Single mass fly wheel conversion

[razo-s.supra]

I know I know use search. Well I did. And I actually found a lot of great information that helped. Although some of my questions were left unanswered.

So I have a 1987 325es. I have the "i" head conversion. So i head, i electronics, i crank pulley gear "i" 525 ecu. Now the 2 reference sensors are disconnected on the transmission and harness end so I know I dont need to worry about getting a flywheel with the reference pin.

I want to convert to single mass but dont know whether to get the more slender "i" solid flywheel, clutch and pilot bearing or the early thicker ETA solid flywheel and its accessories.

I read way too much information that seemed to contradict itself and I know flywheel thickness matters when it comes to choosing the right tob. I just went through this the hard way adapting my 2jz to a Nissan cd009 transmission. 2jz also have the dual mass single mass option.

[ak-]

For what it's worth:

I had a 325i trans and "Stage 3" clutch/fly/pp in it.
Trans blew up.
Purchased a 325e trans and put the same "Stage 3" clutch without issue.

[razo-s.supra]

Any help is appreciated brotha

For what it's worth:

I had a 325i trans and "Stage 3" clutch/fly/pp in it.
Trans blew up.
Purchased a 325e trans and put the same "Stage 3" clutch without issue.

Thanks for that! Still kinda doesnt give me a solid answer as the e trans came in both configurations. I plan on doing an m50 swap in the next year so I would really like to buy the components that could be swapped over to the m50 after I get tired of the m20 or it gets tired of me whatever comes first lol.

edit: Found more info. apparently my car comes equipped with the shallow bellhousing. either f.w. can be used i guess what matters is having the short or long throw out bearing to match the flywheel. I may just wait all together till its m5x swap time so I only have to buy components once. unless I can swap my m20 components to the m50 for example.

[ForcedFirebird]

The transmissions are the same and interchangeable. The "thicker" flywheel is thicker on the engine side, so the clutch kits are the same between the two.

What you read about the deeper bell housing is a moot point. Just like your brakes, the hydraulics will take up the slack. The issue people had was they were using the wrong clutch disc/pressure plate combo. There are 2 different thicknesses of clutch disc's and if you mis-match them, the pedal gets funky and has to be remedied with the e21 throw out.

It's simple, if you use a complete clutch kit purchased as a unit, all the trans work proper.

https://www.r3vlimited.com/board/showthread.php?t=423846

I've done that swap about 5 or 6 times, never had to use any other TOB than what came in the 325i kit.




However, I have had issues when mixing and matching clutch kits. There are two thickness discs and 2 or 3 different shim spring configurations that if you mix up, the pedal will be low engagement. Some people like to use the HD Sach's PP which needs to have the matching disc. The HD plate has more springs putting the friction disc closer to the flywheel, so if you use the thicker clutch disc, you will have problems.



Just last Sept we had a clutch fail at the 14hr of Sebring. Well, the driver managed to toast a second clutch and we were out of spares. We went to all the e30 racers and managed to get a couple clutch discs, and noticed the difference in thicknesses, we slapped the thicker disc in thinking it had "more meat left". The clutch was disengaging directly off the floor. Once we got it back to the shop after the race, we started comparing all the pressure plates and discs, and it became obvious why. The disc was thicker than the kits we have been using, it was so obvious at the point. For craps and giggles, I ordered a couple clutch kits from a few different mfgr's, and again, it was clear. Some discs were 9mm thick, some 7mm, and the thickness of the outer springs on the pressure plate corresponded to how thick the discs were.



As long as you use a full clutch kit that was purchased all together as a kit, you should not have any issues.

Hmmm, that explains a few things, John-
for example, the Ireland puck disc is 7mm, which
doesn't work with the standard Sachs PP.

I too thought the eta bell was deeper-
but I wasn't going to measure it until
I had to use an eta trans...

Different pressure plates (228-215-240, etc) DO
have different height diaphragm fingers when installed...
...I've gotten in trouble with mixing things with trans/
flywheel swaps...

t

The real benefit to having a g260 from an eta car, is that they were never wound out as much, or had as much power put through them as a 325i car. Either way, the g260 is very stout, had a local making over 500whp through one (3.15 diff), and it held up just fine until he decided to 2jz swap FTL.

[zaq123]

. There are 2 different thicknesses of clutch disc's and if you mis-match them, the pedal gets funky and has to be remedied with the e21 throw out.

I thought it was a throwout bearing that came in 2 sizes, no?

[ForcedFirebird]

I thought it was a throwout bearing that came in 2 sizes, no?

They did. But not because the USDM needed them. ;)

Again, I have personally done single mass swaps on at least half a dozen cars. If you click the link for the other thread, so did Jeff. My first e30 was an eta and I swapped in a complete 325is clutch kit and drove it for 8 years that way. I promise, I dont make this stuff up, just can't stand when misguided info is passed around as fact. :(