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YOUR RESEARCHLets talk flywheels
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only package i found
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This is what I purchased, it was the only package I found that was center balanced, and it is for sure parts are marked with yellow paint, and the technician signature on the box with date of balance.
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Install stage 3 clutch, smf and i couldn't be happier
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But my Golf R had a stock DMF and I installed a stage 3 clutch, SMF and I couldn't be happier...
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Waiting for spring to have installed when doing IMS / RMS upgrade.
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Only thing is, the engine was replaced under warranty due to oil/coolant intermix.
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So every engine has harmonics that have to be dealt with, and changing things like the flywheel weight/material, or engine mounts, or muffler weight/material ect will change the harmonics.
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only package i found
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This is what I purchased, it was the only package I found that was center balanced, and it is for sure parts are marked with yellow paint, and the technician signature on the box with date of balance.
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The indy I used assured me that my engine would be fine but it was the stress on the gearbox from improper changing etc that could be an issue, OPC said the same thing.
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My 01 is in the shop getting all the common problems sorted out...RMS, IMS, AOS and all the other initials that go with it. Also replacing clutch/ flywheel. What are the pros/ cons of a lightweight flywheel?
I drive the car almost daily. I haven't done any track days yet bc I wanted to get it all recon'ed first. I do plan to track it though, but maybe only a few times a year.
Lightweight flywheels:
1. Can cause broken crankshafts unless you also add a harmonic balencer.
2. Can cause erratic idle
3. Cause transmission gear noise at idle.
4. Take a little more concentration in stop n go traffic.
1. Enable the engine to rev quicker from idle and when rev matching between shifts.
I wouldn't do it. For a street/track car I think the cons, as mentioned by fpb, outweigh the benefit of a faster reving engine. For a dedicated track car, another story.
I bought an aasco aluminium flywheel , but my Indy scared me with tales of broken crankshafts . He talked me into a single mass flywheel instead to replace the stock dual mass flywheel . The reasoning was smoother running and easier to live with , more robust than the stock dual mass unit , yet a bit more free reving .
It cost 1k CDN .
But there are rennlisters who love the aasco flywheel and I haven't heard of a case of an actual crankshaft breaking . Hopefully if someone has had this happen they will post .
If anyone is interested , I have an aasco still in the box I'd sell for 75% of what I paid for it from pelican .
Kind of what I was leaning towards, I've had lightweight flywheels in RX7's in the past and they suffered from all the same issues discussed here. Ill probably go back with stock
Thanks guys
Some interesting reading:
https://rennlist.com/forums/997-gt2-...l#post10816248
http://www.6speedonline.com/forums/g...-flywheel.html
https://rennlist.com/forums/gt2-and-...track-diy.html
Seems like there is more than one GT3 LWFW:
"Probably they use the same because the pseudo- LWFW double mass of the 997.2GT3 is light enough."
I suspect that any solid flywheel has the same downside as the AASCO LWFW has because the engine wasn't built with a harmonic dampener (which the dual-mass flywheel compensates for).
The Gt3 is is a different matter they had issues with over reving and the bolt shearing on the front pulley
the 996 is a different combo and the Aasco weight is almost 15 pounds vs the steel RS which is mentioned in this thread is 12lbs
Yikes, I wish I saw this thread months ago.
I just purchased a center balanced package from Patrick Motorsports, LW flywheel, and sacks clutch & pressure plate.
Waiting for spring to have installed when doing IMS / RMS upgrade.
I have 2003 996 C2 Coupe 3.6L.
Already done is IPD compitetion plenum 82 mm, Evoms tune, Kline headers and 200 Cell X pipe, Tubi Style mufflers.
This is daily driver and occasional autocross, Drag & going to do PCA DE.
Also planning on doing RSS underdrive pulley.
Am I igniting my own engine destruction??
I'd ask them about it and see what they say. From what I have gathered, the reason why they do cause problems is because it's not balanced. But, not sure about that.
Again, I'd ask them about it.
Mike
I think the consenses is if you don't mind the additional noise of a single mass flywheel which is what the Dual Mass manufacturers say the Dual Mass is intended to do, they do not state is is a Harmonic or Torsional dampner in any way.
And you don't get to racey and extend the RPM past redline or decide that using the engine as a brake and back hole it.
You should be fine alot of People including myself get along just fine with a singel mass.
regards
Right - but that just means that the flywheel itself is balanced. It will not do the job of damping vibrations in your car.
The LuK site has an
informational write-up...
This is based on me installing a 10.4 flywheel in my e36 M3 a few months ago. The transmission does rattle at idle when car is in neutral and clutch pedal is not depressed. Also the engine will stumble at idle a few times before settling at idle. This can be fixed by doing a tune. I understand the 996 will do the same things, I just don't know about the harmonic balancer part. The rattle and idle thing doesn't bother me as this car is turning into a track duty car here in the next few months.
-Jason
I was at the same point a year ago, clutch was up and there was a decision I had to make: keep the LWFW or buy a new DM flywheel. I opted to keep the LWFW and put in the LN IMS instead.
Also I got so used to the LWFW I didnt want to give it up! I also have a matching cargraphic under drive pulley and a sprung Sachs clutch disk (thats very important if going down this path too). I recall reading a GT3 TSB? (if my memory serves me correctly) where dealerships were installing LWFWs without the smaller GT3 CS pulley and it was causing problems.
The chatter on mine is very bearable car is awesome to drive although you need to be constantly on your game or you'll burn the clutch and no one likes clutch smell... The indy I used assured me that my engine would be fine but it was the stress on the gearbox from improper changing etc that could be an issue, OPC said the same thing.
I might be against the crowd here but go for it if you're game!
More info around what i'm referring to:
https://rennlist.com/forums/gt2-and-...track-diy.html
More around track usage but there is an interesting note regarding LWFWs and one side loading
Not the same car...
But my Golf R had a stock DMF and I installed a stage 3 clutch, SMF and I couldn't be happier... Was hoping to do the same with my 996? I guess I'll follow this thread a little more closely
I was told that my new to me 1999 C2 cab. had a LWFW. Mechanic determined this by how fast the car returned to idle after revving it. Is this the case?
No reason it should have a LWFW as it is stock and was a one owner and he never had it installed. Only thing is, the engine was replaced under warranty due to oil/coolant intermix. Might they have put it in then?
Hope I'm not hijacking. It is a flywheel related issue....
This is what I purchased, it was the only package I found that was center balanced, and it is for sure parts are marked with yellow paint, and the technician signature on the box with date of balance.
Sport Single Mass Flywheel & Clutch Package - (1999-2004) PORSCHE 996 Carrera Normally Aspirated
Patrick Motorsports Exclusive
[phone removed] SMFC PMS
29.70 lbs
Sport Single Mass Flywheel & Clutch Package - (1999-2004) PORSCHE 996 Carrera Normally Aspirated - All Non Turbo or GT3 Models - Reduces rotating mass by 14.50 Lbs. (6.58 Kg.) - Designed for sport street and autocross use. - PATRICK MS USA
Complete Package includes:
+ Single Mass Lightweight Aluminum Flywheel (Assembly Weight: 12.50 Lbs. (5.67 Kg.)
+ Pre-installed Sealed Pilot Bearing, Thrust Plate & Flywheel / Clutch Mounting Hardware
+ SACHS Race Engineering Sport Pressure Plate & Torsion Sprung Hub Organic Disc
+ Sachs Release Bearing
+ Certified Computer Balanced Assembly
Package Weight: 28.00 Lbs. (12.70 Kg.)
I have an Evoms Stage IV tune on engine now, after the flywheel and underdrive pulley installed, I will be getting an updated download, to address idle and stalling issue due to flywheel.
Just on the stalling issue, I believe my car had a tune by the previous owner not sure which one and it may not have at all. There are times my car wants to stall but its only when reversing into my slightly inclined garage but I just give it a little gas and its happy so its not an issue.
The real difficulty is takeoffs and hill starts. The reduced inertia makes the rpm drop rapidly, just makes you a better driver though!
Two things to be conscious of with a LWFW driving wise IMO:
1. Dont rev too much and drop the clutch too slowly at high RPMs, you'll burn it (difficult to get right because the engine is free to rev)
2. Make sure your RPMs are correct when shifting to avoid excess strain on the gearbox.
My cars not driven daily, although it was for a few months and you do get used to it, wouldn't have my car without it now.
I don't think you'd have a LWFW based on what you've said but who knows! Without the documentation the only way to determine without mechanical intervention would be to watch this and see if your revs are the same
https://youtu.be/JskRH-fnZxY
What are you referring to about dropping the clutch at higher RPM?
I plan on doing some drag racing and my Evoms tune has a 5000 rpm launch programed in it.
I am confused.
Sorry to confuse you, let me clarify: if you release the clutch too slowly at high RMPs you will burn the clutch this is easy to do with the LWFW as the engine revs so freely, in essence you're more prone to burning it if you don't drive it appropriately
If you're drag racing and you release the clutch properly you won't burn it. I often let family members drive my car and if they haven't driven it for awhile and they release the clutch like a regular or standard manual car coupled with the inexperience of an extremely sensitive throttle you can smell the takeoff...
OK I understand now, back 35 years ago driving a full race engine on the street was a chore, this is before ECU, having a .650" lift, 330 duration camshaft, two 700 cfm carberators sticking through the hood of a car.
Clutches take the most abuse.
Just really concerned about lwfw hurting crankshaft.
You sound more than qualified!
There is a lot of contention around crankshafts breaking etc. IMO and im not a mechanic, if you do it properly and follow the install recommendations which it looks like you have:
- Certified balanced flywheel
- Sprung clutch disk
- Light weight pulley
Then in theory you should be fine! If this is becoming a track car there are lots of other potential considerations around damaging an engine to take into account like lubrication and cooling (all of which have been discussed at length).
Anyway FWIW mines been in since '09!
but are you doing the IMS at the same time?
Yes, Cantech in Syracuse, NY is a full service facility for Porsche, Ferrari, Lambo, etc.
They do a lot of ims/rms , they have a complete service package that includes all new rear cam seals , all new bolts etc.
They are not cheap, but in the northeast they are one of the best.
I think the term "light weight flywheel" gets thrown around a fair bit because as far as I have read there are differences between a) Single mass flywheel and b) light weight flywheel whether or not one is more prone to damaging an engine i'm not entirely sure.
Also I think its important that you put in a new throw out bearing while you're there too (thats and the pressure plate are the only parts I take it you're not changing). I have read they can be a source of chatter with this setup. When I had mine replaced: new sprung sachs disk, throw out bearing, OEM pressure plate and IMS, the chatter was much quieter than it was before.
One other negative to the LWFW is resale, it doesn't suit the majority of the market driving wise and people may run if they hear your gearbox chattering away in neutral if they don't know what they are hearing...
Well that was all for naught, flywheel wound up being fine.
So I'm just replacing the clutch. Along with IMS, RMS, AOS, coil packs, and plugs. (Along with a few other nit picky things) Should be good as new in a couple days.
Yes I am having new pressure plate throw out bearing everything brand new Sachs.
All new bolts on everything, even considered a new clutch fork. But that I wouldn't think would be needed.
However the shop has them in stock and ready if needed.
The clutch package alone was $2k, the install with new semi solid transmission mount is almost $3k. I can't believe it cost $5k to do this, but it should be a good investment, I hope.
I think it's money well spent. Can't wait to take it out and "abuse" it now that it I know it will handle it. I love the balance of these things...they aren't fast, but you can drive them at their absolute limit
It's money terriblly spent!! You guys should get your hand dirty and do your own work. Changing a clutch is not that difficult on these cars. These shops are bending you guys over and laughing all the way to the bank because they charge more than they should. What is the going rate nowadays at these "independent Porsche" shops, $125/hr?
Have someone take a video of this from the bleachers. Would love to see how you do. Took mine but only managed to pull 3 passes before the oil pressure started to be low.
Not all of us have the space, tools, time, inclination, know-how, aptitude, to do that kind of work. And, yes, the going rate is about $125/hr which I will gladly pay for a great P-car mechanic like my indy. Maybe when I retire I will take up the wrench but right now I will pay to have my car professionally pampered.
Right I went with a single mass flywheel and not a light weight one . It's only marginally lighter .
It's less prone to failure than the dual mass but is similar weight , it's closer to the 993 flywheel than the aasco.
It's hardly noticible in daily driver mode compared to the dual mass stock fw
IMO 000,
What do you mean?
You installed a LWFW and then went to a dragstrip, made 3 passes, then you dropped oil pressure?
What happened to lose oil pressure?
NY
I have not yet, I am waiting for new clutch package and semi solid motor mounts before I take it.
Here is a quick video of a launch, you can here the wheel hop.
This is before new suspension was added.
Porsche Evoms stage IV 5K Launch - YouTube
HOPE ITS OK THAT IM REVIVING THIS THREAD... I'm interested to see if any of you guys have had any problems now that the lwfw's have been in your cars for a bit.. I have nearly the same setup as NYOUTFITTER. (We've met at Cantech). I have the 3.4L with Fabspeed intake, RSS underdrive pulley, RSS motor mounts, Function First tranny inserts, Fabspeed Maxflow mufflers, and a high flow catted x-pipe. I want to do the AASCO lwfw and a sprung hubbed clutch. ANY BROKEN CRANKS? ANY FAILURES?
Beautiful Day today in Upstate New York
Good to hear from you.
My car just clicked over to 78,000 miles.
That's 25,000+ miles on the Aasco LWFW and Sachs Stage II sprung clutch disc and pressure plate.
I do Blackstone Oil Analysis every oil change to monitor engine, all good.
The engine accelerates and cruises great. Great MPG.
No issues.
EXCEPT
I installed a Numeric shifter and numeric cables. These cables make some pretty good noise when used with a LWFW.
Last summer I had Cantech install the rubber hoses that can be purchased from Numeric.
It reduced the noise by 50%.
It didn't bother me much, but wife complains "What's that noise?"
I talked with Rocco and the tech that services my car from Cantech, it is basically the same set up (Shifter/cables & LWFW) as one of the 996 GT3 cars they have. Same noise from cables.
It depends on what is your priorities are.
I am considering switching back to the stock dual mass flywheel.
I may be interested in yours if you decide to part with it, I have a new Sachs clutch ready to go in my car. I would do a trade if you wanted, Mine is a 99 C2 with a short shifter and stock cables...
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I drove mine pretty hard and had zero problems with it and my crankshaft is still intact. Just my 2cents. I'm sure Jake sees more failures then I will for sure but of those I know by me who have the same set up.. no one has snapped a crank or complains. I loved mine 100% best mod ever!!
I didn't have a lighweight flywheel. The oil pressure drop was from a failed radiator fan and two back to back hot laps on a hot and humid night. I think the oil got thin and the main bearings almost spun. The crankshaft luckily stayed in one piece and in good condition. Just needed a little polishing to remove the stuck on copper from the cooked bearings.
OEM is all I will use.
The knock sensors work overtime with these single mass flywheels. When creating tunes, and doing back to back dyno runs this is very clear. I have seen them pull 15 degrees of ignition timing, which is a direct loss of power.
Also, every single one I have pulled out of a box brand new is way out of balance. They don't correct the dynamic balance for the 60-2 toothed reluctor wheel affixed to the back side of the flywheel. 8-10 grams is the norm, and no, I still refuse to use one of these after correcting the balance.
Its one of the worst things you can bolt onto one of these engines. Those who say they have ran them with no problems, either don't know how to identify a problem, or they are just trying to justify their decision to make themselves feel better. If you have the tools, the experience, and other engines to compare them to, you will see the negatives very clearly.
I have an R43 on the dyno now, it made 460HP on 91 octane yesterday, and even that engine still uses a stock dual mass flywheel.
The ONLY genuine Porsche parts we use are coolant tanks. The Luk flywheel is fine, and I�ve never noted a significant difference between any of them.
I balance all of the units in house, and check deflection of all of them before use. Assume nothing. Quantify everything.
All engines produce harmonics that cannot be balanced out or canceled out. Four cylinder in-line engines are the worst, I have had plenty of experience with them. My Race Engine 4 banger would produce a harmonic at 12k that would snap the flywheel bolts off like glass. I tried 1/2 inch fine thread grade 12 bolts, with 1/2 dial pins in-between each bolt, Loctite, safety wire, every trick in the book to no avail. Even one of the high dollar Fluidampers and the crank, that just exploded as well. I finally just gave up (ran out of money), and limited the RPMS to 11.5 K.
The M96 crank is made from a relatively soft iron/steel to absorb some of the twist/harmonics, then they use a thin hard nitride on the bearing surfaces for wear resistance.,This helps the crank from being as brittle as a crank that is made from a fully hardened material that would be stronger but also more brittle and sensitive to harmonics.
So every engine has harmonics that have to be dealt with, and changing things like the flywheel weight/material, or engine mounts, or muffler weight/material ect will change the harmonics. Since every engine produces harmonics , some harmonics are not damaging, and some parts are not sensitive to harmonics.
It's like playing music around a some crystal wine glasses hoping to never hit the note that can make the glass explode !!!
Interesting read. I came across this thread purely by accident but have pondered the decision on a LWFW many times before. I currently run the factory single mass flywheel setup as fitted to the GT3RS and clubsport spec GT3�s. I could not be happier. The car still drives well in traffic, heel and toe works great and the added gearbox chatter sound cool in my opinion.
I would personally never opt for an after market setup and definitely not one made out of aluminium. The factory setup is more than enough for fast road use and weekend racers.
Another example of harmonics,, the good old ford 302,, if you run it at 4700 rpm's
for an extended period of time, you can split the block internally from the #3 main (IIRC)
bearing to the cam bearing.. Drivers that know push past 5K as fast as possible or soft shift
at 4500.. Its a firing order thing.
They are the BBS CH-R in Gun Metal, The lip is a polished trim ring that can be replaced if you curb the wheel. I haven't tried it but its good piece of mind.
I love them, much lighter and wider. I had to roll both front and rear fenders to make fit.
This happened to me on my 5.0 Mustang. Always thought it was due to the extra stress of the supercharger. It was one hell of a boom when it let go. I learn something new every day.
