N52 Swap Discussion

[LukeJ]

Cool video!

Congratulations on your new personal best lap time!!!

[nando]

heh, boiling the PS fluid - maybe an underdrive pulley would help that? BMW of course would put in a PS cooler. I actually have one I want to get rid of...

[hoveringuy]

Track event #3 on the N52 and everything is coming together. Event #1 I was in limp mode and way down on power. Event #2 it was making power but not smooth at all. Yesterday it was doing what it's supposed to do, haul-ass!

Some of the other issues also seem resolved. The coolant temps hovered at 190F +/- a few degrees the entire day. No oscillations or spikes. The motor will normally warm to around 205F before the MAP triggers and then it stays at 190 the rest of the time.

The cold air intake works GREAT. Intake temps just a few degrees above ambient.

Motor pulls happily from 4k to 7500 again and again...

Zero issues with oil pressure, not even a concern. No vibrations, thumps, driveline imbalance. Just smooth.

I had a puddle under my power steering rack my first event and thought it might be the rack; turns-out my PS fluid and resevoir are getting extremely hot and it had expanded out of the resevoir. So, that's one system that isn't happy with the high revs.

Other than that, I totally held my own in the advanced group. Ran a 1:38 (new PB!) in the first session and increased top speed to 133. Got passed by a GT350H on the straight, after he couldn't catch me in the corners, no shame in that. Let a bad-ass Honda Civic by that was just a cornering machine.

I'm running the 3.73 diff, and even with the 6th gear I'm turning about 3500 rpm at 80mph, so it's slightly annoying on the freeway but perfect for the track. I also have a 3.25 and I'll need to think about switching back to that.

The car goes back to the dyno today to evaluate the tune with the MAF, will hopefully find a little more smoothness and power.

https://www.youtube.com/watch?v=-uy--aNyIMg

[LukeJ]

Check another problem off the list.

Version 2.0 of the heater hot water hose is a nice touch as well.

[hoveringuy]

Hot air intake problem solved. This is a Vibrant 10952 bellmouth that fits perfectly in place of the high beam. Filter is up and above it internally, so rain shouldn't be a problem although I may add a screen.

The plastic divider is version 1.0 but seems highly effective, intake temps are just a few degrees above ambient for anything but being stopped.

[nando]

I did the first oil change and it was super-duper easy. The drain plug uses a 3/8" square drive which, conveniently, is any 3/8 ratchet wrench. No sockets required!

First, the magnetic drain plug works *great*, although I don't hope to see a pea size dollop of fuzz on it next time...

Total oil drained was just shy of 4 3/4 quarts, so with trapped oil I will call 4 3/4 to 5 quarts the capacity. I had it filled slightly below the top of the wing by around 1/4" so it would easily hold 5. I don't know if that's "good" or "bad', the M20 holds about 4.5 quarts and an M50 around 6 quarts. What's more important is that the oil control seems great, I haven't seen a flickering oil light once yet whereas I did get it on the M54 with a higher capacity.

It's probably from your custom pan. There's not really anything magnetic in the engine that should have any wear at all. Maybe the head, but I've never seen wear on the valvetrain even on engines with a lot of miles (because everything has a roller bearing).

5 quarts is probably fine - the stock sump is 7, but it seems like the first quart is mostly for safety/cooling. the 3 liter N52s don't seem to burn oil (until they get a *lot* of miles) so unless you have a bad leak the level should stay consistent. There's always that heat exchanger thing for the oil filter housing, although it is a bit ugly.

[TobyB]

even if the motor will easily spin to 8k on stock internals.

yeah, you're totally not selling this one.

t
may sell his M54 if you two keep this up...

[hoveringuy]

I did the first oil change and it was super-duper easy. The drain plug uses a 3/8" square drive which, conveniently, is any 3/8 ratchet wrench. No sockets required!

First, the magnetic drain plug works *great*, although I don't hope to see a pea size dollop of fuzz on it next time...

Total oil drained was just shy of 4 3/4 quarts, so with trapped oil I will call 4 3/4 to 5 quarts the capacity. I had it filled slightly below the top of the wing by around 1/4" so it would easily hold 5. I don't know if that's "good" or "bad', the M20 holds about 4.5 quarts and an M50 around 6 quarts. What's more important is that the oil control seems great, I haven't seen a flickering oil light once yet whereas I did get it on the M54 with a higher capacity.

[nando]

I'm pretty sure the crimpers I have will work just fine for those, they were like $40. I can't remember where I got them now, I'd have to dig way back. I use them for basically all the BMW wiring I've done, they work on all but the tiniest Tyco pins I've tried so far (I have another set I use for those). Actually I'm pretty sure I have some of those pins too, lol.

[hoveringuy]

I wanted to document the pins I used for wiring, I mentioned to Luke that I tried to avoid splices to a fault and I did that largely by re-terminating wires with the MSV70 and IVM pins to the largest extent possible. The proper crimper for the job cost like $1000, but any pair of needle nose works fine and I put a tiny dab of solder to make sure they didn't pull loose (don't let solder wick up to where the wire insulation is held)

The connectors come in 3 sizes and are in the Tyco Micro Quadlock series, MQS interconnect system. See Catalog 1307999.

The smallest is used for signals such as temperature sensors, eccentric shaft, crank position and such. Tyco PN 928999-1 Digikey P/N A123797TR-ND

The medium one is used for things like injectors that draw some current but not too much. These are MQS 1.2 series. Tyco PN1355553-1 or 1355556-1. Digikey doesn't seem to carry these.

The large ones carry power for O2 sensors or VVL motor, etc. These are MQS 1.5 series. PN 968075-2, Digikey has them as A122193TR-ND

[nando]

Cool! I heard you were making progress. The second DME I sent to Steve (which I think is yours anyway) just needs the 3-stage mode enabled and the rev limiter tweaked. Probably will re-base that file when Steve revisits the dyno again.

There wasn't really a torque dip, it was a problem with the modeling in the no-MAF mode. It seems like it was switching between operating states suddenly at around 2krpm. So we switched to MAF based for now. I don't know if Steve will want to revisit the no-MAF mode again, it should be able to be just as smooth (if not smoother) but sorting out the model might not be easy and at some point, you just want to drive the car.. lol

And as much as I like the 3-stage, it basically makes it impossible to make more than about 240whp, because you can't rev it past 7krpm, even if the motor will easily spin to 8k on stock internals.

[hubcapboy]

So what you need is like... an intake manifold that routes a little higher and fixes your 2000 rpm torque dip, right?

I've heard legend of such a device.

[hoveringuy]

I think I'll do an "all of the above" approach.

-6" spun aluminum venturi to replace my high beam
-With a 90 at the TB, 3.25" MAF tube, and then either a 45 or 60 (I ordered both...), I should be perfectly aligned to have the filter over the ABS
-I'll put a divider between the radiator outflow and the filter.

The N54 TB is bigger than N52, so the N52 intake stuff doesn't fit.

Like a lot of things, I think this will be my "rev 1" version as I discover what works and doesn't work.

I don't really get the Castro style box; once the corner is sealed-off, where's the air coming from?

[hubcapboy]

The N54 manifold creates a challenge because of the angle of the throttle body:


vs the N52:



I think you need to turn up before you start moving forward so you get over the pump, even if that means moving the PS reservoir. This is another frankensteined engine combo with an n54 manifold, but I don't know what factory rubber piece that is on the N52 throttle body:




That's from a recent post over here if no one else recognizes it: https://www.romraider.com/forum/view...p?f=60&t=16947

How much angle do you get out of the factory n52 plastic elbow? I bet you have one of those.

[nando]

MMMmmm, hot air intake! :p

I have a KAmotors intake on my M20. Ehhh.. we can figure out something better than that. But it at least shields the filter I guess. I think most people though, just run an open filter. Heck, amost 99% of N54/N55s I see with mods have the open filters right on top of the engine.

If you could get that elbow/filter a little higher and closer to the headlight, it wouldn't be too hard to form something with a sheet of ABS or something, at least to shield it from direct airflow off the radiator.