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Engine Specific Info and Questions => IDI Engine => Topic started by: nokivasara on January 20, 2008, 08:07:40 am
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I´ve read a bunch of make-your-car-superfast-threads and I noticed a lot of you have lightened flywheels.
I thought that lighter flywheels on a diesel only would do harm, causing the engine to stall really easily.
Is there any point in lightening the flywheel on a 1.9 N/A without any other mods?
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Less rotating mass, especially on the crankshaft translates into faster acceleration as the engine can rev quicker, at least in lower gears.
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although new here on this forum...
from own experience I can tell you:a lighter flywheel certanly has it's benefits
pro :the car accelerates quicker
contra :the enginebreak is less effective .
and in my opinion as long as the whole rotatingmass is balanced
there is no extra wear on the engine.
just my 2cts. :wink:
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If I could find one for my mk2 I'm building I would be all over it, heck I would have one lightned if I only knew where to have the material removed from..
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I was just going to ask that... where does this meterial come off of?
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Everywhere except the ring gear, bolt and disk area :wink: :lol:
lightened steel 210mm at Euro Sport (http://www.eurosportacc.com/eurosport_aluminum_lightweight_flywheel.htm) I believe that is where my "heavy" spare light flywheel came from. the asembly I put in to try is a touch over 15 lbs presure plate, disk, flyweel, TO plate and bolts.
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Lightened flywheel means less torque off idle but faster acceleration through the RPM range.
Weight should come from as close to the outside diameter diameter as possible. 1 pound from the outside diameter would be the same as several pounds closer to the center.
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so in theroy someone could defonetley take an machine their own?
i suppose any machine shop would'nt have a problem with cutting it down alittle here and there...
What would someone propose it would cost to have something like this done as appose to buying one from somewhere...
alum ones can't possibly last as long as the metal oE ones
what's your thoughts?
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There is one careful word to remember, balance.
It's not a take some off here and there proposistion. It needs to be exact or you will have a fly wheel that is off balance and vibrates like crazy.
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The aluminum ones I've worked with would last longer than OE steel, theoretically. They had steel ring gears that were replaceable and steel friction plates that bolted to the aluminum flywheel that were replaceable as well. These weren't VWs, though. They were on RX-7s spun to 10,500 RPM.
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I have an aluminum GM/Ford one that has a replaceable ceramic type friction plate.
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ECS tuning has some decent kits..
http://www.ecstuning.com/stage/edpd/pagebuild_v2.cgi?searchstring=flywheel&searchqt=byvehicle&make=Volkswagen&model=Jetta+II&submodel=&engine=16v
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There seem to be some decent prices online there as well...
Im told the 16v an most all vw clutchs are the same is this true?
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the tranny you are using determines the clutch...
the 16v and ABA 2.0 motors use a tranny with a bigger spline on the main shaft, the hot setup is to get a 16v pressure plate and a good 8v clutch disc.
the splines on the main shaft on ALL other 020 tranny's are the same size.
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So the tranny to have is most likly the larger spline shaft version?
Im guessing that using a gasser tranny would be a better option?
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Lets back up, what tranny do you have? Give us the code on the bottom..
If you have a 16v tranny.. you will need a 16v clutch disc
If you have an 8v tranny (older than 1993) than you need an 8v clutch disc
You can use the 16v pressure plate with either clutch disc.
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So the 16V version would be better than....Yes?
Or are they both the same mostly?
Which pressure plate do you recomend for the 8V?
Thanks for that last post, It's all coming into perspective now!
I do beleave the gasser pieces are all the same then...clutch wise
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16v pressure plate is what you want
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someone mentioned there 210mm? as appose to?
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early cars, like 1.6 gas had 190mm
around early 80's like a 1.7 gas and 1.6 diesel had 200mm disk
1.8 gas introduced the 210mm disk late 80's should all be 210mm
the splines on the 16v trans are larger than regular 8v trans but the presure plate has a little more presure to it. So, you can use a 16V presure plate with an 8v disk and the above mentioned lightened flywheel for a cheap performance clutch. If you don't ride the clutch pedal ( shouldn't do anyway) there should not be any more wear on thrust bearing or throw out parts with a stronger clutch presure plate.
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where do you messure to deturmain which of the 190mm-210mm you have?
Where on this thing should I messure?
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For the flywheels on 020s, lightening is a simple matter of machining off the massive ring beside the ring gear. What I do (for gassers, diesel similar) is pull the dowel pin(s) from the flywheel (to avoid disasster) and chuck it up in the lathe. Instead of turning the whole thing, I use an abrasive cutoff wheel to slit the vast majority of the material into a ring, and then use the lathe to face off the remaining surface. For balance, I use a static rig I built that mounts onto a clutch cover (which I have very carefully balanced) and just drill the heavy spots until it is in balance. I have used that on race engines that see the high side of 8 grand quite regularly, and on occassion I will take the whole thing to the local shop for electronic balancing as a double check, and I have never been even close to one oz/in off. So, for diesel revs, this is well within tolerance for any practical reason.
You may not want to go so light (but then again you may). Lightening rotating mass neither adds nor removes power or torque, but it DOES allow the drivetrain to respond much more quickly to rev changes. When you are accelerating, that means a lot less power is stored in the flywheel and ultimately will be available to accelerate the car. Most lagginess in a diesel is coming from the turbo controller/wastegate, not from the mass of the driveline, but why throw away perfectly useable power for a smooter idle? I tend to drive my cars, not park them running.
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where do you messure to deturmain which of the 190mm-210mm you have?
Where on this thing should I messure?
measure the diameter of the clutch friction disk. I have seen some presure plates marked 190/200 mm
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For the flywheels on 020s, lightening is a simple matter of machining off the massive ring beside the ring gear. What I do (for gassers, diesel similar) is pull the dowel pin(s) from the flywheel (to avoid disasster) and chuck it up in the lathe. Instead of turning the whole thing, I use an abrasive cutoff wheel to slit the vast majority of the material into a ring, and then use the lathe to face off the remaining surface. For balance, I use a static rig I built that mounts onto a clutch cover (which I have very carefully balanced) and just drill the heavy spots until it is in balance. I have used that on race engines that see the high side of 8 grand quite regularly, and on occassion I will take the whole thing to the local shop for electronic balancing as a double check, and I have never been even close to one oz/in off. So, for diesel revs, this is well within tolerance for any practical reason.
You may not want to go so light (but then again you may). Lightening rotating mass neither adds nor removes power or torque, but it DOES allow the drivetrain to respond much more quickly to rev changes. When you are accelerating, that means a lot less power is stored in the flywheel and ultimately will be available to accelerate the car. Most lagginess in a diesel is coming from the turbo controller/wastegate, not from the mass of the driveline, but why throw away perfectly useable power for a smooter idle? I tend to drive my cars, not park them running.
OK, I think I have a fairly good picture of the benefits, but what about the not-so-good things with a lighter flywheel? Except the idle..
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hmm bad things.
Ive heard on modified Mk3 TDi's lighter flywheel will make the light load & throttle shudder worse.
you need to be better at balancing clutch release on take off. I'm mostly experienced with race cars and light flywheels, and if folks arn't careful they can put the car thru the front of the trailer and into the back of the tow rig ( or at least it feels that way)
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Light flywheels change how the clutch grabs. If u run a 12 pound flywheel on a tdi u get clutch chatter. Even on my 16v ice racer gasser it chatters
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i work at a machine shop where we lighten and balance flywheels all the time, on my audi 90, the stock flywheel was either 24 or 26 lbs, cant remember which, we lightened it down to 14,
we remove the weight by spinning it on a lathe and cutting it with a carbide cutter, which removes the mass evenly, even after taking the same amount off each side it was still over 60 grams out of balance! which is enough to cause some shakes and a rougher idle.
factory vw/audi parts are usually balanced within 5-10 grams. so 60 is deffinitly out of spec, so we have a balancer and balanced it under .1 of a gram, which is better than nascar specs.
needless to say, that car never idled smoother than what it did. it revved so much quicker and made it a lot more fun to drive. my point is professional balancing is a MUST or it can lead to problems! and you can feel the difference with it balanced correctly.
i have not lightened mine on my diesel yet, due to concerns that from the vibrations and power pulses associated with a diesel, and having a lighter flywheel wont absorb and cushion the drive train and lead to problems, any one have any input on this?
but if anyone wants theirs done contact me and i can get you a good price on having it lightened and balanced!
-Jack-
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contra :the enginebreak is less effective .
other way around. engine braking is more effective.
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How are the VW diesels balanced...internally or via balancer (flywheel). I put a Fluidamper on my Dad's Camaro...I checked out their website to see if they offered one for our cars. They don't. :cry:
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How are the VW diesels balanced...internally or via balancer
almost all german cars have each component balanced seperatly, and normally only engines that have a long crank (inline 6, v8 or bigger) have a balancer to lessen the harmonics that are produced.
i was told that back when the bugs were being developed they had bad harmonics that were breaking cranks due to stresses of being horizontally opposed, and the fix was better balancing and having a forged crank instead of cast, reason why all vw's and audis have forged cranks now. if anyone knows different than please correct me!
-Jack-
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anyone know of any good places to get flywheels lightened in the GTA??? I want to get mine lightened to around 14-16 lbs but withing a few grams... gotta keep the vibrations to a minimum :wink:
just seems like a great idea. i want a zippy car so this sounds like what i need!
thanks guys!
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i was told that back when the bugs were being developed they had bad harmonics that were breaking cranks due to stresses of being horizontally opposed, and the fix was better balancing and having a forged crank instead of cast, reason why all vw's and audis have forged cranks now. if anyone knows different than please correct me!
-Jack-
Well, when the bug was being developed, most of the real engineering efforts were in making clandestine war machines.
Horizontally opposed engines have extremely low levels of design-peculiar stress, since they are inherently very well balanced. No production VW air cooled engine of which I am aware ever had (or needed) a forged crank or rods. They didn't even have counterweights (again, not necessary due to being horizontally opposed and relatively low revving). You will also note that they also never had (or needed) any form of vibration damper - due to the relatively short, and thus very stiff crankshaft.
Also, unfortunately, not all VWAG cranks today are forged either (though some are - such as TDIs).
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How are the VW diesels balanced...internally or via balancer
almost all german cars have each component balanced seperatly, and normally only engines that have a long crank (inline 6, v8 or bigger) have a balancer to lessen the harmonics that are produced.
i was told that back when the bugs were being developed they had bad harmonics that were breaking cranks due to stresses of being horizontally opposed, and the fix was better balancing and having a forged crank instead of cast, reason why all vw's and audis have forged cranks now. if anyone knows different than please correct me!
-Jack-
ive logged like 80k on my old td,with a 7 pound 210mm fw
now the setup is on my tdi-m,and no problems so far
heck i turned the weight off in a lathe,and didnt even balance it
my bearings looked fine on recent teardown
yea harmonics are different on a flat engine
heres one,,i dont know of a supplier in the uk,,but they should be avalable somewhere there
http://store.blackforestindustries.com/21lifl.html
thats not a bad deal,actually
since i need to get my 4 puck relined(oildown),instead of surfacing my fw again,i think ill get one of those :wink:
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No production VW air cooled engine of which I am aware ever had (or needed) a forged crank or rods. They didn't even have counterweights (again, not necessary due to being horizontally opposed and relatively low revving). You will also note that they also never had (or needed) any form of vibration damper - due to the relatively short, and thus very stiff crankshaft.
Also, unfortunately, not all VWAG cranks today are forged either (though some are - such as TDIs).
i have never seen a vw/audi crank and/or rod that was not forged from the factory, gas or diesel, except a very very few 1.7 gassers had a cast crank,every bug has forged crank and rods, every idi ive seen has forged crank and rods, all 16v and 1.8 8v have forged, 1.8t's i know are forged, vr6 are forged, and the new 2.0t is also forged, and every audi motor from the old 5 cyl, to the new 4.2 v8 has forged crank/rods. i work at a machine shop that specializes in Audi/VW, and ive seen lots of motors
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I drove in a Mk 2 Jetta with an AAZ and a lightened flywheel. the only thing I didn't like was the noticeable increase in vibration at low revs and idle. Definitely less dampening. I'll stick to the stock flywheel, thanks.