DTA MAF Support Ideas

This section is dedicated to discussion of DTA engine control units such as the DTA E48 EXP, P8 Pro, DTA S40, S60, S80, and S100, as well as all things ECU related.
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Jon K
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DTA MAF Support Ideas

Post by Jon K »

[..other topic started going the way of MAF discussion so I split it...]


I would love for DTA to support a MAF!
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mefmotorsport
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Re: The "other" forum

Post by mefmotorsport »

On the Subaru forums they seem to push to get rid of the MAF, some use ecu's that use MAF signal but they make a simulated maf signal.

A more likely question would be "what is a maf, does a map sensor do the mapping? How does a map sensor sense the map? !!!

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Jon K
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Re: The "other" forum

Post by Jon K »

Haha yeah.

I do like a MAP sensor as well, but MAF is nice if you can input the MAF table. Pick a MAF rated for your horsepower mass flow and away you go. Kind of convenient. Its also annoying at the same time, but either way.
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MarcoV6T
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Re: The "other" forum

Post by MarcoV6T »

Jon K wrote:<would love for DTA to support a MAF!>
I don’t see what is stopping you to use a MAF sensor, use map as load and scale the sensor for the MAF in use.

The advantage of using a MAF, is that you can(could) calculate your fueling map(or you could calculate your VE from the fuel map), also engine wear doesn’t affect a tuned map.
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Re: The "other" forum

Post by stevieturbo »

MarcoV6T wrote:
Jon K wrote:<would love for DTA to support a MAF!>
I don’t see what is stopping you to use a MAF sensor, use map as load and scale the sensor for the MAF in use.

The advantage of using a MAF, is that you can(could) calculate your fueling map(or you could calculate your VE from the fuel map), also engine wear doesn’t affect a tuned map.
I dont think there is enough resolution for that. Any MAF scalings Ive seen in aftermarket stuff really are massive.

With maybe 50 scaling points. The curve is not usually linear at all

Of course, at the same time there isnt anything to stop you logging a MAF input via an analogue purely as a voltage. I'm not sure how stable it would actually be, but it might be usable to see if the engine is actually consuming more air or not.
MarcoV6T
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Re: The "other" forum

Post by MarcoV6T »

stevieturbo wrote:I dont think there is enough resolution for that. Any MAF scalings Ive seen in aftermarket stuff really are massive.

With maybe 50 scaling points. The curve is not usually linear at all

Of course, at the same time there isnt anything to stop you logging a MAF input via an analogue purely as a voltage. I'm not sure how stable it would actually be, but it might be usable to see if the engine is actually consuming more air or not.
You're right it’s not linear, it’s curved, the good thing is that at low mass flow, these sensors have greater resolution(the voltage output ‘line’ is flatter), but at higher mass flow the curve goes up, nothing really interpolation couldn’t handle, just pick the right points, so I don’t see why you would need more resolution(scaling points), after all, the resolution is engine related, not the sensor, they only have to match.

The biggest problem is documentation, finding good(precise and readable) 2D tables with mass air versus voltage output, cause I don’t see anyone making their own, yes you could make yourself some reference points, but it would be difficult to put a number on it.
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mefmotorsport
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Re: The "other" forum

Post by mefmotorsport »

I don't think all this discussion should be on this thread, it would benefit from a thread of its own with a MAF related title, otherwise some useful info will get lost!
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Re: The "other" forum

Post by stevieturbo »

The other issue is many MAF's simply run out of puff at moderate power levels unless you're blowing through them. And even then, many run out.
Plus it has to be said, they arent the most reliable things in the world.

I know in theory they should be great....but Ive no desire whatsoever to use one.
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Re: DTA MAF Support Ideas

Post by VR6Turbo »

As Marco said, if you use a MAF that has the right scale to begin with (as per MAP sensors), you won't run into that problem. OEM MAFs are selected to work within a specific air mass range and then the Subaru et al boys go and double the boost and wonder why the MAF clips :D

ProM Racing in the states sell some excellent MAFs and they've been used sucsessfully on OEM computers on 500+ hp cars.

Unfortunately MAF does have it's drawbacks:-

You have less freedom with intake piping. Many MAFs need to run a specific angle and nearly all MAFs hate compressor vortices (unless specifically designed to handle it), so they need to be mounted far away from the turbo.

MAFs don't like oil contamination from cone filters but in many installs you have no choice but to mount a cone directly onto the MAF.

Over fuelling can occur when metered air escapes downstream, so you BOVs need to be replaced with recirc valves, further complicating the pipework.

MAFs can be expensive, but thankfully the old Platinum wire ones died out years ago, in favour of hot film ones, which are a lot cheaper and simpler.

But in a properly configured setup, they can last for years and provide far more consistent fuelling than TPS or MAP can ever hope to achieve and they also deal with altitude, humidity, temperature & boost automatically.
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