"Lightened Flywheel", Anyone ever heard of this? |
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"Lightened Flywheel", Anyone ever heard of this? |
m170seeker |
Aug 16 2012, 01:04 PM
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#1
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Member Group: Members Posts: 55 Joined: 23-June 11 From: Austin, Texas Member No.: 13,235 Region Association: Southwest Region |
I just had the flywheel changed on my 74 2.0L 914. Mechanic said the old flywheel was a "lightened" one and my new one is stock. I'm curious about you all's opinions on the difference; pros and cons of each. Apparently the PO decided to go for more high end acceleration than low end? I've never seen anything about this on the forum.
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Kraftwerk |
Aug 16 2012, 01:06 PM
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#2
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Member Group: Members Posts: 195 Joined: 6-September 07 From: Bbbbbrroooklynnn Member No.: 8,085 |
I hear a lot about this with race engines over on the 911 forum. Keep the one he removed its worth $ to someone.
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SLITS |
Aug 16 2012, 01:08 PM
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#3
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"This Utah shit is HARSH!" Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None |
It's all over here about advantages / disadvantages of a lightened flywheel.
Basically it comes down to the engine will spin up faster, but stall easier with a lightened flywheel. Sorry, no free horsepower though. |
Jeffs9146 |
Aug 16 2012, 01:11 PM
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#4
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Ski Bum Group: Members Posts: 4,062 Joined: 10-January 03 From: Discovery Bay, Ca Member No.: 128 |
I had a lightened flywheel on a 74 2.0L back in the 80's and it would spool up way quicker but was a bit touchy when releasing the clutch without enough rpms! You could stall it out easier when starting!
Over all I loved the feel!! Edit: Slits beat me!! (IMG:style_emoticons/default/beerchug.gif) |
brant |
Aug 16 2012, 01:12 PM
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#5
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914 Wizard Group: Members Posts: 11,628 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
there are a bunch of threads about this around here.
it might spin up faster definitely race cars use these but yours not be worth a mint, depending on how light is it and wear tolerances... a lot of people like moderately lightened flywheels on the street weigh yours and see how light it is. |
m170seeker |
Aug 16 2012, 02:07 PM
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#6
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Member Group: Members Posts: 55 Joined: 23-June 11 From: Austin, Texas Member No.: 13,235 Region Association: Southwest Region |
there are a bunch of threads about this around here. it might spin up faster definitely race cars use these but yours not be worth a mint, depending on how light is it and wear tolerances... a lot of people like moderately lightened flywheels on the street weigh yours and see how light it is. Thanks, interesting. I'm anxiuos to feel the difference. |
gandalf_025 |
Aug 16 2012, 02:11 PM
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#7
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Senior Member Group: Members Posts: 1,456 Joined: 25-June 09 From: North Shore, Massachusetts Member No.: 10,509 Region Association: North East States |
From my Corvair days... I used aluminum flywheels..
Heavy flywheel tends to smooth out idle and make starting from a dead stop easier. More rotating mass.... let off the gas and the revs drop slower and smoother. Depending on how much less the lightened flywheel weighs... Engine will accelerate faster.. BUT, at the same time... Letting off the gas is like stepping on the brakes. They do take some getting used to. You can go too far and make the car unpleasant to drive in regular traffic. Personally, i really liked the way the car felt with one. I think some early 911 2 liter flywheels had holes drilled in them to make them lighter |
brant |
Aug 16 2012, 02:17 PM
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#8
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914 Wizard Group: Members Posts: 11,628 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
We are using this flywheel currently with an F first gear and a tilton
(similar to an on/off switch) this makes getting started from a dead stop difficult. Attached image(s) |
Drums66 |
Aug 16 2012, 02:24 PM
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#9
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914 Rudiments Group: Members Posts: 5,321 Joined: 15-January 03 From: Coronado,Cali Member No.: 151 Region Association: Southwest Region |
It's all over here about advantages / disadvantages of a lightened flywheel. Basically it comes down to the engine will spin up faster, but stall easier with a lightened flywheel. Sorry, no free horsepower though. ....What he said's rght......have 1 in my 75'..when something's wrong! will stall easier. |
aircooledtechguy |
Aug 16 2012, 02:36 PM
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#10
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The Aircooledtech Guy Group: Members Posts: 1,966 Joined: 8-November 08 From: Anacortes, WA Member No.: 9,730 Region Association: Pacific Northwest |
Good info here on the pros/cons of each.
Fuel economy - A heavier flywheel will increase MPG on the hwy since it's easier on the engine at cruise (flywheels literally store power/torque) A lightened flywheel simply frees-up HP to go to the rear wheels that would otherwise go to spinning the extra weight of the flywheel. Thus the motor feels more powerful on acceleration. |
Brodie |
Aug 18 2012, 10:58 PM
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#11
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Newbie Group: Members Posts: 39 Joined: 28-October 09 From: Kansas Member No.: 10,990 Region Association: None |
aircooledtechguy is right on. I've lightened flywheels for dirt track racers in the past. They say it helps acceleration because it doesn't take as much to spin a light flywheel as it would a heavy one. Flywheels store energy so once up to a steady cruising speed it takes more to slow down a heavy flywheel than a light one. That generally will give you better MPG because the engine doesn't have to work as hard because the momentum of the flywheel keeps the engine turning. One has to be carefull about weakening the flywheel if you take too much off of it. There is a fair amount of pressure on the flywheel.
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