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Discussion Starter · #1 ·
JRV,

I am doing a little 34


JRV,

I am doing a little 348 flywheel experiment. I have the dual disc latest version. I have an extra FW so I took it apart and took out all the pieces dropping a few pounds out of the Fly wheel assembly. Then I took the spider looking thing which now spins in the FW housing and drilled it to fit the retaining bolts that normally house the little spacers that the spider normally bang back and forth against to absorb drive line shock. So now I have a defacto solid FW since the spider now cannot rock back and forth. I am testing the durability of this at the racetrack next week. In street driving there is no problem and I have noticed no driveline vibrations issues. Shifts are more crisp. I do not understand why Ferrari uses this design in the first place. Do you know a better (stronger) way to pin down the spider in the FW housing or do you know someone who has "been there done that" making a simple solid 348 FW housing at reasonable cost.
 
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Discussion Starter · #2 ·
BB,

There are a lot of diff


BB,

There are a lot of different issues in play with these DM flywheels. Dampening, Shockload, Inertia....give me some time to digest all the questions and issues.

Best, JRV
 
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Discussion Starter · #3 ·
Update JRV,

I'll never


Update JRV,

I'll never make it to the track. I drove the solid FW (or should I say pinned FW) around the neighborhood more. I started getting a gear bangging/throwout bearing sounding noise. It did not sound good. It was more at idle than at say 2000rpm. The noise was not good so I took the pinned FW out and replaced it with the stock DM FW. All the noise when away. So it appears that something is amiss. I have not figured out what it is. Perhaps the cars really are designed so badly that they need this DM FW to make for smooth idle. I think I even detected a bit of a miss with the pinned FW. Perhaps the noise/vibration sends bad impulses to the TDC sensors and cause the miss. These damn DM FWS are such POS! The shaft seals are such a bad design that they always leak oil into the FW's and thins out the grease. Anyway on inspection of my pinned FW it looked solid. I do not think the spider was rocking around making the noise although it is possible that the large rpm is adding way more torques etc than I can generate by hand. So if the spider is rocking it can account for the noise. The noise was definately louder in the bell house than the gearbox. Although it sure sounded throwout bearingish. Howver, my bearin is perfect as evidenced by no knoise upon reinstal of the stock DM FW. Perhaps I took too much weight out of the FW and it needs the weight to act like a cank dampner. Do you know anyone who has used solid FW's on these cars?
 
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Discussion Starter · #4 ·
BB,

Solid flywheels are a s


BB,

Solid flywheels are a standard swapout on the Porcshe 911's that came stock with DM FW's. You should get a copy of Excelence Magazine and see if one of the P-car FW makers can machine one for you.

Regards, JRV
 
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Discussion Starter · #5 ·
Yup,
That is where I got the


Yup,
That is where I got the idea to make a solid FW. I see no real reason to have one. Asumming my pinned modified stock FW is really pinned and not making noise which I believe is the case...then these cars really need the DM FW. I can have one make no problem but I hate to drop 1000 bucks just to see. This is a real problem with the Ferraris especially since I race mine. I have to experiment with everything which adds to the cost. I could by a 993 or cup car and just ask for the best set-up on a particular track and get an instant response from 20 guys and be 95% in the ball park. I love the way the Ferrari drives but I continually struggle with wanting to race something else like a Porshe, vette, or viper.
 
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Discussion Starter · #6 ·
BB,

Ferrari has seldom supp


BB,

Ferrari has seldom supplied much in the way of parts or info to privateer racers. And when they have it was short lived. I guess we all have to come to the realization that at times Ferrari is with us and ither times against us. They seem to fear the realease of info and smart techs above all else in the world...to be so great on one hand and so afraid on the other, is part of the Ferrari Inigma.

To the specific issue...348's cerianly don't have to run a DMFW. The DMFW is all about dampening clutch & drive line shock & harmonics. The flip sode however is that heavier flywheels also retain inertia...and since Ferrari engines come on hirher in the rpm band and rev higher maintaining inertia is a good part of striaght line acceleration thru the gears. If one reduces the inertia, I suspect the engine sweet spot would suffer without additional breathing or cams to compensate..

Since a Flywheel Development is as you say a pricey proposition, why not check into some cams from Koenig or ways to improve flow to achieve the extra grunt you're looking for?

Regards, JRV
 
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Discussion Starter · #7 ·
JRV,

Actually, I don't


JRV,

Actually, I don't need any extra grunt. What I need is the skill to use the grunt got. I just figured the lighter FW would be a free improvement since all I do is road race it. I would rather have the ultimate suspension than HP. Also those crappy DMFWs always need to be kept greased. I think since the FW removal is so easy especially with the challenge exhaust it should be part of every 3rd oil change! Those damn pesky oil shaft seals there has to be a trick I'm not getting. Everyone I know has problems with those things. Are you doing anything special besides stretching them out over the shaft with your finger nails and then tapping them back into the shaft seat grooves as you work the input shaft back into its seat against the clutch shaft?
 
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