MD Clutches single conversion kit any good???

He is a 355 Ferrari nut as well and I found all his products and service to be great. He is well respected in the Ferrari UK community.
Regards
Simon UK

 

I have no experience of that particular conversion, but I can vouch for Andrew's products and service - he fitted a kevlar clutch plate, refurbished flywheel and new pumpkin bearing to my 355 and I have had absolutely no problems.

I think he's sold it now, but he used to race a 355 in a hillclimb series, which provided a pretty tough test of his products.

 

All I can say is that Ive had clutch judder since installing in my 348. Been sent back once already and still judders.

Mine cost close to £1800 and I can see myself converting back to a standard clutch this year as it makes very uncomfortable driving

 

That's not the fault of the single plate clutch though. I have an OE single plate in my car and it's perfectly smooth. The only drawback is that the clutch pedal effort is light enough than any old DeMuro can drive it-- I'd prefer the pedal effort be high enough to keep the snowflakes away.

Judder is typically an issue with the friction surface of the flywheel and/or P-plate.

 

Judder is typically an issue with the friction surface of the flywheel and/or P-plate.[/QUOTE]

Can this be helped or even cured by engaging a higher gear when stopped (say 4th) and deliberately slipping the clutch to burn/change the surfaces a bit? I heard about this from an old BMW tech. Is there any truth to it?

 

Not in my experience. In fact, that can lead to glazing that worsens the problem. A light machining of the surfaces should solve the problem as long as the surfaces are cut "true" to the correct plane. But sometimes the clutch disc is affected, especially if someone has tried slipping the clutch in the past. So it's safer to replace the friction material on the clutch disc in addition to the re-machining, especially since it *should* be a pretty inexpensive thing to do.

Sounds like MD may have just goofed on that assembly and inadvertently created a set of conditions where judder occurs. It happens on occasion since there's no way to test it outside of the car. Not sure why their first attempted fix didn't work but hopefully they'll stand behind it and make it right the third time around.

 

One thing I can say with working over the years extensive with lightweight high performance flywheels is.

Proper torquing of the flywheel
Always check runout

Check splines for play or misalignment on clutch
Proper approach angle of the throwout bearing

Andy make high quality stuff he's a professional for sure

 

I purchased the complete bolt in pumpkin, flywheel etc, all fully refurbished. First time it went back was because of some bent spring washers but that didn't cure it. I had the gearbox completely refurbished last year and now the clutch is the only thing that lets the car down now.

Basically in traffic, I have to give it more revs and slip it a little just to make it manageable but that ends up with clutch smell, otherwise its almost shaking the transmission apart.

Andy was very helpful at the time and I guess Im just the unlucky one!

 

Quite possible. A conversion to a solid flywheel completely changes the rotational masses in the relationship gearbox to clutch. The solid flywheel (plus the clutch pressure plate) is a new large, rigidly connected, rotational mass at the end of the slender drive shaft from the transmission to the clutch. In the case of the dual clutch, there is no such large rigid weight at the end of the shaft but just a small weight connecting it to the flywheel via large travel springs which, together with the grease, provide cushioning/damping preventing resonant torsional vibrations of the shaft-flywheel assembly.

Looks like most people who have converted do not have this problem but, in your case, it is possible that the combination of the new mass, the shaft and the masses and rotational gaps at the other end of the shaft (inside the gearbox) is such that it causes some kind of torsional resonance at the revs at which the clutch normally engages.

 

Interesting - I think I'll get hold of him again. Thanks

 

Reading your post I had a brain fart from the past with old sloppy 4 speed american boxes

Sometimes a change in oil viscosity will correct this. We also used a gear extreme pressure concentrate additive like the BG stuff

I would try a little lighter or thicker trans fluid. Never know it cant hurt

 

I was running Redline prior to the box rebuild but now on Shell which Ferrari put back in. No difference between the two!

 

Strange

Has to be a reason, just try finding it

Same when car is cold or hot?

Did you check the clutch friction material or flat?

I bet a few hundered good hard driven miles will fix it, hopefully

 

Do they sell a kit for the 348? I see the F355 kit on the website but not the 348 kit. I know they were working on a flywheel for the 348 a while back. Also what is different about their modified 360 friction plate and a stock 360 friction plate?

 

I'd say worse when hot.

I haven't checked things any further, especially after being sent back once already!

 

Whipped the clutch out this weekend. Its a twin plate system and the flat surfaces are all randomly glazed, on what appears to be high spots. Friction plates are also very smooth, I guess from the extra revs given to relieve the judder.

I'll call MD this morning but I might consider a single plate system

 

I was under the impression that you already had a single clutch plate conversion but I now understand that you have a rebuilt (or new aftermarket?) twin clutch. One thing to note when/if machining the clutch pressure surfaces is that they are not parallel. The picture below shows the shape (including my measurements) of the factory twin clutch plates. I believe that the conical shape helps smooth clutch engagement. One "speculation" could be that, if these surfaces are machined flat (parallel), this could be a cause of clutch judder.
Image Unavailable, Please Login

 

That makes sense.

 

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Often rebuilders don't (re)waffle the metal between the friction facings of the disc. When they don't, they judder.