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Old 05-13-2009, 06:39 PM   #21
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I have the Aasco LWFW with a sprung clutch. Acceleration and responsiveness is great, shifting is butter smooth. I absolutely love it other than the rattling noise in neutral. Because of location / access this is the first vehicle I haven't worked on the motor myself, but do these motors not have balancers in the crank pulleys as well?

Jake, I am fully aware of the damping I am losing and the potential failure it could cause, but it is a risk I've decided to take for the type of driving I do. You clearly know far more about motors than I ever will, but do you really need to repeat multiple times that anyone putting in a solid FW is brainless or an idiot?

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Old 05-13-2009, 07:17 PM   #22
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Quote:
You clearly know far more about motors than I ever will, but do you really need to repeat multiple times that anyone putting in a solid FW is brainless or an idiot?
I never said or implied that!

What I did say was people wouldn't make these decisions if they sat down and actually used their brains before making decisions..(to use a brain you must have one, right??!!)

You assume the risks and you understand them, but you are one of the few that has done this. If it fails you pick up the pieces and go on, thats what I do. If what I learn and share saves one engine in the hands of the normal Porsche driver it is worth it to me.

I see lots of people choose components for these engines for the wrong reasons.. Things like exhaust systems that sound better, but cost efficiency and MPG along with net performance is just one of the dozens of things people do thoughtlessly on a daily basis.

I have strong feelings concerning components and feel that nothing should be added to an engine or vehicle that doesn't increase it's performance in some way, without c reating a compromise.. Performance isn't sound or looks to me, but thats just me.

Sorry if anyone felt I called them brainless.. I never meant to, I just want to stimulate thought so people can put those brains to work that they do have.
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Old 05-13-2009, 09:16 PM   #23
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I'll be first to admit that even if i sat down and thought about light weight flywheels all week i would be no closer to making a better decision much less a "good" one.

I have a brain but it doesn't have the relevant and necessary motor-knowledge to reason through auto performance decisions like this or most (any) others.

I very much respect and appreciate the amount of time/knowledge that you put into these engines Jake. I hope to be able afford buying myself the benefits of that knowledge in the not too distant future. That said, in the mean time please be patient with us commoners.
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Old 05-13-2009, 10:32 PM   #24
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I'll be first to admit that even if i sat down and thought about light weight flywheels all week i would be no closer to making a better decision much less a "good" one.

I have a brain but it doesn't have the relevant and necessary motor-knowledge to reason through auto performance decisions like this or most (any) others.

I very much respect and appreciate the amount of time/knowledge that you put into these engines Jake. I hope to be able afford buying myself the benefits of that knowledge in the not too distant future. That said, in the mean time please be patient with us commoners.
No worries..
This is the reason why I am working hard on the tech articles on my site and putting them in laymans terms as mush as possible..
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Old 05-14-2009, 03:20 AM   #25
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I have the Aasco LWFW with a sprung clutch. Acceleration and responsiveness is great, shifting is butter smooth. I absolutely love it other than the rattling noise in neutral."

I thought others have reported that a Spec or other sprung clutch with LWF got rid of the rattling noise when the car is in neutral and the clutch is out. Mine does the rattling thing in neutral when the clutch is out, but I thought that was because I was using a stock clutch.

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Old 05-14-2009, 07:35 AM   #26
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so can you do a LWFW as long as you do a sprung clutch - and be okay - or do you still throw it all out of balance and risk crank failure??
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Old 05-14-2009, 08:38 AM   #27
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The sprung clutch just absorbs some of the initial shock but does nothing for the harmonics from my understanding. I am putting a stock flywheel back in. I just put the 3.4 in and do not want to chance something as stupid as a flywheel messing the whole thing up.
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Old 05-14-2009, 11:34 AM   #28
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How about a little balance here? 911s until atleast the early 90's had solid flywheels. Some of the early 911s even had cranks without counterweights. No harmonic balancers. None of these had breakage issues.

As for the "using your brain" comments - there isn't alot of info out there, and alot of it is purposefully mis-info. Does an Aasco lwfw come with a warning like "hey, this things gonna break your crank"? If they really had that tendancy, would they still be selling them? Jakes examples are a small statistical sample set, and under extreme conditions. If you're into sidestepping the clutch throttle down, stuff is going to break. There is driver error involvement. That said, I do appreciate Jakes efforts here.
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Old 05-14-2009, 01:09 PM   #29
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First off, prevuious 911 engines had forged steel cranks, not cranks made of sintered material... I have only seen one 911 crank, two 914 cranks and two 356 cranks break in all my days with aircooled Porsches. NOTHING with this engine and the prior 911 or other Porsche engines is the same. The vintage Porsche engine was not designed to have a dual mass arrangement and the design is what is creating some of these issues coupled to the cheap ass materials used in modern engines.

The cranks in early engines were extremely strong and wll over built for the application, never confuse anything that the Porsche engine of yesterday and the Porsche engine of today may have in common. The only thing they have in common is being 6 cylinders and horizontally opposed-

Aasoco and other providers do not build engines and until our program came along not many people had ever torn into or rebuilt these engines. When a crank would break people would just discount it as an extreme case and would never even consider the flywheel as a source, until it happened twice to the same person.

Lots of components are manufactured without the manufacturer having direct interaction with the entire engine as a primary objective, so they may never see the things that their component actually does..

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Old 05-15-2009, 07:30 AM   #30
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So I sent my aasco flywheel to Jake Raby in exchange for a stocker. It will be interesting to see what he does to the aasco. Maybe well see a harmonic balancer in a crank pulley or something cool like that?
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Old 05-15-2009, 07:57 AM   #31
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So I sent my aasco flywheel to Jake Raby in exchange for a stocker. It will be interesting to see what he does to the aasco. Maybe well see a harmonic balancer in a crank pulley or something cool like that?
I'll be using that flywheel to attempt to collect data on engine harmonics with both a stock and LWFW in iterrations per second via a couple of new sensors that I have located that give analog inputs into my data acquisition system.

I may soon be able to see exactly what the engine feels and graph the differences for overlay comparatives. This could make my article very interesting.
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Old 05-15-2009, 12:43 PM   #32
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Originally Posted by edevlin
I have the Aasco LWFW with a sprung clutch. Acceleration and responsiveness is great, shifting is butter smooth. I absolutely love it other than the rattling noise in neutral."

I thought others have reported that a Spec or other sprung clutch with LWF got rid of the rattling noise when the car is in neutral and the clutch is out. Mine does the rattling thing in neutral when the clutch is out, but I thought that was because I was using a stock clutch.

Ed

Yeah, I don't know. Sometimes even pushing the clutch in doesn't eliminate the noise. It can be embarrassing at times when people are drooling over your car and then they hear it rattling like an old Ford. I can live with it for the performance though I'm sure I'd have a hard time selling the car with this flywheel installed. LOL
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Old 05-15-2009, 02:52 PM   #33
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Ummn, what do you think the components feel if they are screaming that way just at idle?
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Old 05-15-2009, 03:35 PM   #34
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Just wanted to chime in and say thanks for a very informative (and civil!) discussion.
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Old 09-20-2009, 09:32 AM   #35
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LWFW to prevent RMS/engine damage

Just curious as to whether anybody knows whether a light fly wheel could mitigate crankshaft and RMS damage by reducing the overhung weight at the back of the crankshaft. I would think the DMFW at 40 lbs, slightly unbalanced, on a slightly untrue crank could cause undue crank shaft deflection resulting in RMS damage and leaks. I would think by the time you have an RMS leak you already have engine damage.

I was thinking of a LWFW just to prevent this scenario but I am just learning about all the negatives associated with it. I have a very low mileage engine (m96) that I would like to make reliable.

What flywheel would I use to be safe? Do I need a clutch to go along with it? It is not a race car so I would like to keep it as streetable as possible. What are the risks? Will a dynamic balance problem be caused?

Thanks,

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Old 09-20-2009, 10:02 AM   #36
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It's questionable to put a lightweight flywheel on the engine without some sort of harmonic balancing to offset the loss of the dual mass flywheel. I have had many phone calls from individuals and shops alike with broken crankshafts, attributed to lightweight flywheels and it's bad enough that Porsche issued a TSB that use of a lightweight flywheel will void the warranty, likely due to harmonics I would imagine. It's been touched upon in this thread and I highly doubt that a reduction in mass would fix the RMS issue. Engines with multiple RMS failures are indicative of a larger problem - drooping of the crankshaft carrier in the crankcase.
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Old 09-20-2009, 10:46 PM   #37
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Thanks Charles. I was not aware of the crank carrier issue and have never seen the internals of these engines. That big heavy DMFW hanging off the end of the crank right beside the RMS got me wondering.....

I would like to keep my 2000 3.2 from ever developing problems if I can..

Take care
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Old 09-21-2009, 06:51 AM   #38
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I concur with Charles' statements. These days the RMS leaks are few and far between. Much more significant failures are taking the engines out of service.

The LWFW continually creates problems for these engines related to harmonic dampening.
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Old 09-24-2009, 07:34 PM   #39
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Thanks Jake.....hopefully I will be able to install the L and N IMS retrofit to give me some insurance. I would think this actually the most common issue.....if things go bad I will be calling you, although I kind of want a 3.6 now!

Do you have any test cars or customers yet? I sure would like to hear what a Box is like with this power..
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Old 09-27-2009, 09:28 AM   #40
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Yes I have many clients who would be willing to share their experiences of the 3.6 big bore engine with you.. Some of these have my Stage I and Stage II versions of the engine.

We do ALL our own evaluation work, we do not depend on our purchasers to give us feedback on new products.. Our fleet of 4 M96 powered test cars helps us to understand our components on the street and track from DEs and AXs to Land Speed Racing.

These same track cars see 83 mile per day round trip commutes.

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