PDA

View Full Version : BMW 5 Series E28 81-88 (installing an EFIE, and other info)



Eli87
01-27-2009, 02:13 PM
Greetings everyone,

I've recently got my cell running in my 1986 BMW 535i, I have started looking into installing an MAP/MAF Adjuster.

I have found this information on a BMW forum. MyE28.com


The air metering device on E28s is an AFM, not a MAF -- no E28s came stock with a MAF. While the objective is to end up with a measurement of the total amount (by mass) of air that is going in, the function and method of signal interpretation is entirely different.

An AFM is not a "mass flow device." Air flowing through the AFM causes a spring-loaded "flapper" door to deflect an amount proportional to the dynamic pressure of the flow. The AFM sends both flapper door angle and temperature to the ECU in separate signals. The ECU interprets the flapper door angle as dynamic pressure and combines this with the temperature reading to determine the mass flow.

A MAF is a "mass flow device." The ECU interprets the cooling of a heated wire element in the MAF to determine the mass flow. The lower the temperature, the greater the density, and/or the greater the volume passing over the heated element, the greater the cooling. Again, no E28s came stock with a MAF.

I could see the voltage change in the AFM sensors being very similar as MAF or MAP voltage change. My concern is that there are several sensors determining what the computer sees, and all the variability of that

So has anyone installed a MAP/MAF adjuster in a BMW with an AFM or an automobile with a similar air flow monitoring device. Or have any ideas on how to deal with something like this.

Any other tips or insight dealing with HHO and BMW's would be awesome.

Thanks, these forums are great and have help me greatly already.

-Eli

Eli87
01-28-2009, 02:21 PM
Please excuse my ignorance, it appears that I did not know the difference between an EFIE and a MAP/MAF adjuster.

I assumed an EFIE (Electronic Fuel Injection Enhancer) was a blanket term for a device that adjusted air/fuel signals to your computer, but that is not the case.

For those of you that don't know, a EFIE adjusts the signal your computer gets from your 02 sensor, while a MAP/MAF adjuster adjusts the signal your computer gets from your MAP/MAF sensor. It seems so simple.

So for my application (in my BMW) I have decided to go with an EFIE because my air/fuel monitoring device in my intake (MAP/MAF) is an AMF (as you can read above), and it just seems simpler to use the 02 sensor to modify what the computer is seeing. I'll let you know how it turns out.

Anyone have any input?

Thanks, and I hope this helps anyone else who might one day be in this predicament.

-Eli

burntdiesel
03-22-2009, 01:06 PM
I have a 87' 528e with around 250k on it. I have been dabling with hho for about 6months now. My first design was a wet bath +-+-+ config. Intalled my gen for 3months and saw a average of 3-5 mile increase with no additional electonics. Over the winter I have been doing a redesign on the generator. The current design is -nnnn+nnnn- using corrogated ss in a wet bath. I have just recieved a pwm and a efie. Soon to be installed. Hopefully this time my mileage will hold a constant and hopefully gain more with the use of the efie.

Marlon
02-09-2010, 04:28 PM
I had some great results, I turned 18-20 mpg into 26-30 mpg, here's how:

12 plate wet cell, mounted near the battery behind the right side headlight. 2pos 2 neg 8 neutrals. Relay switched off the coil.
30A fuse, Bubbler, flash arrestor, check valve
1/2 tsp sodium hydroxide per gallon
3/4" O2 sensor extender

Great mileage, easy access for maintenance and check out these smog results.
http://myhhohybrid.com/images/smog.jpg

hymer
04-19-2010, 03:12 AM
I had some great results, I turned 18-20 mpg into 26-30 mpg, here's how:

12 plate wet cell, mounted near the battery behind the right side headlight. 2pos 2 neg 8 neutrals. Relay switched off the coil.
30A fuse, Bubbler, flash arrestor, check valve
1/2 tsp sodium hydroxide per gallon
3/4" O2 sensor extender

Great mileage, easy access for maintenance and check out these smog results.
http://myhhohybrid.com/images/smog.jpg

Marlon, tell me please what kind of O2 sensor extender you have used?

I am new to this and have just started to geather information about parts I need for my BMW 730i 1992 strait six M30 engine.

I will be very glad to receive any information for HHO generator on BMW and electronics need to be used for that.

Thanks!

hymer
04-19-2010, 03:15 AM
I have a 87' 528e with around 250k on it. I have been dabling with hho for about 6months now. My first design was a wet bath +-+-+ config. Intalled my gen for 3months and saw a average of 3-5 mile increase with no additional electonics. Over the winter I have been doing a redesign on the generator. The current design is -nnnn+nnnn- using corrogated ss in a wet bath. I have just recieved a pwm and a efie. Soon to be installed. Hopefully this time my mileage will hold a constant and hopefully gain more with the use of the efie.

Can you please tell what kind of pwm and a efie are you going to use on your BMW and how do you attach them?

Thanks!