LWFW Advice Needed...My Clutch is Toast

When I bought my car over a year ago to rebuild, I knew from riding in it with Chuck Jones (previous owner), that the clutch was weak. I have been driving it since the beginning of the year, like it was meant to be driven, without any problems. Today, the clutch started slipping severely. Now I finally can buy the light weight flywheel that I have always wanted. I have searched the posts here and on 6-speed on the LWFW. I would appreciate any opinions on what parts to buy and how much they will cost. I read that GMG had a clutch that resolved the noise issue...I emailed them and never heard back. Can anybody with personal experience tell me how bad the noise issue really is? Will I be able to live with the LWFW on a car that, if I'm lucky, will see the track a half dozen times a year? I just had a roll bar installed last week, and this was the only issue waiting to be resolved, before I can track the car. Thanks for any advice.

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I'm going to try to dig up the research I did on this. Based on my research, I concluded that the LWFW was not a good idea (for me anyway). It's fuzzy now, but I recall that there was not enough mass to compensate for harmonics/vibration, which could cause certain parts to fail catastrophically. Although there were some with positive feedback, the technical info I found did not support a LWFW on an otherwise stock 996. There were also issues with standing starts and (as you mentioned) noise. The biggest upside I found was rev matching. There was very little technical information substantiating performance gains across the torque band, although many butt-dynos swore the LWFW helped acceleration. I don't doubt it helps the accelaration, but the extent of the improvement was not clear to me. Others have had success with theirs, but I'm not into tempting fate. I ended up simply replacing the clutch with OEM parts. -td

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Here's one . A bit newer than my research, but illustrates the issue. Might not be related, then again, it might be. Not trying to scare you, just passing along my 996 hypochondria to you, lol. -td

I did it... If you track your car you, will appreciate this modification... The acceleration is quicker... how much I cannot say... Lighter rotating mass=quicker acceleration IMHO.... So far I have 5,000 miles on my LWFW... no issues so far (knocking on wood) I can't remembbr the brand (AASCO)? but I also went with a sport clutch at the same time (stiffer than OEM) and had a modified transmission installed too. With these combined I can say that the noise is similar to a cement truck under the car... similar to marbles rolling around in a coffee can... You get used to it.. If you track this car and do not take the wife for long trips in it.. you'll be fine...... Also, the revs drop very quickly, which took some getting used to...... Great at the track, cumbersome on the street I don't regret doing this mod by a long shot... PM me if you want more details.....

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Yikes.

My understanding is that you will like the LWFW for track use(ie. quicker acceleration), but you will pay a price in the form of 'noise' that would bother me while driving on the street, but might not bother you.Let us know what you find. Will you replace the clutch yourself Mark?

TD, that post contained some great information. It sounds like I might want to contact Jake regarding the LWFW before I jump. I wonder if he has a harmonic balancer available yet to offset the LWFW. I thought that the LWFW would be a benefit for engine and RMS longevity because it is reducing the rotating mass. It sounds like I thought wrong. SMR, thanks for your input as well. My wife rides in the Porsche frequently and drives it occasionally. I don't want to make it so she won't drive it (she is actually a good driver, so I don't mind). The cement truck sound does not sound like much fun on a street car. I should probably listen to a 996 with the LWFW before I make a decision. Any additional opinions are greatly appreciated.

Steve, I had spine surgery number 6 a month ago...so I will probably pay an independant shop the 6 hours of labor to do it for me. The noise would probably bother me also, if it is as bad as SMR described. I'll keep you posted on what I find.

If it was me, I would stick with the OEM clutch. I see no meaninful advantages with an aftermarket clutch, just potential headaches. Just my opinion.

Mark, I've my LWFW now in since >1 year and like it. However, you're right that there's a noise issue. It's actually when idling but then only/especially when the clutch is out and the AC is on. The other noise issue is when you drive around with +/-3k RMP. Whenever you accelerate with low RPM, there's this rattle. I got used to it and for me the benefits outweight the noise issue. The main benefit is clearly that heel and toe/rev matching is so much easier (and much more necessary). I rev match every shift on the street and track. I did replace my clutch with a stock clutch and don't have any issues in this area (to date).

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The LWF/RS clutch kit is Porsche OEM and one of the best mods you can do for your car. The single mass flywheel will enable your engine to spin so much more freely the car will feel different alltogether. Yes, there is some chatter but I have yet to meet anyone who regretted this mod. As others have noted, go for a drive with someone who already has it then decide.

Mark, When you get the clutch replaced, just send the bill to Chuck. Not only did he burn up his car, he also burned up the clutch, but he didn't tell you about the clutch! I can hear Chuck's response already "Tim, you're a dick head!"

Just had my flywheel replaced. Had to make the same choice. The Porsche LWFW was actually cheaper by $40. Not a lot , considering, but $40 is $40. My advantage is that there was a car being picked while I was there and had the LWFW. Made a lot of noise in the service bay, in the parking lot, in the driveway. Too much noise for me. Went with the stock OEM. Wish I had thought to record it at that time.

OEM clutch. I was pondering this option and decided against it due to the fact that I live in the hills and to get to a main road, I have to traverse a pretty steep uphill which I'd have a more difficult time w/ the LFFW and sport clutch. OEM was a better idea. My track/street mileage is not absurdly skewed to the track so it made more sense w/ the OEM. here is a breakdown of what I got quoted (i have no idea on the accuracy of the costs).... OEM: 996 Carrera 4 Clutch estimate Labor; Remove and install engine and gearbox, replace complete clutch including flywheel/rear crankshaft seal, pilot bearing, operating fork and bushing, throw out bearing guide, clean complete gearbox bell housing and engine flywheel areas. $1375.00 Parts; Factory clutch kit $725.00 Flywheel bolts $20.00 Pressure plate bolts $20.00 Guide tube $50.00 Release lever $40.00 Release lever spring clip $2.00 Release lever bushing $3.50 Pilot bearing $40.00 Flywheel seal $20.00 Labor $1375.00 Parts $920.50 Tax $75.00 Other $100.00 Total $2470.50 Estimate $2650.00 Flywheel and fasteners $1100.00 Intermediate shaft flange reseal $400.00 (Includes labor) 996 Carrera 4 Clutch with light weight flywheel estimate Labor; Remove and install engine and gearbox, replace complete clutch including light weight flywheel, flywheel/rear crankshaft seal, pilot bearing, operating fork and bushing, throw out bearing guide, clean complete gearbox bell housing and engine flywheel areas. $1500.00 Parts; Sachs performance kit with lightweight flywheel $2595.00 Fasteners $50.00 Labor $1500.00 Parts $2645.00 Tax $220.00 Other $100.00 Total $4465.00 Estimate $4575.00 Intermediate shaft flange reseal $400.00 (includes labor)

Riad and EJ, thanks for the input. Hwk and Palting, I really appreciate both of your honest opinions, since you went through the same decision process. I went overboard on my previous track toy and made it so I no longer enjoyed driving it on the street. I recognize that 95% of my driving will be on the street with the wife or kids in the car. Flat -6, what are the pros and cons of the Porsche Motorsport LWFW versus the Aasco LWFW? Thanks for your advice. Tim, I may have helped Chuck with the clutch. When I had my tiptronic car, we took both cars out and played with the G-tech performance meter. Standing starts are harder on a 6-speed than a tiptronic car, judging by the smell of burning clutch every time Chuck took off. You are probably right about what he wopuld say. Are there any benefits to be gained by going with a heavy duty or sport clutch and pressure plate over the stock unit? I have already deleted the clutch helper spring and prefer the feel of it to stock. The first estimate I received from an independant is $2,904.75 for the Aasco LWFW, sport pressure plate, sport clutch plate, release bearing, pilot bearing, bolts, and installation (5.75 hours or $718.75). I am waiting for another estimate. Are there any other parts that I need to replace like the Clutch fork? Should I touch the RMS since the car has about 36,000 miles and no leaks? Thanks again for the help guys.

Jyoteen, WOW...thank you very much for taking the time to give me a detailed price list. That really helps a lot. I guess the quote I got for $2,904 on the LWFW installation was pretty good. You also gave me something else to check into. Do you worry about the intermediate shaft if it isn't leaking?

Some owners have used the spring hub to reduce noise and a little harshness also solid motor or trans mounts can have a significant effect on NVH for street use. As a side note there has not been an issue with balance and or premature wear of any engine or driveline components where a front balancer would be required, there are probably 750 Aasco units on the road. That being said it probably is not for everybody . I think the replacement of the dual mass units on the GT3's by some of the dealers and perhaps the change in rotating mass and the resultant adapation needed by a driver used to the old MOI has stirred the nest a bit. regards

Get the AASCO LWFW and have "Spec Clutch" make you a upgraded but spring loaded clutch which will eliminate the vibration/noise. No snake oil.

Clutch Masters (Luis Gomez) is another good source for a clutch Disc

Racing 97 and Paul, thanks for the information guys. I had read that the correct clutch would significantly reduce or eliminate the noise issue. I don't mind having to replace a part on my car if I can upgrade to something that makes it perform or look better.

Mark, IIRC.... TRG makes an awesome clutch/LWFW combo... pricey in the $4k range. Race proven and no chatter as well... GL with your decision. When is the aerokit gonna get mounted???

http://www.ultrarev.com/product.php?productid=27606 http://www.vividracing.com/catalog/aasco-m-445.html I have this combo and I have no regrets

Just to add to the experience list. I have an Aasco lwfw with the factory clutch. Engine revs a lot faster than stock and also rpms will drop very fast. At first I would stall a lot due to the rpm dropping so fast but I have gotten used to it. Chatter is definetly there and is noticable when AC is on while at idle. If you press down the clutch, the chatter goes away. The noise does not bother me much because I can only hear it if I am parked next to a wall or in a parking structure. In normal street driving, I can hardly hear it at all. no regrets here.

Just to add to the experience list. I have an Aasco lwfw with the factory clutch. Engine revs a lot faster than stock and also rpms will drop very fast. At first I would stall a lot due to the rpm dropping so fast but I have gotten used to it. Chatter is definetly there and is noticable when AC is on while at idle. If you press down the clutch, the chatter goes away. The noise does not bother me much because I can only hear it if I am parked next to a wall or in a parking structure. In normal street driving, I can hardly hear it at all. no regrets here.

If you don't use a sprung disc, you may be putting your shafts at increased risks of failure.

Who here has put in a LWFW and a sprung-hub clutch like those form Spec or Clutch Masters? I think there could be a significant difference between the two scenarios. I drove a Cayman S with a LWFW and the stock (unsprung) clutch, and there are two distinct noises: 1) At idle, in neutral with clutch out, there is a very light chatter which is barely audible and would not bother me nor worry me too much. 2) At around 2500-3000 under moderate or higher load, there is a pronounced (MUCH louder) noise that sounds harmonic-induced. It seems almost as if there are enough tolerances (lash?) in the gears to absorb some vibration, but when that is used up, you get what was referred to as "sizzle". The noise is almost like an on/off switch and only happens in that RPM range and under load. I am much more concerned about this latter noise and its long-term effects on the engine/transmission. Of course, people then "avoid" that range, but I'm hoping a sprung-hub clutch is the better solution. It would be interesting if the failures referenced are with our without a sprung-hub clutch. I have always heard that you should go with a sprung-hub clutch if you are eliminating the dual-mass flywheel and am surprised to see a lot of folks using the stock clutch.

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The "sizzle" you refer to is correct... and a very good description of the sound the LWFW makes when under load or no load at higher RPM's (4k to 6k). I notice this sound while driving much more than the rattle/chatter at idle when the clutch is out.... 5,000 miles on this set up and no driveline issues yet... (knocking on wood again) Again, this mod is probably not for everyone but if the car is tracked frequently and excellent upgrade... Cheers

Redridge, I'm sure TRG's setup is great, but that's a little steep for me...it's over double the AAsco/Spec combination that I'm leaning toward. What are you using with the SC? I took your advice and I'm enjoying the car as-is for a while. This will definately put a serious dent in the mod budget. It is going to cost me $2,000 to have the aero kit painted. I'm also going to have the hood and fenders (tops) repainted to get rid of any rock chips. 9nine6, that sounds like the right combo for me also. How is the noise with that clutch? vwrado, thanks for the information. 99porsche911, I plan on using a spring type clutch, thanks. Are you using a LWFW with the SC? Arenared, The spring hub clutch sounds like the way to go. Thanks. SMR996, I appreciate benefiting from your experience. I am yet to hear from anyone who has the LWFW and does not recommend it. Thanks again for the help guys.