Messages

1

Engine management / Re: Can this work for an M42 (MAF conversion)

« on: February 08, 2023, 04:36:19 PM »

I am not 100% sure what all Split Second has these days, but I think they have a system that can deal with temperature. That's the easy part. The trickier part is that the ECU still expects an air temperature input signal, and just about every IAT thermistor will be different between models. The M10, M20B25, M20B27 and M30 AFMs all have different IAT thermistors (I measured their resistance curves). A universal one is tricky in that sense.

Then there is the fact that every AFM and MAF has a different transfer function (air flow vs voltage relationship). That is tough to guess at, and you will really want to dial a universal type unit in on a dyno, which is $$$.

Finally, there is the issue of intake resonances and back-flow. A MAF can measure those things, but the ECU just cannot handle a sinusoidally pulsing voltage input since it is designed for the AFM which damps those things out. Look up Nyquist's Theorem and Aliasing. At least on the M42, you can't just plug in a MAF. The converter I built involved years of experimenting, and ultimately a solid 2000+ lines of microcontroller code and careful digital+analog filtering to get right. In short there is literally, honest to god, no way to just plug a MAF into the M42 and expect it to work anywhere as well as the stock AFM.

Just find a used AFM on the forum for $30. No big expense, and it swaps right in without any nonsense. Unless you are going to try to make 200+ HP with your M42, the stock AFM isn't causing any loss of power.

I am trying to run m42 (In a euro M43 1.8 Z3) with itbs and for that I am running a motronic 1.7.3 and will need to run without the AFM.
So I want to use the AFM Limp Mode table (Alpha N), but I want to keep the IAT corrections.
Is there any IAT sensor with a similar curve  to the thermistor in the AFM that I could use? (the one from the m44 airbox  for example)
Or could you help me figure out where is the transfer function in the ecu code? so I could change it to the new sensor

Thanks

2

Engine + Driveline / Re: VW hydro lifters?

« on: January 27, 2023, 11:56:33 AM »

Hey guys,
I found this video about having to remove the spring inside the lifter to make them true hidraulic lifters or the camshaft would wear very fast.
Here is the video:
https://www.youtube.com/watch?v=ty-sdftGx40

Does this make any sense?
Do I also need to do this on the lifters on this thread?

Thanks

3

Swaps, Turbos, Buildups / Re: ITB's info/projects

« on: January 27, 2023, 11:22:46 AM »

Are 38mm throttle bodies good for a itb setup in a fairly stock m42?

4

Swaps, Turbos, Buildups / Re: M42/M44 ITB Kit Design

« on: January 27, 2023, 10:54:09 AM »

Would 38mm throttle bodies be enough for a fairly stock m42?

5

Engine + Driveline / Re: E36 M42 stock exhaust tubing

« on: August 18, 2020, 08:23:04 PM »

Thanks for the reply,
My engine is mostly stock, the only mods are :
- Modded Airbox with K&N panel filter;
- e90 Coil on Plug
- Camshaft sprokets tuned for more overlap.
- Custom Chip with 7000rpm redline and ignition tuned for 98 octane gas.

I am asking because everywhere on the web I find the max recommended power for 2" is 140hp and 2.25" around 180/190hp, and even hondas b series that have around the same displacement/power as our m42 use 2.25" stock exhausts.

The idea is to run a sport cat, a resonator and a higher flowing muffler at the end.
Do you thing I would benefit from a full 2.25" exhaust or should the 2" and increased flow from the mufler and cat is enough.

6

Engine + Driveline / E36 M42 stock exhaust tubing

« on: August 14, 2020, 03:32:54 AM »

Hello,
I was checking here on the forum what diameter is the stock exhaust and what I found was that it is 2.25” (57mm) before the resonator and 2” (51mm) after.
The thing is that I used a caliper to measure the exhaust on my car and it is 2” (51mm) before the resonator and 1.88” (48mm) after.
Is this normal?
I am planing on upgrading the exhaust, should I keep the 2” diameter through all the exhaust or increase it to 2.25 ?

7

Engine + Driveline / Re: e90 coils for M42 COP conversion

« on: January 22, 2020, 12:29:19 PM »

Yes I made my own harness because like you I like to keep my mods reversable if I change my mind later.
I used the parts  that I stated on the previous post, one 12521718125 plug to connect to the exisiting car harness and four 12527519996 plugs to connect to the e90 ignition coils.
I also used a rubber boot to protect the cables from the 12521718125 plug that I can get you the part number if you want;

I dont think you will need this two parts:
Male pin terminal #12521718125
Lock Ring #12521718127

Here it is

Thinking of doing this to my 95 318ti (m42) with Turner/Conforti chip and “Fogged”.

Wondering what you used for your wiring harness or did you make your own?

I’m planning to make my own using:

Male pin terminal #12521718125
Plug housing #12521718126
Lock Ring #12521718127
Male Pin Wire Connector #61131376193 1.0-2.5mm

To connect this to my existing ignition coil pack harness so if this COP does not work I haven’t destroyed any of the original wiring harness.

Then I was going to use the socket shown #12527519996 for connection to each ignition coil.

Any additional help is appreciated.

8

Engine + Driveline / Re: e90 coils for M42 COP conversion

« on: January 03, 2020, 05:07:29 AM »

Found out one of my friends did this to his m42 5 years ago and is still going strong.
He used bosch coils used on the latest e46, e90 and minis.

Here are the part numbers from real oem https://www.realoem.com/bmw/enUS/showparts?id=BL93-USA-05-2006-E46-BMW-M3&diagId=12_1104

I got the pinouts from newtis.info
The plug pn is 12527519996 and the pinout is :

   1   Trigger      
   2   Ground      
   3   12v


My car uses a round plug with 7 pins pn. 12521718125.
only 6 pins are used and the pinout for the plug is :

      
Pin assignment, primary connection      
Pin 1 = terminal 1 of ignition coil 1      
Pin 2 = 12v
Pin 3 = Ground
Pin 4 = not allocated      
Pin 5 = terminal 1 of ignition coil 4      
Pin 6 = terminal 1 of ignition coil 2      
Pin 7 = terminal 1 of ignition coil 3

Hope this helps anyone trying to upgrade the coils on their m42s

9

Engine + Driveline / e90 coils for M42 COP conversion

« on: June 21, 2019, 05:17:31 AM »

Hi,
I am trying to do a Coil on Plug conversion to my M42 and i found that the e90 ignition coils are cheaper and more compact than the M52s that everyone seems to use.
Has anyone here used this coils in a M42?

Regards

10

Swaps, Turbos, Buildups / z3 1.8 M43 swap to M42

« on: May 15, 2019, 05:15:28 AM »

Hi All,
I am in the process of swaping my M43B18 with a cracked head from my BMW Z3 for a M42B18 from a e36 318IS.
I want to keep the wiring harness of the M43 so i will change the two M42 coolant sensors and put the double temperature sensor from the M43.
I am also getting a M44 intake manifold and TB so i can use the DISA and ICV from the M43.
The problem is that the ICV from the M42 is two pin and instead of the three pins of the M43/M44 (and my harness) that i will be using, will this ICV work with the M42 318IS ECU?

Regards.

Edit:
Here are the part numbers from realoem.

M42 ICV 13411433627

M43/M44 ICV  13411435846

11

Swaps, Turbos, Buildups / Re: m42/m44 stock manifold turbo adapter

« on: August 16, 2018, 11:17:39 AM »

Where did you buy this adapter? I am turboing my z3 with m43 engine and if i could find one of this adapters i would maintain the stock manifold.

Regards