LeonV

Wow, excuse me for hurting your feelings. Also, thanks for the condescension, that was a nice touch. I was hoping that discourse on the technical forum would be a bit more mature. I made the mistake of using the term ductility loosely, that's a mistake on my part. In your words, "Aluminum does not deform elastically". This is absolutely not true and is what I was getting at, and you actually contradicted yourself and confirmed that in your last post. That's all.

I understand elasticity, there is no need to be ostentatiously pedantic.

Regarding flywheel temperatures, have you measured flywheel temps yourself? Your professional swag is as good as mine.

Let's skip all the internet engineering masturbation BS and get to the point. Can you give me an example of a properly constructed and installed Aluminum flywheel that failed catastrophically because of its construction? Can you show me the failure point? I would truly be interested. We can sit on our respective asses and talk theory all night long but it will not get anyone anywhere. I'm not trying to turn this discussion into an ego-touting pissing match, but rather something that people can learn from.

s2000Junky

Ran the Aluminum Findaza for five years without problems, but as soon as I replaced the wearable friction disc, I couldn't get a PP to want to stay attached to it. It caused a lot of frustration and money to drop the trans twice to finally give up, not sure what the problem was but figured the flywheel had to be warped just enough to cause vibration and separation from the PP. Needless to say it was successful for a long time but now run the 8.3lb Act pro light. Nearly identical weight, but one piece Cromo.

LeonV

Thanks for the post! Out of curiosity, did you get the flywheel balanced and the friction surfaced checked for flatness after fastening it to the flywheel?

s2000Junky

Nope never did, I just said F it and replaced. Problem solved. I still have it hanging on the wall with a brand new friction disc, you want it? Sell cheap

whiteflash

I'm really shocked no one has recommended the SOS 11 lbs flywheel.

slipstream444

My feelings weren't hurt in the least - you just should have all your information correct before you start waiving your finger around in someone's face. And when you do that - be ready to receive what you have given.

My data points are in the material - the numbers speak for themselves. A hard driven S can easily warp an aluminum flywheel over time. A heavily modified or frequently track driven one can most certainly damage one to the point it may fail. That is my point.
I hate to point out you contradicted yourself in your attempt to be clever - you request we skip the engineering "masterbation", yet you ask for engineering data. You can't have it both ways. Again - the proof is in the mechanical properties of the materials in question - and unquestionably Chromoly Steel is significantly better.

If nothing else - just take note of S2000Junky's experience, and that would be enough of an experience to avoid the use of an Aluminum flywheel. Dangerous for normal to mild street? Probably not. Dangerous for anything above that? Possibly so - and that's more than enough to use a little common sense and not recommend it.

Billman has been around the automotive industry for a long time - he's an expert mechanic and technician, and likely the best S2000 mechanic I know of (I drove ~1500 miles to have him work on my car - and typically I'm the only person allowed to touch my car). If he says something isn't a good idea, I'd listen. If I'm telling you something, it's because I have researched it and felt it was worth passing the word (and some technical data if need be). Trust me - I have better things to do than play patty cake with your ego. It's nothing personal, I just don't have time to stroke everyone's ego on here - and when someone gives out bad gouge, I'll do my best to let them know to knock it off.

LeonV

Nope never did, I just said F it and replaced. Problem solved. I still have it hanging on the wall with a brand new friction disc, you want it? Sell cheap
[/quote]

Thanks for the offer, but I think I'm staying stock on the S2k for now! I'll keep you in mind if that changes though.

dwight

Obviously aluminum can undergo elastic deformation; even diamond does. I think it's reasonable to assume that slipstream444 meant it doesn't to it well when compared to other engineering materials like steel. Taking what he said to mean that elastic deformation of aluminum is impossible is "ostentatiously pedantic".

As far as talking about ductility when talking about elasticity, they are leagues apart. It's like confusing the brake pedal with the accelerator.

LeonV

The engineering data request for flywheel temp data was a purely rhetorical one, as clearly nobody here has this data...

Sure, I agree that CrMo Steel is "stronger" but that in no way automatically discounts Al as good material as well. By your logic then, Beryllium is a better material than the rest. Why take your chances, when you can have a Beryllium flywheel? The point here is this, and I'll rephrase once again, while one material may be stronger than the other, it does not rule-out the use of other materials. Aluminum has proven to work great in these applications, and besides the point, the OP asked for a recommendation on a street-use flywheel. I have no problem at all with recommending Aluminum, and in fact I'd do it myself in a heartbeat if I were looking for a lighter flywheel.

So, this comes down to practical, real world applications and testing. We can sit at a table and run through theoretical numbers to make ourselves happy, but it comes down to what works in real life. Again, I ask for you to provide me ONE example of a properly constructed and installed Aluminum flywheel that failed catastrophically because of its construction, showing its failure mode. Just one. So far, you have zero data points. "I'm certain" and "probably" don't count.

The only thing I take note of in Junky's experience is to make sure the friction surface is flat before installing. Hell, I can do this myself with a dial indicator and granite table. I take note that he ran it for 5 years in his S2k without a problem. That is a real-world data point and a darn good one at that.

With all due respect to billman, and I'm sure he is a fantastic mechanic, I'm not going to blindly listen to somebody just because they say so. I'll evaluate the situation first and then decide on what to believe. This is why I asked the question in the first place. Maybe billman didn't see it.

This is not about stroking egos, but rather having at least a modicum of professional courtesy when involved in a discussion within a technical forum.

Billman250

The issue with aluminum flywheels is the holes in the friction surface used to bolt the steel to the aluminum. During heat cycles, the edges of the holes get hotter quicker than the rest of the surface. Just as if you hold a torch on the edge of a one inch piece steel, the edge will turn red right away. Yet if you hold it in the center, it takes a while to concentrate that heat.

It is during this heat cycle that the edges of the holes raise up like a volcano. not to that extent of course And in turn, shave the disc like a file. I have found disc life to be horrible on the S2000 with an aluminum flywheel. I believe this is the reason.

Nothing beats function, reliability, or clutch life like a one piece steel flywheel.

As far as SOS I am not familiar with their product but if its a one piece steel I'm sure it's a nice piece.