[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Lightened Flywheels

Subject: Lightened Flywheels
From: jdbubb@ix.netcom.com (Dan Bubb)
Date: Thu, 28 Mar 2002 12:04:46 -0500
References: <20020327205907.16811.qmail@web10301.mail.yahoo.com> <3CA2145A.1020506@qwest.net> <3CA309E8.6401C27E@ix.netcom.com> <3CA31B3C.3070905@qwest.net>
Well Mike, physics is physics. Less rotational inertia takes less energy
to change RPM.=20
Maybe the issues you have are specific to the Porsche's layout; front
engine and clutch, rear transaxle. The synchros have to do alot of work
in that car to speed up that longassed driveshaft on top of the normal
parts synchros need to deal with.
Dan

Mike Blain wrote:
>=20
> Yeah?  someone tell that to the Porsche. But i doubt she'll pay
> attention. And this is not an individual trait- according to the
> Rennlist inhabitants.  However, actual cause being from flywheel is
> arguable.
>=20
> Dan Bubb wrote:
>=20
> > If an engine has a very heavy flywheel it will have a large effect on
> > the speed of the car if the revs are not matched correctly since a lo=
t
> > of energy is transfered from the car to the flywheel to speed up the
> > flywheel. With a light flywheel litte energy is required to speed it =
up,
> > so a lighter flywheel requires LESS precision in matching revs to shi=
ft
> > smoothly.
> > Dan
> >
> > Mike Blain wrote:
> >
> >>I believe that the lighter the flywheel the more you'll have to match
> >>RPMs to downshift- case and point being my 928 which has the lightest
> >>flywheel ive ever seen (it's a thin piece of tin). I have to gas it a=
nd
> >>match RPMs  (called heel/toeing) to drop a gear smoothly for
> >>acceleration. There is little effect from engine braking.
> >>
> >>Ron Pieper wrote:
> >>
> >>
> >>>I disagree...engine braking would be hindered by NOT having the
> >>>flywheel helping to maintain the existing RPM.  Having the engine
> >>>quickly drop revs *decreases* the effect of engine braking - it woul=
d
> >>>provide little resistance.  Example:  imagine a massive flywheel - 5=
'
> >>>diameter - ...if you have a given car speed, and drop a gear and
> >>>release the clutch, your engine braking effects will be significant
> >>>since the engine *won't* easily change revs to match the car/gear.  =
If
> >>>you have a tiny flywheel, the engine RPM can more easily change,
> >>>reducing the effects of the engine's braking on car speed.  It's not
> >>>the speed of the engine that provides braking, it's the engine's
> >>>resistance to a change in speed (it's rotating mass, of which the
> >>>flywheel is a part).
> >>>
> >>>Now, OTOH, engine braking is not something I do or recommend...I hav=
e a
> >>>tool for that, it's the brakes!
> >>>
> >>>Ron
> >>>
> >>>--- Dan Bubb <jdbubb@ix.netcom.com> wrote:
> >>>
> >>>
> >>>>Wait a minute! Why would there be less engine braking?
> >>>>The braking effect of the engine is not changed by lightening the
> >>>>flywheel (since engine braking is a function of the engine trying t=
o
> >>>>pump air against a closed throttle) and the reduced inertia means t=
he
> >>>>engine revs will drop faster. As a matter of fact with the reduced
> >>>>inertia there is less mass holding the engine revs up so the net
> >>>>effect
> >>>>is slightly (very slightly) MORE engine braking.
> >>>>Dan
> >>>>
> >>>>Ken Bates wrote:
> >>>>
> >>>>
> >>>>>Oooohh,  That is a good pont.  I would not have thought of that.
> >>>>>
> >>>>>
> >>>>This mod
> >>>>
> >>>>
> >>>>>would be on my "list" the next time I do a clutch.    I am a
> >>>>>
> >>>>>
> >>>>"downshifter"
> >>>>
> >>>>
> >>>>>when i am driving hard and this diminished effect would be missed.
> >>>>>
> >>>>>
> >>>>Thank
> >>>>
> >>>>
> >>>>>you for bringing that up.
> >>>>>Ken
> >>>>>'79 Scirocco 16v project "McFly"
> >>>>>'86 16v (parts car)
> >>>>>VORTEX:  "Indiana Red"
> >>>>>
> >>>>>----- Original Message -----
> >>>>>From: "Robert Piwonka" <tpiwonka@TTACS.TTU.EDU>
> >>>>>To: "Scirocco" <scirocco-l@scirocco.org>
> >>>>>Sent: Monday, March 25, 2002 2:32 PM
> >>>>>Subject: RE: Lightened Flywheels
> >>>>>
> >>>>>
> >>>>>
> >>>>>>on stock cams I noticed no difference in idle characteristics
> >>>>>>
> >>>>>>
> >>>>when I had
> >>>>
> >>>>
> >>>>>the
> >>>>>
> >>>>>
> >>>>>>Velocity lightened flywheel.  However donwshifts have less effect
> >>>>>>
> >>>>>>
> >>>>ie. less
> >>>>
> >>>>
> >>>>>>engine breaking and the car reved(sp) like a motorcycle ;)
> >>>>>>
> >>>>>>Robert Piwonka
> >>>>>>86 16V
> >>>>>>
> >>>>>>-----Original Message-----
> >>>>>>From: scirocco-l-admin@scirocco.org
> >>>>>>[mailto:scirocco-l-admin@scirocco.org]On Behalf Of Allyn
> >>>>>>Sent: Monday, March 25, 2002 2:18 PM
> >>>>>>To: Euroroc II; Brian Wagner; Scirocco-l@scirocco.org
> >>>>>>Subject: Re: Lightened Flywheels
> >>>>>>
> >>>>>>
> >>>>>>Heavy - slower acceleration, smooth idle
> >>>>>>Light - lumpy idle, at an extreme you may have to raise idle
> >>>>>>
> >>>>>>
> >>>>speed to
> >>>>
> >>>>
> >>>>>>maintain idle without stall
> >>>>>>Al
> >>>>>>
> >>>>>>----- Original Message -----
> >>>>>>From: "Euroroc II" <flaatr@yahoo.com>
> >>>>>>To: "Brian Wagner" <scirocco_88_16v@hotmail.com>;
> >>>>>>
> >>>>>>
> >>>>><Scirocco-l@scirocco.org>
> >>>>>
> >>>>>>Sent: Monday, March 25, 2002 2:12 PM
> >>>>>>Subject: Re: Lightened Flywheels
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>>So anyone want to clear up the pros and cons of lightening the
> >>>>>>>
> >>>>>>>
> >>>>fly
> >>>>
> >>>>
> >>>>>wheel?
> >>>>>
> >>>>>
> >>>>>>>I've got a good idea of the advantages and disadvantages but
> >>>>>>>
> >>>>>>>
> >>>>I'd like to
> >>>>
> >>>>
> >>>>>>>get them confirmed.
> >>>>>>>
> >>>>>>>-Raffi
> >>>>>>>
> >>>>>>>
> >>>>>>>At 12:07 PM 3/25/02 -0600, you wrote:
> >>>>>>>
> >>>>>>>
> >>>>>>>>6 is extremely light, most of the lightened flywheels you buy
> >>>>>>>>
> >>>>>>>>
> >>>>are
> >>>>
> >>>>
> >>>>>8.3lbs
> >>>>>
> >>>>>
> >>>>>>>>that might be a better bet.
> >>>>>>>>
> >>>>>>>>Brian
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>>From: "Sal Guzzo" <pellom@YorkU.CA>
> >>>>>>>>>To: "Scirocco" <scirocco-l@scirocco.org>
> >>>>>>>>>Subject: Lightened Flywheels
> >>>>>>>>>Date: Mon, 25 Mar 2002 12:20:57 -0800
> >>>>>>>>>
> >>>>>>>>>Hi all,
> >>>>>>>>>
> >>>>>>>>>I wanna lighten my flywheel but I'm not sure how much to take
> >>>>>>>>>
> >>>>>>>>>
> >>>>off.
> >>>>
> >>>>
> >>>>>It's
> >>>>>
> >>>>>
> >>>>>>a
> >>>>>>
> >>>>>>
> >>>>>>>>>210mm flywheel for an 8V.  I think that it weighs about 12
> >>>>>>>>>
> >>>>>>>>>
> >>>>pounds now
> >>>>
> >>>>
> >>>>>>and I
> >>>>>>
> >>>>>>
> >>>>>>>>>was thinking of having it reduced to about 6 pounds.  Is that
> >>>>>>>>>
> >>>>>>>>>
> >>>>kewl?
> >>>>
> >>>>
> >>>>>>>>>TIA
> >>>>>>>>>
> >>>>>>>>>Sal
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>_______________________________________________
> >>>>>>>>>Scirocco-l mailing list
> >>>>>>>>>Scirocco-l@scirocco.org
> >>>>>>>>>http://neubayern.net/mailman/listinfo/scirocco-l
> >>>>>>>>>
> >>>>>>>>>
> >>>>>_________________________________________________________________
> >>>>>
> >>>>>
> >>>>>>>>Chat with friends online, try MSN Messenger:
> >>>>>>>>
> >>>>>>>>
> >>>>http://messenger.msn.com
> >>>>
> >>>>
> >>>>>>>>_______________________________________________
> >>>>>>>>Scirocco-l mailing list
> >>>>>>>>Scirocco-l@scirocco.org
> >>>>>>>>http://neubayern.net/mailman/listinfo/scirocco-l
> >>>>>>>>
> >>>>>>>>
> >>>>>>>_________________________________________________________
> >>>>>>>Do You Yahoo!?
> >>>>>>>Get your free @yahoo.com address at http://mail.yahoo.com
> >>>>>>>
> >>>>>>>
> >>>>>>>_______________________________________________
> >>>>>>>Scirocco-l mailing list
> >>>>>>>Scirocco-l@scirocco.org
> >>>>>>>http://neubayern.net/mailman/listinfo/scirocco-l
> >>>>>>>
> >>>>>>>
> >>>>>>_______________________________________________
> >>>>>>Scirocco-l mailing list
> >>>>>>Scirocco-l@scirocco.org
> >>>>>>http://neubayern.net/mailman/listinfo/scirocco-l
> >>>>>>
> >>>>>>
> >>>>>>_______________________________________________
> >>>>>>Scirocco-l mailing list
> >>>>>>Scirocco-l@scirocco.org
> >>>>>>http://neubayern.net/mailman/listinfo/scirocco-l
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>_______________________________________________
> >>>>>Scirocco-l mailing list
> >>>>>Scirocco-l@scirocco.org
> >>>>>http://neubayern.net/mailman/listinfo/scirocco-l
> >>>>>
> >>>>>
> >>>>_______________________________________________
> >>>>Scirocco-l mailing list
> >>>>Scirocco-l@scirocco.org
> >>>>http://neubayern.net/mailman/listinfo/scirocco-l
> >>>>
> >>>>
> >>>
> >>>=3D=3D=3D=3D=3D
> >>>Cheapass Ron
> >>>"Victor" '87 16V Scirocco
> >>>"Teufelhasen" '93 Cabby <-For sale
> >>>
> >>>If it ain't foggy, TURN OFF YOUR FOG LIGHTS.
> >>>
> >>>__________________________________________________
> >>>Do You Yahoo!?
> >>>Yahoo! Movies - coverage of the 74th Academy Awards=AE
> >>>http://movies.yahoo.com/
> >>>
> >>>_______________________________________________
> >>>Scirocco-l mailing list
> >>>Scirocco-l@scirocco.org
> >>>http://neubayern.net/mailman/listinfo/scirocco-l
> >>>
> >>>
> >>>
> >>>
> >>_______________________________________________
> >>Scirocco-l mailing list
> >>Scirocco-l@scirocco.org
> >>http://neubayern.net/mailman/listinfo/scirocco-l
> >>
> >
> > _______________________________________________
> > Scirocco-l mailing list
> > Scirocco-l@scirocco.org
> > http://neubayern.net/mailman/listinfo/scirocco-l
> >
> >
> >
References:
- Lightened Flywheels
  - From: rapieper@yahoo.com (Ron Pieper)
- Lightened Flywheels
  - From: rept@qwest.net (Mike Blain)
- Lightened Flywheels
  - From: jdbubb@ix.netcom.com (Dan Bubb)
- Lightened Flywheels
  - From: rept@qwest.net (Mike Blain)
Prev by Date: Battery Reloq. - wire size, routing, battery location etc.
Next by Date: [A2] Bilstein v. H&R Cup
Previous by thread: Lightened Flywheels
Next by thread: Lightened Flywheels
Index(es):
- Date
- Thread