What's the difference between cast iron and chromoly steel flywheels?

[amodoko]

Hi, I have a question regarding flywheels. I have a 2000 Toyota Celica GT-S that is completely stock (I drive it fast only a few times a year). For my car, can someone please tell me what the benefits/drawbacks are to a cast iron flywheel vs a chromoly steel flywheel?

The cast iron flywheel is specifically manufactured using GG25 cast iron. The US equivalent is ASTM A48 Class 35.

I plan to have my car for over another decade (it has low miles), so if someone can tell me which type of metal flywheel is better and why, I would appreciate it. I don't know too much about cars yet, still learning. Thanks

[oldblu65]

Originally Posted by amodoko

Hi, I have a question regarding flywheels. I have a 2000 Toyota Celica GT-S that is completely stock (I drive it fast only a few times a year). For my car, can someone please tell me what the benefits/drawbacks are to a cast iron flywheel vs a chromoly steel flywheel?

The cast iron flywheel is specifically manufactured using GG25 cast iron. The US equivalent is ASTM A48 Class 35.

I plan to have my car for over another decade (it has low miles), so if someone can tell me which type of metal flywheel is better and why, I would appreciate it. I don't know too much about cars yet, still learning. Thanks

I'd have to say the best flywheel for your vehicle is the same one the manufacturer used as original equipment . They spent millions of dollars engineering and developing the vehicle and the flywheel they eventually chose to use was the result of all the testing .Now if you intend to use the vehicle for something other than daily transportation ( i.e. - racing , etc. ) , then you might look at having an aftermarket flywheel installed . But for everyday commuting , I'd stay with the original equipment type of flywheel . Likely some on AF might disagree and may ridicule me for my statement but ...well , it's just my honest opinion . Good luck !

[amodoko]

Thanks so much for your answer. The only reason I actually was asking is because I am doing a clutch change right now, and I looked around for a reputable shop to resurface my flywheel for $50. But I hate giving control of my car parts to other people for fear they may not do it right. And I found a cast iron version of my flywheel that is brand new and made to OEM specs for a little under $50. If I bought that, it would take away the issue of a bad resurfacing job, but it would also give me a non-oem flywheel. So I've been debating whether to buy a new cast iron one for cheap, or resurface my OEM one on my car and run the risk of a bad resurfacing job.

[oldblu65]

One other thing I forgot to mention is the GTS was the high performance version ( model ) of the Celica so the flywheel originally installed by the manufacturer is likely different and an upgrade from the base model Celica . I can't say that for certain but would think Toyota would do so to insure the reliability and performance of this option ?

[vgames33]

Base models got the 1ZZFE engine and GT-S got the 2ZZGE (according to a quick skim of the wiki). As long as you chose the correct trim, you should get the correct flywheel.

For a stock daily driver, I would not be terribly worried about the flywheel material. If you ever plan to modify the car I would look into a more durable unit and an uprated clutch.

[amodoko]

The reason I'm asking is because I can either get my stock flywheel, which is chromoly steel, resurfaced... or I can just get a new cast iron one for about the same cost as a resurfacing job. Didn't know which route to go. Getting the cast iron one would be less hassle since it would get shipped to me and I wouldn't have to take the stock flywheel to the machine shop for resurfacing, and it would be a bit cheaper. But I will just stick with the stock chromoly steel flywheel probably. I was just worried the shop would resurface it poorly since I believe my flywheel is a 2 step flywheel.

But no one has technical information about the differences between the two metals? I heard that cast iron is more abrasive on the clutch and runs hotter while chromoly will skim coat a bit more.

Which option would you go with? $55 to resurface my stock flywheel (no idea about if the machine shop is good or not) or $30 to get a cast iron flywheel shipped to my door?

[jdmccright]

Cr-Mo steel is the better choice as it is stronger and better able to handle heat loads. Cast iron is nonhomogeneous, with flake graphite in a grey iron matrix. This is good for wear and heat resistance and that's about it.

Cr-Mo is stronger and more wear-resistant and less chance of warpage. If you can salvage the OEM flywheel, I'd do it for longevity...$20 isn't that much more. Another option would be to find a used one.

[amodoko]

Okay, thanks guys, going to just resurface my OEM flywheel then. I appreciate all the information