Has anyone actually lightened the factory flywheel?
 

So from what I have found the factory flywheel is 20.6lbs or so. I have bought the Aluminum single piece driveshaft and Perrin Water Pump, Alternator and Crank Pulleys but I also want to run a lighter flywheel however the ACT Streetlight is apparently back ordered everywhere.

This has brought me to considering just having the factory flywheel lightened but I have not found any threads yet of anyone who has done this and just how light there were safely able to get it to.

Can anyone chime in who has done this or even heard of someone doing it and how light they were able to make the stock flywheel?

Thanks.

Wouldn't lightening the factory flywheel simply weaken it? As opposed to getting a flywheel designed to be lighter?

This is a concern that's why I asked what level had the factory one been taken to safely.

I have lightened a few flywheels over the years a good example is the Mazda KL 2.5L V6 and 1.8L V6 Motors. Both motors were very similar but they had different weight flywheels. It was common to run the 1.8L Flywheel because it was 5 or so pounds lighter and then a few of us would lighten that flywheel 3-4 pounds and have a really nice light weight flywheel for less than 110.00 new. But this was years ago... (I actually just thought about how long ago and feel old... my son wasn't even born yet so that's over 10 years ago... damn being old)

I honestly would like to just buy one but when they seem to be out of stock for the one I want or I have to buy one at 3 times the price... meh I want to consider other options when faced with that situation.

The Streetlight is supposed to be a little heavier than the Fidanza and Prolight Flywheels, with all the other weight I am removing and keeping in mind I will be daily driving the car I almost find that maybe 14-15 pounds would be a good option to consider which lead me to look into what people had done to the stock flywheel.

You're running with stock NA power as well?

Yes this will be an NA E85 Bolt on setup for now, but knowing me that will not last I have already been thinking about building another turbo kit or going with the Edelbrock Supercharger kit when they hit the market.

I havent really looked at our flywheel, but most just add ballast to the outer most edge of the plate, and removing it has little effect on strength. I plan on having mine lightened as opposed to buying an aliminum plate. $100 compaired to $500.

[ame="https://www.youtube.com/watch?v=sl8F_ZtMhNk"]Subaru Flywheel lightening and Balancing - YouTube[/ame]
[ame="https://www.youtube.com/watch?v=dX7xftnAE0U"]VR6 Flywheel Lightening - YouTube[/ame]

I know it's another application, but people do it in the Turbo Dodge world:

http://turbosunleashed.com/shop/ligh...lve-p-324.html

But no one has done it on our side yet it seems, hmm well I guess I will do some more research on it.

Please read the following in a genuine, non douchebag tone:

Why would someone want the stock unit machined vs buying a new lightweight unit? They can be had for $300 and will be much lighter and likely stronger than a machined stock unit.

A few other things to consider:
1. I don't think the flywheel you mentioned works with a stock clutch. Keep that in consideration.
2. It has been claimed, by some, that running a lightweight flywheel and crank pully together is not a good idea. You may want to read up on that topic before you make the jump.

The ACT Streetlight works with the Factory Clutch the Prolight does not.

The only other Flywheel Under 300 I have found so far is the Fidanza and I have never liked the fact that they bolt on removing surface area from use which is why I avoid them. (I also believe Spec sells the Fidanaza just with a Spec sticker added, but I could be mistaken)

The Cusco is over 600 so that's out.

As for strength that's been addressed above by myself and others so that answers your concerns there.

So as I originally stated, I want the ACT Streetlight, it works, it fits but its back ordered everywhere this leaves me the Fidanza or Lightening a stock one.

As for the concerns of running a lightweight pulley and flywheel that's a tuning issue if you are concerned with idle. Even then it's honestly not that big of an issue and considering I also bought the Lighter Single Piece Driveshaft that is yet another point of weight reduction that would have an effect on idle.
If it's about getting used to the feeling well that's really any change done to a car. When I turboed it there were changes to get used to, when I put the 408 Stroker in the Vette and then the GTO again that was a big change. None of that makes it detrimental unless it somehow exceeds your ability to handle it which a flywheel, pulleys and driveshaft should not.

And no I am not being mean to you here I am just quickly addressing what could turn into misinformation.

This is correct.
Most of the rotational inertia in the FW is at the perimeter.
You can easily shed more than half of the rotational inertia while shedding less than half the FW's weight.

So removing from only the perimeter will make it lighter and less likely to fly apart (effectively stronger).

I hear you.

The exedy stage one clutch kit comes with a 12lb wheel and clutch for under $400. That's what I went with, but I got mine for a lot less (on sale). Exedy also sells a direct fit 12lb flywheel for around $300. I believe it's chromoly but don't quote me on that. I understand your hesitation with the bolt on surface areas. That said, I have yet to hear about any problems with them. If it was me, I would research them more before passing. If I could go back I would likely buy one to get an even lighter flywheel. I confess I don't know much about ACT products. Any word when they will be back on the shelf?

When I was referring to issues with running a crank pully and flywheel I wasn't pointing to drivability issues. One of the engine builders on the forum (the name escapes me) posted that they never suggest FA20 customers run both as, they claim, it puts a lot of extra stress on the bearings. They claimed to have seen a few failures... Maybe look it up and take it for what it's worth I guess. Not trying to sour the punch, just trying to add to the conversation.

Please by all means keep adding that's good information I want to try and find it now. I would like to see what the builder had to say.

I keep hearing about this Exedy kit but I can't seem to find just the flywheel so far because that I would buy without hesitation as well. I have never had a product from them give me issues.


I remember hearing about people talk about Dampeners and Balancers and this always starts a heated debate but honestly most engines since the early 90's have been internally balanced and the small rubber insert that rots after a few years really is more of a noise dampener, I always ask how something that I constantly see failed, cracked and coming apart is doing it's job any better than an aftermarket lightweight version. (Of course this is directed at Crank Pulleys) Flywheels being lighter just don't strike me as something to cause issues unless they were not properly balanced. I believe a vendor recently did a write up on the Crank side explaining that part but I want to find the information on the Flywheel side so I can read it, I am always over protective with my vehicles.

Let me go find that Vendor and hopefully the thread on the Crank Pulley one.
Found it, @NonStopTuning did the write up
http://www.ft86club.com/forums/showp...56&postcount=3

So the stock flywheel on our little 2.0L weighs more than the stock flywheel on a truck.

Bring it to a shop and shave some weight. Report back with findings :w00t: