[mitch968]

Well, at long last I now have a new Fidanza flywheel and sport clutch kit installed. Thanks a lot to everyone here who offered advice and answered my voluminous questions. First impressions after driving around for an hour or so... I'm loving it!!!



1. My sometimes nasty vibration around 3k is now gone. I had originally thought that this was due to a bad DMF, but it might have just been caused by siezed clutch fork bearings that intermittently prevented proper engagement. My old clutch disc was mostly worn but intact, the old pressure plate had some scoring, but the original flywheel might actually have some life left in it. It is slightly scored, but my mechanic said if it was his car he would have just kept it in there, as it's easy for him to just swap it out again whenever it would eventually fail.



2. Noticeably more peppy, especially in 1st and 2nd, and somewhat quicker revving. Maybe it's because I've been looking forward to this change for a while, but the revs don't rise and drop quite as quickly as I had expected. This flywheel is supposedly 13.5 pounds, so maybe it's a bit more civil than some of the others out there that may be around 11.5 pounds.



3. Absolutely no stalling or driveability issues at all...yay! After all the cautioning about doing this mod, I was expecting at least some added difficulty and to stall and have rough shifts until I got used to it. Even with the higher clamping pressure plate, I personally find it quite easy to drive. Maybe it's because I've adapted to dealing with the bad fork bearings and a heavy feeling in the clutch pedal, but I'm shocked at how driveable it is compared to what I was expecting. And the engagement is real nice - I feel much more directly connected with the car.



The only downside is the added noise, which isn't really better or worse than I had expected, just different. I've heard it compared to loose marbles rolling around in the tranny, but to me it sounds more raspy, like a loose heat shield resonating....a lot. It only seems to make noise between about 2 - 2.8k. On the way up, it passes by rather quickly and inoffensively, but if I'm slowing down off-throttle in say 2nd or 3rd, as it passes through that range it's fairly loud. I can also feel the resonance in addition to hearing it. The noise is a worthwhile trade-off to me, but I just want to be sure it's the normal expected noise and not something wrong with the installation. It definitely seems to be coming from the rear of the car, but noises and vibes have a way of spreading all over these cars. My mechanic said nothing's loose, but I'll get under there when I have some time to doublecheck all the heat shields and stuff.



Now I just have to wait for this Nor'easter to clear out, so I can really let loose. Not too good an idea to be heavy footed on these wet roads.



Those of you with the Fidanza...any thoughts on the noise/vibes felt in the 2-2.8k range on decel? Should I only be hearing and not feeling anything, or is a bit of a resonance/vibe normal? Could it be *gasp* less-than-perfect torque tube bearings that are now unveiled by removing the DMF?



Well...back to enjoying the car...

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[flash]

the noise is exactly as you describe - there isn't much of a vibration associated - it's extremely sublte and really no worse than any other shifter vibration that happens elsewhere - if you have any real vibration, it may indeed be the torque tube bearings - drive it for a while and feel it out - you have no damping in there anymore, so anything out of whack will show up



how far out of balance was yours? (please tell me you had it and the pressure plate balanced)



according to both fidanza and spec, the spring center clutch won't work with the fidanza

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[mitch968]

Yes, my mechanic had it balanced by a local shop they deal with. I didn't get the specs on how far out it was. I picked the car up at the end of the day when they were closing up so we didn't have much time to chat. I'll probably give them and the machine shop a call to get the scoop.



Drove it again, and there is definitely a vibration, but maybe the volume of the noise is making it seem worse than it actually is. It's kind of a buzzing, in the low 2k range on decel. Everywhere else it's really smooth other than slight normal vibes on the gearshift.



I suppose I'll live with it for a while to get some perspective. It's not like I spend a lot of time around 2k anyway. Sure is lots of fun though. Can't wait to get it out on dry roads....seems like it's been raining forever out here.

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[Eric_K]

It sounds like you have the normal rattle you get with the Fidanza. I don't remember there being much vibration with the sound however - maybe a little buzzing. Definitely only on deceleration.



I still have the setup on the race car but I never notice it with all the other noise and vibration going on.



I told you it wouldn't feel thaaat different from stock. <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" /> Now go and enjoy it.



Eric

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[mitch968]

I guess every gearbox probably has it's own character, so it's probably difficult to get a real apples to apples comparison anyway.



It does feel great and I'm going to enjoy it on my way to the office right now! <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" /> 3 day weekend coming up too.....life is good.

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[mitch968]

Update.... To be on the safe side, I swung by my mechanic this afternoon for a review of the new vibration/resonance issue. He hadn't test driven it after the service was completed - one of his employees had. Within a few minutes of driving it, he assessed that it definitely wasn't normal and should be looked at. He's going to look at it on Tuesday, first seeing if the balance belt has jumped a tooth, and then failing that opening up the bell housing again to have a look-see. He's taking ownership of the problem, but unfortunately that leaves me without the 968 for the holiday weekend. Great timing, eh?



I sure hope it's just a coincidence that the balance belt jumped a tooth when they had it out for their test run.....nice easy fix. And so now I play the waiting game......

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[TheMirror]

[quote name='mitch968' date='May 27 2005, 02:07 PM']Update.... To be on the safe side, I swung by my mechanic this afternoon for a review of the new vibration/resonance issue.  He hadn't test driven it after the service was completed - one of his employees had.  Within a few minutes of driving it, he assessed that it definitely wasn't normal and should be looked at.  He's going to look at it on Tuesday, first seeing if the balance belt has jumped a tooth, and then failing that opening up the bell housing again to have a look-see.  He's taking ownership of the problem, but unfortunately that leaves me without the 968 for the holiday weekend.  Great timing, eh?



I sure hope it's just a coincidence that the balance belt jumped a tooth when they had it out for their test run.....nice easy fix.  And so now I play the waiting game......

[right][post="5148"]<{POST_SNAPBACK}>[/post][/right][/quote]





Hey Mitch, I found this thread on a search. What was the eventual outcome of the vibration issue?



Thanks,

-Mirror

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[mitch968]

Still unsolved. The balance belt is definitely on the mark, so that's not it. I actually had my mechanic replace the balance belt right after this, as it was showing some minor nicks on the belt ribs - better safe than sorry. The timing was also verified when the flywheel was installed, so that's not it either. The vibration is still there, but I've just adjusted my driving to avoid that RPM range on deceleration. I'm really enjoying it despite this issue. I had email exchanges with a few others, who had the same exact issue with the Fidanza, so it's not completely unheard of.



I have another idea of what might be contributing to the vibration. I'm wondering if some misfiring under a heavy load while decelerating could cause additional high enough torque spikes that I would feel them in addition to hearing the rattle. I've recently run through a few bottles of Techron, and while there is still some rough running, I could swear that the vibration seems somewhat diminished. My car still idles/runs a little rough and could probably use a good induction cleaning, since the other tuneup items, motor mounts, etc have already been addressed.



To this end....I'm looking for a good place to get a MotorVac service done since I've heard rave reviews from some people. If anyone here has any thoughts good or bad on MotorVac, I'm all ears. I know a proper injector cleaning service would be ideal, but the 968 is my daily driver and I'd prefer the convenience of a while-you-wait service.



I'll be sure to post an update with any progress.

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[flash]

just a thought



we wrestled with ron's car for a while chasing down a vibration - everything looked fine - that is, until we actually removed and checked the pulleys again to see that one of them had been installed upside down - marks all lined up, but the pulley itself was 180 degrees out on the balance shaft



very frustrating - finally got it though

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[mitch968]

Good thought and I wish it was that simple, but it's not the same symptoms. My lower balance shaft was 180 degrees out when I first got it, so I know what that's like. You can definitely hear the difference especially when flooring it. This is just in the low to mid 2k range on deceleration and was totally masked by the original DMF.



Both mechanics I've used so far are Porsche specialist independents and have made a point of showing me how easy it is to put the pulley on wrong. They're very careful to avoid that mixup and they both have extensive 944/968 experience.

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[flash]

cool



there is a very "normal" vibration and rattle, most noticeably on deceleration, that is associated with the single mass light flywheels - this is because there is no longer any damping going on - there is nothing that can be done about it



if you did not balance your flywheel and pressure plate, it would very likely be worse



it sounds a lot like a coffee can full of nuts and bolts - there is also a slight buzz in the shifter that can come along with it



the only solution i know of is the anti-rattle knob on the center console, just below the climate controls

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[ether_joe]

flash i am looking forward to experiencing this on your car. I'm interested in the mod myself, prolly when my clutch comes due



thing is, with the parking in San Francisco we have to valet our cars pretty often. I don't want some valet dude popping my clutch and diving into the next car. <img src="/forum/images/smilies/968/tongue.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/sad.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/blink.gif" class="smilie" alt="" />

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[ether_joe]

hold on - am I reading this right, this thread is a year old?



whoa mitch that's a long break in period! <img src="/forum/images/smilies/968/ohmy.gif" class="smilie" alt="" />

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[flash]

hmmm - san francisco - if you're there a lot, i don't think i'd do it - i've driven those hills - that would be a challenge from time to time in traffic - as of the last time i was there, the other side of the bay would be comparitively no issue



i'm batting about .500 with valets stalling it - i just don't like the thought of all that jerking around and what it could be doing



but, if colin's flywheel works out, that could be a mid point option

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[mitch968]

ether_joe, I don't really consider it a break-in period...I've been living with and enjoying this mod for a while now. <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" /> The only downside for me is that it will be tougher to sell if and when the time comes unless I replace it with a DMF. Most potential buyers may not be familiar with the noise and assume something's wrong with the tranny. I personally don't care much about the noise and as flash said, the stereo easily takes care of it. Bystanders in a parking lot may look at you funny though.



I also find it pretty easy to drive on a daily basis. I might have stalled it once or twice at most in the beginning. The positive engagement of the sport clutch is really nice too. I drove a friend's 5-speed BMW recently and was actually hating the light engagement of his clutch, as it was so gentle that I could barely tell when it hooked up. I also wouldn't overly worry about a valet. Any experienced valet has to deal with a range of clutches every day, so they should be able to adapt. I would just let 'em know about the clutch/fw and noise, so they know what to expect. If you're already dealing with a clutch in San Fran, then I don't think this would be that much worse than a regular setup.



I'll see about recording the noise one of these days, just to give a better idea.

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[orphanowner]

[quote name='mitch968' date='Mar 20 2006, 12:33 PM']To this end....I'm looking for a good place to get a MotorVac service done since I've heard rave reviews from some people.  If anyone here has any thoughts good or bad on MotorVac, I'm all ears.  I know a proper injector cleaning service would be ideal, but the 968 is my daily driver and I'd prefer the convenience of a while-you-wait service.



I'll be sure to post an update with any progress.

[right][post="17650"]<{POST_SNAPBACK}>[/post][/right][/quote]



Mitch I wouldn't waste money on a MotorVac service unless you're sure you have intake valve deposits sucking up fuel, which is very rare on our cars.



If your car has some miles on it, a better idea is to have the fuel injectors removed and sent out for cleaning. I've done this on a number of cars and found that on the 4 cylinder Porsches, it's ALWAYS made a difference. I think when you have a large displacement 4 cylinder engine, the effects of a power imbalance from cylinder to cylinder are quite noticeable.



I have RC Engineering in Torrance California do my injectors. They test them before and after, remove the O rings and screens, clean them and return them with new screens, O rings and caps. Quick turnaround and they once even sent back a set of Mercedes injectors that I thought had a problem with a test sheet and the note that they had excellent spray patterns and were balanced within 1 %. They do charge for testing, but less than for testing and cleaning. I know there are several places on the East coast that do the same service. Marren comes to mind on the East Coast.

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