Machining the flywheel

but how much weight will it reduce? do you enjoy low end torque?

At 28.5# I feel its actually hurting torque. Everyone who gets a light weight aluminum flywheels love the extra power and easily it revs.

I'm hoping to drop the weight of the flywheel by at least 50%. People have had good experiences with 8# Fidanzas and 16.5# Exedys, so anywhere inbetween would keep me happy. It appears that I will eventually end up running a supercharger, so I won't need to keep the weight up in order to help with spool.

lightweight flywheel = no low end torque, but you will feel more power up top in the butt dyno

Somehow I doubt you will drop that much weight. Don't know for certain.. but machining it that low may be impossible, way below specs, and may hurt integrity.
Pony up the bucks and get an alum.

You lose some low end torque, but certainly not all of it at long as your flywheel has some weight to it. I am more than willing to loose a little bit down low to gain a lot up top as well as to be able to accelerate faster.

you should've gotten the MPS version if you wanted to be quick :lol:

Zach said:

but how much weight will it reduce? do you enjoy low end torque?

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lightweight flywheel = no low end torque, but you will feel more power up top in the butt dyno

Click to expand...

ey?

By "machined" what do you mean??? It is normal practice to machine the surface of the flywheel and perfectly safe. Lightening CAN be safe (see mine) but can also be dangerous (see various amusing threads out there). If you want it to be revvy etc you won't achieve much with the stocker without compromising safety.

In any case, the benefits and drawbacks performance wise are not significant at all really. Still it can be fun

Nealio said:

You lose some low end torque

Click to expand...

ey?? .

By machined, I mean lightened or turned down in order to remove some rotational mass.

Lighter flywheel doesn't decrease torque, it reduces inertia. There is a difference.

But that inertia is translated into driveline shock that does temporarily increase torque, but it soon their after hurts both HP and Torque across the rest of the RPM band.

Honestly, it's all on paper power which is totally irrelevant. What does matter is how quickly you can get to the power. Which is more achievable with a lighter flywheel.

id rather get an ebay lightened flywheel than fuck around with the stock one.

Find me one and I'll do it. But $300 is as cheap as I've seen 'em.

Zach said:

lightweight flywheel = no low end torque, but you will feel more power up top in the butt dyno

Click to expand...

How accurate is your butt dyno are is that too sensitive? :muhaha:

I'm confused. Torque is "twisting power" produced by the engine. The speed at which the torque is produced doesn't change the amount of torque. You would arrive at the peak torque rpm quicker, but I don't understand how that would actually reduce the torque. That's produced "in" the engine and simply measured at the flywheel. I think.

wbibb said:

but I don't understand how that would actually reduce the torque.

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It is hard to understand things that are not true.

It's a good thing you have your entire fucking car as a flywheel, a few kg of rotational inertia don't make a lick of difference to torque or power delivered anywhere in the rpm band. Listen to STW if you don't like me, he's an actual engineer, not a back yard hack like me ;-)

Fred.

Its safe and a great way to save $ and to gain "power", so as long as you dont take it down to far. I don't really know much about the 6s but in the 2gen mx6 case, we can take ours down to a safe 13lbs which to me is still pushing it, (id rather take a mx3 and shave it down to 13lbs). But just keep your eyes open for someone parting/selling theirs and u can just have it resurfaced if needed.

fredio54 said:

It is hard to understand things that are not true.

It's a good thing you have your entire [fizzle]ing car as a flywheel, a few kg of rotational inertia don't make a lick of difference to torque or power delivered anywhere in the rpm band. Listen to STW if you don't like me, he's an actual engineer, not a back yard hack like me ;-)

Fred.

Click to expand...

I can't find the link, but it only has to do with launching. When you have a heavy clutch and launch, the extra rotational mass provides an extra kick in the teeth to get the drivetrain in motion from a static position (provided that the clutch doesn't slip). Where as with the lightweight flywheel doesn't have the same ability.

Damn it, that page had a dyno plot and everything. Where did I put it.

i had 5 lbs turned off my stock f2t flywheel, all i did was have it machined down to the minimum thickness and had the small step machined off the back. (also had it balanced to very close accuracy.)