Fidanza Upgrade

[CAJUN C4]

How many of you have installed the Fidanza Alum. Flywheel ? Any Noise issues? I heard of some potential ones.?

 

[Vettelt193]

How many of you have installed the Fidanza Alum. Flywheel ? Any Noise issues? I heard of some potential ones.?

It's loud. sounds like someone through a bag of rocks in the tranny.

The fly needs to be balanced properly, and most important installed properly. I don't think mine is and I get chatter when the clutch gets hot.

On the other side of the coin, it grabs like heck, and the car revs quicker... it is a bit harder to drive in town because the car is much easier to stall now. There is a noticable performance increase though.

When you compare the fidanza to stock flywheels you will be blown away by the weight difference. the fidanza can be almost thrown like a disc. the stock fly is so heavy it is tough to pick up.

In summary: if you don't race, don't get one. the benefits are great, but the downsides are always noticable.

 

[LlanoBill]

How many of you have installed the Fidanza Alum. Flywheel ? Any Noise issues? I heard of some potential ones.?

Not to cast stones, but why would you consider this an upgrade? I know, speaking only for myself, I would not pay as much for the car after the change as before. As an aside, I believe the engineers did a fantastic job on the LT4 drive train! Thus, why mess with it on a street driven car?

 

[stgry1]

The Fidanza is an "upgrade" in my opinion for several reasons. Weight loss is key. With the substantial loss of rotating mass, you gain (actually you recapture) lost HP from the DM. You have less weight hanging on the end of the crank,which will help with longevity and reliability of the engine. You are able to rev the motor much much faster which is important to you quarter milers. And of course the cost;The Fidanza costs a fraction of the DM.
Of course everyone hates the noise caused by it etc etc. I don't have first hand experience with it YET but from all my research and weighing out the pros and cons, I will NOT be replacing the OEM DM anytime in the future. -- only aftermarket for me. YES it's a weekend driver and yes my main goal is horsepower so it's obvious which route I prefer. My .02

 

[lone73]

Fidanza in a '96 LT-4

Got it.
Hate it.
Counting the days 'till I can justify getting rid of it.

I have about 40K on it and its starting to chatter especially when I back up slowly. The balance is a significant issue. I've read that when the F/W gets lighter the balance has to be even closer to prevent vibration. These cars are externally balanced with a very massive F/W so GM didn't have to get it too close to keep the Vib's down. You throw in an "approximately" balanced VERY light F/W and it might be balanced for your car...it might not. In my case it isn't. I get vibration coming on at about 3.4K rpm up to about 5k. Right where you live when you're "lead-footin" it. I actually feel a HP LOSS as a result of the excessive vibration. Needless to say I drive it pretty much in "Docile" mode now that it vibrates above 3400rpm. That is all in ADDITION to the added noise, the added difficulty in taking off from a red light, you tend to either over-rev it or bog because the rotating mass is so drastically reduced.

And as far as reving up quicker... well maybe, just barely quicker. All in all, with the headaches it causes, it is in no way worth the cost savings over the stock F/W if your car is a street driven and the performance is noticeably degraded if you are one of the "lucky ones" with vibration. This is of course my opinion after having driven with it for a couple of years and about 40K miles. Want to buy a used one cheap...?
good luck
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[stgry1]

sorry to hear about your bad experience with it...that definately sux. I assume you used a sprung hub clutch disc. I would hope to hear from those of you who HAVE done the swap and have some positive feedback. I've talked to, ridin in and read about others who love it..time to offer a balance of experience..i hope :eyerole

 

[96CERon]

Fidanza and Stage 2 clutch

I have been driving a Fidanze and Stage 2 clutch for over a year. Does have gear rattle noise at idle. You also get what some call clutch spring resonance between 1 and 2K rpm under moderate to heavy load--lugging if you will but you can drive around this issue. RPM picks up faster. No problem with drivability. Yes you must match balance to the old dual mass flywheel! Yes I would do it again. I hated the dual mass design(39 lbs etc.) and the concept of same. It was a bandaid to fix a transmission design problem. I have no engagement problems it is smooth and can easily start from a stop.

 

[LlanoBill]

I’m sorry, I did not clearly communicate. I HAVE owned two C4s with the Fidanza aluminum flywheel “upgrades”. Both were LT1s which had the F/W in place when I purchased the vehicles. Both were loud with serious vibration. My butt dynometer could not discern a decrease in performance when they were replaced with used duel-mass fly wheels from low mileage cars. As to the lower rotating mass, you are correct. The Fidanza does allow the recapture of previously used horse power. However, the real gain in performance quoted by the advertisements and others was not that evident to me. Unless balanced, engine life is decreased. In both afore mentioned vehicles, drive train vibration was very noticeable and both leaked oil via the rear main seals severely! Vibration is a bad thing!

Again, not casting stones but my opinion was based on experience, not conjecture.

 

[lone73]

Yes you must match balance to the old dual mass flywheel! Yes I would do it again. I hated the dual mass design(39 lbs etc.) and the concept of same. It was a bandaid to fix a transmission design problem. I have no engagement problems

I wasn't saying that I liked the old dual mass. I agree, that design is abysmal and has its own problems! I hate it too. That's one of the reasons I went with a single mass F/W. I will probably try out a single mass STEEL F/W next time even if I have to grind down an old camaro F/W which I really didn't want to do this last time I changed it out.

I listened to a local guys car that had the steel single mass F/W before I made the decision to buy the Fidanza. Didn't sound too bad at all but he had pretty loud pipes. I think a big part of the difference now is in the mass of the f/w not whether it's single or dual mass. I am betting that a heavier steel single mass f/w would be much quieter than the fidanza and eliminate some of the drivability issues as well. I think it would be a closer approximation to a "happy medium" between the dual mass expense and problems and the Fidanza's noise and other issues.
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[stgry1]

IMO you're defeating the purpose by getting a steel FW. Might as well just replaced the DM. If you're doing it for performance and weight loss then stick with the AL. IF cost is your motivation then Steel would be an option. I'm surprised to hear everyone talking about balancing issues. You talk to the sellers of these parts and they will tell you that about 10% of people have vibration issues. Most have a clean install. I've tried to get people down here to match balance the 2 flywheels but can't find a machine shop willing to do it or able for that matter. Good luck in your hunt.

 

[Vettelt193]

IMO you're defeating the purpose by getting a steel FW. Might as well just replaced the DM. If you're doing it for performance and weight loss then stick with the AL. IF cost is your motivation then Steel would be an option. I'm surprised to hear everyone talking about balancing issues. You talk to the sellers of these parts and they will tell you that about 10% of people have vibrtion issues. Most have a clean install. I've tried to get people down here to match balance the 2 flywheels but can't find a machine shop willing to do it or able for that matter. Good luck in your hunt.

I think the 10% number is BS. If they are saying 10% it is probably more like 30% or more. However, if you take your time on the install you should be ok in the end. The kicker really is the balancing. it isn't easy to match balance two flywheels that are so different in overall weight. I also have a feeling that changing the weight of the flywheel leads to requiring a different balance all together since the fly works 'with' the engine, and you change the overall weight with it. My guess is the people that have these with positive results are lucky enough to have near neutral balanced engines, although I can't be sure.

 

[stgry1]

I think the 10% number is BS.

You could be 100% right but what the heck can you do? I want the advantages of an AFW just like the next guy WITHOUT the vibration. If you can't get a shop to do it locally, then you need to send both pieces out. By the time you add up freight both ways plus machine time PLUS shop time while the vehicle sits and waits for the parts....man I tell ya. It adds up quick. PIA!!! I still might roll the dice with the Fidanza..if I do i will post back.

 

[Vettelt193]

You could be 100% right but what the heck can you do? I want the advantages of an AFW just like the next guy WITHOUT the vibration. If you can't get a shop to do it locally, then you need to send both pieces out. By the time you add up freight both ways plus machine time PLUS shop time while the vehicle sits and waits for the parts....man I tell ya. It adds up quick. PIA!!! I still might roll the dice with the Fidanza..if I do i will post back.

you really can't beat the price compared to stock. I think power / $$ is there, even with a gamble that it won't work (especially if you can do the work yourself)... this of course assumes you are in it for the power

Either route you choose... good luck This is one of the few mods that really has distinct positive / negative factors that are hard to decide on

 

[96CERon]

Here is some info regarding my LT-4 and my Fidanza fun and games. I did all the work myself laying on the garage floor with a transmission jack from Harbor Freight. AND, I GOT TO DO IT TWICE. I used the Carolina clutch stage 2 kit. When I asked Carolina Clutches before I spent the $900 for the kit, Tom said that the flywheel and pressure plate were individually balanced and should go right in without a problem. There was a caution label on the flywheel that said you need to match balance the old one and new one, but assuming that Carolina Tom knew what he was talking about, I ignored it-- Bill Boudreau at ZR51 Performance, says "these engines required post assembly balancing via variable weights added to the flywheel and some were very difficult to get balanced. Dave (Tech support at Fidanza) confirmed that you have to match balance his flywheel to the dual mass unit. He said that they build these with a nominal (mid point) balance job but if the original balancing was at either end of the spectrum you must match balance flywheel to the old dual mass flywheel. I really didn't enjoy taking it down again and getting it match balanced. Sure enough the balancing was off by 30 gms. This is a tremendous amount at RPM-->100 pounds. It wwould have knocked our the rear main and seal if I had continued to drive it.

I had another problem which was that the clutch disc from Carolina was miss-stamped as to which side is the flywheel side. On a "regular" car the clutch disc springs stick out more to the transmission side, but with this conversion the springs go the flywheel side but unfortunately the part was metal stamped incorrectly. You can put the clutch assembly together wrong, but the transmission will not go all the way up against the bell housing because of the input shaft cover hitting the backward clutch disc. Another thing, when I took it back down to do the match balancing, I found that the flywheel bolts and washer provided by Carolina were of poor quality. i.e. the washer were soft and the bolts really had no shoulders near the heads and therefore the washers and holes in the aluminum flywheel where deformed as well as the area under the washers was concaved. This could be a long-term problem with the flywheel coming loose over time! You must use hardened washers and bolts from ARP actually Summit--I believe these are the numbers-- bolts 200-2807 for $15.99 and washers 200-8539 for $8. Call ARP and verify. I also used the beam plates from ZFDoc. It makes taking the beam up and down much easier. Also make sure you mark the drive shaft relationship to the rear axle yoke so you can put it back in the same position.

After driving it for 12 months, I have no drivability problem as reported by some. I take off just fine with no more issue than when it was stock. I can take off in second gear if I want to. It does have gear rattle in neutral at idle. The engine pulses cause the gears to clatter back and forth--goes away at higher idle speed. I just say--racing transmission! I also get a resonance under heavy load--lugging from about 1K RPM to about 2K RPM--some say it is the resonance of the clutch springs--who knows but whatever it is you can drive around it and there is no problem in 6th gear. I think a lot of the noise issue is the hard mounting of the transmission to the beam and to the rear axle. It is a great amplifier. Do put in the 10-60 BMW oil in the transmission. It helps a little and is the best. I tried all different types.

Here is what theory says regarding the rotating weight reduction and resulting virtual weigh loss and rule of thumb horsepower increase and therefore faster acceleration. It is a function of overall gear ratio?i.e. this is for 3.54:1 rear axle ratio:

Trans gearGear 1 2 3 4 5 6
Mass Reduction in pounds 303 203 116 80 56 39
Equiv HP gain 30.3 20.3 11.6 8.0 5.6 3.9

Hope this helps.

 

[lone73]

Beam plates

96CERon,

What are the beam plates you're talking about? How do they accomplish making the beam easier to deal with? I will probably be removing my Fidanza within a year from now.
Sounds like you spent more going the Fidanza route than if you had just gone back stock. When I was doing mine I couldn't find anyone locally that would even try to match balance the two F/W's.

I also had the issue with the F/W bolts. I can't remember if I actually got any from Fidanza or not but I do recall noting that the ones I was going to use (I do remember buying a set from the local parts store) had a smallish shoulder to them. Not wanting to wait on Summit I went down to the local Caterpillar (as in backhoes and bulldozers) parts department and found a bolt that was near perfect for my application. The other issue I had with them was that they didn't extend into the crank as far as the originals did, they were shy by about 3/16" - 1/4". I was worried about stripping out the crank holes when torquing to spec.

I've since tossed my old F/W, I am pretty set on trying the steel single mass route next time. I guess I'll end up buying one from the dealer long enough to match balance then return it...or send it to someone that has an OEM F/W that they could match it to.

 

[stgry1]

Ron, even tho this isn't my thread, I really appreciate the time it took to write up that long response. Your effort and experience is greatly appreciated. I do not know you but I know OF you. Tom and I have had a discussion regarding your problems. I believe he thinks you are in the minority. Regardless, I know I'd be ****ed if I went thru all that effort and had those results. I'm glad to hear once it was right, you were happy. Just a heck of a lot of effort involved especially with limited down time available in the shop. I think I'll do my nitrous install first and worry about the clutch ltr. :L Thanks!!

 

[96CERon]

Go to zfdoc.com for beam plates and description of them--he is here in Arizona.