BIGGER AIR MASS METER????

[WerkdE30]

Ok sum thread about airboxs just reminded me of how shocked i was when i saw the size of the opening on the air mass meter. i have heard some american does a complete conversion for sum rediculous price but surely someone has a way around this.

are any other models interchangeable?

i was lookin at an m50 one the other day and that looked far more suitable but i doubt itll work.

any knowledge around the zone on this one???

[Demlotcrew]

The E30 has AFM and the E36/M50 has a MAF totally different method of air flow measurements. There is no cheap way to get a MAF to run on the M20, all installs will need to have a piggyback ECU to convert the signal for the ECU from a MAF signal to AFM signal. All parts new are expensive and then there's rolling road setting up costs, so all in all here in the uk you are looking at around £800 for something that will give you a little more torque. I would rather go with a Stand alone EMS for a couple of hundred pounds more.

Andrew

[WerkdE30]

what about an m30 one?

[Martinaston]

So can anyone tell me what kind of signal the MAF puts out ?
£800 seems a bit steep for a few bits you can get out of maplins

[Widge]

If you want to go bigger, or less restrictive you basically have two choses. I have a BBTB and a chip so I will next go to an M30 3.5 AFM with the M20 circuit board soldered in, or I have read on some American sites you can just ajust the spring inside till it idles right.

Or if you are more tuned than me, you might as well go the whole hog to Mega Squirt, which would be £500 ish if you install it yourself and get a map off Ant, less even if you assemble it yourself. And then use the spare £300 to make // buy individual throttle bodies. Even without the ITBS you would be able to do away with the AFM all togeather, you could basically put a cone filter on the throttle body, but that's not adviseable obviously.

Personally I don't see the point of Mass Air Flow meters when they can be dumped totally and for less money.

ITB's with sock filters and a nice big cold air box that's what I'm aiming for

[Martinaston]

I'm thinking more along the lines of £20 in maplins and a MAF meter from a 328i. Just need to know what kind of output to convert so the ecu can accept it.

[Widge]

TBH mate, if you pull it off I will buy plans off you for it. Should improve throttle response, be rather nice. I'm gonna do the M30 AFM, if you get any where let me know.

[bottlecapE30]

I m putting on a m30 afm this is the method i used
http://davelength.net/car/bigsix.html
Some good info and needs no spring ajustment (i have never heard of this...more info?)

[Widge]

I found the spring ajustment thing on e30tech.com, but I think I'm gonna go the M20 board route then it will run exactly the same but with less restriction.

[Templ8e30]

If you get a late 535i M30 AFM from a motronic equipped car you don't need to arse about swapping boards etc as they use the same parts anyway. You'll still need to back off the flap spring though and it'll take quite a bit of tweaking to get it right.

I ended up ditching mine because although I gained a healthy amount of top end power I lost some bottom end torque too.

I'm trying out dual M20 afm's next, the original stays as-is but a second one is plumbed in with the spring tightened up and left un-connected to the electronics. Under normal running conditions the second AFM stays closed and th engine runs as normal, when the throttle is wide open any extra air needed is sucked through the second AFM. Obviously more fuel will be required, I already have a rising rate adjustable FPR so this will be set-up accordingly.

This sort of set-up has been used successfully for years by Nissan 260z tuners. A new guy at work has this setup on his 260z racer.

Cheers,

Iain T

[Widge]

So it's just like a kinda a regulating flap really, thta's quite a good idea. Do you have any photos of where this spring is that needs ajusting?
If I unplug the ecu for an hour when I do it woun't the ECU relear the AFM's settings? Cos if it's another Motronic AFM then it should beasically be the same signal sholdn't it?

[WerkdE30]

late 335i sounds like the way to go but by adjusting the spring tension do u mean there is an adjuster on it or u hafto change the spring till u find the right one?

[Widge]

As far as I understand it the spring is on a ratchet thing and you can just move it up by a tooth each time. But I don't know where the spring is!!
Con the spring from the M20 AFM be used?? Long shot I know.

[WerkdE30]

i was thinking that but if its adjutable im sure thatd be no hassle.

[lentec]

I had a lucas afm from a jaguar xj6 with bosch m20 internals running on my old engine just adjusted the spring.

That was twice the size of the oem unit.

[Widge]

You havent wtill got it have you Lennie???

[lentec]

Prob have will look thiseve!

[Widge]

Oh, legend mate, cheers, if you do mate, any chance of taking it off your hands?

[bottlecapE30]

I see the ajustment is the v clip on the toothed wheel. I did have to ajust this i just forgot that there was a spring in it .

[WerkdE30]

so what are you adjusting exactly ? will it need to go on a dyno to get it right?