1985 BMW 745

[gunni]

Sounds like it´s moving along nicely.

Abpout the injectors why not get high impedence injectors now and not have to mess with anything .

[DevInAz]

Gunni - Normally I would just get other injectors but I just spent $100 getting these injectors cleaned before I realized i had to make modifications for them to work. I would also need to spend at least $300 for a decent set of big injectors for this car.  I was thinking if all I needed was some power resistors for a total of $30 I could use my old but clean stock low imp injectors.

[DevInAz]

[mattias]

You can add a lot of timing to that map, especially on load. Could be it's getting knock sensitive if you add like 10 degrees up top - I wouldn't know as I haven't tried tuning this restricted engine with stock manifold and turbo. Like the stock injectors - those are usually  replaced with better stuff.

Simple manifold adapters to stock N/A cast headers and a Holset HX40 will probably yield more torque at every rpm on the same boost, and spool as quick or faster. With your goal of 500 hp/tq that is where you're headed anyway.

[DevInAz]

You can add a lot of timing to that map, especially on load. Could be it's getting knock sensitive if you add like 10 degrees up top

Do you think adding in 3-4 degrees is a lot? I'll add some in and post up the map so you can tell me if its still to conservative.  Thanks Mattias

[DevInAz]

[mattias]

It's a starting point, sort out the fuel (VE table hits lambda target) with that ignition map.

You'll notice where the torque peak is from the VE map, you can be more careful at that point. Where VE drops at higher rpm you can usually add in many degrees more.
Run at least 30 degrees timing at 20-60 kPa from 2000-3500 rpm. This is where the fuel economy comes in.
Rarely visited load cells, but above 3500 rpm and below 80 kPa, at no point should you be lower than 30 degrees. 35-40 degrees at 20-40 kPa is more likely.

When you aim for 500 hp/tq without the horrible 745 turbo gear, here's what you should aim at and it may still be a few degrees conservative (this map is for an M20 turbo engine on pump gasoline). The larger bore on the M30 means you can also use a bit more timing on cruise load.

[DevInAz]

Here are my factory injectors that are 30lbs. They are 2.9ohms low impedance injectors. I was talking to the guy that cleaned these injectors for me and he is under the impression I just need 10ohm 10watt resistors in each signal wire running to each injector.  BUT on the webshop they sell power resistors that are 50w.  I'd rather not harm this board that is running great. Does anyone have any suggestions?

[gunni]

I used some 50w 6ohm resistors on 2.5ohm injectors once and it worked like a charm. Ran them like saturated injectors.

It´s better to have higher wattage resistors then not.

[DevInAz]

Awesome thanks Gunni! I'll go pick some up and wire them in tonight.

[DevInAz]

Here is what maxed out injectors look like  ;D  13lbs injectors with 6psi on a bmw m106.

http://www.box.net/shared/uoph9lbszo9nya42sa8z

i really need to get my real injectors installed in this thing.

[DevInAz]

I wired up my resistors. I used 50watt 10ohm resistors with a 1 percent tolerance level. I've been tuning and driving on the for a week or so now. I used connectors inline from the vems to the resistors out to the injectors. If I ever need bigger injectors it will be an easy plug and play setup to remove the resistors from ever being there. pictures will be up soon.

[DevInAz]

http://www.box.com/s/2ok7sh792k74yxo6nsaj       < --- Config
http://www.box.com/s/91dboiurhgsp6jr2vecb         < --- Log file

I've wired up and turned on the my idle control valve.

[DevInAz]

Latest log:   http://www.box.com/files#/files/0/f/244953348/1/f_1903548606/0/comment

Can someone tell me if my accel enrichments look ok in this log?

Here is my latest config:

http://www.box.com/files#/files/0/f/244953348/1/f_1903547556/0/comment

here is a picture of my spark plugs after a few thousand miles of daily driving on them. They look like they are running a little lean to me but my fuel mileage is really bad. I have a 20 gallon tank and i'm getting about 240 miles out of each tank. Thats only about 12 miles per gallon which is awful! Most of these cars get about 25mpg. I should do a compression and leak down test on this motor to see what that is sitting at. The BMW m106 is a 8:1

[gunni]

Without looking at the logs I´ll ask at what lambda do you target your cruise?

I´ve seen on M30´s they can run 1.05 rather easily without any side effects for cruise.