Lightweight flywheel on a 997.1 S?
#31
Former Vendor
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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.
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.
#32
Rennlist Member
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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.
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.
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.
Last edited by Kevin997; 03-04-2021 at 02:28 PM. Reason: questions
#33
Former Vendor
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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.
#34
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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.
#35
Former Vendor
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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.
#36
Rennlist Member
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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.
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.
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.
#37
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That makes sense. I will get stock. I was thinking of getting numeric shifter and shifter cables. Is that overkill for my 997.1?
#38
Former Vendor
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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.
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!
#39
Rennlist Member
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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.
#40
Burning Brakes
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Yes, I think you are right! Which demonstrates perfectly, that this is the type of mod that one person may love, and another dislike. I can give my positive feedback on the LWFW, but I cant necessarily recommend it to anyone. People have to decide for themselves, as the investment in parts and labor is not a small one.
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.
#41
RL Community Team
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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.
#42
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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.
#43
RL Community Team
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#44
Former Vendor
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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.
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.
#45
Rennlist Member
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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.
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.