Pros/Cons of having lightweight flywheel with boost?

[aznstylez254]

Question, im in the process of building my extra motor for boost. What are the pros/cons of having a lightweight flywheel opposed to using heavy factory one?

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[eye_see_you]

revs will stay higher in between shifts

[5.0calypso93lx]

Originally Posted by eye_see_you

revs will stay higher in between shifts

I may be really dumb, but that makes absolutely no sense to me. I would actually think the opposite would happen. Since the flywheel is so much lighter than stock, and there is less rotating mass on the driveline, wouldn't the RPM's fall way faster with an aluminum flywheel? I mean the engine wants to slow down because of friction, and this only makes it easier. At least thats what i hear from a lot of my mustang buddies. In general, i've always been told you want an aluminum flywheel if your road racing, because you're not shifting that much all the time. Drag racing you want a billet steel piece, because it doesn't fall in RPM's as fast as the aluminum, but still gives good reving benefits over stock.

I mean, unless you are superman at shifting, i think the revs will fall way faster during shifts.

I could be completely wrong though, so someone please chime in and correct me if i'm wrong, but thats just me trying to think logically, lol.

[04civic07]

thats right.... revs fall faster because of the lack of intertia. the benefit if that when down shifting, the revs fly up real fast. the down side.... many if you're talking about a street car. when you let of the gas in gear, the car will slow down faster. you'll get that jolt of the car effect but even more so. (i believe this in the long run btw, will wear down the head) this will also lower your mpg because you'll have to be on the gas all the time to maintain speed. over all if youre looking for a race car, thats fine. for a street..... personal opinion. thats why ACT makes a "prolite" and a heavier "street lite"

[familycar]

i wouldnt reccomend a flywheel for this car. it makes it hard to keep the rpms up. and it doesnt like to make power until your in the higher rpm range. it does rev quicker but for DD use dont do it.

[TransformedBG]

Originally Posted by 04civic07

thats right.... revs fall faster because of the lack of intertia. the benefit if that when down shifting, the revs fly up real fast. the down side.... many if you're talking about a street car. when you let of the gas in gear, the car will slow down faster. you'll get that jolt of the car effect but even more so. (i believe this in the long run btw, will wear down the head) this will also lower your mpg because you'll have to be on the gas all the time to maintain speed. over all if youre looking for a race car, thats fine. for a street..... personal opinion. thats why ACT makes a "prolite" and a heavier "street lite"

Ill vouch for that.. act prolight flywheel *only like 1.5lbs ligter than that of a type R* but its more responsive when reving the engine up, and its a hello of a lot quicker to slow down, if your not giving it enough gas and the clutch is fully engadged it can jerk too. Kind of anoying but worth the extra money in my book!

[02BLKCIVIC]

Originally Posted by familycar

i wouldnt reccomend a flywheel for this car. it makes it hard to keep the rpms up. and it doesnt like to make power until your in the higher rpm range. it does rev quicker but for DD use dont do it.

LIES!!!

I love my 7lbs fidanza flywheel! 4 puck clutch for the WIN YALLL!!!

Hey Fam!

[supermex]

I heard that a light fly wheel will affect the internal balance of the motor

[yamahaSHO]

I used to have a 9lbs flywheel (stock was 21lbs) with my boosted Taurus SHO I didn't mind it, however, the car was a little harder to get going. I had to ride the clutch a little bit longer than normal. Revs come up and go down quicker due to lack of stored energy.

The biggest problem I found with my aluminum flywheel that caused me to change it back to stock was that the clutch I used seem like too strong for the flywheel. The clutch I use has a double diaphragm (two sets of pressure plate fingers, stacked) which give the clutch 3,500 lbs of clamp load. The flywheel didn't like that since it was aluminum. It puts a lot of stress on it and it flexed. One of my friends had he ring gear fall off.

Considering the Civic is fairly light and the power levels you're looking at don't include 600hp/500tq + you probably won't need such a heavy duty clutch. I think the biggest problem you'll see is taking off from a stop.

[02BLKCIVIC]

taking off is a bi*ch!

[yamahaSHO]

Originally Posted by supermex

I heard that a light fly wheel will affect the internal balance of the motor

That's ONLY if the motor was externally balanced. In many cases, a lot of small block V8's are done this way. I would assume that Honda balanced these motors internally, which means you can mess with the flywheel weight all you want as long as the flywheel is balanced itself.

[supermex]

Originally Posted by yamahaSHO

That's ONLY if the motor was externally balanced. In many cases, a lot of small block V8's are done this way. I would assume that Honda balanced these motors internally, which means you can mess with the flywheel weight all you want as long as the flywheel is balanced itself.

learn somthing new everyday.
How would you get the FW balance?

[yamahaSHO]

Originally Posted by familycar

i wouldnt reccomend a flywheel for this car. it makes it hard to keep the rpms up. and it doesnt like to make power until your in the higher rpm range. it does rev quicker but for DD use dont do it.

Once the flywheel is engaged, you'll have MORE available power being transmitting through the driveline. The only way you'll see a gain with a heavy flywheel is when you're actually revving up and engaging the flywheel. Again, once you're engaged, you'll lose torque to the wheels with the heavier flywheel at ALL RPM's.

It's not hard to keep the RPM's up and it makes rev matching much easier.

[5.0calypso93lx]

Originally Posted by yamahaSHO

That's ONLY if the motor was externally balanced. In many cases, a lot of small block V8's are done this way. I would assume that Honda balanced these motors internally, which means you can mess with the flywheel weight all you want as long as the flywheel is balanced itself.

You would be correct. Well at least the small block v8 part. Mine has a 50oz weight bolted to the flywheel, and that balances everything out. If i had to guess, i would say that the d17 is internally balanced, external balancing is kind of old school.

I would also be against this flywheel for your car. Thats just another piece you could have bought for a k20 swap.

[yamahaSHO]

Originally Posted by supermex

learn somthing new everyday.
How would you get the FW balance?

Most, if not all flywheels will be balanced from the factory. You can tell when they've been balanced as they'll have drill marks in them (generally on the outer edge). You could always take it to a machine shop and have them check/balance it.