N52 Swap Discussion

[nando]

https://www.eliminatorproducts.com/u...l1R0E9PQ==.pdf

I'll let someone else be the guinea pig for this :)

The N52's cyclone oil separator already does a great job of keeping oil out - providing it's not plugged up. I don't think it even needs vacuum to work.

Using the vac pump to boost power though? well, it would be pretty easy to testy on a dyno, lol. But my guess is it doesn't do anything.

[nando]

I believe the exhaust flap is vacuum operated, but I don't know which models had flaps. It doesn't seem to be teed off this vacuum pump for any of the applications I see.

Thinking about the "work" being done by a vacuum pump, it's nice that just capping the outlet will basically fool the pump into thinking it's doing its job (there's no circulation, just a much smaller diaphragm.

We might conclude that the losses from the pump are 90% the bearing and 10% the pumping... there's no fluid being moved, so once it pulls down the pressure it might seriously just be spinning that stick in a "lubricated vacuum"

Only the 330i and 335i have it. you don't need it at all, it's just used tor very low speeds to make for a quiet idle.

[hubcapboy]

https://www.eliminatorproducts.com/uploads/assets/h_testimonials/cll6clRpdHdydlR2MzV1cTBMclhZL2R1SlZJeXkyUENSMTVPUzJXY2VmNmdpbnI1eFo3aGxLc2x6Rmt3aW5VVUhhSHVDMFQrN0JKY0xBNDB5RFl1R0E9PQ==.pdf

I'll let someone else be the guinea pig for this :)

[hubcapboy]

I believe the exhaust flap is vacuum operated, but I don't know which models had flaps. It doesn't seem to be teed off this vacuum pump for any of the applications I see.

Thinking about the "work" being done by a vacuum pump, it's nice that just capping the outlet will basically fool the pump into thinking it's doing its job (there's no circulation, just a much smaller diaphragm.

We might conclude that the losses from the pump are 90% the bearing and 10% the pumping... there's no fluid being moved, so once it pulls down the pressure it might seriously just be spinning that stick in a "lubricated vacuum"

[nando]

so yeah, you can take it out - but what I wonder is, will it just fill up with oil without the arm being in there? Some oil has to be in there to lubricate it - but without the vacuum I think it's just going to pool up in there.

Is anything else other than the brake booster connected to the vacuum source?

[nando]

From the video, it looked like there was holes in the "bearing" of the pump to provide lubrication. I don't think you need that rotor arm at all.

[hubcapboy]

I think that photo is of an n52 pump, but the video is a 4 cyl. And yea... I definitely picked it because it was the funniest.

please do take the one you have apart. I’m very interested in whether removing the arm will create a lubrication problem (is the air pump somehow responsible for getting engine oil into the bearing and pump cavity?) If the arm is that easy to pull out, great... unless it means the bearing burns out or that arm fixture burns through the back of the pump case

[nando]

cool, I'll have to take apart the one on my junk motor, I assume it's built in a similar way, except it has a sprocket on the other side driven by the oil pump.

heh, whenever that guy says "vacuum pump" it sounds like "fuck you pump".

[hubcapboy]

https://youtu.be/Yrcn3unbwOc

skip to 6 min to see what the pump looks like inside. With that sweep arm removed, the vacuum pump just turns into a guide for the oil pump.

honestly if you aren’t using the vacuum pump, pulling this arm before you plug the vacuum port is a great way of making sure you aren’t sucking air into the engine. I looked into this a little bit when I realized I wasn’t going to be using the pump.

[nick496]

Wow, that booster is definitely a game changer.
I guess once you've sorted out the wiring it's all downhill from there.

Looking forward to the finished product so then I can make a start on mine and take from all your learnings along the way.

[nando]

dang, that clears the 3-stage manifold by a country mile.

bending some metal pipes to connect to the other side seems trivial.

Now, I wonder what you'd do with the vacuum pump on the N52/N54. It no longer needs it (it's only used for the brakes). I'd have to look, but I wonder if you can just remove it and plug the hole with something else. One less failure point and no parasitic losses.

looking at the diagrams, the vac pump is driven off the oil pump chain. You probably need the sprocket for the vac pump for all the guides and tensioners to function. But I think if you either left the port on the pump open, or gutted the internals and just left the shaft/gear, you could eliminate the (admittedly minor) parasitic losses.

https://www.realoem.com/bmw/enUS/showparts?id=VB33-USA-03-2006-E90-BMW-330i&diagId=11_3752

[hubcapboy]

OK... this isn't specific to the engine swap, has me pretty excited. I wrote it up over here since it has a broader application than just this engine:

https://www.r3vlimited.com/board/forum/e30-technical-forums/suspension-unsprung/brakes-subframe-arms/9953368-new-booster-option-for-e30-bosch-ibooster

I'm unable to put into words how surprised I am that this fits like this, and how excited I am to use this booster. The braking system was a huge chunk of getting my car back on the road that I was completely holding off on until I had confidence I was going to be happy with the engine.

[nando]

I'm going to be running at least the PT-CAN [edit: this is wrong. D-Can, not PT-CAN to the cluster) to a connector to be able to plug in a Z4 cluster (partially because it looks like its so easy, but also because it might be a route for getting a check engine light... the CEL in the z4 cluster is it's own standalone symbol (not in the main LCD) so it may be possible to just light the e30 dash light from that trace.

Slightly more digging... That L-CAN runs to the OBD plug directly on the E83 X3...

https://www.newtis.info/tisv2/a/en/e...si-sav/weByGnM

based on this description, it's 50x faster than the K-line:

https://www.newtis.info/tisv2/a/en/e...system/20IcTCM

Is there any practical use for this? From the pins it looks like it would be ISO 15765? Does the Z4 software (int the DME flash) even support that protocol?

yeah, it's faster - but, it doesn't make a big difference. Flashing the calibration for MSV70 over K-line only takes like 30-60 seconds anyway.

You can't actually have K-line active with D-CAN, and AFAIK, the Z4 calibration only uses K-line for the DME.

[hubcapboy]

Real-time update: Here's the useful parts of the IVM module from the Z4/X3. This is part number 12637560626:



And I expect it'll replace most of, if not all, of this harness:



Which is a complete mess that I'd just stuff into a box. I was HOPING that this box would have one set of connectors for dash, C101, and power supply, and another set for DME and engine harness (so it was a clean interface between the car and the engine) but that doesn't seem to be the case. Fuse 2 seems to power some stuff that we don't have (DSC, Ebox fan, etc). If the wire run is less than 4' it could be a 15 amp, so I left it in case there was more to power. Pin 13 highlighted in yellow is unfused power to the transmission controller. Weird that it wouldn't be fused here, but whatever. I'll leave it in for now in case I have more than 10-15 amps to add (which I'd stick on Fuse 2)

There may be enough pass-throughs on this junction board to put everything else that goes out to the C101 (like the oil pressure switch, tach). It would be nice if all the C101 connections went here rather than just disappearing to tapped DME wires. (for instance, the tach signal has to go to OBD and C101... they could split here). We'll see.

[hubcapboy]

I'm going to be running at least the PT-CAN [edit: this is wrong. D-Can, not PT-CAN to the cluster) to a connector to be able to plug in a Z4 cluster (partially because it looks like its so easy, but also because it might be a route for getting a check engine light... the CEL in the z4 cluster is it's own standalone symbol (not in the main LCD) so it may be possible to just light the e30 dash light from that trace.

Slightly more digging... That L-CAN runs to the OBD plug directly on the E83 X3...

https://www.newtis.info/tisv2/a/en/e...si-sav/weByGnM

based on this description, it's 50x faster than the K-line:

https://www.newtis.info/tisv2/a/en/e...system/20IcTCM

Is there any practical use for this? From the pins it looks like it would be ISO 15765? Does the Z4 software (int the DME flash) even support that protocol?