N52 Swap Discussion

[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.

[Victell]

This is a 3.25" MAF to match the N54 throttle body... What are the cool kids with ABS doing for cold air?

If you dont mind stepping down to 3" then it looks like the Kamotors intake kit would fit.

[nick496]

No that I've purchased, but you'd probably want something like this: https://castromotorsport.bigcartel.c...ce-air-box-e30
Which puts the filter almost above the ABS unit, and boxes it in there.

I'm sure you'd be able to make something similar like this guy: https://www.bimmerforums.com/forum/s...34#post9817834

[hoveringuy]

"Cause if you liked it than you should have put a MAF on it..."

or something like that.

Yes, the consensus was that I needed a MAF to go from engine model inferred airflow to measured airflow, and what a difference! Whereas before it was rough, hesitated, had flat spots and was no fun to drive around town, the MAF made it perfectly happy pulling from 1000rpm in 5th gear.

This is a 3.25" MAF to match the N54 throttle body.

HELP NEEDED. My intake temps are awful with my hot air intake. What are the cool kids with ABS doing for cold air?

[Bored]

also looking at N55 rockers for the exhaust, should be a similar bump in lift on the exhaust cam (different rocker ratios). I have them on hand, going to stick them on a head and measure the change in lift directly.

So MILVs for the intake, and N55 exhaust rockers? Sounds rad.

[LukeJ]

Your bracket assembly for the DME and IVM is well executed. Thanks for posting it up.

Engine bay looks clean too.... Very nice.

[nando]

also looking at N55 rockers for the exhaust, should be a similar bump in lift on the exhaust cam (different rocker ratios). I have them on hand, going to stick them on a head and measure the change in lift directly.

[hoveringuy]

ok, that just got my attention.

Especially given how much the N52 doesn't weigh...

t
now buying up wrecked E90's...

That's on a motor with stock internals! No Schrick cam, porting, pistons, etc.
There's a bolt on mod for the N52 called MILV (Modified Intake Valve Lift) that increases max lift by 1mm by changing the shim on the eccentric shaft. Takes it from 9.7mm to 10.7mm.

It's making that with 0.5mm less lift than a stock S52.

[TobyB]

with 288hp at 7500rpm,

ok, that just got my attention.

Especially given how much the N52 doesn't weigh...

t
now buying up wrecked E90's...

[hoveringuy]

I'm pleased with how the engine bay looks, it's come a long way from the wiring shit-show when I first had it running! This is using a Z4 harness. I highly recommend Z4 as the base harness because of the IVM, which replaces a tangle of plugs, fuse boxes and relays with one simple, svelte little box. It combines all the relays, fuses and plugs and makes things a lot easier.

Now, the drivers side of the Z4 harness is too short to reach the glovebox, but the e90 harness is perfect, so I swapped all the wires on that side from Z4 to E90. It's simple, trust me, only takes an hour or two. On the passenger side, the Z4 harness is 2 1/2 ft too LONG, but there's not nearly as many wires and they're quite simple to shorten.

Pictures with and without the M3 beauty cover.