LWFW

[normank]

I am thinking about putting a LWFW in my 997 GT3. Would appreciate comments and/or experience of anyone who has done it. Interested in noticeable differences, benefits and any dislikes. An idea of the cost of the project would be helpful.

[drpeter]

I am thinking about putting a LWFW in my 997 GT3. Would appreciate comments and/or experience of anyone who has done it. Interested in noticeable differences, benefits and any dislikes. An idea of the cost of the project would be helpful.

What's a LWFW?

[Loren]

Light Weight FlyWheel

[Edge]

I am not sure how much lighter you intend to go with the flywheel but you could experience problems with engine idle. When you reduce the weight of the flywheel engine idle becomes erratic and its difficult to maintain a smoth tickover ( bad in traffic for example ) , but if constantly blipping the throttle is your thing then thats fine but it would be more suited to a car that spends most of its time on the track.

[clord]

Another result can be more noise/rattling from the gear box at idle. This is the result of less damping of the individual cylinder firing pulses reaching the gearbox.

[maximus136]

why would you want to do that??....I think the gains by doing something like that does not make it worthwhile.........and it would just kill your resale value........

[john.jay@hotmail.com]

why would you want to do that??....I think the gains by doing something like that does not make it worthwhile.........and it would just kill your resale value........

I have a LWSMFW stock in my RS. I assume you would install the OEM item. Is so you will have the usual clatter in idle...no big thing AND you won't have any problem with stalling at lights. You will find it revs more freely almost as if you were running carbs. That said as far as installation, do it through Porsche. :)

[EmilGH]

I have a LWSMFW stock in my RS. I assume you would install the OEM item. Is so you will have the usual clatter in idle...no big thing AND you won't have any problem with stalling at lights. You will find it revs more freely almost as if you were running carbs. That said as far as installation, do it through Porsche. :)

I've got the OEM part in my 997 GT3. It certainly does rev more freely... Was it worth the $$ on the upgrade? Jury's still out. I'm not convinced. Yet.

[TRAKCAR]

Eventually we all need an new RMS (Mine at 1250 miles, now 7800 miles, so far so good.), so when the engine is out and the transmission is off the engine you might as well get it done.

[omahaGT]

The LWFW is awesome! I love it, and don't plan on taking it out. The only problem is this Porsche statement...

Since the 911 GT3 (997) engine application is designed for the dual-mass flywheel, conversion to the

single-mass flywheel results in the following problems and consequences:

• The single-mass flywheel causes fluctuations and vibration in the lower rpm range, thereby reducing

the smooth-running performance of the engine.

• The crankshaft is subjected to one-sided loading, causing stress peaks that can result in damage to

the crankshaft.

• The one-sided loading of the crankshaft can cause the pulley to come loose, resulting in damage to

the belt drive and engine.

• Any damage relating to conversion or damage that can be attributed to conversion is not covered

under warranty.

Reply With Quote

[RonCT]

Here's the expanded version of the PCNA bulletin. I wouldn't do it...

October 15, 2008.

Technical Information

Service

36/08 ENU 1360 1

GT3 Engine: Flywheel and Pulley

Vehicle Type: 911 GT3 (997)

Model Year: As of 2007

Concerns: Flywheel and pulley

Information: Replacing dual-mass flywheel with single-mass flywheel.

We have discovered that the dual-mass flywheel, which is installed as standard in the GT3 engine (vehicle type 997810/-811), is being replaced in the dealer organization with the single-mass flywheel from the GT3 RS engine (vehicle type 997850/-851).

Information

Due to an increasing number of reported faults, we expressly wish to point out that the installation of the single-mass flywheel (from the GT3 RS) in the GT3 engine is not approved by Porsche.

Since the 911 GT3 (997) engine application is designed for the dual-mass flywheel, conversion to the single-mass flywheel results in the following problems and consequences:

• The single-mass flywheel causes fluctuations and vibration in the lower rpm range, thereby reducing the smooth-running performance of the engine.

• The crankshaft is subjected to one-sided loading, causing stress peaks that can result in damage to the crankshaft.

• The one-sided loading of the crankshaft can cause the pulley to come loose, resulting in damage to the belt drive and engine.

• Any damage relating to conversion or damage that can be attributed to conversion is not covered under warranty.

Please advise your customers of this information accordingly.

©Porsche Cars North America, Inc.

October 15, 2008

Edited November 7, 2008 by RonCT

[1schoir]

I am thinking about putting a LWFW in my 997 GT3. Would appreciate comments and/or experience of anyone who has done it. Interested in noticeable differences, benefits and any dislikes. An idea of the cost of the project would be helpful.

Norman:

Do a search in the archives here. IIRC, there is a definite problem with longevity of the engine if the LWFW is not balanced with the particular crankshaft to which it will be assembled.

Regards, Maurice.

[blue72s]

Here's the expanded version of the PCNA bulletin. I wouldn't do it...

October 15, 2008.

Technical Information

Service

36/08 ENU 1360 1

GT3 Engine: Flywheel and Pulley

Vehicle Type: 911 GT3 (997)

Model Year: As of 2007

Concerns: Flywheel and pulley

Information: Replacing dual-mass flywheel with single-mass flywheel.

We have discovered that the dual-mass flywheel, which is installed as standard in the GT3 engine (vehicle type 997810/-811), is being replaced in the dealer organization with the single-mass flywheel from the GT3 RS engine (vehicle type 997850/-851).

Information

Due to an increasing number of reported faults, we expressly wish to point out that the installation of the single-mass flywheel (from the GT3 RS) in the GT3 engine is not approved by Porsche.

Since the 911 GT3 (997) engine application is designed for the dual-mass flywheel, conversion to the single-mass flywheel results in the following problems and consequences:

• The single-mass flywheel causes fluctuations and vibration in the lower rpm range, thereby reducing the smooth-running performance of the engine.

• The crankshaft is subjected to one-sided loading, causing stress peaks that can result in damage to the crankshaft.

• The one-sided loading of the crankshaft can cause the pulley to come loose, resulting in damage to the belt drive and engine.

• Any damage relating to conversion or damage that can be attributed to conversion is not covered under warranty.

Please advise your customers of this information accordingly.

©Porsche Cars North America, Inc.

October 15, 2008

Why is it okay for an RS engine to have a single mass flywheel, and not standard GT3 engine? I thought these 2 engines were one and the same?

[blue72s]

1. Does 997.1 RS crankshaft have the same part number as the non-RS 997.1 GT3?

2. What's funny is that the Technical Info Service above states 'As of 2007'. Does this mean only applies to 997, not 996?

[Loren]

As I recall the GT3RS engines are built at Porsche Motorsports - which means the tolerances are tighter and the moving parts are balanced to a tighter standard.

My guess is that "stock GT3" does not get that extra balancing that could result in engine damage with a LWFW.

[blue72s]

As I recall the GT3RS engines are built at Porsche Motorsports

Thanks for the response but AFAIK only 996 GT3 mk1 (never delivered to US) were built at Porsche motorsports. Models later than that weren't built there.

Anyway, I've just been reading the article about 2010 GT3 in the latest Excellence mag today. It says the crankshaft is now shot-peened for extra strength.

So, maybe that's what it is. Could anybody verify whether RS cranks were shot-peened? I really need the part number of RS crank.

[snowboarder54]

I have an 07 GT3 with nearly 36K miles on it. I have had a sharkwerks by-pass installed on the car since about 12,000 miles and an OEM RS LWF since about 16,000 miles. These are the best mods I have ever had on any Porsche I have owned, period!! I can't imagian not having this combo on my GT3. I owned my first Porsche in 1962 and this Gen-1 GT3 is by far the best one so far. The only thing that could make it better is Sharkwerks 3.9 conversion, which will be installed on my car later this month!!! :D

[tekky]

woohoo! can you update you registry plz?

I have an 07 GT3 with nearly 36K miles on it. I have had a sharkwerks by-pass installed on the car since about 12,000 miles and an OEM RS LWF since about 16,000 miles. These are the best mods I have ever had on any Porsche I have owned, period!! I can't imagian not having this combo on my GT3. I owned my first Porsche in 1962 and this Gen-1 GT3 is by far the best one so far. The only thing that could make it better is Sharkwerks 3.9 conversion, which will be installed on my car later this month!!! :D

[snowboarder54]

I now have 65,000 miles on my car, 53,000 with LWF and 28,000 miles on my Sharkwerks 3.9 conversion. Absolutely zero problems! I love the 3.9.

[phillipj]

I have an 07 GT3 with nearly 36K miles on it. I have had a sharkwerks by-pass installed on the car since about 12,000 miles and an OEM RS LWF since about 16,000 miles. These are the best mods I have ever had on any Porsche I have owned, period!! I can't imagian not having this combo on my GT3. I owned my first Porsche in 1962 and this Gen-1 GT3 is by far the best one so far. The only thing that could make it better is Sharkwerks 3.9 conversion, which will be installed on my car later this month!!!

Woo Hoo! Kermits brother!!!!!

[harmonyjim]

I have a 2007 RS, and the LWFW does rattle a bit, and it doesn't pull away from a dead stop quite as easily as the heavier unit on non-RS cars. The idle is a little rough, but not horribly so. Snowboarder, I hope to someday emulate you with a 3.9 conversion of my own. I have read of your experiences, and it seems to be a great - if very expensive - mod.

[danadaen]

Here's the expanded version of the PCNA bulletin. I wouldn't do it...October 15, 2008.Technical InformationService36/08 ENU 1360 1GT3 Engine: Flywheel and PulleyVehicle Type: 911 GT3 (997)Model Year: As of 2007Concerns: Flywheel and pulleyInformation: Replacing dual-mass flywheel with single-mass flywheel.We have discovered that the dual-mass flywheel, which is installed as standard in the GT3 engine (vehicle type 997810/-811), is being replaced in the dealer organization with the single-mass flywheel from the GT3 RS engine (vehicle type 997850/-851).InformationDue to an increasing number of reported faults, we expressly wish to point out that the installation of the single-mass flywheel (from the GT3 RS) in the GT3 engine is not approved by Porsche.Since the 911 GT3 (997) engine application is designed for the dual-mass flywheel, conversion to the single-mass flywheel results in the following problems and consequences:• The single-mass flywheel causes fluctuations and vibration in the lower rpm range, thereby reducing the smooth-running performance of the engine.• The crankshaft is subjected to one-sided loading, causing stress peaks that can result in damage to the crankshaft.• The one-sided loading of the crankshaft can cause the pulley to come loose, resulting in damage to the belt drive and engine.• Any damage relating to conversion or damage that can be attributed to conversion is not covered under warranty.Please advise your customers of this information accordingly.©Porsche Cars North America, Inc.October 15, 2008

sh*t!

I would keep away from this modification.

Dane

[danadaen]

I now have 65,000 miles on my car, 53,000 with LWF and 28,000 miles on my Sharkwerks 3.9 conversion. Absolutely zero problems! I love the 3.9.

Drool....the 3.9 Modification.... :cheers: