Ok, there are two schools of thought when it comes to flyewheels.Light or heavy?For the motor i'm building (h23vtec-turbo later) i'll be drag racing.Some say to have a lightened one would be better to keep the rpms up with out slouching off after a shift.then some say lightened one would be better so that the rpms would raise quicker.i guess its like 6 of one, a half dozen of another.

in my position, which one do you think would be better?explanations would be great, i'd really like some informative information to come out of this.

i work at a machine shop, and the thought crossed my mind, that IF indeed, i were to go with a lightened flywheel, i could try to make one myself using my stock h22 flywheel and machining it as well as turning it.

so let the discussion commence.......

 

Welcome to H-T
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just wanted to let you know...

 

id like to know the same thing heard that lightened is better for road racing cuz quicker reving but drag and launching stock or shaved is better due to mass of inertia lightened would loose torque and also cause a harder hook up

 

how would lightning a flywheel loose torque? I guess that dosent make any sense to me. I have a fidanza 7.5lb flywheel and i love it. I put down 140ft-lbs of torque with it.

 

yeah i'm just wondering bc i've heard both things talked about being better, not that i agree with one or the other

 

some are telling me for drag racing 11 orr 12lb would be best for launching, as there IS a too light....anyone agree?

 

here is what someone else posted on another forum....exactly the other side of things that i wondered about, and does make sense in a way...


"umm, it may be me, but in a high revving drag application you SHOULD use a heavier flywheel.

here comes the arguement about "rotating mass" etc. that only applies when accelerating in a positive or negative.

look at a rotary drag car....heavy *** flywheel. why? so there is absolutely on loss during shifts, and it carries momentum better into the next gear.

feel free to argue with me. road race, any thing with down and upshifts, use lighter. if all you are doing is accelerating as hard as you can, and upshifting, heavier is better. assuming you can get your car upto rpm before the lights go green. lol"

 

The only reason I can see to use a very heavy flywheel is to improve low speed drivability.

Someone mentioned that they could take a 400 pound flywheel, rev it up and the car would travel down the length of the 1/4 mile unassisted. That was how they tried to make a point. I didn't get it.

Lighter flywheels will be harder to launch. Heavy fly's are easier to keep the RPM up and not bog out because they have so much inertia. After the initial launch difficulties, lighter is nearly always better.

Think about this...

You have a stick with a plate on the end of it. You have to rotate that stick 100 times per minute to get horsepower. Say that plate is 30lbs. Its going to be pretty hard to get that thing going. Now assume that the same plate is 5 lbs. Its going to spin very easily, letting you get up to speed with less effort. That's the basic principle.

Most of the people that are going to tell you differently are the guys who use the reasoning "my car was Mad hard to LuANch, Y0!".

Common sense dictates that - if anything - a lighter rotating mass would increase power...ALL forms of power, not detract from it.

 

the less rotating mass the better... lighter is better

if you are drag racing then use the lightest you can. this will help the car keep traction when you hit the next gear, as well as allow more power to go to the wheels when you launch, instead of the flywheel soaking it all up. weight is bad

 

First of all:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 92 DA B16a &raquo;</TD></TR><TR><TD CLASS="quote">Welcome to H-T
u have a limit of 5 posts per day
just wanted to let you know...</TD></TR></TABLE>

^^^ Worthless Post Of The Year.

Here's what I have to say about flywheels. First of all, never lighten the stock flywheel, unless you want to lose your legs if it explodes. It's not designed to take all that stress with all that material removed. There was a post on here a while back of a flywheel exploding, I can post pics if someone wants to see the carnage.

I have a lightened flywheel, and I love it. I don't drag race much, I road race, so it's great for downshifting and all that bullshit. I did go drag racing with it and turned some pretty good times for my first time out, 2.3 60' on shitty 185 tires. My thought on drag racing with a lightened flywheel is this: It might help a little in keeping the revs up on the launch, and it might help keep the revs up between shifts, but think of the percentage of time you launch and shift versus have your foot on the floor accelerating. The tiny bit that having the revs up between shifts isn't worth the slower acceleration of the engine. If you had a ton of traction, AWD or RWD, I would consider something heavier to keep from dropping too many rpms during the launch, but something tells me you won't have much problem breaking the front tires loose from a stop.

I welcome any arguments.

 

everyone has good points, so i'm still confused on which i should chose.i think im kinda leaning towards the stock one, but keep the comments coming either way

 

the porche carerra gt for 05, was designed on the princable of making the enitre rotating assembly as light as possible and as srtrong as possible... The people who were writing about the car said even experienced drivers stalled froma dead stop,but once moving they said that the revs rose at an alarming rate 8-)
if its good enough for porche then i'll take my rotating assembly light also with a side order of lightest possible.
really what you need to decide is if you want a comfortable driving car or if you want to win.

 

you figure people want to use the lightest crank, the lightest rods and pistons.. why top it off with a heavy flywheel

 

yeah but how strong is a aftermarket lightweight flywheel gonna be?normally aftermarket stuff is not as durable as oem and i can see how lightweight flywheel would be good in auto x and things when your upshifting and downshifting alot but why in drag racing when you want to keep your rpms up the whole time and not slouch off between shifts....heavy flywheel holds inertia thus keeping rpms up longer and not needing a light flywheel to bring your rpms up quicker after dropping down to nothing bc of it

 

Your not going to put in the clutch and immediately be at idle. I have the clutchmasters flywheel, and when I shift at 8000 rpm with my YS1 trans, as fast as I can get into the next gear, the engine speed is right there. It doesn't quit turning immediately, but you can't drag the clutch in the next gear, the rpms of the motor match the transmission after every shift. My clutch might last forever.

 

Its true, its not going to immediately fall back to idle speed when you go to neutral or anything so dramatic, but it will be a whole hell of a lot faster than what your used to.

Ive got the CM 7.5lb and the CM stage 3 Kevlar clutch, engagement is tricky, but when its good its REALLY good. The biggest improvement is going to be throttle response. Engine response in my car went from "pretty responsive" to "right now".

Unless you happen to like laggy engine response, you'll love this mod. As for saying that you want to keep the RPM's up during drag race situations....look, when you shift, your RPM are going to go to a predestined point due to engine speed and gear ratio. How fast the engine gets to that RPM wont slow your car down or speed it up, it will simply make the change happen faster.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by notstock93 &raquo;</TD></TR><TR><TD CLASS="quote">Its CM 7.5lb and the CM stage 3 Kevlar clutch</TD></TR></TABLE>

Thats what I have, best combo evar. Yay for chirping 5th. I don't find engagement difficult at all, it never chatters, and has a stock feel on the pedal.

 

the pedal has a stock feel, but mine does chatter a bit when trying to let it out slowly (not the best tactic for a heavy duty clutch to begin with) but its barely noticeable. I cant chirp 5th....I have a B16 with LS gears I probably cant even chirp 4th (never tried with this combo). I have to do some very fast shifting with the current combo to chirp.

I wouldn't give up my clutch/flywheel combo for the world. I did them both on the same day, so you can imagine what a surprise it was to stall my own car after a years worth of driving with the stockers in place.

 

I have an ACT ProLite 8.8lb flywheel with 6-puck cerametallic clutch. Boy was it hard to drive at first. But now that i'm used to it, I would have it no other way. It totally sucks driving a friends car after driving mine. And ALL of my friends that I let drive my car stalled the first time. It just takes some getting used to. So like the above post, Its not the easiest setup to drive, but it is sure as hell sporty and fun. If your car is going to be a daily driver in a lot of stop-and-go conditions, I personally would not reccomend a super light flywheel. But anything else I would DEF go for it.

 

I am trying to decide if I should go with the lightweight Spoon flywheel. Its either that, or get an ITR for half the price of that, or get my stock LS one shaved for half of the cost of the ITR one. Does anyone know if the B16 is lighter than the LS?
I am currently driving an LsVtec CRX with Spoon cams, ITR IM, ITR 4-1, ITR pistons, ITR TB, N1 pully, and S1 trans and using the stock LS flywheel.
I am mostly concerned with street/drag racing performance and I am not concered with drivability. I am concerned with the Spoon flywheel grinding however. I just bought a new OEM starter and I don't want to ruin it.

 

so whats the verdict ?? I want my car to launch quick and drag a few cars on the road nothing too hectic...will be getting NOS later

 

How might a lighter flywheel then effect fuel mileage?