MazdaManiac

iTrader: (3)

I wasn't advocating the method. It is just the method that Eric said he preferred (though he wont actually engage in it, apparently).

I prefer calibrated results along with the largest possible dataset, laid bare with little or no commentary.

RIWWP

iTrader: (2)

I agree with that. The 'no commentary' is probably the hardest to achieve

TeamRX8

iTrader: (25)

As hard as you might find this to believe, not everyone is focused on your every post and otherwise engaging you on the usual tit-for-tat forum argument challenge, which only made me laugh more when I read the last two words of your post. Its not like he has more important things to do in addition to being employed and running his own Grand Am race team.

OD, thanks for the gesture and I hope you won't mind that I paid your kind gesture forward by giving the CR to someone who also did me a favor and could enjoy it more.

MazdaManiac

iTrader: (3)

I'm not really sure what you are on about here, but:
Eric is asking for questions to be posed to him in this thread (that is what the Socratic method is about). Who cares what or who reads my posts. As long as the pertinent info gets out there from the people that are volunteering it, any reader should be satisfied.

dannobre

iTrader: (3)

Popcorn on the table...beside a bottle of good rum....Bring it on :

EricMeyer

Guys, guys, guys. This is getting so far off base. Here's the deal. The huge majority of people on this forum have never heard of the term MOI and have a belief that "lighter is best or better or preferred". We were all one of these folks at one day in our life because it makes sense. The majority of people are in this box. They may be on the "will this fit thread" or make posts that people say "use the search function". Others may be more familiar with performance products and have just puchased or are contemplating a new purchase. I do NOT post information to begin a debate (which a few people enjoy doing).

My ENTIRE point for googling MOI was to help those in this majority camp understand the concept of MOI and to understand that lighter doesn't always mean better. This applies to wheels, driveshafts, flywheels, crankshafts or things that spin. This google comment was meant for the masses and for educating folks (which I so enjoy doing as not too long ago I was that guy that came from beginner roots, didn't know diddly squat about anything. I have enjoyed a journey of learning about cars, racing, engines, etc. and share this to help people who want to learn. Quite honestly I was never mechanically inclined until I started racing and since being bitten by this stupid racing bug have enjoyed open minded learning from many, many, many experts in various racing disciplines (suspension engineeers, piston engine gurus, engine management folks, chassis builders, guys with dozens of years of real hands on experience etc.). Some of these folks had belief systems about XYZ that were contray to the choices I eventually ended up making. Did I feel the need to argue that they are stupid? Hell no. Everyone has a belief system that they feel is preferred. Good for you and good luck in your endeavors whatever they may be. Mine has, and is, a fantastic journey of learning info. My personality is to share as much as I can in life for those who get a kick out of accelerating their learning curve, possibly save a few bucks by changing their buying habits and avoiding purchases that they may later regret. One of these examples is the flywheel. Understanding that lighter isn't paramount for a flywheel/clutch/disc assembly allows you knowledge to pass on those current aftermarket heavy, high MOI flywheel and pressure plate folks that currently buy from the aftermarket street market. That's it. We have found racing products (not really smart choices for the street) that have HUGE, HUGE MOI benefits over the best (lightest) flywheel and pressure plates on the market today.

MOI numbers for these aftermarket products are not readily available. They, IMHO, are sold to the majority that hasn't been exposed to the MOI concept and purchase based on how much these items weigh as many of you probably already know. If this may be new to you, take a look at the currently available pressure plates and flywheels and most of them will promote their weight. There are no MOI numbers---why? Probably because these huge majority market hasn't YET learned MOI as someone has mentioned. Maybe these folks care about learning and maybe some don't. Whatever. Who cares. My purpose in sharing is to reach those that are looking for a different perspective. Do I think I'm god? F___ no. I am just sharing my current belief system that I've found to be the best system thus far in my world. Do better concepts exist that may provide better rotating benefits? Maybe. I don't think they do but maybe they exist. I have yet to find them, learn about them or meet those folks that share better concepts about flywheel and clutch performance. Quite frankly I would love a person who has experience in this subject to post on this thread so I can learn something. Maybe they test products for MOI all day long and have been doing this for dozens of years. Maybe they run a CNC machine for a living and make flywheels out of unobtanium. It could be other things but I'm not hear to post all day long on who these folks may be.

If it was me and I was reselling or manufacturing these items I would know and share MOI numbers as a way of earning business. Most high value added vendors I have run across in my racing travels don't frequent these forums because, and they've told me this, their are ******** on these forums that enjoy arguing and counter those things that they have built honest business models on. A few guys I have relationships with have been using, making or testing aluminum RX-8 rotors for years. They have designed their own. They have made their own flywheels that weight less than 5 lbs. Do they post on these forums? No. I honestly feel educating a customer is the key to providing value and earning their business. In fact, I've started a company and retired at age 40 using this method without a college degree or a rich daddy or inheriting daddy's biz or hitting the lotto. Why do I say this? Because I believe education adds value and people buy value. If you don't believe this then your business is leaving money on the table. I have a small consulting company and we help business who are trying to do this get their faster and go to the bank more often with larger deposits. Do all business and customers value this logic? No. I could care less if they do or not. ME, ERIC, enjoys sharing what I've learned and do so because some of you enjoy learning. I get private messages or phone calls or emails from some of you and love these dialogues. Sincerely. I do not, for the millionth time, enjoy debate or dealing with know it alls.

Now this next comment is to share a perspective of what lighter and better MOI is for a clutch, flywheel and clutch discs. It is, contrary to what some people on this thread understand. It is information to help understand a different perspective that has very little to do with the street market. You might categorize this information as more racing specific. It may apply to you the street car daily driver person, the Auto-X guy, the person who loves buying new stuff or anyone else. I don't lose sleep about who you are or your buying motivations. I'm just sharing my personal experiences.

The flywheel and clutch pack we have found to be the best for racing our RX-8 has individual MOI numbers for the individual componetns. These numbers come from both the manufacturer of the clutch basket and clutch plates and also the manufacturer of the flywheel. Both of these manufacturers understand MOI, share these MOI numbers and build these items with MOI in mind. We have found our entire rotating flywheel and clutch assembly to be lighter than the best aftermarket pressure plate we could find on the market. Might there be one that is lighter? Sure. Did I find it? No. Please don't tell me you have one or argue that one exists. I could care F----ing less if you have one, know of one or resell one. That is not the point of this post. I have no need to chest pound about how much info I know. Doing this is close minded and doesn't allow you to learn as much as approaching life with eyes wide open. I've seen too many stubbord people in life know it alls miss the boat and earn a reputation of "that guys is a dick and I won't do business with them". Others have built large business with this attitude that I don't chose to do business with. On the other hand those in racing in my travels that follow the life long path of learning are so enjoyable to deal with and have been very collaborative in problem solving for several of our RX-8 projects. I do business with them, may have done business in the past and some of them I would suggest working with and others you may want to stay away from. Someone who is quiet on here and who started this thread is my friend Brian Cain. I would have him build my motor if I was looking for a guy to do this. He is knowledgable, provides lots of value and knows more about the RX-8 engine that he shares on this forum. He is very fairly priced and I recommend him to you folks. In addition to him I've learned stuff from other providers including building lighter chassis, cooling the engine, suspension tuning, engine tuning, lowering rotating mass and reducing friction. Most of these folks build their specific products exclusivly. Radiators for example. C&R radiator builds radiators for the NASCAR market, the IndyCar market, the off road market, the road racing market. Do I think they are the best in their industry? Yes. Do I recommend them? Yes. Are their many people who feel the need to debate on this forum that no more then them? I think not. I they were smarter than these folks they would probably run thriving businesses that built these items and had strong market place presense. Other people have learned these radiator concepts as an example too---they just don't happen to frequent these forums and post this info. I do. I enjoy it. I do not enjoy ******** that get their rocks off telling me I'm wrong and they are in god like status. At all. Now back to the entire reason of this post.

We've had a couple of custom flywheels made by Taylor race engineering. They are well known in the racing circles as providers of performance drivetrain solutions. Check them out. Expensive carbon clutch packs and discs are available from them. $4,000 clutches. Custom products. You could call them and tell them you want a 6.2 lb flywheel anodized red with a hello kitty engraved logo. They are very good at what they do. Perhaps your looking for them. I say this for educating those who may be reading this that have no idea a $4,000 clutch could ever exist. The same for titanium flywheels and heavy drilled out swiss cheesed flywheels. Same for a $13,000 close ratio transmission that I had made for a project car of ours (another great discussion to help inform those about the differences of a close ratio box and a stocker trans).

Our lighter MOI assembly will spool up and spool down lickity split. It allows the engine (the Renesis in our case) to rev more quickly. We have found this to make the same power. We have found it to accelerate more quickly and if you were to change your X axis on your dyno to TIME rather than rpm you will find that the slope of the acceleration is faster. To put this another way your car (our car) will reach 6,000 or 7,000 or 9,000 rpm sooner than a flywheel/clutch/etc. with a higher MOI. This is proven in the industry by zillions of people and this is why these racing folks use this stuff. it works. Period. Google an F1 or NASCAR clutch and you'll see this stuff being used. These are not bring *** pressure plates that are almost the diameter of a stock RX-8 flywheel. They are smaller 5 and 4" clutch assemblies. They have super low MOI values (again the reason why I share this post and info). They are usually expensive and in some cases custom. In others they are right off the shelf and bolt up easily to a performance Chevy or Ford or Mopar based engines. Contrary to what the some of the newboo surfers on this forum may understand, the RX-8 is a freakin car just like any other car. The best radiator or oil cooler or wheel or brake pad uses the same logic as those for an Edsel or ALMS Porsche. It's a car gang. A car. It has 4 wheels, seats and a steering wheel. Google stuff about ANY car and you'll find MOI or suspension or aero or the weight of lighter rear lexan windshields or painting your race car with very light weight paint to save a few pounds. Just like this MOI discussion there is tons of info at your fingertips. Check it out. I'll suggest to you it will make your journey in life as it pertains to learning about performance products for your cars more enjoyable.

Happy Rotoring and enjoy your journey. Quit debating and arguing with me.

Eric

stinksause

iTrader: (5)

damn. ... let me find my reading glasses

rx 8speciale

iTrader: (3)

thanks for sharing !!

RIWWP

iTrader: (2)

Ah hah! This is what was tumbling around in my head, but I couldn't figure out a way to explain it.




Thanks as always Eric. You are 100% correct in the rest of the (admittedly) ranting post. Sharing of information gathered through your experience can never be "wrong" information. And I feel the exact same way about Ray Hill, MazdaManiac, TeamRX8, and any of the other people that have alot of experience in their heads. Different experiences bring different opinions, different knowledge sets, especially because each is in a different environment, different goals, and (most importantly) different methods of communicating those experiences.

And I often wish that the headbutting over the fact that the experiences are different would end. It doesn't make any of you wrong, or incorrect.

It's just different, honestly and acceptably so.

RotaryTherapy

iTrader: (1)

Love the info !

Charles R. Hill

iTrader: (7)

That pretty much encapsulates it all, doesn't it?
BTW, Your Polar Moment of Inertia topic has been discussed several times over the years on this forum (ad NAUSEUM).

9krpmrx8

iTrader: (46)

Thanks Eric!! I had to copy that to Word and bump up the font size to read it but thanks.

Reaver

iTrader: (1)

Nice post Eric. Another thing that I don't think that was directly said that might spell it out a bit more clearly for folks is this:

If you're comparing two flywheels, you might have flywheel A that is 5kg and flywheel B that is 6kg, which one will spool quicker thus giving you a quicker acceleration over the stock components? not enough info! It's possible that the 6kg flywheel could have the majority of it's weight concentrated near the axis of rotation and the 5kg flywheel could have it's concentration of mass near the edges of the flywheel, and this could result in the heavier flywheel being better.

Hey Eric, I noticed you're in Indy, I'm in Fort Wayne, I don't know if this is possible but I share the same philosophies you mentioned in your post there (eager to learn, open-minded, etc.) do you have anything coming up there could be a great learning experience that you wouldn't mind me checking out? Racing, tuning, fixing anything on your car, etc. I won't touch anything :D I'm a math tutor and a current mechanical engineering BSME student and terribly interested in my new (got it about 3 weeks ago) rx8 and most things mechanical but my real word experience isn't so great.

pdxhak

iTrader: (2)

cntrl + will increase the font (actually zoom in) in the browser

9krpmrx8

iTrader: (46)

Yeah for some reason it distorts my browser and I have to scroll left and right to see it all, its quicker to just copy and paste.

Charles R. Hill

iTrader: (7)

This concern was exactly why the mathematical concept of Polar Moment of Inertia was created. However, as was alluded to earlier, when flywheel manufacturers are dealing with the OEM size clutch disc/pressure plate/starter ring gear (since we have a fixed dimension we are dealing with) the importance of that concept is largely moot for purposes of product comparison because we all try to center the mass as close to the axis as we can.

As regards Meyer's particular clutch, since the diameter is substantially smaller than the OEM unit, his MOI will be different.

How driveable that is on the street depends on the subtleties/capabilities of the driver.

This is one reason why I have always said that flywheels are for people, not engines.

EricMeyer

^a+ 100%

EricMeyer

I'm from the Fort. Come down anytime!

MazdaManiac

iTrader: (3)

lol

If life were only so easy.

This ^^

I think the reason I enjoy "arguing" with you so much (though it really isn't much of an "argument" since you wont engage in anything except rambling lectures) is because you are like that kid that comes running into science class and starts lecturing the teacher about how he has discovered - all on his own - that water is actually made of hydrogen and oxygen.

RIWWP

iTrader: (2)

Though those of us that have only ever seen the teacher asleep at the desk, perk up at a chance to learn about those molecules. Even if the environment, setting, goals, and application are different.

Similar to how we enjoy learning about military or space equipment we will probably never see, much less touch or control.

MazdaManiac

iTrader: (3)

Hmm. Deletions. lol

MazdaManiac

iTrader: (3)

Indeed.

However, when we got to the "space equipment" part of this thread (MOI), what we got was a guy in silver pajamas standing next to a '57 Buick Roadmaster with a surplus JATO pack strapped to the roof.

PhillipM

Best way to do it, is to take huge fecking chunks off both the weight and the MOI, discussion ended

alnielsen

iTrader: (4)

Then how do you get the starter to engage?

Brettus

iTrader: (2)

you welded your clutch to the flywheel ? Novel approach .