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flywheel weight with supercharger?

Discussion in 'General Tech and Maintenance' started by FLounder, Apr 10, 2009.

  1. FLounder

    FLounder power hungry VIP

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    shopping for a clutch and flywheel for my jrsc build... cant decide what flywheel to get. i wonder if a really light flywheel would be good with a supercharger. i have found 7.5, 9.5, and 12.5 lbs... any input on this?
     
  2. efhondakid

    efhondakid My name is Byron. VIP

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    I would imagine a lighter one would help, faster revs=boost quicker? Im not exactly sure though, in for teh info.
     
  3. FLounder

    FLounder power hungry VIP

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    i know a lighter flywheel is good to help a turbo spool faster, but of course thats not an issue with a belt driven supercharger. i just wonder if going too light might make it hard to drive :shrug:
     
  4. K2e2vin

    K2e2vin Senior Member

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    I don't run turbo but I've actually heard opposite and that a heavier flywheel helps turbos spool faster.

    I'd imagine you'd be fine with a lightweight flywheel, although ~12lb seems preferred for street and drag use.
     
  5. TurboRex90

    TurboRex90 Golden EG

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    Im in on this to find out too :ph34r:.
     
  6. K2e2vin

    K2e2vin Senior Member

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    Think "brake boosting".

    The theory is a heavier flywheel requires more energy to spin faster(inertia); therefore for a given rpm at WOT, the engine would be under more load which means higher exhaust energy which then turns the turbine. You can say the heavier flywheel is like a slingshot that can possible give the turbo a head start vs. a lighter flywheel.. This is all theory and non-scientific speculation as I don't know anyone who's tried to test it out.
     
  7. CAFROG

    CAFROG Honda Minion VIP

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    I agree with K2e2vin about a heavier flywheel. Inertia is what it's all about. Momentum would help aide the turbo/supercharger to climb and spool. I always thought that flywheels need to be heavy for drag and light for track racing and all motor set ups. But I could be wrong...you mightr be able to get away with it. Look into hp limits on these flywheels. I have a lightened flywheel but I don't plan on going over 225whp with an frankenstein motor (Hopefully this fall!!) And I'm only running maybe 155whp with my B16 and bolt ons right now but if you're boosting high on a built motor, thats some horsepower to deal with. Snap a flywheel and drama ensues when schrapnel (spelling?) flys into the cab.
     
  8. TurboRex90

    TurboRex90 Golden EG

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    well i "brake boost" on my stock flywheel, stage 5(shop mix up) competition clutch, but i mean at low end.. not 60mph building boost... more the "initial" spools.
     
  9. K2e2vin

    K2e2vin Senior Member

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    Flywheel weight is more dependent on application; not necessarily a power limit. You have multiplate clutch setups with like 6lb flywheels capable of 1000hp and such.

    In general;
    heavier flywheels are more suited towards daily driving(easier to drive really, helps get rid of bogging and compensates for slower shifting)
    medium(10lb-15lb) is towards aggressive street and drag racing,
    lighter usually suited towards road course/autocross where revs are constantly going up and down(pretty much where engine/throttle response matters).
     
  10. TurboRex90

    TurboRex90 Golden EG

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    so should i get a lighter flywheel to compensate with my 4 puck stage 5 clutch and 240whp.. my final goal is like 350.. so should i change flywheels? because you seem to know more about them then i do...
     
  11. K2e2vin

    K2e2vin Senior Member

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    Well, why are you getting such a strong clutch? A heavy duty pressure plate with 6-puck, or kevlar disc, should be fine with those power levels and less harsh.

    Also, a flywheel does not compensate for a strong clutch. For drag racing/street, a heavier flywheel is recommend; usually around 12lb is fine.
     
  12. FLounder

    FLounder power hungry VIP

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    alright well now im debating between just keeping the stock flywheel or going with a 12.5lb one.... or isnt a ITR flywheel like 14 lbs? that might be good.
     
  13. K2e2vin

    K2e2vin Senior Member

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    ITR is about 15-16lbs; it'll work just fine for street.
     
  14. TurboRex90

    TurboRex90 Golden EG

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    Long story short, i ordered the stage three. the shop ordered clutch for wrong motor then when they got one for my motor they ordered the stage 5... my car was on a lift for days waiting the first time.. so i didnt bother. It really isnt that hard to drive on the street, i mean ive broken only 1 tranny so far :D
     
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