flywheel lightening

[Cjz89civic]

Compare a hf flywheel to a si flywheel you will find that the hf is about 2lbs lighter. and it will fit I have one on mine. "cheap mods" basiclly they take out the area around the bolts. But if ya got lighter you will lose some tourqe just so ya know. I wont go into the phyicis of it but rotating mass, the more weight ya have moving the the more it takes to slow it down. Do you understand I just confused myself. lol

[91civicDXdude]

good point. i just happen to have a CRX HF lying around that i've been meaning to steal the clutch and pressure plate off of, might as well make it a package deal and grab the flywheel while im at it

[WMX267]

i'm also in the process of lightening the flywheel on my '00 civic (d16y8 i think... it's sohc vtec [correct me]). i already asked around and they say that i should only take off 1kilo from it because I have a heavy car. is that true? did a little research and they said that it would be best to try to take the weight from the outer part of the flywheel. it's physics basically. they also said that you'd lose 3rd gear onwards if you shed too much wieight.

i don't really get some parts of it though like the loss of mass therefore torque to turn the wheels because you didn't exact change the circumference of the flywheel, ergo, no change in ratio in engine rotation and drivetrain. therefore your wheels should turn in much the same way in proportion to the engine... the same speed. lightening the fly relieves the engine of some weight, allowing it be able to turn the fly much easier. so in my mind, there shouldn't be any problem. right? except that of the idling because of lessening the momentum between combustion strokes.

i'm thinking that you'd lose something as regards to the relationship of the fly and the clutch. since your engine would be turning the fly much easier, faster, the clutch will most probably slip more during engagement. maybe that's how you lose torque.

more information please!!!

[FrodoGT]

A heavier flywheel will lose less momentum when the clutch engages, because it has more energy from the weight and mass it carries.

[hondacivic99sivtec]

i have a 9.75 lbs. fly wheel it works just fine.

[FrodoGT]

A lighter flywheel will spin up faster and cause less drag on the engine when accelerating..

[YZ125rider21]

Originally Posted by Fishcat37

91civicDXdude- just curious man- in your sig it says that you have a D16Z6 and are running it with a 90 CRX Si ECU- how does your VTEC engage with that ECU ...because we know that the D16A6 is non VTEC.

they also chip are pm6 ecu's to work with vtec in a/c memory...thats if you dont have a/c in your car anymore like mine....I know a guy who does it an hour away from me from Honda-Tech

[jusg19]

an aluminum crank, rods, pistons and a lightweight flywheel would get you increased throttle response because there is less mass to get moving. Wouldn't be bad for a NA car, but forget it turbo.

[2poor2tune]

the way i see it is if you can make your car lighter you should do it. especialy if you can do it without cutting up your body supports. get me? it can only help. i have actually heard somone saying if you make your flywheel to light you can do damage or somthing but could have been stupid people. idk. but dont say it like "whats the point of lightening your flywheel? it only makes the car lighter" i mean yeah if you arent going all out this probly ain the upgrade for you but its i good one if you are planning on replacing your clutch soon.

[jusg19]

Originally Posted by 2poor2tune

the way i see it is if you can make your car lighter you should do it.

The idea isn't to get the car lighter, if you were that obsessed with car weight, take out all the bolts and replace them with aluminum bolts. What a lightened flywheel is all about is essentially increasing your RPM response time from idle to redline. If you could hit Vtec sooner, you would be faster. If the engine doesn't have so much weight in the rotation to get moving, it can get to higher RPM's sooner.

[2poor2tune]

ok now i see. thanks for that response. i think i dident actually read this before i posted. i thought i posted a long time ago and read it just now and i was toward the end of it. oh well. good info here

[hondacivic99sivtec]

Originally Posted by jusg19

The idea isn't to get the car lighter, if you were that obsessed with car weight, take out all the bolts and replace them with aluminum bolts. What a lightened flywheel is all about is essentially increasing your RPM response time from idle to redline. If you could hit Vtec sooner, you would be faster. If the engine doesn't have so much weight in the rotation to get moving, it can get to higher RPM's sooner.

yes but if you get too light of a flywheel than it will be bad.i think anything under 8 lbs (because that's what a spoon is) is TOO light.