turbo with light ass toda flywheel

[redsprinter]

looking through ebay on my lunch break today and saw a toda flywheel going for cheap.

question is :

would a toda 3.5kg flywheel be able to withstand a 170rwkw 4agte motor with a brass button cutch with a w58 gearbox...

will turbo response increase?


thanks guys ...

[70XIN]

yes to the first

no to the second.. but in a way yes.. it will get you to the revs you're making boost at quicker .. but wont directly affect the turbo spoolup

i hope that makes more sense to you than it did me :P

[Bustin_86]

Flywheel's that are that light are bad ideas full stop in my opinion

1.6's have very little torque already so why decrease this even further to gain a bit more response on what is already a responsive motor!

I would suggest going for something a bit heavier, though still lighter than stock.

Especially since your going turbo, you will lose revs very quickly and it will be all to easy to fall off boost, though turbo lag may decrease slightly.

[redsprinter]

how does thewiehgt of the flywheel effect torque? ???

wouldn't torque remain the same... just less stress on other compoents...

[skin]

Na mate the weight of the flyweel gives the engine more torque cause of some bullcrap centrifugal force or some shiz lol

Im also not sure about lightened flys on turbos

I chose to go one so ill let ya know if its anygood.

Mines an extreme 3.9 i think...

[Bustin_86]

^^^ pretty much what scumdog said, more technical shit behind it but basically lighter flywheel = less torque

So, buy a wife and install a lighter flywheel.

An extra .4kg could make a healthy difference, what is the next size up in the TODA range?

[stefan]

i had a 4.1 kg flywheel was really good when gasing it but when going up a hill you have to shift down more

and for turbo i wouldn't recomend it

NA i would for sure

[skin]

<_<

Well it may be up for sale soon enough

[redsprinter]

Why wouldn't you go light flywheel on a turbo setup ?

how bad will power delvery be affected if your making 170rkw. ?

skin. let us know how you go with the install .

what application would you use a light fly wheel for .. ? grip driving

apologies if im question alot of the responses . ive just read to many thread why i shouldnt without a in depth
reason behind it .

[stefan]

yeah N/A grip/hillclimb cars

turbo needs the extra weight to hold the motors rpm more

[skit]

<div class='quotetop'>QUOTE (Skin @ Jan 15 2008, 04:01 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=469121)</div>
Na mate the weight of the flyweel gives the engine more torque[/b]

I would like to know how it gives you more or less torque. Engine torque is generated about the crank, what you do afterwards on the output shaft or flywheel does nothing to change it. The flywheel is a mass which requires work that your engine produces to rotate. It is a load torque on the engine.

A lighter flywheel requires less work (in the form of output shaft torque) to rotate, hence more work is available to be trasmitted through the rest of the driveline. A lighter flywheel reduces "parasitic losses" if you like.

The downside is that engine inertia is reduced, so when the load torque on your motor rises (eg when you reach a steep hill) the revs drop quicker because there is less rotational momentum to keep it turning.

Definition of momentum "The property that allows moving things (your rotating engine) to overcome resistance (load torque caused by a hill) and keep moving in the at the same velocity (which is your engine speed)".

This is a broad definition, but it is fairly clear.

So, lighter flywheel = less ability to overcome a resistance and keep your engine rotating at the same speed.

This gives the illusion that torque is lost with a lighter flywheel.

Not actually the case :crazy: :2thumbs:

[af300e]

Torque is basically the lever effect of the pistion on the crank. It's similar to pushing open a door, creating a torsional force about a fulcrum or hinge. The distance between centres of the crank mains and the big end bearings is the effective lever in an engine. The longer this distance, the greater the torque. The torque can also be influenced buy increasing the force on the lever or in this case, the piston eg. turbo charging or higher comp ratio.
An engine supplies energy in bursts at each firing of a cylinder. If the rotation of the crank ceases or decreases beyond a certain velocity between firings the engine will stall or chug to a stop. This is because the crank has not presented the next piston for firing. Many single cylinder engines will not run without a flywheel of some description.
The job of a flywheel is to keep the crank turning between firings. The heavier the flywheel the greater the inertia and the less crank velocity lost between firings. This may give a feeling of increased torque but the turning force is unaffected.
The negative affect is that a heavier flywheel will take more energy to accelerate. The correct weight flywheel will be different for different applications.

[Hen is a total nutcase]

I agree completely with the previous two posts, but can never be bothered trying to explain it.

Flywheel weight has zero effect on torque. Engine may "feel" torquier due to extra "momentum" stored in the fly, but engine output will not actually change.

Light flywheels are good. Not as needed on FI as NA since there are easier ways to make the car quicker.

Hen

[riojin]

:crazy:

interesting

[redsprinter]

<div class='quotetop'>QUOTE (skit @ Jan 15 2008, 05:12 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=469186)</div>
<div class='quotetop'>QUOTE (Skin @ Jan 15 2008, 04:01 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=469121)
Na mate the weight of the flyweel gives the engine more torque[/b]

I would like to know how it gives you more or less torque. Engine torque is generated about the crank, what you do afterwards on the output shaft or flywheel does nothing to change it. The flywheel is a mass which requires work that your engine produces to rotate. It is a load torque on the engine.

A lighter flywheel requires less work (in the form of output shaft torque) to rotate, hence more work is available to be trasmitted through the rest of the driveline. A lighter flywheel reduces "parasitic losses" if you like.

The downside is that engine inertia is reduced, so when the load torque on your motor rises (eg when you reach a steep hill) the revs drop quicker because there is less rotational momentum to keep it turning.

Definition of momentum "The property that allows moving things (your rotating engine) to overcome resistance (load torque caused by a hill) and keep moving in the at the same velocity (which is your engine speed)".

This is a broad definition, but it is fairly clear.

So, lighter flywheel = less ability to overcome a resistance and keep your engine rotating at the same speed.

This gives the illusion that torque is lost with a lighter flywheel.

Not actually the case :crazy: :2thumbs:
[/b][/quote]


<div class='quotetop'>QUOTE (af300e @ Jan 15 2008, 05:39 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=469207)</div>
Torque is basically the lever effect of the pistion on the crank. It's similar to pushing open a door, creating a torsional force about a fulcrum or hinge. The distance between centres of the crank mains and the big end bearings is the effective lever in an engine. The longer this distance, the greater the torque. The torque can also be influenced buy increasing the force on the lever or in this case, the piston eg. turbo charging or higher comp ratio.
An engine supplies energy in bursts at each firing of a cylinder. If the rotation of the crank ceases or decreases beyond a certain velocity between firings the engine will stall or chug to a stop. This is because the crank has not presented the next piston for firing. Many single cylinder engines will not run without a flywheel of some description.
The job of a flywheel is to keep the crank turning between firings. The heavier the flywheel the greater the inertia and the less crank velocity lost between firings. This may give a feeling of increased torque but the turning force is unaffected.
The negative affect is that a heavier flywheel will take more energy to accelerate. The correct weight flywheel will be different for different applications.[/b]

thats more like it ... i thought it was along the line of that...

cheers .

[RobertoX]

best mod a mate did to his ze was a light fly

will comment more when im on a decent comp

[af300e]

ZE may respond differently lighter flywheel than a turbo setup due to the supercharger making boost earlier. T28 on a 1.6 for instance will probably lag until over 3500rpm.
But, there is always a happy medium, perhaps a slightly lighter flywheel would be an improvement, allowing the motor to reach boost revs more quickly.

[Benno]

<div class='quotetop'>QUOTE (af300e @ Jan 15 2008, 10:06 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=469420)</div>
ZE may respond differently lighter flywheel than a turbo setup due to the supercharger making boost earlier. T28 on a 1.6 for instance will probably lag until over 3500rpm.
But, there is always a happy medium, perhaps a slightly lighter flywheel would be an improvement, allowing the motor to reach boost revs more quickly.[/b]

why would a motor make boost earlier with a lighter flywheel? this has already been spelt out, flywheel weight only effects crank speed (de)acceleration.
light flywheel reduces crank inertia.

when an engine can overpower a given load and accelerate, a lighter flywheel will accel quicker
when an engine is overpowerd by a given load and deccelerates, the lighter flywheel will deccel quicker, thus why some people say it decreases torque but it doesn't, most cases you should see a slight increase in power output(power= work done over time, you're effectivly reducing the time)