stock flywheel Vs. aluminum flywheel

[kuuldigs]

ok, this isn't about a DSM but you guys seem more knowledgable than some forums, my friend has a 1999 ford escort ZX2 (I told him to get a DSM) and he's agruing with people on his forum about flywheels. I know it's not the same application but it's the same concept. So, for 0-60mph and 1/4 mile times, which flywheel would provide more efficent and faster times, the stock flywheel or an aluminum flywheel(taking into consideration the physics behind it)?

 

[GVR4592]

Aluminum

 

[Dtab123]

aluminum it reduces your rotating mass

 

[Catbox_95]

Aluminum, IF you think you'll even notice it on an Escort. My guess is no. But yes, aluminum has less rotating mass, therefore easier to spin, therefore easier to turn the tires. There are some more factors involved, but unless you're talking about an 8 second car, they hardly matter.

 

[kuuldigs]

that's what I thought, but people are arguing that the stock flywheel is heavier, so once it's in motion it's easier to keep in motion and the aluminum flywheel would take more power to keep it rotating because it would lose momentum quicker because it didn't have as much mass behind it

 

[Catbox_95]

No true. Take the extreme and see the results: If your flywheel weighed 125 lbs, how fast do you think the car would be? Now that's a pretty damn heavy flywheel, so by that logic, once it's spinning and it's harder to slow down, the car should be faster, right? That would be true if the engine stuck at 7,000 rpm the whole time, but it doesn't and it has to accelerate in RPM just as well as the car has to accelerate in speed, and the engine can accelerate faster with lighter rotating mass.

 

[andymoraitis]

No true. Take the extreme and see the results: If your flywheel weighed 125 lbs, how fast do you think the car would be? Now that's a pretty damn heavy flywheel, so by that logic, once it's spinning and it's harder to slow down, the car should be faster, right? That would be true if the engine stuck at 7,000 rpm the whole time, but it doesn't and it has to accelerate in RPM just as well as the car has to accelerate in speed, and the engine can accelerate faster with lighter rotating mass.

Well said! Sometimes going to the extreme to make an example makes the concept easier to understand.

Cheers,

Andy

 

[MNGSX]

that's what I thought, but people are arguing that the stock flywheel is heavier, so once it's in motion it's easier to keep in motion and the aluminum flywheel would take more power to keep it rotating because it would lose momentum quicker because it didn't have as much mass behind it

They own escorts... nuf said.

Maybe on a escort because the engine is weak and it would bog with a lightweight... Their explaination is 100% wrong when it comes to physics.. Yes it has more momentum and harder to bog when slipping the clutch at low RPM... At a 4K rpm slip launch the lightweight has more momentum than the factory at 1,000 rpm..


Lighter is faster... For lesser skilled stick drivers it can be hard to run on the street...

I have no problems... You just have to be good with your left foot.

 

[kuuldigs]

I posted them your guys' replys and most people agree with them, but there are those few who still chose to argue, so I told them to quit playing with 130hp cars and get a real car and join us

 

[suicidal2af]

Aluminum, IF you think you'll even notice it on an Escort. My guess is no. But yes, aluminum has less rotating mass, therefore easier to spin, therefore easier to turn the tires. There are some more factors involved, but unless you're talking about an 8 second car, they hardly matter.

The less power you have, the more you'll notice the difference.

How easy would it be for a 4hp engine to turn 21 pounds?

Now change that to 8 pounds. Much easier for the 4hp engine.

Now, a 400hp engine would see less of a gain.

 

[1LE]

I posted them your guys' replys and most people agree with them, but there are those few who still chose to argue, so I told them to quit playing with 130hp cars and get a real car and join us

I just had a 9lb flywheel dropped into my 130hp car (MR2), replacing the stock 21lb unit and it feels like the car gained about 5hp! Man, what a difference in acceleration! I never expected to feel any difference, I got it so I wouldn't have to pause 2 seconds while shifting anymore...