fidanza flywheels

[futurevowner]

fidanza came out with a flywheel for our car recently, i think its only available from speed corps, what are the performance benefits? is it worth it?

http://stores.speedcorps.com/Detail.bok?no=331

[cRc`22]

good question.. i wanna know too.. would this mess with the engine at all or just help it?? pros and cons??

[Blacksheepdj]

Performance benefits - quicker revs. The car can go from 0 RPM to redline faster and drop from redline back to 0 RPM faster. Doesn't add HP or anything like that, but it'll let the car feel faster.

Doesn't "mess" with the engine at all. It's just a drivetrain component.
Pros - see above.
Cons - can make driving harder until you get used to the new way the car works.

[fuz_dnz]

I herd it would reduce gas mileage?

[crypto]

it actually increases gas mileage a little, because it is less work for the engine

[ambystom01]

I've heard the same thing (that it reduces gas mileage) because the drivetrain doesn't have the momentum it had with the older, heavier flywheel.

[CamShaft]

^ a heavier flywheel carries more momentum to keep the engine turning, a light one will have the engine putting in a little more gas to accomplish the same.

[cRc`22]

so would the combo of pulley + flywheel be a lil much?? so itll rev double the quickness..?? haha

[FinestSoldier]

in alot of my friends cars once they through a lighter flywheel they loss about 1 to 2mpg.

[Blacksheepdj]

Originally Posted by cRc`22

so would the combo of pulley + flywheel be a lil much?? so itll rev double the quickness..?? haha

It won't double it, but it should feel much quicker, yes.

[gq_jumper]

Originally Posted by Blacksheepdj

Performance benefits - quicker revs. The car can go from 0 RPM to redline faster and drop from redline back to 0 RPM faster. Doesn't add HP or anything like that, but it'll let the car feel faster.

Doesn't "mess" with the engine at all. It's just a drivetrain component.
Pros - see above.
Cons - can make driving harder until you get used to the new way the car works.

Actually a lighter flywheel can help HP, I've seen this proven with dynos, not just people saying it makes them "feel" faster. The flywheels that come standard are incredibly heavy, and as we all know unsprung weight is a big knock on HP, making the flywheel lighter will allow the engine to work more efficiently and reducing the strain on the engine will free up a little bit of power that was already there.

I've seen people get gains of 8-15 HP from a lightened flywheel, obviously it's different from engine to engine, but there very well might be a gain for our engine.

[ambystom01]

By definition a flywheel does not increase horsepower since it doesn't increase how much air is taken in or let out. You're confusing HP with revving ability. Unsprung weight has nothing to do with the engine, that is a suspension issue. Lighter parts do not increase efficiency (ie. they don't make combustion any more powerful).

[MasterAK]

Originally Posted by ambystom01

By definition a flywheel does not increase horsepower since it doesn't increase how much air is taken in or let out. You're confusing HP with revving ability. Unsprung weight has nothing to do with the engine, that is a suspension issue. Lighter parts do not increase efficiency (ie. they don't make combustion any more powerful).

You're right it can't affect BHP but I think he meant that a lighter flywheel would increase the WHP the power that makes it to the wheels because the the power loss at the flywheel would be reduced.

[ambystom01]

BHP and WHP are integrally related. All a lighter flywheel does is let the car rev faster, it doesn't increase power since it doesn't change the motor dynamics. Drivetrain lose isn't so much a weight issue as a friction issue. You can use all the lightweight parts you want but they won't make power.

[Al Bundy]

Originally Posted by ambystom01

By definition a flywheel does not increase horsepower since it doesn't increase how much air is taken in or let out. You're confusing HP with revving ability. Unsprung weight has nothing to do with the engine, that is a suspension issue. Lighter parts do not increase efficiency (ie. they don't make combustion any more powerful).

Here's the Engineer's opinion: (And I'm working through this for my benefit too)

Lighter parts can increase efficiency, assuming efficiency is measured by mpg, not crank hp. For example, shaving 100 lbs off the car will reduce the friction loss of the tires on the road, and thus more miles per gallon will occur.

It's all based on Newton's Laws:

A lighter flywheel will require less energy to go from a lower rpm (ie 0) to a higher rpm when compared to a heavier flywheel. Less energy used in increasing the angular rotation of the flywheel will allow for quicker acceleration, assuming the driver uses the same amount of gas.

At a constant rpm, the fuel consumption will not be affected, as the only forces on the car is friction at the tires and wind resistance. (the reduction in vehicle weight with the lighter flywheel only has a marginal effect on friction) However, a lighter flywheel will have much less of a buffer effect on velocity during driving. This means the car will have a tendancy to slow down faster when you take your foot off the pedal.

Now this is where the higher gas mileage that some people may experience could come from: When a car slows and speeds up faster, people adjust speed using the gas pedal. But people have a tendancy to react late, and overreact to speed fluctuations. Reacting late and overreacting are detrimental to good gas mileage.

A lighter flywheel could have greater frequency of speed fluctuations, and hence it would be possible for gas mileage to suffer slightly. Use of cruise control would eliminate the human error, and better gas mileage performance may occur.