Flat6 Innovations

Watch your engine roughness values, and ignition timing angle before and after the LWFW is added. You'll see just how much the engine "likes" the modification.

There's a good reason why I remove these and refuse to reinstall them on my engines if someone already has one.. That's the same reason why I won't ever offer one as an option for one of my engines, under any circumstance.

Kevin997

Thanks for chiming in Jake, I thought maybe there were some other reasons since I knew you weren't a fan of them.

Thoughts on the harmonic balancer side of the conversation? Tried any aftermarket ones or is the 3.8 damper good enough?

Edit: Also do you believe that the problems are due to the light weight or the deletion of the dual mass mechanism? Makes me wonder if a mid weight steel flywheel would have the same problems as the lightweight aluminum ones.

Flat6 Innovations

A 3.5# dampener is never going to make up for the loss of a 37 pound harmonically dampened dual mass flywheel. It won't even come close. The bigger picture is that removing the second mass then rigidly connects your crankshaft directly to the entire drivetrain, all the way to the wheels and brakes. That means that every harmonic in the drivetrain goes straight to the crankshaft, as the second dampening mass has been eliminated.

Now, pay attention to your LWFW.. You'll see that it has no balance marks anywhere on it. Then notice that it has a 60 minus 2 toothed reluctor wheel fitted among its outer radius. Those two "missing teeth" create an imbalance that was never corrected for. The issue here is you are losing a huge amount of dampening, PLUS you are fitting a component that is compromising the dynamic balance.

I have had state of the art balancing equipment in my facility for the last 20 years, and I have seen what this does to parts straight out of the box. No, balancing the LWFW doesn't help the big picture, that's why I don't offer to do it. That's the same reason why I don't use the harmonic dampeners, these things are band aids that should never need to be applied.

techjunkie

I think I and definitely not going to do the LWFW. I do however want to get a new flywheel and clutch kit for my 997.1 . Which flywheel and clutch kit would you recommend? I will be doing 10% track and 90% street driving.

Flat6 Innovations

100% stock parts, we don't "need" a performance clutch to hold power until after we surpass 420HP and the torque that comes along with that. Adding a more aggressive clutch at levels below this just makes the car a bitch to drive.

Kevin997

Thanks for the info Jake, confirms my thoughts on LWFW's (though maybe not for the reasons I was thinking if it's actually doing a substantial amount of damping). Hopefully this info saves some people some trouble.

techjunkie

That makes sense. I will get stock. I was thinking of getting numeric shifter and shifter cables. Is that overkill for my 997.1?

Flat6 Innovations

I hope so. It usually just leads to an argument.
I can throw a part on my balancer and show the reality in less than 3 minutes with a video, so if anyone wants to argue, just let me know!

Kevin997

While I'm not going to argue, maybe a video on LWFW's is a good idea regardless. lots of people use youtube for research and videos often come up in search results first. I suspect the concept of torsional vibration damping is not on the average enthusiast's radar so maybe a decent video would help people learn.

Saaboteur

I may have neglected to mention in my other post that I did not like the aluminum flywheel. I've enjoyed aluminum flywheels in my other cars, but I found on my 997 it was too finicky, especially in traffic or starting uphill. Reasons are obvious. The car was just more difficult to drive in regular driving. I rarely see the track. The chatter was another negative. When the shop took the trans off to do the clutch job, they told me the chattering was due to the flywheel. I'm not convinced of that, as I mentioned it was dependent on engine temperature and whether the pedal was depressed, which still leads me to believe it was the release bearing. Perhaps the engine temperature variability in the equation had something to do with the flywheel, but of course was not going to go through that whole exercise of just changing out the release bearing. I was glad to get an OE replacement dual mass back in the car. Instantly felt easier to drive. Can't say I noticed much difference in response, but as I say I don't drive it hard on track much.

There was another question about the Numeric shifter. I am a big fan. I've had the Numeric for a few years now, set in the middle setting. It changes the shift feel tremendously. My previous sportscar was an S2000, with perhaps the best ever feel. The Numeric gets the 997 close. I have not done the shift cables, for fear of added NVH. I also had the Function First trans mount - the softest orange one I believe - and I didn't like it either because of the added NVH. That said, last summer I added 964/993 RS solid engine mounts and that wasn't too bad.

Petza914

In addition to everything already discussed here, those harmonics and noise from the LWFW can also trigger the engines knock sensors putting it into protection mode, which means it pulls timing, reduced fueling, and essentially negates the higher performance you're trying to achieve with it, not to mention it shaking your engine apart from the inside. My supercharged C2S is putting down something line 475 HP on a completely stock C2S clutch setup with zero slippage or longevity problems, so on an even slightly modified NA car there is really no reason to use anything else, especially for one that will be driven 90% on the street.

techjunkie

I wish I could get the VF supercharger for my 997.1 Unfortunately living in SoCal, I don't think I can get it to pass the smog test.

Petza914

Yeah, you'd never get that through "visual". Mine is actually a RUF one.

Flat6 Innovations

Which is why I noted above that watching ignition angle and engine roughness before and after the LWFW tell the full story.

Yes, a video is necessary on this topic. I'll have to wait till I have another car come in that already has a LWFW, and hasn't failed yet. That may take a while.

Kevin997

I have a numeric with cables, its a little vibey at certain rpm, but smooth when cruising. I think all it needs is a custom grommet for the cables through the body, the stock one has holes too small so holds the cables too tight. A polyurethane plug with proper size holes might fix the vibes. I would also leave it in the middle or longer throw positions, the shortest is too notchy and i think just increases the chance of missing a shift.

Yeah I agree, my car is 4.2L n/a, makes 360whp(400+crank I'm sure). Stock clutch has zero issue holding. Not sure if longevity is affected, probably not enough to matter for me, its a wear item..