wow a lot of ppl regurgitating what they have read


let a real user talk

I have the exedy lightweight flywheel
I love it
Only thing I'd do over again would be to get a lighter flywheel

I belive stock integra FW is 16 lbs ??
mine is ~9lbs
wish i would have gotten the fidanza 7 lb flywheel

made a noticable difference...and i don't notice any negative effects.....maybe makes the car harder to drive....but hell....u just gotta know how to control your car.

 

I would buy that a very light flywheel will reduce gas milage. Here's my train of thought:

What do you need to ensure decent gas milage? Consistency. Keeping variations in engine speed to a minumum, essentially the derivative of the engine cycle over time: spin the engine at the same speed. Changes in engine cycle speed require fuel adjustments, and changes in the engine cycle speed will cause changes in component temperature, oil temp, etc. Change isn't good for milage. The heavier flywheel provides more rotational inertia which will resist acceleration (we know this from HS physics), such that it requires more energy to change the engine speed whether under acceleration or decceleration. A lighter flywheel requires less energy to turn and hence engine speed can change more easily, and it does. So gas milage decreases with the lighter f-wheel.

Anyone agree, disagree, think I should quit this topic?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GSpeedR &raquo;</TD></TR><TR><TD CLASS="quote">I would buy that a very light flywheel will reduce gas milage. Here's my train of thought:

What do you need to ensure decent gas milage? Consistency. Keeping variations in engine speed to a minumum, essentially the derivative of the engine cycle over time: spin the engine at the same speed. Changes in engine cycle speed require fuel adjustments, and changes in the engine cycle speed will cause changes in component temperature, oil temp, etc. Change isn't good for milage. The heavier flywheel provides more rotational inertia which will resist acceleration (we know this from HS physics), such that it requires more energy to change the engine speed whether under acceleration or decceleration. A lighter flywheel requires less energy to turn and hence engine speed can change more easily, and it does. So gas milage decreases with the lighter f-wheel.

Anyone agree, disagree, think I should quit this topic?</TD></TR></TABLE>

Couldn't have said it better myself.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GSpeedR &raquo;</TD></TR><TR><TD CLASS="quote">. So gas milage decreases with the lighter f-wheel.

</TD></TR></TABLE>

huh?
are you saying you will get more mpg or less mpg ?
I understand what you are saying in your explanation....but this part confuses me

by your logic shouldn't you get better gas mileage....so it would increase??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dan GSR &raquo;</TD></TR><TR><TD CLASS="quote">

huh?
are you saying you will get more mpg or less mpg ?
I understand what you are saying in your explanation....but this part confuses me

by your logic shouldn't you get better gas mileage....so it would increase??</TD></TR></TABLE>

You get worst gas mileage with a lighter flywheel because the engine deccelerates faster.

 

i would think its a matter of how you drive......if you use cruise control....then you should get better gas mileage because it will take less energy to move a lighter mass


but if you are the type of person who is either full on or full off...and uses brakes a lot...then yeah....you will get worse gas mileage

 

Theres more stored energy in a heavier flywheel. So it has more momentum. Try to roll a basketball down a hill compared to a beach ball.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Al Bundy &raquo;</TD></TR><TR><TD CLASS="quote">Try to roll a basketball down a hill compared to a beach ball.</TD></TR></TABLE>

Bad analogy

I actually noticed better gas mileage after installing my flywheel

it will take more energy to get that heavier flywheel up to speed

take for example my case
I have an LS with CAI and exhaust
I don't have any dyno's but lets just say i make 140hp at the crank
We all know that hp is the ability to do work
now if nothing changed but the flywheel....then I'm still making 140hp at the crank.

there are only two ways to go faster....maker more power, or make it easier for the power to do its job ( ie : weight reduction)

so then why is my car faster?
cuz my car still has 140hp but now it is easier for that energy to accelerate this mass (my car)

its plain physics
have only one variable

lets say we havea 10g ball bearing and exert a 10 netwon force on it
it will travel farther than a 20g ball bearing with the same 10 newton force

and since the lighter one traveled farther we can say it got better " mileage"

again...this is idealy
i still say its mostly the driver
any time you hit your brakes you are killing your gas mileage

so if you can use cruise control....i say that you will get better mileage with a lighter flywheel

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dan GSR &raquo;</TD></TR><TR><TD CLASS="quote">

Bad analogy

I actually noticed better gas mileage after installing my flywheel

it will take more energy to get that heavier flywheel up to speed

take for example my case
I have an LS with CAI and exhaust
I don't have any dyno's but lets just say i make 140hp at the crank
We all know that hp is the ability to do work
now if nothing changed but the flywheel....then I'm still making 140hp at the crank.

there are only two ways to go faster....maker more power, or make it easier for the power to do its job ( ie : weight reduction)

so then why is my car faster?
cuz my car still has 140hp but now it is easier for that energy to accelerate this mass (my car)

its plain physics
have only one variable

lets say we havea 10g ball bearing and exert a 10 netwon force on it
it will travel farther than a 20g ball bearing with the same 10 newton force

and since the lighter one traveled farther we can say it got better " mileage"

again...this is idealy
i still say its mostly the driver
any time you hit your brakes you are killing your gas mileage

so if you can use cruise control....i say that you will get better mileage with a lighter flywheel</TD></TR></TABLE>

hats the most logical answer ive heard in this entire thread

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dan GSR &raquo;</TD></TR><TR><TD CLASS="quote">i would think its a matter of how you drive......if you use cruise control....then you should get better gas mileage because it will take less energy to move a lighter mass</TD></TR></TABLE>

Good point, but even Criuse Control is making constant adjustments of the throttle (% grade, changes in wind resistance, etc). On my G2, I can actually see the movements in the gas pedal, but even on newer cars, the CC is changing the throttle position all the time. These small adjustments would be damped out a little more by the heavier flywheel because of its larger mass.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">but if you are the type of person who is either full on or full off...and uses brakes a lot...then yeah....you will get worse gas mileage</TD></TR></TABLE>

It comes down to driving, but like you said earlier, we want to minimize the variables =&gt; driver. This is true for both flywheels.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GSpeedR &raquo;</TD></TR><TR><TD CLASS="quote">

Thank you. If anything, a flywheel will increase torque compared to a standard flywheel. The rotational inertia of the flywheel has the exact same relationship to the crankshaft as the rotational inertia of the wheel does to the axle, in terms of physics. It's simply less mass, which means less energy is required to rotate it. </TD></TR></TABLE>

Okay first things first... A FW Light or Heavy will have NO effect on PEAK HP/Tq. A lighter FW will not increase Power in an engine it merely moves the placement of Power.
Take this Equation energy=(1/2) mass x velocity-squared. We can see that MASS Effects the Energy output directly. Given all things constant. Increase Mass and you increase power. Having said that ONE can understand that the power of a car with a Lighter FW is greatly effected off the line. In order to compensate One Must do WHAT??? INCREASE 'V' Increase RPM's THUS Moving the Power Higher in the rev's
Too much of a good thing is BAD!!! There is another Thread on this same Subject https://honda-tech.com/zerothread?id=594248
The Wheel Theory you mentioned is percisely but is on a much smaller scale. Lighter Wheels DONT MAKE MORE POWER. Just allows you to accelerate faster.

Don't go too low. If Lighter was Better then Why not go with a 3 pounder??? Simple TOO MUCH OF A GOOD THING IS BAD.
Down Side to Lighter FW. Longevity of the engine suffers. I guess we should ask the question then WHY DID HONDA MAKE THEM HEAVY in the forst place?
FW was designed to make the car run smoothe. Reduce Stress on the internals of the Tranny prevent RPM's from dropping off quickly between gear changes. Dampen Power Pulses in the engine.

A good Light weight FW should be STONG (That's why I like Cromoly... Very good balance between Strength and Lightweight) Rpm's will climb faster and Also drop faster Accelerate faster and that is the MAIN BENIFITS of a Lighter FW.

There are PROS and CONS in simplest terms you will notice a decrease in TORQUE off the line. Less weight greater chance for stall. I have driven 12 pounds and 8.6 pounds. I personally would not go lighter than 8.6 I didn't really want it that light but I couldn't pass on the deal.
It is Simple Math Plug in the numbers your car ill not instantaneously go from 0 to 8k

I am not saying that it is a bad or unnecessary upgrade at all. I am just trying to make a point that the LIGHTER you go the better you will have it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Spoond TEG &raquo;</TD></TR><TR><TD CLASS="quote">
A good Light weight FW should be STONG </TD></TR></TABLE>

 

Where did I say it will have an effect on peak HP/torque? That peak torque produced by the engine only accelerates the car after tramistting that power through the rest of the drive train. It takes more energy to accelerate a heavier flywheel, and that energy comes from the engine. Therefore with a heavier flywheel a significant portion of the total peak torque at the crank is "wasted" by accelerating a heavier flywheel.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Take this Equation energy=(1/2) mass x velocity-squared. We can see that MASS Effects the Energy output directly. Given all things constant. Increase Mass and you increase power. Having said that ONE can understand that the power of a car with a Lighter FW is greatly effected off the line. In order to compensate One Must do WHAT??? INCREASE 'V' Increase RPM's THUS Moving the Power Higher in the rev's</TD></TR></TABLE>

Kinetic Energy = 1/2*Mass*velocity^2, you are correct here.

However, what kinetic energy are we talking about? You're increasing the kinetic energy of the flywheel. This is more energy that the engine must overcome in order to accelerate the flywheel. It's conservation of energy. The energy of the flywheel (E' or final energy) is greater since we've increased its mass and therefore the energy of the engine (E or initial energy) must now increase to compensate. So, the lighter flywheel will be moving faster at the same energy input from the engine. This isn't really debatable.

You are confusing the power exerted by the accelerating flywheel with that of the accelerating crankshaft. Increasing the mass of any drive train components will increase the load that the engine experiences. It's a shame that nobody challenged you to this in your other posts.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Too much of a good thing is BAD!!! There is another Thread on this same Subject https://honda-tech.com/zerothread?id=594248
The Wheel Theory you mentioned is percisely but is on a much smaller scale. Lighter Wheels DONT MAKE MORE POWER. Just allows you to accelerate faster.</TD></TR></TABLE>

I never said that anything makes more power. Less rotational inertia means that it requires less energy from the engine to rotate it. I would say that the effect of wheels only seems less pronounced because of the rotational velocities involved. Gear reductions mean that the wheels and axles are moving at a fraction of the engine speed. Things are far more noticable at 8000 rpms that at 500 rpms. If you change the rdial concentration of mass then things really change (I = .5MR^2), especially since nobody is changing the radius of the flywheel. That is a different story that I don't want to get into, however.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Don't go too low. If Lighter was Better then Why not go with a 3 pounder??? Simple TOO MUCH OF A GOOD THING IS BAD.
Down Side to Lighter FW. Longevity of the engine suffers. I guess we should ask the question then WHY DID HONDA MAKE THEM HEAVY in the forst place?
FW was designed to make the car run smoothe. Reduce Stress on the internals of the Tranny prevent RPM's from dropping off quickly between gear changes. Dampen Power Pulses in the engine.</TD></TR></TABLE>

I agree with this, but we can no longer use the basic mechanics that we have used earlier to describe the situation. Heat transfer (and other thermodynamics), vibration absorption, and more "math-intensive" physics are required here. You can't use a 1 pound flywheel and expect things to work. However, like everyone said, the limit is drivability. I won't argue this, and I won't argue with the advice that Too Low is Not Good. It's the same thing with wheels. A 4 pound wheel is probably going to break.

 

Sorry My comment wasn't directed Directly at your Statement I just clicked on your post in order to reply.


I am not trying to get all deep into the science of it all but Just being basic. I know from my personal experience that When I chage to the lighter FW the car lost some umff off the line. I had to launch at a Higher RPM to compensate.

I used the equasion to give a mathematical basis to this calim. It still holds true.
I am not debating on the effects. I think I made it clear that the Lighter FW will allow the car to accellerate faster. NEVER DENIED THAT. I believe I stated that I have an 8.6 pound FW on my car.
Many people are trying to make it seem that the lighter a FW is the better it is. and this is just not true. There is a LIMIT and a Balance and that is what I am stressing here. I am stressing that with GOOD comes BAD. There are trade offs involved and some are just trying to deny that. It is not a win win situation otherwise the cars would come stock from the factory with 3 pound FW made of Ti or something like that.

Lightweight FW has a purpose and you have to (as with any performance upgrade) weight the pros and cons

The system is well balanced fromthe factory it's not the case that the 'man' wants to keep us from going fast in out econoboxes. The Stock FW has weight to it for a many of reasons.
I am trying to put some of the CONS out there so people can make informed decisions about HOW LIGHT they want to go.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Spoond TEG &raquo;</TD></TR><TR><TD CLASS="quote">Sorry My comment wasn't directed Directly at your Statement I just clicked on your post in order to reply.</TD></TR></TABLE>

It's cool. Consider me simply pointing out an error in part of your explanation of increasing mass to increase power.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">I am not trying to get all deep into the science of it all but Just being basic. I know from my personal experience that When I chage to the lighter FW the car lost some umff off the line. I had to launch at a Higher RPM to compensate.</TD></TR></TABLE>

Many people feel this same effect. It's not that you lost power, but that with less mass in the drive train, you have to be more precise with the clutch. A heavy flywheel will dampen out changes that occur with the friction of the PP. I think that this is a large part of why drivability is compromised with the lighter flywheel.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Many people are trying to make it seem that the lighter a FW is the better it is. and this is just not true. There is a LIMIT and a Balance and that is what I am stressing here. I am stressing that with GOOD comes BAD. There are trade offs involved and some are just trying to deny that. It is not a win win situation otherwise the cars would come stock from the factory with 3 pound FW made of Ti or something like that. Lightweight FW has a purpose and you have to (as with any performance upgrade) weight the pros and cons
</TD></TR></TABLE>

Fair enough.

 

....damn some people are just bored at work I take it? lol

Calm down everyone. Its only a freekin' flywheel we're talkin about!

 

lol holy ****. mad debates on a flywheel.

 

Okay let me state it a bit Better this time:

Over all HP and TORQUE will not be effected. HOWEVER, if you could take a REAL TIME DYNO of the power and Torque at a certain RPM you will realize that with a Lighter FW you moving the torque HIGHER in the RPMs and therefore you will realize a DECREASE on The lower RPM's

Sorry if I didn't make that clear. The More you lighten the FW the more ineffective your engine is at lower RMP

 

LOL. My friend just got a Tom's 3 lb titanium flywheel for his '01 Celica. I can't wait to see how many times it stalls and how much damage it's gonna do to the car.

The guy that sold it to him said it would give him at LEAST 40 torque...and he's supposed to be the respected import guy in town.

Sounds like there's 2 side to this flywheel business, sucks to not know what you're talking about.

 

do you have proof ??

i wanna see a dyno of the only variable being fw

cuz i know my car feels faster after installing the lighter flywheel

have you tried out different flywheels in the same car?

I think ppl are being brain washed into regurgitating what they may have read...and if enough ppl say it " it must be true"

if u think about it since the mass ( flywheel) is spinning at the same rpm's but weights less it has less stored energy ( or momentum)

so when the car is at a stop, and your rev the car to say 3k rpm and let off the clutch with the heavier FW , the friction from the clutch grabs the flywheel and spins the input shaft of the tranny

but with a lighter flywheel you will need more rpms in order to achieve the same momentum ( stored energy)

so you may think you lose torque...but its just a feeling...

again this is just my theory....I have no dyno proof.....if some will do a real dyno where the conditions were the same and the only modification was the FW....

then I will shut my *** up

 

Ask anyone with a sub-9lb flywheel, and they'll tell you it's 100% streetable. Mine is, ACT Prolite 8.8lb... Love it to death, not one problem since i've had it.

 

Okay LOOK at my posts I think I have stated atleast a 1/2 dozen times or so that I AM CURRENTLY USING A 8.6 pounds J's Racing CROMOLY FW
For my taste it is a BIT lighter than I wanted but I can live with it. I would not want one lighter than Mine.

Drop in torque at that certain RPM... You stated it quiet well above. If you NORMALLY (Stock FW) Launch your car from Stop at say 3k if you lighten the FW you will have to launch at a Higher RPM to realize the same torque from a STOP.

Another thing is that the RPM drop faster between Shifts and this is another thing you have to get used to. I think FOR ME a 9 pound FW would be more suitable for my setup.


No i don't have a Dyno Chart to show this. This is base on information I have heard from other reliable sources, Reading, Personal Experience with my Own Vehicle.
I went from a 16 pound Stock USDM ITR to a 12 pound JDM ITR FW to the Current 8.6 pound J's Racing FW the one I have now.
For me I liked the 12 better than the 16 but I think I would personally prefer something between 12 and 8.6. Closer to 9 or so I think is Ideal for my driving style.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Spoond TEG &raquo;</TD></TR><TR><TD CLASS="quote"> For me I liked the 12 better than the 16 but I think I would personally prefer something between 12 and 8.6. Closer to 9 or so I think is Ideal for my driving style.</TD></TR></TABLE>


EXACTLY...what it mainly boils down to is USER PREFERENCE.

So, call it a truce.

Lets end this thread on a happy note, yes?
(or LOS LOCOS will kick ALL of your asses )

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by realfasthonda &raquo;</TD></TR><TR><TD CLASS="quote">lighter is not better... to light and you lose tq.... also i personally would never get a alluminum flywheel bc when alluminum gets hot and cold it will exspand and contract alot and this can cause the flywheel bolts to come loose easy</TD></TR></TABLE>
as a side note ACT flywheels are chromoly(sp?) not aluminum

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Katman &raquo;</TD></TR><TR><TD CLASS="quote">So, call it a truce.

Lets end this thread on a happy note, yes?
(or LOS LOCOS will kick ALL of your asses )</TD></TR></TABLE>

I don't think either of us were mad. I just corrected a technical error. There's nothing wrong with a good debate.