Another MAF Conversion hits the streets

[genphreak]

Hey everybody,

I thought I'd try one of these (http://www.millerperformancecars.com/)out as I have far too much work at present: no time for a weekend or 3 to install the MegaSquirt quite yet.

Just got it in the post. My neighbour recently bought an M20 powered E30 which needed a few things fixing so we decided to buy our new MAF upgrades together. Miller charged us no extra for the postage... and have been very conscientious throughout.

For those not so in the know here; A MAF does not bring a heap of perfromance, but it does give better efficiency and if your AFM is worn out, its a great thing to do. Saves you in Gas, makes the engine run better and adds at least 3HP... LOL

Actually it comes with a performance chip so with the benefits of that one gets significantly more over a bog-stock Normally Aspirated engine.

As you can see from the pics, it is surprisingly well made. The custom alluminium body is milled beautifully and its really solid. I was worried it would be plastic but am now relieved. I tried to take some decent macro shots so you could see the level of finish.

If it works, it'll be well worth it...

They will both go on this weekend. I'll be comparing mine to how she ran on both the stock chip and the performance chips I have borrowed from Big Kriss, after running each for some months. The AFMs on both cars are pretty good (after an internal inspection, output measurement and flap position) but they are as old as the cars...

Have tried Mark's infamous EAT chip and the Australian PowerChip, both of which are excellent chips. I'll let y'all know how she goes...

[BigKriss]

Nice one nick, keep us updated.

[genphreak]

Nice one nick, keep us updated.Heh, with pics of speedos off the clock and power drifts? Maybe I should get it professionally road-tested on a French motorway :D Nick

[genphreak]

Installation

Dead easy, make sure you have 3mm heat shrink tube and a foot of 15mm wire protector on hand, a soldering iron and wire clippers. Big philips screewdriver, 6 and 10mm sockets, an extension bar and ratchet.

I managed to mis-connect it with a poor splice on the positive feed, so was surprised after buttoning the ECU back up and heading out for a drive that she just paused when I gave her some throttle. Not a splutter, just a 'kind of nothing' (after all this anticipation it was something of a let-down!!).

So we went carefully round the block and back into the shed. After finding the 12V feed was not working, I fixed it and started her again. Previously (without the MAF powered up), the idle was as smooth as a kitten's fur... but with the MAF now powered I watched the tacho showing the ECU hunting a little during initial warmup (pulsing the revs around +/- 50rpm) before settling after about 20secs later on a calmer and slightly lower 750 odd rpm... much better!

Buttometer readings (after first short drive)

Off the mark
- Definately smoother throttle response
- Same power

Mid range
- Noticably more power (maybe as much as 10%)
- certainly more responsive to change I can only compare it to how a lightened flywheel can liven up an M30

Upper rev range
- Noticably more power (maybe as much as 10%)
- Flicks the tail when turning sharply with much more ease
- Definately faster up hills (completely different car under Wide Open Throttle) once you open it up

Economy
(The main reason I did this)
- NFI yet


Important Note:
Traditionally these cars perform better after a CPU reset (but use more fuel and output worse emissions). I will klnow more after running a few tanks of fuel through it and the CPU has learnt about its new inputs.

[genphreak]

It is a completetly different car.

Even the brakes feel better... (really weird)!

This is, without a doubt the best budget mod you can do to the M30. If you have a 535 or 735 powered car, either get one of these or install a MegaSquirt. The AFM will limit everything you do to the car and makes it drive like a pig in comparison.

I don't know how much difference a new AFM would make to other people's cars, but my old one was in very good shape (had been rebuilt) and was physically perfect... the electronics were fine. I expect the problem was the spring had lost its tension.

The difference made is like night and day. My guesstimate of a 10% power increase seems pretty conservative now... :) Nick

[s_ribbens]

Interesting info. I'm very glad to read some first hand info on this!

[genphreak]

I'll post some pics and chronicle the effect it has on the M20 when we get around to it this week...

[Martin in Bellevue]

Glad to hear the maf kit is working out for you. Does the maf sensor need 12v switched, or can it work off the 4.7v~ish from the afm harness? Are you using the ground from the afm harness? This can be important, as motronic sensors seem to like to be grounded with the dme, especially the innovate wideband o2 stuff.
You should realize quite a bump in midrange torque with the maf. The modern perf maf I had in my 535 dyno'd with a healthy improvement about the midrange.

http://www.bimmer.info/bmw/Martin5er/dyno535Nov04.jpg

[Martin in Bellevue]

Here's Jeffrey's dyno run with the same maf kit, from Bruno. Unfortunately, the dyno wasn't calibrated for metric mechanic horsepower. :(

http://home.comcast.net/~jsnord/images/dyno_2.jpg

This post is intended as added disclosure to the topic at hand. ;)

[Robin-535im]

I'll post some pics and chronicle the effect it has on the M20 when we get around to it this week...
It's entirely likely the speed-up is due to the lost weight of the AFM!

Martin - that sheet is nice... sure Jeff doesn't mind you showing his dirty laundry?

:)

[rob101]

question
will my 528i be able to use this mod? and how much did it cost nick?

[Randell]

$489US according to the web site... seems kinda pricey for the midrange power gain

[genphreak]

$489US according to the web site... seems kinda pricey for the midrange power gainBest option is a Megasquirt as it is 'scalable' and supported forever. You even get the software AND the source code so you can always change it... but $500 is the price of an AFM so its not too bad. I reckon Miller are mad not selling a breakout box for $100 (theirs is $500 so noone slse other than the turbo customers will buy it). That way you could at least log (and adjust) on a laptop... still even fro $100 you'd go Megasquirt for that feature and more. I just wanted a quick fix for now. A decent one sounded good. This is way better (or my car was way worse) than I expected... I really reccommend it to anyone wanting a simple fix.

Martin, the MAF works on 12V from the ECU. The ground is also from the loom and the MAF itself is not even mounted to the old AFM bracket.

Maybe it goes faster than I thought since the bracket was removed as well as the AFM, so the weight loss was more considerable.... :D thanks for those dyno readouts, I better take mine and have it done too once I adjust my valves again to prove you all wrong...

Seriously people, this is just returning my car to glory. Maybe before this I've lived with what must be a dead AFM. The power difference I am noting is not imagined... thanks for the dyno readouts though, they look pretty good for a stock M30, but mine is at least 10% faster you do understand... ;)

[alexander525]

this might be a dumbthing to ask but can i get one for a 525?

[Jon K]

this might be a dumbthing to ask but can i get one for a 525?

If your '91 has the M50 motor, you already have a MAF you silly goose!

[winfred]

e12? id go megasquirt or carb's


question
will my 528i be able to use this mod? and how much did it cost nick?

[Martin in Bellevue]

I forgot to mention, that you should split that WOT signal wire from the throttle position sensor. Motronic 1.3 (and earlier) goes too rich under wide open throttle. This was shown to be true on the Carb Conn dyno. I have a 2 position switch on the plastic harness cover over the injectors, to enable code reading, when I want the WOT signal to get to the dme.
This WOT condition isn't isolated to my 535 with 21lb injectors. Duke's e28 had the same thing with his old maf setup.

[rob101]

e12? id go megasquirt or carb's
e28, its a euro only model. but pretty much the same its still L-jet

[clevertd]

Hey guys, I'm not sure if any or all of you have seen this, but I've got the MAF conversion as well and this is my dyno graph:

http://img252.imageshack.us/img252/4432/dynoresultsuw9.jpg

Sorry for not linking picture here, but it's huge. I don't have a before/after comparison, just that after graph. However, I am very pleased with my motor:)

[Jeff N.]

That was pre-bottom end. :)


It's entirely likely the speed-up is due to the lost weight of the AFM!

Martin - that sheet is nice... sure Jeff doesn't mind you showing his dirty laundry?

:)

[Michael999]

Genphreak, hows the Car doing now that you have been driving with the new MAF for a couple of months?