Mfletch

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.

himself

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

himself

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

SMR996

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.....

Riad

Yikes.

Barn996

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?

Mfletch

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.

Mfletch

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.

ejdoherty911

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.

hwk72

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).

Analog Theory

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.

gota911

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!"

Palting

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.

jyoteen

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)

Mfletch

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.