Single Mass Flywheel options for MT cars

[e39_touring]

I know a few of you have done single-mass conversions with lightweight flywheels, and I'm looking to see if there are any new options out there. I'm in the midst of a MAJOR refreshing under my car (diff swap, clutch, trans detents, oil pan gasket, front axles, etc.), and at 117k miles, I think I'd like to ditch the DMF 'while I'm in there'.

This is what I'm seeing out there with respect to SMF options:

1) Valeo flywheel conversion kit (p/n 52401220) - about $400. This converts to a 24lb steel flywheel only a couple pounds lighter than the stock DMF. It doesn't say it works for the X5 but I'm guessing it does since I've verified that every other clutch part except the pressure plate (can't find a part # on the X5 pressure plate alone) is the same between E53 and E46/E39, which the Valeo kit is listed for. This is attractive because it's got a standard weight flywheel and sprung hub clutch that should perform well in a truck and deliver minimal gear rattle. The big downside is replacement clutches are non-standard and could be difficult to source if Valeo decides to stop providing 'service kits' (clutch only set).

2) Fidanza (p/n 195461) - about $400 plus clutch set. This is a direct replacement for the DMF but weighs in at 13 lb. It will work with the stock clutch (which I already bought a new kit), but the stock clutch disc is unsprung. I suspect it will chatter with absolutely no dampening in either the flywheel or disc. I like this middle of the road option - maybe an E34 M5 sprung disc could be used instead?

3) UUC/JD Racing, etc - about $400-$550 plus choice of clutch set. These are all more extreme in their lightweightedness at about 8 lbs. Older sets seem to use an E36 M3 clutch set (only sprung if aftermarket) while newer ones rely on the sprong E34 M5 clutch set. I like this option, too, except for the lightness of the flywheels.

Any thoughts or advice on choosing? My goals are not to spend $1k on a clutch set for a $7k car. I wouldn't mind a little more performance/edginess and am OK with a little gearbox rattle (my GS-80 covette has a ZF 6 speed and SMF so I can handle that aspect). I also want durability and future serviceability, which has me leaning to #2 (or #3 if I could find quality heavier flywheel options - not the china-made 15lb steel ones).

[Happy]

Originally Posted by e39_touring

3) UUC/JD Racing, etc - about $400-$550 plus choice of clutch set. These are all more extreme in their lightweightedness at about 8 lbs. Older sets seem to use an E36 M3 clutch set (only sprung if aftermarket) while newer ones rely on the sprong E34 M5 clutch set. I like this option, too, except for the lightness of the flywheels.

This formula will give your E53 a lightweight feeling while you throw. I highly recommend changing the bushings on your shifter and deleting your CDV. E34 M5 OEM clutch is more than sufficient.

[e39_touring]

Originally Posted by Happy

This formula will give your E53 a lightweight feeling while you throw. I highly recommend changing the bushings on your shifter and deleting your CDV. E34 M5 OEM clutch is more than sufficient.

I may not go as radical as an 8lb flywheel, but we'll see what I can scrounge

I delete the CDV as soon as I acquire a manual trans BMW, and highly recommend it as the best FREE mod!

I ordered a handful of bushings for the shifter as well as all the detents (5th, reverse, and those other 3). The only shifter bushing I didn't get was the rubber one that stays with the car when the trans is dropped that the upper rod pivots into - it was like $65, and I wanted to see mine first before shelling out the cash (looks ok from what I can tell). I did get the plasticy ball socket and two other oblong rubber bushes (that go on the lower pivot).

I was surprised to see a leak where the shift rod goes into the trans since that's way above the oil level. I did not order that seal - is that easily replaceable? Any others that are must-do while I'm in there?

[Happy]

Originally Posted by e39_touring

I was surprised to see a leak where the shift rod goes into the trans since that's way above the oil level. I did not order that seal - is that easily replaceable? Any others that are must-do while I'm in there?

I ordered a handful of bushings for the shifter as well as all the detents (5th, reverse, and those other 3). The only shifter bushing I didn't get was the rubber one that stays with the car when the trans is dropped that the upper rod pivots into - it was like $65, and I wanted to see mine first before shelling out the cash (looks ok from what I can tell). I did get the plasticy ball socket and two other oblong rubber bushes (that go on the lower pivot).

I had the same leak.

I refreshed my linkage and detents. It fixed all my issues with gearing.

[Cyrix2k]

I installed the Valeo in my friend's E46 330i/5 and really liked the feel. The engagement was very smooth and there were no noticeable noises from the transmission. While I've been told you should always match a single mass flywheel with a sprung hub clutch (at least for the street), we're running a twin disc clutch in our LS-swapped E39 project and it also engages smoothly. By its nature, it's a solid hub and the flywheel is solid as well. And because we're running a GM transmission now, we eliminated the guibo too so it's about as direct as possible.

[e39_touring]

Originally Posted by Cyrix2k

I installed the Valeo in my friend's E46 330i/5 and really liked the feel. The engagement was very smooth and there were no noticeable noises from the transmission. While I've been told you should always match a single mass flywheel with a sprung hub clutch (at least for the street), we're running a twin disc clutch in our LS-swapped E39 project and it also engages smoothly. By its nature, it's a solid hub and the flywheel is solid as well. And because we're running a GM transmission now, we eliminated the guibo too so it's about as direct as possible.

Well, I kind of let black friday deals make my decision, and I ended up finding a Valeo kit on Amazon for about the cost of the Luk clutch kit alone (not black friday, but the amazon algorithms sometimes doe weird things on pricing to clear stuff out that's been sitting in their warehouses). So, it's good to know your friend's experience was good. Over on e46fanatics, where there is more experience with these kits, reviews seemed to be positive except when, in my estimation, there were installation problems.

Anyway, for anyone considering this option, here's some info:

Even though valeo does not list a kit for the X5, I used kit part number 52401210. Amazon says it fits, but no one else does. I believe any of the M54-targeted kits will work on the 5 speed X5 (52401220 and 52401225), and the differences are in the clutch disc size and/or pressure plate spring rates.

My kit included the following parts, and I weighed some for fun:
702453 throw-out bearing
702369 pressure plate (11.2 lbs)
702371 disc (3.7 lbs)
702372 (casting # 701794) flywheel (23.4 lbs)

Stock weights are: used flywheel (24.7 lbs), new clutch disc (2.4 lbs), and new pressure plate (11.5 lbs).

As you can see, the totals are very close at 38.3 for the Valeo kit and 38.6 for stock.

Here are some pics of old and new. I had some strange wear patterns on my old clutch, though I only occasionally got chatter. Incidentally, I couldn't find a part # in any of the catalogs for the E53 pressure plate. On my original pressure plate, it's 21 21 7 503 501, but I can't find anything online about this part #.

[Happy]

Oh yeah, you’re due!

Nice refresh by the way!