MAP ECU or E-Manage Ultimate?

[Kieran]

Those of you in the know, which is the stronger product?

I am considering my options on the fuelling side and if I do go with MAF deletion, I will need one of the above....

Discuss.

[bradc]

I think the map, but valmes will vote for EMU

The real option though is an Autronic SM4

[Kieran]

Brad - Can you quantify why you'd choose MAP over EMU?

[Turbo_Steve]

MAP ECU lies to factory ECU. Fine if you're just removing the AFM, but not my weapon of choice for modifying, as changing the AFM signal also affects the ignition timings. The MAP2 looks a significantly better option, but I bet it costs more.

Valmes is onto something with the EMU. The MAP2 works in a similar way: rather than just feeding a modified signal to the factory ECU, and hoping it gives the output you want at all times, the EMU (and I believe the MAP2) sits on both the input and output sides to ensure it corrects any output from the factory unit that is short of what is required. It also enables you to adjust your ignition timing, which will improve power, time to boost and drievability, as well as correcting timin at higher boost levels. It's often better to run less boost and more timing to get optimum power output.

I'd ask why you want to remove the MAF. If you're going for bigger injectors, uprated fuelling, have a bigger intercooler and (as I believe the turbos run out before the injectors on the leggies) you've got bigger turbos, then okay.

If you're thinking that the Factory MAF is an inlet restriction that's costing you power....then you may be right, but we're not talking much...bear in mind that unless you're bouncing off the fuel cut boost limit, the MAF isn't even close to it's flow limits. Manufacturers use MAFs (which are more expensive than MAPs) because they are more accurate, and don't need barometric compensation, or in many cases temperature compensation. They also react faster to throttle changes than MAP sensors.

Expensive outlay to replace the MAF if you're purely doing it because it's a restriction. There is power to be had elsewhere first.
However, if you have a long-term plan, then I'd go for the EMU or the MAP2 or a really good piggyback that controls everything. Or , as Brad did, go for the Autronic, which is bloody pricey but easy to setup yourself and will grow to just about any system, and control lots of extras as well. The EMU doesn't seem to be particularly limited either, but it's a different style of working, and requires a little more expertise. It depends how good the base map you have for the Autronic is. Assuming Brad is happy to share, then most of the work is done for you.

So more info required, really. Sorry.

[Nick Mann]

A couple of points:

1st: The MAF is probably a restriction in the intake, but have you seen the piping from the maf back to the front turbo? That can't be good.

2nd: Brad found a problem with the Autronic in that it didn't work with the auto's ecu. So a manual conversion is the only way forwards. (It may be anyway!) So with a good piggyback at least you have the option of keeping the slushbox.

I am seriously considering MAP2 at the moment, so if there is a reason why the EMU is better, I want to know!!

[Gowf]

The main difference that hasnt been pointed out is the way that the ECU's calculate load. The EMU uses throttle possition as a reference where as the MAP2 uses, as the name suggests MAP.

Now it is true that most of the worlds ecu's are mapped with the throttle possition as a reference, but the simple reason for that is that its easier. You can easily set the throttle to required possitons (load cells) and use the dyno to increase the revs, adjusting the fuel/timing as neccessary.

MAP is a little different, as obviously you can not easily set the engine to run at specific pressures/loads. If you take a turbo car and disconnect the actuator so that it will not make possitive pressure and set it at WOT, then you can have a specific load line at 0psi. This can be used for whatever max boost your running also, but the loads inbetween are a lot more difficult to get as the boost will tend to rise.

The difference in the practical applications of these maps and the reason why MAP is deamed to be the 'proper' way of doing it (its how all the high end motorsport maps are created) is this. Imagine you are driving along a flat road with your foot at 35% throttle. You then come to a hill. Leaving your foot at 35% throttle will tell the ecu that your still at the same load level when infact the load has increased and therefore the engine runs lean. With MAP, obviously this isnt the case as its the engine thats telling the ECU what the load level is, not the driver.

This is why i would choose MAP2 over EMU everytime regardless of features

[bradc]

Quite simply with me I wanted to get rid of the MAF, as Nick said, not because it is much of a bottleneck itself, but the piping behind it is terrible. Also I wanted to have completely custom intake piping and we know that the MAF sensor doesn't take kindly to that at all. imho for a reasonably quick VR-4 you want to change to MAF. There isn't enough room in the engine bay to keep it and have nice intake piping.

I have no problems sharing the stock map, however my in car computer doesn't like talking to the Autronic for some reason. I intend to get it sorted but at the moment my main goal is to get the bmw on the road.

[Kieran]

Thanks for the input guys... I think Gareth's point about load calculation puts this one to bed.

Map ECU Methinks.

[Turbo_Steve]

I'm fairly sure the EMU will take any load input you choose: MAF, MAP, TPS or even RPM load calculation (!!!!! horrid!).

I've generally found that the MAF starts to run out of measurement hedroom before it becomes a serious inlet restrictions. The are usually bigger than the inlet on the turbos, and as Nick says, the piping between the MAF and the turbo is usually hellish.



Kieran, I assume you're talking about the MAP2 rather than just the MAP?

I didn't know Autronic had problems with the Auto...I suppose I shouldn't be surprised that it communicates more than TPS, RPM and ground speed.

[bradc]

it wouldn't get out of first gear

[Paul C]

Map 2 is probably easier to tune than emu.