lightweight flywheel on stock motor

[kyle10182]

anybody using a lightweight flywheel on an otherwise stock engine?

I wanna get one for a b20 but i'm a little nervous that without tuning it might help more then it hurts. I noticed when i had a fidanza 7lb flywheel on a GSR that when i was at higher RPMs and would hit the clutch to drop down to idle that the engine would drop WAY down (sometimes even stall) before coming back up to idle speed. I was told that it could've had something to do with the flywheel and that tuning could fix the problem. I do NOT plan on tuning this engine. just swap and reuse the PR4 thats already in the car. maybe i'll go with a 10lb flywheel?

 

[PhntmSk8r]

I ran an 8lb flywheel on my stock H and never had that problem. Id say that was more tuning related, or the motor getting to much fuel from letting off suddenly and dropping to idle, oppose to letting the rpm drop in gear to burn off the extra fuel.

I think you'd be 100% problem free with it, but every motors different.

 

[ej2rey]

You're theory is right. A very light flywheel will just drop the rpms really low when engaging the clutch which is not good on a honda engine. You wanna keep the rpms high at all times.
I think a 10lb fly should do you justice. Or you can always go for the 7lb and add weights to your prefference.

 

[newtron63h]

not quite sure what the point of a lighter flywheel is on a stock engine. its a stock engine so you arent racing. a lightweight flywheel hurts daily drivability. and has very marginal gains. if someone has some other view or know something i dont then please let me know.

 

[PhntmSk8r]

I dont understand all of the hype about how a light weight flywheel kills 'driveability', i dont have to rev my car any higher to get moving than i had to before, shifting still feels the same. Only difference is RPM's drop faster between gears, and they pick up a little faster (less rotational mass DIRECTLY off the crank)

 

[newtron63h]

didnt say it kills it, but it does hurt it. maybe you dont have to rev higher but you have to give it more throttle, its physics. if the weight of the flywheel isnt there, it still takes the same energy to get the car going, so that energy has to come from somewhere else. you obviously adapted to it well. my point is that there are plenty of other things you can do that will give more gains with ALOT less work and less money.

plus, what is the point on a stock motor? of all the things to do, why THAT?

 

[kyle10182]

my point is that there are plenty of other things you can do that will give more gains with ALOT less work and less money.

plus, what is the point on a stock motor? of all the things to do, why THAT?

its a $150 part. it doesn't cost THAT much. And the work isn't an issue since i need to change the clutch anyway. i'm just not beefing the clutch up to a stage 2 or anything since its a stock car.

i honestly think that for performance that a lightweight flywheel and a short shifter are probably the absolute best bang for your buck.

My main reason for wanting it on a stock motor is the improve gas mileage. Helping the engine spin easier is sure to make it more efficient.

 

[ryanM]

i never liked the feel of light flywheels.

the only time i will ever upgrade my flywheel is if i go with twin disc or hyper single

 

[kyle10182]

oh man. i've always LOVED driving with my 10lb flywheel on my CRX.

 

[slowcivic E G]

i don't notice a difference between my stock flywheel on the LS in the wag, or the 8.5 on the h22 in my hatch? Kyle I don't know if I gave you my opinion when we discussed it, but i say 10 or 12.

 

[kyle10182]

i don't notice a difference between my stock flywheel on the LS in the wag, or the 8.5 on the h22 in my hatch? Kyle I don't know if I gave you my opinion when we discussed it, but i say 10 or 12.

you really don't notice??? you barely touch the gas and you're at 3,000 rpms almost instantly with my 10lb flywheel. but my stock ls flywheel would take a whole second to get there. i'm talkin about in neutral.

I went with a 12lb because the price was right and i'm sure that will be good enough. better then stock, and there is no real risk of over-doing it.

 

[newtron63h]

it takes less work from the engine to keep it at a certain rpm with a heavier flywheel. i dont see how a lighter flywheel can help mileage. it takes more energy to get it moving, but once thats done it takes less to keep it moving.

 

[ej2rey]

it takes less work from the engine to keep it at a certain rpm with a heavier flywheel. i dont see how a lighter flywheel can help mileage. it takes more energy to get it moving, but once thats done it takes less to keep it moving.

Half of your statemen is false.
It doesn't take more energy to get a lighter flywheel moving. When its lighter it take less effort/less energy since its lighter. It is harder to keep in motion of coarse because it won't have the weight to keep the momentum going. That's why lighter flywheels are best for racing where you need to keep your rpms always high.

But like I said before you can add weights to the flywheel to suit your needs.

 

[kyle10182]

there's no way it takes more energy to turn a lighter rotating assembly then a heavier one. Anytime u can make that 10lbs lighter it's going to be more efficient.

think about the difference between a roots supercharger and a centrifugal. The roots makes less power (ie less efficient) because it runs off of the crankshaft. It robs power from the crankshaft in order to make power.

The same goes for the stock 22lb flywheel.

Also think about removing A/C from a car....just cutting the belt and relieving the crankshaft of its duties of spinning that compressor improves efficiency.

 

[sincivic_vx]

I have a 7.5lb flywheel in a VX. You want to talk about flying through gears... Wow lol
I got mine just because... When I bought the car it need a new clutch and flywheel. A friend told me that if I bought a 7.5 Fidanza he would buy it off of me when I do my motor swap.

So why not. I plan on doing the swap by end of winter. I drive less then 5 miles TO AND FROM work 5 days a week. So it should hold up for him.