skool me on flywheels

[wodcutr]

I am doing a 5 speed swap into an 86 325es and am having difficulty understanding all the information out there on flywheels. It looks to me that there are several to choose from and that most e motors had the dual mass flywheel, but that the es model came with a single one. I need to know which one is better and why to be able to find the proper one I need for the swap. I have a brand new sachs clutch and the flywheel off an 89 i motor. It is my understanding that I can't use the flywheel because it does not have the sensor magnets in it so I need an e flywheel.

If I use an e single mass can I use the brand new clutch I already have? Also a side note question...will the sensors used for the auto tranny work with the manual? Thanks!

[TurboJake]

The pressure plate between the E single mass and I single mass is the same. The clutch disk is a different part number, but *should* work all the same. I don't know 100% about the clutch disc itself, but on realoem the pressure plates are the same part number between an 85 325e, and an 89 325i

You will need a single mass flywheel from an 05/86 and BEFORE 325e, as they came with the single mass with reference sensors.

Your transmission sensors will work fine, especially since your keeping the same DME.

[idanity]

afaik SACHs has 2 seperate clutch discs...

for the e, there are double springs and made (i guess) for more torque)
the i's have (what appears) to be the same disc, but less internal springs. (4)

now, the flywheel, if you can, definately get the single mass flywheel, and lighten it, then balance it to your pressure plate. you will get much faster shifts, and less rotational weight= more power...the dual mass is not able to be lightened, and its much heavier...but on the flip side, it is supposed to be smoother (although mine is pretty smooth, at 12 lbs, its great)

also, it needs a step cut for your clutch pedal to be setup in a nice/ quick way

just visit this link and read through it, to understand a little bit (at least) about what im spouting off about.

then, pm me, or reply, or reply to that thread too..
heres the "i" disc...the "e" disc has tinier springs inside the 4 that you see

[wodcutr]

That is a great write up for doing a clutch. Thanks for the info!

[TrentW]

Nice writeup indeed!

[CR325IS]

So match your flywheel and clutch to the same model as your geartag came out of? or the model of the car?

[Smelser]

I thought those springs on the clutch disc are for the torsional vibration. all the pressure comes from the pressure plate its self. while we are here, any light weight flywheels for a M10?

[jeffnhiscars]

I have an 84 318i that I converted from an auto to g240 at which time I installed a JB Racing aluminum flywheel as well as a header and full Ansa cat delete. Thats alot of changes at once so I cant say with certainty what improvements came from which change, but enough has been said about the lightened flywheel to make it a good upgrade. GL

[Varinn]

This thread is relevant to my interests so I'm going to throw in my own bit.

I've got an 8/84 325e that has a brand new clutch in it (bought from a friend a few months back). I'm looking to pick up an 87 m20b25 in the next couple weeks but the motor has no flywheel installed. Can anyone confirm I have a single mass flywheel on the 1984 b27 or should I find one before I begin the swap? I don't want to button it all up with a dual mass if I don't need to (only have 2 days to complete the swap once I start)