Yeah, my 7 pound is a joke. Wont idle for shit. 12lbs is the way to go.

 

I have a 7lb Fidanza. idles perfectly. no driveability problems either.

 

I run a 7.5lbs flywheel and have never once ran into any issues with it. It hasn't ever hurt my idle at all. It just reduces rotating mass which frees up HP. That just my opinion ?

 

not an opinion but fact. it takes less torque to accelerate the flywheel so more is available at the wheels. the price you pay is a sharp drop in revs but that can always be mitigated by shifting quicker.

 

I've had a 7lbs flywheels to and loved it man the engine revved so freely it makes a difference and I aswel never had no proems mine had a 500mile break in.



XxTACTIKZxX

 

My daily has had a 7lb for almost 3 years and I don't even notice it any more, unless I've just gotten out of a stock car.

 

I still have no luck what so ever on finding a 10lb or heavier flywheel from Fidanza, and with everybody except for one chiming in on the 7lb and liking it. I don't know, maybe I will go ahead and try the 7lb and see where it gets me. If I don't like it I can always replace it, and sell it.

 

I would look around for 12lb I got the act pro lite (7lb) and damn as soon as I let go of the clutch from light to light it'll sometimes spin the wheels I also have a 6 pad disc. It grabs good but for dd too much and I feel some what of a loss in top end
My launch is awesome tho.

 

You guys and your idles. Well, in my case, idle DOES suffer. High CR, stiff valve springs, high lift cam, and light flywheel make an awful idle combo. I'm not saying it cant idle smoothly, just when it comes off revs, it rarely saves itself from going straight down to zero rpms without help from the gas pedal. The inertia just isn't there.

But again, maybe it's just my setup that aggravates it to an extent that it creates a problem.
In any case, there's no real reason to go with such a light flywheel. A 12lbs would make a much better compromise.

 

See I'm leaning towards finding a different flywheel other than Fidanza because I'm only finding 7lb flywheels from them. I really like the replaceable faceplate they have on them. But I also have a high compression build with stiff springs and a bigger cam. But you knew that

 

No problems here with 11:1 compression and turbo with a Fidanza 7lb flywheel. I absolutely love it on the street. I have a 4 puck unsprung clutch as well. A light weight flywheel will not give you idle problems. I idle at 900 rpm.

 

I guess I drive an imaginary car.

 

Fidanza doesn't make replaceable face 10-12 lb flywheel. Look into other brands IMO I don't see you gaining any thing by having a replaceable face.
*side note you flywheel also acts like a heat sink

 

No I idle problem here too must be something else?

 

I've got a comp clutch ~8-9 lbs flywheel waiting for me to finish my engine. I'm expecting great things from it.

 

Competition clutch 11.5 lbs flywheel and centerforce dual friction clutch. Problem is I haven't installed the motor back in the car yet so I can't tell you how much I love it yet... but I will.

 

Black91CRXSi is not crazy, a wild cam with a light flywheel makes it very difficult to get a good idle. Thats why so many racecars have to idle at such high rpm.

 

dude this is on a stock ECU with no modifications to the map, a 7lb flywheel and a 2lb crank pulley:

as you can see, it has no problem idling or recovering.

 

dude this is on a stock ECU with no modifications to the map, a 7lb flywheel and a 2lb crank pulley:

D13 revving after ECU reset - YouTube

as you can see, it has no problem idling or recovering.

That does rev crazy fast, not gonna lie and looks like it would be a lot of fun for sure.

 

You see how yours floats to about 1100 after recovering? Mine either does something similar then dies or just dies immediately. I'm so glad it works just fine for you. I'm just saying there can be a downside to going too light.

 

I reckon that would be the ECU kicking IACV into action and accelerating the flywheel a tad too much and then compensating for it.

my point is that irrespective of weight, the ECU should be able to arrest the RPM drop if everything is calibrated correctly.

 

Should*
In my case? No...lol

 

With what cam is that?

 

stock cam. head code is P2A-9.

 

Trippin me ou tmna!!!!!

 

My 7lb flywheel didn't hurt my idle. 10 years of use on 2 different motors.

Decreasing rotational mass does free up HP. Unorthodox underdrive pulleys, 7lb fidenza and lighter wheels netted me a couple HP on the dyno. That was many years ago and I obviously didn't do a back to back comparison. WHP went from 117.3 to 120.1.

 

Same here it frees up more hp my 8lbs flywheel from a 18lbs on my type r was a major difference no idle problem

I think the member withy he idle problem it could be your iacv acting up mines did replaced it and boom All good to go



XxTACTIKZxX

 

It takes a bit of time to relearn your shifting techniques with an ultra light flywheel, other than that I would never not go with one if the option is there.

If you have ever swapped wheels to something ghetto fabulous you may have noticed a drop in MPG, this drop in fuel economy is due to the engine needing to work harder to accelerate, the same applies to the flywheel.

In my opinion if you can afford to buy lighter rotating assemblies (clutch, flywheel, wheels, rotors, pullies, crank, etc.) Do it.

You'll see more gains in acceleration and less fuel use as well, for a DD that sees mostly fair weather there is no loss. Then again driving on light snow or rain slick roads is not quite as fun (at least in my experience)

JGTC-EG

 

my question has always been do you have to get the engine re balanced after you get a light weight flywheel?