N52 Swap Discussion

[Caperix]

With the front sump design I think the wings like the moroso pan would be best as you could get the best ground clearance without loosing capacity. The boxes shape may be easier to fabricate as well.
Back to the ac compressor, n52 e70's use a separate belt for the compressor like the m54 cars.

[nando]

Interesting. I wonder what belt they use for the main pulleys - I'm not planning on using it, so I was trying to figure out another way to route the belts properly. Some guys just put on a shorter belt, but the angle the tensioner is at doesn't really inspire confidence it won't slip IMO.

[Caperix]

The e70 setup uses a different tensioner with a upper & lower pulleys. I'm having trouble finding a good shareable image, but this gives you an idea. https://xoutpost.com/bmw-sav-forums/...t-routing.html
I am leaning towards the n52 for my wife's e30 when the n20, or more likely when the 4hp24 fails. She wants to keep it auto, but a dct will bolt up to the n52, so that would be a compromise. Even if it brings its own problems.

[nick496]

Hey hubcapboy, you've done lots of photos of the exhaust side, but just curious about how the intake side clears along with the brake booster.
I might have skipped over the thread, but what is your plan there? 3 Stage intake with E90 booster?

[hubcapboy]

I mentioned it somewhere back. I’m planning on abandoning the power booster and retaining ABS. I don’t like the idea of a single circuit brake system on the street (having blown a front brake hose on my truck in the past) so I expect to do this with a balance bar, cylinders and pedal box with the reservoirs under the hood.

I’ll take a look at booster clearance. If I get lucky and something fits then great. Once I added the cost of a new e30 master cylinder to a booster setup the separate cylinders started to look affordable.

I’m definitely keeping the 3-stage.

[nando]

It's funny how different some of our goals are. I think that's totally fine, and probably helps in some ways, while making it more confusing to others.

So, I'll just state my own goals here for my swap plans:

ABS/boosted brakes is a must - having daily driven manual drum brake cars from the 1960s with big V8s - yeah, no thanks on the non-boosted brakes and no ABS. The X3 booster seems like a great choice. I'll do whatever that takes to keep boosted brakes and ABS.

3-stage vs N54 manifold - well, I still can't get over the sound of the E46 M3 CSL. And I see the N52 as an evolution/brother to the S54. The 3 stage likely means I can't run a brake booster, the N54 manifold has a lot of compromises IMO (although it's dirt cheap, bolts up, and is proven). So I'm going my own way with retrofitted S54 throttles. I believe they will suit, even if they're slightly too big. And the sound should be epic, plus I retain safety backups that a hacked up manifold doesn't.

A/C - I fully recognize A/C is a must in many parts of the US. I could never live in Arizona or Georgia (I've spent time in both). But let's be real - it's 75 degrees in my house right now and I think it's hot. Some of you guys would probably be turning on the heater. A/C is just not a requirement where I live - it's a luxury, and one I don't mind compromising to have what I really want (300bhp, 8k redline, less weight, CSL sounds).

edit: I forgot #1 - I have an ix, so I want to keep AWD. That complicates the oil pan and transmission - one of which is fully solved..

[nando]

Oh, I forgot a couple more!

Power Steering - I'd like to keep it, but I think I could live without it. On the ix, I'd take a faster ratio rack over PS any day (and there are realistic options), but both would be a holy grail of sorts. Eliminating it would obviously be simpler and lighter. I could go either way.

Gauges/diagnostics - the E30 has at the same time advanced diagnostics (for even the 1990s) and is also very primative. I'd like to at least keep what it already has. I could honestly live without a coolant gage - it works fine on the E90, and the way these are programmed would make an analog gage mostly useless anyway. But I'd love to keep the oil level indicator on the check panel functional, for one. The MPG gage should be pretty easy (I already have the convertor board).

A working OBD2 port is definitely a requirement, but that is also pretty trivial IMO. And the diagnostics on the N52 are generations above what you get with any stock E30.

[nick496]

Cheers guys. Considering the swap myself, and trying to figure out if I can keep Power Steering, Brake booster (though not ABS), and AC while using the 3 stage intake.
Made a little more complex on my end as I'm down on the other side of the world with RHD, so headers are a bit more of a pain.
Hopefully fairly achievable.

[hubcapboy]

I haven’t thought of a reason why power steering can’t be retained. I think the n52 pump is conventional... I hope I haven’t overlooked that.

The car this is all going into already has the 2.7 turn z3 rack, which is a phenomenal improvement over the 4.0 turn factory e30 power rack. The biggest difference for me isn’t that it’s faster at the center, but that you rarely have to change your hand position (for most corners you can just cross over) which means you never lose track of center.

Don’t forget that without power, steering input effort increases with the reduction in rate... I can’t turn the wheels sitting still without the engine running, and I could with the factory rack. On a track car you could easily go with the fastest rack without power, but I have to be able to parallel park.

[hubcapboy]

The brake booster is the only thing that should conflict with the 3 stage. Unless it’s hopeless, I’ll probably take a swing at finding a smaller booster that’ll work, but looking at the sliver of clearance on the other m5x swaps I think it’s probably a nonstarter.

looking at how it’s set up I expect that it’s more work to delete ABS, since you have to re-route the lines.

[nando]

It's more of an ix thing. The simplest and cheapest way to get a faster ratio is to send your rack to Britain, but it can only be manual. Someone figured out you can use an X3 rack that (mostly) lines up, but it's a bit expensive, and the tie rods need to be shorter which messes with steering geometry (Ackerman, bump steer, etc).

So it really depends on which compromise you're willing to live with - better geometry and harder input, or power input and potentially worse handling? I don't daily the E30, so I'm leaning towards manual.

[nick496]

The brake booster is the only thing that should conflict with the 3 stage. Unless it’s hopeless, I’ll probably take a swing at finding a smaller booster that’ll work, but looking at the sliver of clearance on the other m5x swaps I think it’s probably a nonstarter.

looking at how it’s set up I expect that it’s more work to delete ABS, since you have to re-route the lines.

I look forward to your progress :) I would be more inclined to swap to an N54 manifold if it doesn't fit, but as Nando says, our end goals are slightly different.
You would think that, but I don't have ABS, so it's more work for me to retrofit it :P

[LukeJ]

I made some discoveries in the last week or so. One thing I'd like to mention is the height difference between the stock E30 M20 (47.5mm) engine mount and the Z4 E85 (67.5mm) engine mount.
The Z4 mount is 20mm taller than the E30 mount. Sorry about the reflection off of my calipers.



I was also able to get into the machine shop for a bit and I machined the right side E85 mount arm. Once that was done, I could test fit the two different mounts. It turned out that the E30 mount that I planned to use is too large in diameter to fit down flush against the mount arm. The E85 mount fits fine, but then there's the 20mm change in height towards the hood.... It looked like the Garagistic 80A mounts were smaller in diameter, so I'll find out later in the week. I could probably machine the E30 or 80A mounts to fit, but it would be better if it didn't need it.

[LukeJ]

I was also able to machine the left side E85 mount arm. I haven't had the parts welded yet. Here's what I'm trying to do.

[nando]

That's a cool idea. Surely, easier than fabbing an entire mount! But it does require you have a machine shop and some skill. :p