'88 325is M30 street car-->S54 -->S50 -->M54 Enduro Race car

[gills]

Perfect timing on this. Just started researching this swap a few days ago too. Looking forward to your progression.

sub'd...

[FredK]

nice!

personally I'd mount the FPR/filter up by the front frame rail like it is on the E46, and use as many of the E46 fuel line bits as possible. you could get the entire mount bracket if you wanted, but that's probably a bit overkill.

I guess the E46 M3 and S54 Z3M have the filter on the inner side of the frame rail underneath the driver. However, the filter will sit proud of the rail, making it possible to rub against the ground / debris. I thought long and hard about sectioning the floor and welding in a half of some 2.5" muffler pipe to make a little cubby hole for the filter, but then got lazy about executing on that idea.

Why a dual mass flywheel and why a M3 reservoir?

I'd think because the coolant lines run similar on the S54 as they do in the E30 M3, with the coolant pipe header piece on the passenger side.

Right. You have the option to install a Z3M S54 metal coolant pipe, which allows you to then use the stock E30 late model reservoir in the stock location.

Having the reservoir and ABS pump there, though, may frustrate what you choose to do for routing a CF intake plenum.

[nando]

I'd put the FPR further up the frame rail, basically inside the engine compartment.

if I ever did the MK60 conversion, the unit actually should be mounted close to the master cylinder, so it'd be out of the way of the intake anyway. you could also relocate the stock ABS to the battery tray. Or just remove it, but I can't see doing ghetto duct tape mods to a car you're doing an S54 swap to..

[LJ851]

I guess the E46 M3 and S54 Z3M have the filter on the inner side of the frame rail underneath the driver. However, the filter will sit proud of the rail, making it possible to rub against the ground / debris. I thought long and hard about sectioning the floor and welding in a half of some 2.5" muffler pipe to make a little cubby hole for the filter, but then got lazy about executing on that idea.

This was my first thought as well and a fine idea. I think i would do this if no other easy spots became available.

[Jb325is]

I can't decide what I want to do about the ABS, its out right now and I'm getting a non-abs master cylinder. I kind of want to run without it, but I also like the idea of relocating it to the battery tray. I autocrossed with ABS not working for a season, and I had no issues once I got used to it, but I am worried about not having a booster. Might make modulating a lot harder, especially somewhere like 10A at Road Atlanta, which is much harder braking than anything I've done before.

I have a new late model e30 coolant resevoir, and the Z3M coolant pipe. I bought the m3 res. because it popped up on the forums and I wanted to have the option of running it. I think it looks much cleaner and it mounts really high, which is always good.

I put a deposit on a set of Status Gruppe V3 headers yesterday. I barely missed a set of equal length, stepped Kromer Krafts a couple weeks back and I'm kicking myself for that. The SGT's seem to be a pretty good option though. They are made in America and fitment is supposed to be great. Also, finally got to cut up my brake pedal for the Massive kit yesterday. I am in the middle of changing jobs, so finishing all that up and getting all of my tools home (Yay!) has taken up a lot of time. Here are a couple pics of the pedal. Not hard to do, just make sure your measurements are right, supposed 6.4:1 pedal ratio will cause problems, and the difference between 6.2 and 6.4 is only a couple MM.

[golde30]

why run the dual mass flywheel with a sprung hub m5 clutch? i think you may want to run a LTW flywheel, or a solid disk clutch. thats the way they are paired from the factory.

[Jb325is]

why run the dual mass flywheel with a sprung hub m5 clutch? i think you may want to run a LTW flywheel, or a solid disk clutch. thats the way they are paired from the factory.

Well I want to run the dual mass to help with harmonics. I've always bought e34 m5 clutches for everything, so when I decided to run a ZF310/20 it was an obvious choice, I didn't even consider the sprung hub though. I'm going to read up on it a little I suppose. People still run the dual mass in m3's when they upgrade to e34 m5 clutches, don't they?

Now that I read up on it a bit it makes sense, my m5 has a sprung hub and a dual mass and it the clutch engagement is definitely a lot softer than my e30 with the same clutch and e12 single mass flywheel. I would definitely prefer the clutch to feel more like my e30 did and less like my m5. I think I may stick with the dual mass and get a solid clutch

[JGood]

I can't imagine it would hurt anything. The reason for dual mass and sprung hubs is harmonics and lash wear from what I understand, running both would just ensure a quiet setup and a safe transmission.

[e30lov]

sub'd

[JGood]

Didn't see your ninja edit before I posted....

Now that I read up on it a bit it makes sense, my m5 has a sprung hub and a dual mass and it the clutch engagement is definitely a lot softer than my e30 with the same clutch and e12 single mass flywheel. I would definitely prefer the clutch to feel more like my e30 did and less like my m5. I think I may stick with the dual mass and get a solid clutch

You may want to talk to someone experienced with clutch setups before pulling the trigger there. Maybe UUC or Bimmerworld, or one of the major clutch companies. From everything I've read, clutch 'feel' or engagement is not related to being sprung hub or single/dual mass, they are purely for harmonics and wear & tear on the trans. The ~1" of movement that the springs provide is not going to change the way the clutch feels as it's engaging at 1k RPM's, that movement would be taken up almost instantaneously with such a vast difference of speed from the crank to the trans input shaft. It's just there to absorb the vibrations with the clutch engaged at idle. When the RPM's are so low, each cylinder fire pulses the crank, and I think that's what causes the chattering when you run a single mass with an unsprung disc. But, ask someone who knows, I'm only regurgitating info I've read.

[JGood]

http://www.uucmotorwerks.com/flywheel/gear_rattle.htm

[nando]

it's not the springs that help with the "rattle" at idle - it's the weight. the mass of a heavy flywheel helps absorb the vibrations. that's why a 318is has that massive flywheel - what is it, 44lbs? I think they filled it with lead or something. :p

but, it makes it drive smoothly.

the springs absorb some of the shock when you let out the clutch. I actually do think having both a sprung clutch and a sprung flywheel would make clutch engagement feel soft. think about it this way - race cars (and hard parkers) use unsprung disks with unsprung flywheels. Engagement is like an on/off switch - there's no slop or cushioning.

[gills]

I can't decide what I want to do about the ABS, its out right now and I'm getting a non-abs master cylinder. I kind of want to run without it, but I also like the idea of relocating it to the battery tray. I autocrossed with ABS not working for a season, and I had no issues once I got used to it, but I am worried about not having a booster. Might make modulating a lot harder, especially somewhere like 10A at Road Atlanta, which is much harder braking than anything I've done before.

I have a new late model e30 coolant resevoir, and the Z3M coolant pipe. I bought the m3 res. because it popped up on the forums and I wanted to have the option of running it. I think it looks much cleaner and it mounts really high, which is always good.

I put a deposit on a set of Status Gruppe V3 headers yesterday. I barely missed a set of equal length, stepped Kromer Krafts a couple weeks back and I'm kicking myself for that. The SGT's seem to be a pretty good option though. They are made in America and fitment is supposed to be great. Also, finally got to cut up my brake pedal for the Massive kit yesterday. I am in the middle of changing jobs, so finishing all that up and getting all of my tools home (Yay!) has taken up a lot of time. Here are a couple pics of the pedal. Not hard to do, just make sure your measurements are right, supposed 6.4:1 pedal ratio will cause problems, and the difference between 6.2 and 6.4 is only a couple MM.

Interesting. What kind of problems? Like bottoming out the brake pedal? A couple of mm is probably the tolerance most people will be able to machine to so hopefully they don't shoot for the 6.4:1 ratio in the first place. From his website: "Pedal leverage is increased from a stock 4:1 to up to 6.4: 1, while 6:1 is suggested. Will clear Euro S50 and S52 as well as S54 swaps". Have you thought about going with a Wilwood MC by any chance?

As for the coolant reservoirs, the M3 reservoir goes behind the passenger side strut tower and late model is behind the driver side headlight? I'm assuming the M3 res is the more popular choice. Can you shed a little more light on the Z3M coolant pipe part?

And those headers look great! Great deal. Hopefully they run another GB when I'm ready for this.

[FredK]

As for the coolant reservoirs, the M3 reservoir goes behind the passenger side strut tower and late model is behind the driver side headlight? I'm assuming the M3 res is the more popular choice.

Yes, those are the locations of the coolant expansion tanks. I already had a late model expansion tank, so I figured I'd use it as-is.

Can you shed a little more light on the Z3M coolant pipe part?

It is part number 11537830988. It branches off, similar to how the S52 metal coolant pipe branches off, on the intake side of the engine.

[The Dark Side of Will]

it's not the springs that help with the "rattle" at idle - it's the weight. the mass of a heavy flywheel helps absorb the vibrations. that's why a 318is has that massive flywheel - what is it, 44lbs? I think they filled it with lead or something. :p

but, it makes it drive smoothly.

the springs absorb some of the shock when you let out the clutch. I actually do think having both a sprung clutch and a sprung flywheel would make clutch engagement feel soft. think about it this way - race cars (and hard parkers) use unsprung disks with unsprung flywheels. Engagement is like an on/off switch - there's no slop or cushioning.

Weight: Yes and no... The weight of the flywheel smooths out power pulses from the engine, as you point out. This makes the engine feel smoother to the driver.
However, the weight by itself does not really affect gear rattle. That's what the elastomer in the dual mass flywheel or the springs in the sprung hub clutch do.
So a single mass with sprung hub clutch will still be mostly free of gear rattle, but the driver will feel (somewhat) more vibration from the engine, as well as the accompanying performance benefits from the lighter flywheel.

Springs: It takes, what... 15 ftlbs to bottom out the springs in the clutch hub? They don't do anything for engagement smoothness... purely for reduction of gear rattle.