ECU #153

[Wh33lhop]

That's what I thought--wasn't sure how you'd adjust timing without coil-on-plug anyway, but I figured they did it somehow, maybe within a very small tolerance, since most "chips" require premium and obviously don't affect the compression ratio of the engine.

[nando]

you don't need COP to adjust timing. the cap and rotor doesn't really have anything to do with it either. it's controlled by the computer, it just doesn't have any feedback to know where to adjust it.

Even ECUs with knock sensors don't, they have a base timing map for "good" conditions (the right fuel, no carbon build up, well running engine) and then the sensor can retard timing from there (87 octane from AM/PM, no maintenance, heavy carbon build up). They never advance timing based off a knock sensor.

a chip just has an much higher advance programmed into it than the factory. the JC maps I've seen were pretty aggressive with 42 degrees peak. stock is ~37.

[Wh33lhop]

you don't need COP to adjust timing. the cap and rotor doesn't really have anything to do with it either. it's controlled by the computer, it just doesn't have any feedback to know where to adjust it.

Even ECUs with knock sensors don't, they have a base timing map for "good" conditions (the right fuel, no carbon build up, well running engine) and then the sensor can retard timing from there (87 octane from AM/PM, no maintenance, heavy carbon build up). They never advance timing based off a knock sensor.

Gotcha, it's just two preset maps.

a chip just has an much higher advance programmed into it than the factory. the JC maps I've seen were pretty aggressive with 42 degrees peak. stock is ~37.

I'm curious how you'd do this with the power going through a dizzy. I can see maybe 15 degrees of timing adjustment without rotating the cap relative to the rotor, as that's about all the contact overlap you get.

Obviously it's possible, I'm just curious how.

[nando]

I'm curious how you'd do this with the power going through a dizzy. I can see maybe 15 degrees of timing adjustment without rotating the cap relative to the rotor, as that's about all the contact overlap you get.

Obviously it's possible, I'm just curious how.

you are right to think that. there is a limit to how far you can advance or retard, but M20s that operate outside of that range are few and far between.

[Too Short]

I know this is an old post and everything but can i put an after market 173 chip in place of the 153 ecu?

[nando]

only if you have the 173 ecu to go with the chip..

[Too Short]

thanks

[transatlantic0207]

a couple of months old buuuut.....
I have two ecus and I have a 1987 325is 5/24/1987 build date
I am currently running the red label ecu which came stock sans the TMS chip (i forgot the numbers)
I have a spare yellow label 380 ecu

Will the chip that I have in the red label ecu work in the yellow 380 ecu? And is it even worth it to put the yellow ecu in my car to replace the red?

[nando]

colors don't mean anything. What matters is if it's motronic 1.0, 1.1 or 1.3. you can swap any 1.1/1.3 ecu into any car and it will work.

[transatlantic0207]

colors mean everything when there is a specific number associated with them
for instance the yellow one is always 380 and mine the red label is always 525 and they're both motronic 1.3

so is their a difference between the two? my stock red one 525 is from 1987 and the yellow 380 is from 1991 both from m20b25 cars

[nando]

yes but you're assuming the colors are always the same for a particular #. what is really important is what # it is. the color isn't trustworthy or useful.

also isn't a 413 from an E36?

[transatlantic0207]

with all due respect i've yet to an ecu that didn't have a color associated with the specific number, you're right though it is important to double check what number you're actually putting in your car....anyway would it be beneficial to put the newer ecu in? and will the chip I have work with it?

[transatlantic0207]

before you catch me, i listed an ecu for the wrong engine...the red label I have is 525

[nando]

no real benefit to the newer ecu, use whatever ecu you have that you know will work with your chip.

[transatlantic0207]

smart advice, thanks
no need in screwing around with what works!