banzaisan

I have a 93 911 with 58K miles and my clutch is starting to slip. I’ve called my local shop and they quoted me $2600 to replace the clutch and install the LWF. Is this fair price?

I understand that the car will perform differently with the LWF. Can someone tell me the benefits?

Is there anything else I should do while the engine is out? I just had a valve adjustment and plugs replaced less than 5000 miles ago.

Thanks in advance.

Adrian

Dear Dave,
I suggest to look in the archives for comments on fitting LWFs. I can see no reason to go to this expense until you are going racing. LWFs and stalling problems go hand in hand. You only replace the flywheel if you have a problem. You should have a LUK DMF and if it ain´t broke why replace it.
Just replace the clutch make sure the clutch fork is the correct new version, check the clutch fork bushes, check the the thrust bearing and have the clutch hydraulic system bled after the whole thing is put back together.
Oh by the way just in case you were going to ask. The DMF equipped 964s already have the lightest sport clutch plate so do not be sold a sports clutch plate. The standard clutch plate is the best you can use apart from the RS Touring version where the clutch plate lining material is bonded instead of rivetted. Yes they have the same part number.
Ciao,
Adrian
964C4

Christer

I have pointed this out before, but my mechanics here in the UK are not aware of any stalling issues at all on LWF installations, providing the installation is done 'properly'. And they have done quite a few. I think at some stage I am going to need to get more details from them on what they look at and do to avoid stalling problems and post them here. When I asked them in a hurry the other day, the reply was that 'well, if you just install a LWF on a tired engine with a CAT installed and without checking the electronics then anything is possible'.

The LWF is a very worthwhile (if not THE) modification to do providing your specialist does not make the car a pain the backside by not sorting out any stalling issues.

Cupcar

Hi Christer-

Was air conditioning an option in England on the 964? Does your car have air conditioning and a LWF conversion with no problems with the air conditioning on?

Here in the USA, essentially 100% of 964's have air conditioning that is run most of the time when driving. There is a tendency for these cars to stall when the air conditioning cycles on an off once equipped with the LWF unless some extra mass is bolted to the perimeter as the tuner Andial does.

I'm sure many would be interested in how a LWF is installed on an air conditioned car without problems. What are the secrets of the UK masters?

Adrian

Dear Cupcar,
Many 964s in the UK and Germany were not fitted with aircon. However the 964 RS is also known to be a bit of a staller if the rpm is not kept up. Aircon was not available on the RS basic and NGT. I think you will find that Christers 964 is somewhat modified including using an altitude compensation capsule instead of an O2 sensor. Way from standard and impossible to compare with a standard emissions compliant 964 and associated LWF problems. Even the RS has a kat installed. Christers does not.
Ciao,
Adrian
964C4

Cupcar

My American Cup basically is a Euro RS and I have driven it for over 10 years and thousands of miles. I do not consider there is a stalling issue of concern at all and would not change my quicker reving LWF for the dual mass flywheel.

I have always figured that any stalling was due to the taller first gear of the RS along with the LWF. It seems though that the heavier normal cars with A/C have more problems despite the lower first gear whan a LWF is installed.

My question is, do Normal C2's without A/C and fitted with a LWF stall any more than a Euro RS does?

Adrian

Dear Cupcar,
I very much doubt you will ever get a valid answer to your question. I have never come across a C2 owner or C4 owner for that matter who just replaced a DMF with a LWF and di nothing more. What LWF? You would have to know exactly the weight of LWF. Andial fit a 19 lb LWF to overcome this problem. There are just too many variables to get a correct answer.
Then of course you have to know the geabox ratios used. Gearbox model G50/03/04/05/10 etc.
This gets very frustration and sometimes you have to up the medication but in 2003 so many years after the product was built very few 964s even remain standard. The only way to do this would be to purchase C2s set them up back to standard and start experimenting. A very expensive solution though.
Ciao,
Adrian
964C4

PS: The other issue is honesty. A lot of people do not like to admit they have problems or had problems. Another almost impossible hurdle to overcome.

Randall G.

I have written this before many time in the past, but will go ahead and write it again. Used to have the RS LWF in my car, installed to replace the failed Freudenberg. No other modifications. Car started stalling once the LWF was installed. Not just when running the A/C, but (for example) when pulling into the driveway of the local Italian restaurant--where lots of people got to ogle at the guy in the Porsche that doesn't know how to operate a clutch. Or, would stall when trying to maneuver in a parking lot.

Running the A/C didn't make the car more likely to stall. What it did was to cause the idle to fluctuate wildly, from around 600-1300 rpm. So, you would be sitting at a stop-light, and the cute girl in the car next to you would be wondering what the hell the guy in the Porsche was up to. It was actually embarrassing.

I finally ditched the LWF for a LUK. I've been much happier since. Loved the way the LWF revved, but absolutely could not tolerate the stalling and erratic idle. In my mind, a street car should never stall, unless it's not running right (which means it needs to get fixed).

Now, when I had my problems back in 94/95, I wasn't aware of, or told of, any of the software or ISV fixes (they may not have existed then). These fixes may or may not work, I dunno'. Most the guys on the 993 board are having good luck with the ISV fix. '95 993s are just as susceptible to stalling as 964s when running a LWF. The '96 and later 993s handle the LWF without a problem.

If I was to put a lightened flywheel in a 964 again, I would go with Andial's semi-LWF. They say it won't stall, and I believe them. Split the difference between fully lightweight and dual mass flywheel, while getting rid of the possibly-may-fail DMF (the LUK has proven to be pretty good).

Dave...the price you were quoted for the clutch and flywheel replacement is not bad, in the ball-park for a reasonable charge.

Cupcar

Thanks for the replies, I just want to figure out what all the fuss over LWF's is about and why.

Driving my USA Cup, a car factory equipped with a LWF, NO A/C, and G50/10 gearbox (now has a G50/32 6 speed which has same first gear as a G50/10), is a little touchier to drive off than most cars but nothing to fret about and I don't really think about it except starting on hills. Perhaps I have driven the car so long it's a part of me.

I think the big difference is this discussion is the weight of the cars and the reason for stalling problems with the LWF.

My car and the Euro RS weigh less than 2700 pounds so it is easier overcome inertia and drive off despite having a taller 3.154 first gear than a normal C2's 3.5:1 with a slightly taller overall ratio (ratio X R&P ratio) of 10.85:1 vs the 11.67:1 of a normal C2 (my car has a 3.44 R&P, normal C2 is 3.33 for later cars). It's interesting the 993 owners still have a problem with their 3.818:1 first gears.

I thought the car stalled with A/C, but as Randall points out the engine just hunts at idle so badly it drives you nuts, a good reason for a Dual Mass Flywheel.

I think the moral to this story is, if you have a car that is lighter and has no A/C you can get away with the LWF. If you have a car that is heavier, perhaps particularly a C4, you will go nuts with a LWF.

A friend has a 993 with the Andial modified LWF and has no problems BTW and really likes it, so Randall has a good point here as an alternative to a factory LWF.

Adrian

Dear Cupcar,
You also have a specially programmed DME and a different timing ring on the LWF.
Ciao,
Adrian
964C4

Randall G.

Cupcar...nice choice for a second car. I've been eyeballing the G35 Coupe. I prefer the 350Z's exterior (both style and dimensions), but prefer the G35's interior, emergency backseat, and sunroof availability (I gotta' have at least a sunroof). Maybe I'll pull the trigger once the car isn't so hot, and dealers come off of MSRP.

Speaking of the G35C, I've been following their "Fresh Alloy" board, and there have been a few reports of failed DMFs. Perhaps you've seen the same on the 350Z board? A little disturbing.

Cupcar

Adrian- Do you know what the programming differences in the RS DME are and what is difference in the ring gear, number of teeth or something?

Randall- You have email about the Z.

Adrian

Dear Cupcar,
I do not know all the internal technical details but the rpm maps were replaced with LWF versions and for the motronic timing ring, the gap or pitch between the teeth was slightly altered to allow more accurate detection of flywheel speed. I do know the changes are quite extensive in the software department and the pre-programmed maps. This is where normal 964s run into trouble with the maps not lining up. Close enough is not always good enough if you know what I mean. Of course the standard RS LWF messes up the standard DME as well.
Ciao,
Adrian
964C4

Kahdmus

I am also looking to have similiar work performed. Does anyone have any input as to expected cost, includin labor, to replace both clutch and flywheel?

Adrian

Why would you want to replace the single mass flywheel of the 89 C4. With the clutch, you replace the rubber centred cersion with a spring centre version but I cannot see the point in creating problems in replacing the 19 lb SMF with a 12 lb LWF. There are other considerations as well with the 89 C4. You will have to replace the DME and you will end up with stalling problems and running problems peculiar with the 89 C4.
I can assure you that you will see no benefit from the LWF on a C4. The driveline (power transfer front and rear) is too long and regulated.
Ciao,
Adrian
964C4