Jayhova

Hi All,
I am going down the slippery slope of trying to figure out what work I should do if I have the cooling lines welded on my new to me 997.2 GT3. Specifically addition of a harmonic damper/pulley if moving to an RS 4.0 flywheel and clutch combo (whole kit). I have seen a few posts regarding the Dundon unit. Seems all good however very expensive. I came across a unit from RSS that is a fraction of the cost and lists this car as one of the applications. Does anyone have experience with this item? Is the thought that Dundon put more research into tuning it for our cars and thus the extra cost? Just markup? Any other suggestions? Does everyone still consider this a must have addition if moving to the RS 4.0 setup? Appreciate any insights and real world experiences for this newbie. Thanks!

RSS Pulley/Damper
https://lnengineering.com/rss-underd...ayman-911.html
https://competitionmotorsport.com/rs...86-987-996-997

Dundon Damper
https://www.dundonmotorsports.com/pr...armonic-damper

ky_gt3

I have the ATI damper and I've put about 15k miles after getting the lwfw installed and my cam actuator bolts are fine and in place.

Maybe I am reading it wrong, but I don't think the RSS damper works on GT3s

Jayhova

Thanks for the feedback. Ah my bad! I read that wrong!

8Lug

Doesn't adding a larger/heavier damper offset the benefit of adding the lighter flywheel? You're removing mass on one side of the crank but adding it to the other side.

Bxstr

On their website, Dundon mentions this:

"This added mass at the correct end of the crankshaft will allow owners to remove the stock heavy mass dual flywheels and change to the single mass flywheels. The greatest dimensional change in the crankshaft happens at the pulley end of the crankshaft. Even if no other changes are done to the engine the owner can now have confidence that the known parts to fail should not!"

https://www.dundonmotorsports.com/pr...armonic-damper

I do remember some talk on here about that exact point. If I remember correctly, you're 100% right, but it was basically the compromise of adding a bit of weight, when removing even more weight, but preventing the camshaft actuator bolts from backing out and causing an entire engine failure.

If it was my car and I was interested in a LWFW, especially on a 3.8, I'd do the balancer.

MJFDDS

I did the dampener after upgrading to LWFW and 4.0 clutch for peace of mind. I ran without the dampener for a few weeks before installing it. I did notice that it reduced the "free revving" feel of the LWFW a bit though.

Robocop305

Do you have the link for the ATI damper? Thank you.

Bxstr

As far as I know ATI makes the damper for Dundon. I’ve never seen it sold just by ATI.

Robocop305

Does the pulley comes as a kit or do you need to buy additional parts? Is this where the front main seal goes too? Should I replace it while I'm there? Thanks

Bxstr

Looks like the Pulley does come with a new belt. But I'd probably want a fresh bolt and I'd want to know whether to use the RS bolt or the standard GT3 bolt. I believe there was a difference. I'd reach out to Dundon about that.

Regarding front main seal, yes, that is where it goes, you could definitely replace it while you're in there. I had my front main seal and rear main seal replaced last year when my engine was out for coolant line work.

ky_gt3

Mine came with just the pulley, new 4mm dowel pin and a new bolt. Had to get a new belt separately. I replaced the pulley myself it took an hour or two to do

Wind911

You have LWFW correct? How does the car feel before/ after the damper install?

ky_gt3

Yep. Car is less chattery and smoother now, but I did lose a bit of the revy-ness. It's worth it for the peace of mind for me

997_rich

Interesting to hear that there is less chatter.. is it noticeable at idle when out of gear. Would you say it's a night and day difference or just a subtle difference.

ky_gt3

For me at the time it was a pretty noticeable difference when the car was idling out of gear. Now that I added EvoMS headers I really don't hear it all lol