Many (I think all, but not 100% sure) Hyundai's with the 2.7L V6 have dual mass flywheels.


I have seen more "lightened or modified" OEM flywheels break fly apart. Search the various automotive fourms. You'll find many more horror stories of improperly modified "stock" flywheels compared to problems with quality Aluminum Flywheels. If you doubt me, talk to any team fielding a race car. Ask them what type of flyweel do they use? (Modified stock flywheels or lightweight aluminum flywheels?) 99% of the answers will be lightweight aluminum (the remaining 1% the change is probably not allowed by the rules).
Ask the machine shop doing the work to your flywheel are they willing to guarantee the modified stock flywheel, and cover any damage expense if the flywheel breaks? I'll be suprised if you can find a single shop that will answer "yes" to that question.

The only time I have ever seen Aluminum Flywheels fly apart/damaged were one of the following.
#1. Low quality part to begin with from 'no name' company (ebay)
#2. Backyard mechanic installing flywheel/clutch improperly (over/under torquing the bolts)
#3. Moron behind the wheel/clutch pedal using them improperly (6000 RPM clutch dumps)
#4. Much higher than stock HP levels.

Please find an example on a forum (with photos) of a QUALITY flywheel installed by a competent mechanic, driven by a competent driver with near stock HP levels that was damaged/shattered.


That guy needs to learn how to drive with the new flywheel. The ligher flywheel will allow the engine to REV faster and also put more HP/Torque to the wheels (power that was used before to spin the heavy flywheel). Once he gets used to it, He should find that it should shave time off his ET, not add to it.

 

Now, that's nearly impossible as anyone with stock/close to stock HP numbers are not going to run an aluminum flywheel. It's just too light and makes everyday drivability turn to utter crap.
All quoted from http://forums.vwvortex.com (all quotes are referring to the 200hp VR6):

Now, if you're running big HP numbers, aluminum probably won't be able to stand up to the heat and will more than likely crack or warp (atleast before a steel flywheel would).

 

Some people just can't drive... I'm running a Stage IV clutch and aluminum flywheel (8-9lbs I believe) and it takes some getting used to, but it doesn't make daily driving a pain in the ass if you know how to drive a manual transmission properly. I have no problems with it.

 

my car is pretty muc hstock, only have a cone filter, and have had a fidanza installed since early 2002, absolutly no drivability issues at all. and i actually get better gas milage now. id recomend it on a pretty much stock car, it gave me a very noticeable gain in power, now i can spin them into 3rd if im beating on it with the stock rims. never could do the before the flywheel.

 

You know GLI.. do not base all cars on VWs.. Volkswagon uses an odd system with their flywheel clutch assembly. The pressure plate bolts to the crank and the flywheel bolts to it. In such a case, it might be possible for a lightweight flywheel to cause problems.

Personally though, I have hear more good about light weight aluminum flywheels than bad.

 

I was using the VW's as a reference because that's what I know best. However, here's something from the Honda group:
http://www.honda-tech.com/zerothread?id=646654

Also, using VW's as a reference still doesn't change the fact that aluminum is not as strong as steel or chromoly and expands/warps easier from heat.

 

Aluminum absorbs heat faster than steel or chro/mo meaning that's less heat in your friction disc (heat is transfered to the flywheel). That's good for clutch friction disc life. Less chance of a heat glazed friction disc.

Aluminum also SHEDS heat faster than steel or Chro/mo, meaning it cools faster, again, less heat in your friction disc, less chance of glazing.

Assuming you're doing 20+ bad clutch slip launches 0-30 mph in a row...then yeah, heat in the aluminum flywheel MIGHT be an issue. But given time to cool down between runs/attempts, as most engines/flywheels are, and you won't have a problem. Chances are you'll glaze the friction disc regardless which flywheel you are using (cast iron, steel, chro/mo or aluminum).

As stated in that Hondatech article you linked to...


Again, you have yet to show a post where an aluminum flywheel came apart in a near stock HP car. That post is simply talking about advantages/disadvantages, with no "proof" or even annedotal evidence of aluminum flywheel failures.

If given the choice between a ChromeMoly flywheel and an Aluminum flywheel, I would choose the aluminum unit for it's lighter weight, lower cost and better heat ability. Assuming cost and weight were not an issue, I would STILL choose aluminum for it's better thermal properties. Simply put, if you're warping a forged aluminum flywheel due to heat, you need to be driving an autotragic slushbox. Manual trannies are not your Forte.

Let's look at other rotational parts... Wheels for example. Wheels have an argubably tougher or at least similar life to flywheels. They both have high rotational speed, heat and inertial accelerative and delerative forces, but wheels must also suffer potholes and speed bumps. What do people/race teams switch to for performance improvment? Forged aluminum wheels.

Strange, I see a pattern here! Anyone else?

 

I'm definitely with you Random. I only hear good stuff about aluminum flywheels as well as it's very commonly used for aftermarket flywheels!

 

if I am not mistaken, aluminum flywheels usually have a steel mating surface for the clutch plate anyway, so it is not like you are letting the softer aluminum get chewn up by the clutch.

 

And clutches can still chew up steel flywheels. RED bought the old HVE Ceramic/Metalic Clutch. It started eating it's way into his flywheel. He mentioned that the last time he had it all apart, the clutch had eaten away about 1/8" of flywheel material!


[edit] and that was with the stock steel flywheel.