GrRx8MaZdA

I am between SR Motorsports with 9.75 pounds and 400+ dollars and mazdaspeed but i don't know which is the best in quality and the strongest one..

I also want to know which gives better performance...?In SR Motorports site they have their 9,75 pounds flywheel and a mazdaspeed flywheel with 600+ dollars...
I looked in Rosenthal and saw that the one that they sell is 15,3lb and 550dollars and i think that it isn't such a good weight..
I need a strong flywheel and i don't want to rip my car with a cheap flywheel with no quality at all..
I Just saw another flywheel in rx8 stor,prolite flywheel 250dollars and 9.5lb. This is the link: http://www.rx8store.com/product.asp?0=659&1=660&3=324

Please give me some advice..Thanks

shelleys_man_06

You have to remember that lightened flywheels free up more power because there's less rotational inertia, which I believe follows the form,

I[disc]=(1/2)mr^2

where I[disc] is the rotational inertia, m is the mass and r is the radius. As you can see, I[disc] is directly proportional to the mass. What does this mean exactly? Lower the mass, and the inertial moment is less. Thus, a flywheel of lesser mass will free up some power. The method is to select a flywheel that isn't too light; from what I have heard, too light a flywheel causes low-rpm problems. I wish I could explain it mathematically, but that would be just plain nutty. It's a principle of physics, and I'm not going to explain it because it's relatively useless and I haven't eaten breakfast yet. The stock flywheel is heavy for a reason: IMO it's built for normal, everyday, low-speed driving. The heavy flywheel needs the weight for low-rpm operation, otherwise, it will have more of a tendency to stall. I hear the SR flywheel is a good buy. Unfortunately, there may be minimal power gains, especially in the RX-8's N/A state of tune. I hope I'm somewhere near the answer. If I'm wrong, may the gods of this forum strike me down.

BTW, the equation for I[disc] comes from an integration.

GrRx8MaZdA

Yeah but i ve heard from a lot of people who installed ms flywheel that with this modification u can turn a race car into and exotic car.the gains are big!!

shelleys_man_06

Is that true? My BS indicator is on "haywire." Anyways, I'm not too sure about the origin of the equation,

I[disc]=(1/2)mr^2

It might be from an integration, I'll look it up. I hope I didn't goof :o .

pret

as shellys man stated, it is directionally proportional to the mass. for one, the 8 is a sports car, not a race car. i my mind, i distinguish between the two. two, how does it transform a race car into an exotic? do the areodynymics change, do we magically get 500+ more hp and torque, what exactly do you mean by this magical transformation? please explain it to me, as i must be limited in my thinking. (just my scarasam creeping out ). what you DO get from a lightened flywheel: reduction in weight and ability to rev (and de-rev) quicker. the ability to rev quicker allows you to utilize the maximum potential of the renesis engine (between the 6500-9000 RPM range) quicker.

Charles R. Hill

iTrader: (7)

There have been several threads on this one. It won't be too much longer before someone urges the author to "do a search". I have the SR 9.75 aluminum fly and it works pretty well. The lower mass of the flywheel means that less kinetic energy is stored so starting from a dead stop requires a little more clutch/throttle pedal finnesse. I think the reason stock flys are heavy is because most people really aren't that well-experienced in driving clutch cars in the first place. A heavier flywheel means more average people can enjoy the driving experience and Mazda probably would rather sell cars than alienate the average driver.

Charles

GrRx8MaZdA

More whp in the car with a lightened flywheel.."The car turns into an exotic car" are not my words i just read it in another thread.I have mada a big search but i couldnt's make up my mind...

GiN

I haven't upgraded the flywheel on my RX-8 yet, but from what I hear it makes a significant difference in terms of engine response. I believe CortC had a commentary about the flywheel somewhere on this forum...

The_Bean

I have the SR 9.75 lb and I'm happy w/ it. Performance gains will not be overly dramatic, but it does seem to make the car feel a little lighter in the lower gears and seems to rev slightly faster.

So far no issues with daily driving.

RX8FOREAL

I have the SR Motorsports light flywheel as well and have been very happy with it. The issue that it is harder to drive with the light flywheel is definitely BS. I actually stalled more when I initially got the RX-8, but after the flywheel was put in I was slightly hestitant when I got in for the first time. If you can drive stick well, no big deal. Not a hugh power increase but the revs do come quicker and the car seems more lively. SR Motorsports make quality products, IMHO.

GooOnYou

Check out this Prolite flywheel too...its only $250 from the rx8 store and says its 9.5 pounds. Anyone installed this one?

http://www.rx8store.com/product.asp?0=659&1=660&3=324

That equation shelly's man posted is rotational inertia and it mentions inertia in the caption below.

shelleys_man_06

Neat. It feels good to be right (everyone in the RX-7 Forum says I'm wrong ). I'm sorry, I'm being arrogant. I'm letting the engineer in me out :o. Well, I am always glad to help you clear up anything with the power of math, and its lesbian counterpart physics. Happy tuning

Charles R. Hill

iTrader: (7)

If physics is the lesbian counterpart to math, what is the relationship between people who wish to do mods on their 8's and those who actually pony up the time, money, and nerve to start whacking on these cars? Just wondering, Shell's Man(haha)

Charles

RX8FOREAL

Fo shizel my nizel

shelleys_man_06

Easy. Chronic auto-******* :D. J/K...

BlackAero

ORC is one of the best from Japan. Flywheel + Clutch together and is quite cheap. I think I will likely be getting this too, it save me on the labour too ... to install 2 items at the same time. Cheers.

http://www.oguraclutch.co.jp/product...INGLEPREAT.HTM

cortc

Mazdaspeed...

Charles R. Hill

iTrader: (7)

That would accurately define my behavior, but it doesn't define my realtionship to those who don't wish to modify/whack/**** their cars. BTW, my nitrous kit came in today. Next day of nice weather and I will install it.

Charles
The Chronic Auto-******

Omicron

Those that are unwilling are what's know as "wannabes."

Charles R. Hill

iTrader: (7)

I don't know if I would be so harsh as to call them "wannabes" as some people are just not interested in modifying a good thing. Give 'em a ride with my Racing Beat suspension and they might change their minds. Only a slightly harsher ride and nearly flat(body roll) handling. No more wheelhop, either. We'll see how it handles the nitrous kit.

Charles

GooOnYou

Send over some $$$ for a suspension and I'll change mine out in a heartbeat.

WTF no turbo

fyi i believe that the weights are the same.My MS flywheel weighed about 10lbs.Counterweight weighed 5ishlbs.I believe they advertise fw weight only.

shelleys_man_06

Good luck with the nitrous install. The ricers are going to love the fact you're running NOZZ. Just kidding bro' . Well anyways, back to the subject on flywheels, I just want a lower moment of inertia compared to that of the stock flywheel. If I had some money, which I so do not, I would put every conceivable (rational) aftermarket part on my car. If the name is auto-******, then **** me up.

Charles R. Hill

iTrader: (7)

That's my attitude, as well. I'll carefully consider any part available and, if it makes sense as an improvement, I'll get it. I don't wish to "personalize" my car with body kits and other parts which don't necessarily improve the performance or road feel. The reason I chose to do nitrous is because everyone else is waiting for FI. Of course, the reason I chose the RX-8 is because any fool can add parts to a Mustang, Camaro, or Honda and run 10's. I like to take turns and stop on a dime and have a nice interior and decent sounds and nicer body lines and four decent seats and 22-24 mpg and.........sorry I got lost in my own world for a minute there.

Charles

shelleys_man_06

I'm happy to see your approach on adding power isn't limited to forced induction, like so many of us, Charles. There are alternative methods for extracting power. Nitrous technology has come a long way since its inception; quite frankly I would take anything as long as it made safe, reliable, and reasonable power. Charles, you are a true pioneer of RX-8-dom .