Question about a flywheel

[kiwi87]

I have asked alot of honda guys and nobody can give me a true or straight answer....I am looking to Lighten my flywheel just pick up...will that increase my gas mileage at all due to less of a load on the engine??

[Velocifero]

I have asked alot of honda guys and nobody can give me a true or straight answer....I am looking to Lighten my flywheel just pick up...will that increase my gas mileage at all due to less of a load on the engine??

Just did a quick Google search and answered your question. You're welcome.

 

"Actually I think that in theory, lightening a flywheel might actually decrease fuel mileage.

 

The purpose of taking weight away from the flywheel is to increase the rate of acceleration - you have less rotating mass so it is less work for the engine to spin it.

 

The downside is that when you let off the gas, the engine braking effect is greater so you have to use more engine effort to keep the car moving forward. The mass of the spinning flywheel (or torque converter) builds-in momentum...when you let off the gas, a heavier flywheel will want to keep rotating and will resist the braking effect better. This means you have to work the engine more to keep up vehicle speed where before you could 'coast' a bit more.

 

Again, this is in theory..in real world, as mentioned, you aren't going to notice a difference in fuel economy. "

[kiwi87]

Just did a quick Google search and answered your question. You're welcome.

 

"Actually I think that in theory, lightening a flywheel might actually decrease fuel mileage.

 

The purpose of taking weight away from the flywheel is to increase the rate of acceleration - you have less rotating mass so it is less work for the engine to spin it.

 

The downside is that when you let off the gas, the engine braking effect is greater so you have to use more engine effort to keep the car moving forward. The mass of the spinning flywheel (or torque converter) builds-in momentum...when you let off the gas, a heavier flywheel will want to keep rotating and will resist the braking effect better. This means you have to work the engine more to keep up vehicle speed where before you could 'coast' a bit more.

 

Again, this is in theory..in real world, as mentioned, you aren't going to notice a difference in fuel economy. "

 

Wow wel thank you for the that it's a big help in a determening factor....THANK YOU

[Velocifero]

Now that I think about it, I'm not sure that's entirely true. Isn't there a fuel cutoff on from the ECU when you take your foot of the gas? This comes from the what gives you better gas mileage: putting the clutch in neutral and braking vs. leaving the clutch in gear and braking. Hmmmm...

[Kegger]

In newer drive by wire cars, yes.

 

In anything with a throttle cable, no.

[Xeryon]

Like kegger said, in new automatics when you take your foot off the accelerator the fuel is cut to reduce the engine break effect and increase fuel mileage. in manual transmission cars, even newer ones I don't think this is the case. for a car of her vintage this is certainly not the case.

 

the engineer in me thinks that a lighter flywheel should improve your fuel mileage IF you do not utilize the quicker acceleration rate to perform more quick acceleration starts. what velo noted on the momentum issue would also be true, but would be negated if you took the car out of gear when you coasted to stops (which you should be doing anyway if you are already trying to be fuel conscious)

 

This is actually a very good question, although the affect would be minimal it would still be a small piece of the larger puzzle. I bet James would have some good insight on this as well.

Edited October 11, 2010 by Xeryon

[kiwi87]

Like kegger said, in new automatics when you take your foot off the accelerator the fuel is cut to reduce the engine break effect and increase fuel mileage. in manual transmission cars, even newer ones I don't think this is the case. for a car of her vintage this is certainly not the case.

 

the engineer in me thinks that a lighter flywheel should improve your fuel mileage IF you do not utilize the quicker acceleration rate to perform more quick acceleration starts. what velo noted on the momentum issue would also be true, but would be negated if you took the car out of gear when you coasted to stops (which you should be doing anyway if you are already trying to be fuel conscious)

 

This is actually a very good question, although the affect would be minimal it would still be a small piece of the larger puzzle. I bet James would have some good insight on this as well.

 

Thanks bro that was a good answer....this is one of the few on the forums I have posted and seen like scientific responces it's pretty cool....thank all of you for your imput

[Xeryon]

I try.

 

1/2 of the topics around forums like these tend to be 'what wheel looks better on my hoopty? the green one or the purple?', the other 1/2 are often something you can search google for in 20 seconds and find 500 answers for. That's why there are not a lot of technical posts on this site. There is very little new information or ideas so most of the people just use it as their social pages.

[kiwi87]

I try.

 

1/2 of the topics around forums like these tend to be 'what wheel looks better on my hoopty? the green one or the purple?', the other 1/2 are often something you can search google for in 20 seconds and find 500 answers for. That's why there are not a lot of technical posts on this site. There is very little new information or ideas so most of the people just use it as their social pages.

 

Yeah I gotcha thanks again bro