8744S

I recently recived my rennlist group buy gears(Thank Paul!) and my mechanic said that I would be getting rid of the harmonic balancer. Does anyone else know how to keep it but still use my gears? Any help would be much appreciated!

Thanks, Ben

Mighty Shilling

do what now? is he talking about the balance shafts?

Mongo

We don't have harmonic balancers. Our engines use balance shafts to dampen these vibrations.

V2Rocket

None of that fancy language here. We call them rumblesticks.

8744S

My car is an S if that makes any difference, alot of things are different on my car then a NA or a Turbo. I still haven't heard anything like a harmonic balancer on our cars. I was just checking. I knew that the all mighty rennlist knew more than me.

xsboost90

the large pully is mounted in rubber IIRC but is not a harmonic balancer. Balance shafts take care of that.

chrly924s

Mine doesn't have any rubber. The clutch in my 924S has rubber in it; is that the same?

xsboost90

well i think it has a thin piece of rubber between the pulley surface and the center- rubber sucks, i hate rubber.

Lemming

The 3L engines came with an harmonic damper (944 102 123 02 or later models 944 102 123 06) that replaced the old pulley (944 102 116 10). The damper is in addition to the balance shafts and help to eliminate vibration. The damper was done away with on the 968 since they went with a dual-mass flywheel. I put one on my 968 frankencar which runs a normal flywheel and the vibration was greatly reduced. So much so, that I've gone to solid engine mounts to lower my center of gravity.

The dampers are quite heavy (10lbs?) so you lose a bit of rev speed.

Riff

Tim-

Trying to add the harmonic damper to my friend's 968. Did you end up swapping the pulley on your crank to overcome the 4 bolt mount vs 6 bolt on the 968 or did you simply drill different mounting holes in the damper?

Thanks!

Lemming

I didn't have this problem, the damper that I got from Sunset had the correct mounting holes???????

FRporscheman

Ben-
Before reading this thread I didn't know any 944 series car had a harmonic balancer. I know from experience the 2.5 NA, 951, and 968 don't have one. As Lemming said though the 3L engines vibrate more and the 968 had a dual-mass flywheel... but I would think the 2.5L 944S still uses only balance shafts. Just check PET to see what parts go on there. I think your mechanic is smokin' somethin'.

Lemming-
In going from a DMFW to a normal FW I assume you shed about 13lbs or so right there. Then you added 10lbs with the harmonic damper. You still have a rotational mass reduction of 3lbs, and remember that the damper is small, and has a smaller radius than a flywheel, so its moment of inertia would be much less than 10lbs of flywheel. Overall this sounds like a worthwhile mod. Especially if my $800 DMFW ever breaks.

Riff

Well now that I think about it, the harmonic balancer I gave him was from a grenaded 2.5l S motor, perhaps that was it?? Gonna have to look at my S2 on the next belt change.