E30 Zone

what are the differences between the m20 and m30 airflow meters???

can a m30 airflow meter be fitted to an m20 ???

would it be plug and play ???

I was just reading the new wiki entry on building a 2.8 (clicky) and in the 'other stuff' bit it says that the 535i AFM won't work. It doesn't say why though.

It does work on m20 but makes no difference at all when they are both set up correctly.

has it got a bigger centre bore? And why would it be put on if there is no difference?

This is just a question as i've seen somewhere someone has or had it on their sig 'm20 325 with m30 afm'

its been done alot before used to be a popular mod back in the day, i never bothered. Alot of people say its sh!te alot say its a great mod. Depends who you talk too!

A fairly involved job for not much power gain really.

that was on a standard car though with no other mods, i have cams, bbtb and 6branch, may make a difference, every little helps

Yes do it, with those modifications your m20 afm will be a restriction, the best thing to do is to fit bigger injectors too.
If you do so just fit one thing at the time: fit injectors, start the car let idle for a while and after that fit the afm and start again and let it idle again.

And yes the m30 afm has a bigger bore, so fitting the rubber hose won't be easy.

Just see it like: Would you like to drink a large milkschake at McDonald's through a straw that's like 1/2 the size of a normal straw?

not unless you want brain freeze

I've done it for a play more than anything else, it's got a 50% bigger bore area.

The standard AFM has been shown to be good for 200bhp.

It really needs a lambda sensor for the ECU to calibrate itself properly. The loom for this is in-place, but usually the relay is not present next the DME/fuel pump relay near the nearside shock tower/ AFM under a plastic cover. Also the exhaust do not tend to come with a lambda boss so one will need to be welded on.

The standard rubber hose between AFM and throttle body is under £20 from the dealer, buy a new one, heat it in boiling water and it can be stretched around the M30 AFM.

Try this article http://www.davelength.net/car/bigsix.html

Alex

Mine's slightly different now as I've got LPG running but this is how I had mine fitted.

thanks, did it make a difference, or is not worth the effort?

It's not huge effort or cost, so I'd say it'd be worth a go with your mods, get it fitted and have it rolling roaded to see how it works. That pic was before AFPR too. . . the electrical plug is a direct fit whcih makes life easier . Follow the guy's instructions on the link and get the lambda setup up and running and you'll get cheap extra power IMO

hongkongfuey, are you bidding on some M30 530i yellow injectors? I am. . .

so looking at that build that bloke did, you swap over the circuit board from the m20, afm to the m30 one?

Err, no. I just plugged it in and adjusted the black gear spring tensioner 7 notches (by trail and error) althought the car is not brilliant to start, it does go well!
I'm doing it properly now, I've got a spare M20 AFM to cannabalise and am getting some yellow injectors. I cycle to work so my car is not in daily use, more of a toy to play with!!!

are you going to swap over the circuit boards???

which way adjustment , clock or anticlock wise???

wont the bigger injectors over fuel it?

turned the gear anticlockwise, reduces the spring tension. The yellow 19lb injectors are the ones from the same (M30 3.0L, M30 3.5L, Ford Mustang!!!) car as the M30 AFM so match. This is where the lambda setup is needed for the ECU to know what's going on fuel wise.

Essentially, the M30 uses the same ECU as the M20, just with a different chip, hence fit the M30 AFM, M30 injectors, lambda setup and all should run sweetly!

Ps) I've just ordered 8 yellow mustang injectors posted from U.S ebay for £21. Bargain. I've got an ultrasonic cleaner at work so that will be put to good use!!

If you get the m30 afm ending in the numbers 027 you won't have to switch the circuitboards, it will be plug and play this model reads the same values as the m20 afm .
If you get any other m30 afm then you have to change the circuitboard so that the readings will be off the correct value.

thats cool the one i got is 027

put it on today

i fitted it to the air box, didn't want cone filter( tape is temp until i get some more sealer


the difference in size, the right one is a standard 325 one


i cut the hole in the airbox to fit the larger afm, used the studs from the 325 afm then bolted on

nice job, looks like it belongs there.
Did you get to test it allready? and did you rememberto let the ecu to adjust to it?

i let it idle for a while, gave it a blast home, will check tomorrow, then dyno

How's it going?? getting a chip made by ant will give great results!!
The M30 injectors, are supposed to be an upgrade, they spray in a 4 hole pattern rather than the M20 1 hole type, this supposedly mixes the fuel better giving better economy!!
M20 injectors are good for 200+bhp, but I'd imagine you're getting close to their limit!! I'd personally rather have some spare capacity. Ultrasonic cleaning will be worthwhile on any injector!!! Overall just do what ANT says, and I really like the standard look you've achieved!!!

i had m50 injectors in before 4 hole spray patten ant said to put the normal ones in, i thought m30 ones were the same as m20 one just higher flow, 4 holed injectors are for multi valve engines.

I'm getting the lambda sensor this weekend, once thats on before i go with bigger injectors, i'll get it dyno'd, then see what ant says

Took about 20 mins to put it onto airbox, didn't want to mess around with cone filters and heat shields, i have k and n pannel filter too

chinese wrote:If you get the m30 afm ending in the numbers 027 you won't have to switch the circuitboards, it will be plug and play this model reads the same values as the m20 afm .
If you get any other m30 afm then you have to change the circuitboard so that the readings will be off the correct value.

Mine's an 027, just by luck though!!! I used my multimeter on the M20 and M30 AFM, I found the M30 AFM to have 150% of the resistance of the M20 one, makes sense as it's 150% bigger, that's why I didn't change the circuit board!

i had mine dynoed today and am up from 169.9 to 177.7, the torque is up from 175lb/ft to almost 185lb/ft.

the bloke says i'm running lean but i'm getting a chip from ant to match all of my mods so this is not finished yet

this is the dyno sheet before


this is todays

e301988325i wrote:

chinese wrote:If you get the m30 afm ending in the numbers 027 you won't have to switch the circuitboards, it will be plug and play this model reads the same values as the m20 afm .
If you get any other m30 afm then you have to change the circuitboard so that the readings will be off the correct value.

Mine's an 027, just by luck though!!! I used my multimeter on the M20 and M30 AFM, I found the M30 AFM to have 150% of the resistance of the M20 one, makes sense as it's 150% bigger, that's why I didn't change the circuit board!

Should anyone want one of these i have a perfect one ending in 027

Hongkongfuey, was anything else changed apart from the AFM?? Running lean I believe is a symptom of not having the bigger injectors, 17lb vs 19lb with the larger ones fitted I'm guessing you'd not be lean anymore, remember on WOT the ECU does not listen to the lambda sensor.

I think it was a different dyno going on what Rob posted in another thread. I don't think putting in 19lb injectors is the right solution, unless you can remap the ECU so that it knows they are in there.

From what I've worked out Jon, the AFM's and injectors seem to be matched sets (M20 AFM 17lb, M30 AFM 19lb). The ECU is the same for both, just with a different chip for spark timing and fuel mixture.

Mine did the same on M20 injectors with an M30 AFM, ran lean on WOT. With the matching injectors it should run correctly!

i put back the standard 325 injectors, i had m50 b20 ones in there, then put on the afm on,

i was told that too, that if you put in bigger injectors the ecu still thinks normal ones in there and more fuel is pumped in , could then over fuel???

still i'm using the wrong ecu so its not fueling right and the timing is out, so i'm getting a chip from ant , then take it from there

The ECU reads the lambda sensor siganal and compensates accordingly. On WOT (wide open throttle) the ECU uses stored data for fuel injection quantities, the M30 AFM lets in more air, this = lean on WOT. The 19lb injectors are only 11% bigger than the standards and should balance this nicely.

you got any 19lb injectors spare?

2 spare, loads of sets on ebay. . . same injectors in the old mustang like I bought. I guess any yellow bosch injector will do.

I reset my ECU earlier, and have been for a drive for the ecu to learn it's settings and it's running really nicely!