’re answering one of the common questions we receive about flywheel replacement.

Steel Flywheel vs. Aluminum Flywheel? How to Decide

Question: Steel flywheel vs. aluminum flywheel. Which one is better?

Answer: Most domestic factory vehicles are supplied with nodular iron steel flywheels. These flywheels either come in a neutral balance, for internally balanced engines, or externally balanced, like a lot of “push-rod” cars come equipped with.

The nodular flywheels usually only come with one clutch bolt pattern to attach the original equipment (OE) clutch to it.  Some flywheels also include dowel-pin holes to help “center” the clutch being attached.

When a clutch burns up, or simply wears out, a flywheel can take a pretty good amount of abuse. But you’ll want to consider replacing or upgrading the flywheel if there are heat cracks across the clutch disc mating surface or an uneven or “warped” clutch disc surface.

Of course with the addition of aftermarket billet steel & billet aluminum flywheels, it can be quite a challenge for some to figure out the best option for replacement.

For customers who are considering replacing a flywheel, we suggest asking these questions:

  • What is the weight of the vehicle?
  • How much horsepower at the flywheel?
  • RPM at which the customer plans to shift?
  • If racing, is an S.F.I. approved flywheel one to consider?

Cars with less than 450 horse power at flywheel that weigh more than 3,400 pounds would benefit more from a nodular or billet-steel flywheel. This is recommended as a heavier car benefits from heavier rotational weight off the end of the crankshaft helping “propel” the car through each of the shifts.

However, a car that makes more than 500 horse power at flywheel that is 3,400 pounds or less would benefit from a lighter aluminum flywheel as it will “spin up” quicker to keep the RPMs up in between shifts.

So, to answer the question “Steel flywheel vs. aluminum flywheel, which one is better?”, the answer lies in the application you own! It also depends on the end user’s budget. Nodular iron flywheels are definitely cheaper than billet steel or billet aluminum flywheels.

But, for safety, certification and high horsepower, consider a McLeod or RAM billet steel or aluminum flywheel from Astro Performance.  Please feel free to send over the application and specs of your engine.  And don’t forget to put the plans for the car and list any SFI certification that your car will be subjected to.

Do you have more questions about flywheels or any of our other products? Comment below or contact us today. We’d love to use your question in a future blog post.

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