Looking for a S70 850CSI broken maf to do research on

How do they differ from the MAF in the 850ci?

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[TD="class: part, align: left"]13 62 1 316 166

Last pice: € 746,25
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[TD="class: part"]Delivery discontinued by the factory

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Last price € 258,-
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[TD="class: part"]BOSCH
Delivery discontinued by the factory

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Zitat von hmg;131726

How do they differ from the MAF in the 850ci?

The S70 mass air flow sensor (MAF) has a much less restrictive large mesh grille and the platinum wire is shorter (different resistance) than the M70 MAF. The MAFs can be exchanged but an S70 runs very poorly with M70 MAFs and vice versa.

The later M73 MAF uses a modern hot-film instead of the fragile platinum hot-wire. Hot-film MAFs are cheaper and more reliable than hot-wire MAFs but they are not electrically exchangeable. Nevertheless, member fuzzifikation developed an adapter to use modern hot-film MAFs on the M70 (and with software adjustments probably the S70 as well).

Hello Everyone,

I have done this - but the progress is unfinished.
What I have: We have produced an electronics that allows us to connect to certain available modern MAFs.
It works and was in my car for some time.

BUT: I have no connector from the electronics to the old wiring loom.
On the last alpina tour (in Italy) we have discussed this and Reinhard and Khuni said that they might look into manufacturing the connectors to the wiring loom using 3D printing. THEN we would have a nice usable product.

I have not heard anything so far..

As of right now, the only thing I could offer (after some production which hasn't started) is to cut the wiring loom and use after-marked connectors. Not nice.

Prices: We are looking at about 250€ per modern MAF and about 200€ (maybe - unsure) for the electronics. That would result in about 450€per side.
It's not the super cheap solution most are looking for.

Is there demand? Should I persue this? (mind the prices)

Fuzzi

I would be interested in a pair and will ask if any other Norwegians would be interested.

For me I see a solution using an old connector from M70 MAF to connect to the original wiring loom without destroying this.
have was you car performing with these "new" MAF's?

I really hope you will pursue this as it will be a show stopper for the CSI if no solution comes up here or can the ECU's be reprogrammed to take M70 MAF's with little loss of performance?

Regards
Terje

Zitat von fuzzifikation;131798

BUT: I have no connector from the electronics to the old wiring loom.
On the last alpina tour (in Italy) we have discussed this and Reinhard and Khuni said that they might look into manufacturing the connectors to the wiring loom using 3D printing. THEN we would have a nice usable product.

Servus Dieter,

falls es hilft, ich kann der Stecker in 3D nachbauen. Brauchte dafür nur ein in Einzelteile zerlegte Stecker die ich ausmessen kann.
Man könnte es auch einscannen aber erfahrungsgemäß ist der Qualität der Scans bei so kleinen Teilen nicht besonders gut und die Polygondaten nachzuarbeiten ist schwieriger als das Nachbau.

Grüße
Steve

For the S70 no third party MAFs are available but for the M70 you can find cheap knockoff MAFs on eBay. User experiences at bimmerforums.com however suggest that they do not work well at all. So basically that leaves M70 and S70 owners only with the OEM MAFs. Nothing wrong with that if they weren't so ridiculously expensive - if still available! For the M70 you might get lucky finding MAFs cheap from a breaker but for the S70 I would not count on that...

So at 450 EUR per side your option is still viable, fuzzifikation. The problem is that a lot of the M70 in need of new MAFs are cheaply bought E31. I doubt their owners will want to cough up this kind of money. On the other side of the spectrum are the owners of garage queens who will only accept a solution that looks 100% OEM - some may even only want the real deal.

I would pursue the project but if you are looking to cut down the costs by manufacturing a batch, be very careful... Experiences from previous group buys learn us that many people want something but when it comes to paying up the enthusiasm is a lot less. It's probably best to go ahead on a build-to-order base.

I assume your electronic module performs an accurate mapping between the new hot-film MAF and the original M70 MAF. In other words, it's a plug-and-play replacement. I wonder however if you couldn't make it cheaper by leaving the mapping to the DME. Just have your module output a signal that is within the range of the DME and then recalculate new fuel-to-air maps using the difference between the original curve and the new one. I mean the DME is designed to convert analog signals from sensors using maps. Why not re-use that? Naturally you'll loose drop-in compatibility with tuned chips like those from Wokke.

In the end I do wonder why we have to go through all these troubles, though. Why can't we simply have the MAFs refurbished?

Any chance Bosch has a cross reference with the same electrical output/flow in the same or larger diameter? I think the 840 version has been used as a high flow M3 swap so maybe?
.

revtor,

all of what you say makes perfect sense.
I am very afraid of dumping a lot of money in a batch production and then end up not selling any. And even if I do that I won't be making profit at it. So at most, this project can either result in simply "fun" but not much financial loss or I'm down a few thousand euros. Ouch.

I did some sort of survey many years back (I wasn't on here for years). At that time virtually nobody was willing to pay much more than 150 a side. I guess the cheap ebay knock-offs (which DO NOT WORK properly - they can't, but folks don't seem to care..) kinda set peoples' expectations for very cheap prices. So I'm unsure..

A batch makes sense if I produce well over 100 units. That's A LOT. Otherwise we are looking at hand-soldering and programming - that will be expensive!

However, if somebody else wants to produce that - I'm fine with it. Just say so.

As of how it works what we have done:
Yes, we have a modern MAF (no, not M73 or any of that - a MAF from Bosch (for VW) at the time from a car from 2003, I believe.. Anyway, it was a MAF that was build in the millions and can be readily bought all over the world and also fit perfectly (diameter and distance)).
We take that MAF (which needs to output voltage) and convert it to the original MAFs (S70 or M70) Voltage at this airflow. I did the conversion using official Bosch technical data (at the time I was working there and got the info). This conversion is done by a tiny microprocessor in a separate box that we would attach to the new MAF.

It would look like this:
[New MAF] -> [New Conversion Electronics] -> [New 3D printed Connector] -> [Original Wiring Loom]

Your question was: Why not convert the tables within the ECU. Sure. that would also work - but I do not have ANY clue as to how to do that.
If folks would prefer that - sure, that's also fine with me. I'll happily provide the data.
Still this would leave the connector issue unresolved.

Steve: What would you need? I can send you old connectors (attached to old broken MAFS) - is that enough?
Also, can you use high-temp plastics for the 3D printing (we have temperatures of up to 120°C - will the plastic survive that?)

Someone asked me how the car drives with the new MAF:
It's just fine. The old MAFS take about 1Ampere per side during driving - the new MAFs take virtually nothing. So that's 24Watts of more power that you can use for increadible acceleration...
(seriously: It works like an original new MAF)

I guess I could hand-make maybe 10 pieces just to see if I can sell them at all. If Steve can resolve the 3D printing issue, that is. But these would be almost as expensive as original MAFs. I'm meeting my electronics specialist next week.. let's see what price we would come up with.

Dieter

Just having the electronics available would for me be an assurance and i could buy the VW Maf later on if needed.
Then obviously it would be interesting to see if a new MAF would improve performance , but not sure it uses any info from the MAF at full trottle?

For the connector issue, if we have a connector matching the ( VW maf ) you only need 10cm cable from that to get under the acoustic engine cover , so any crossovers should not show anyway.

Regards
Terje

Hi Dieter,

I can't help with the printing. We have here 3D printers but due to the high security I can't brig in our out anything. Here we have to count on Reinhard and Kuhni.
Regarding temperature resistant 3D printing, that is possible. You can even print metal.

What I can offer is to create the 3D data required for printing.
For that, I would need all parts which have to be printed (if the connector is assembled from more then one part).
It's also helpful to have the connector counterpart (on the MAF) as it is sometimes hard to make correct measurements inside a deep cavity.
We can communicate the rest vie PN.

Schönes Wochenende und Gruß,
Steve

Hey all,

Terje: Not sure what you mean by the wiring thing. In my mind, all you will see is a slightly bigger connector than before. We need no cables to the ECU (in case you meant that?)
If we were successful in delivering this project, if I were you, I'd only use the modern MAFs and save the originals.
Also - and I may very well be wrong here - I think that at higher throttle/rpm values, it is the oxygen sensor that is not used anymore but the mafs are still used.

Steve: I might get back to you on that - Neither Reinhard nor Kuhni have commented thus far.

Fatandre: A new MAF will not change anything. It will behave exactly as a perfect original MAF.

My original project was simply geared towards using a modern MAF instead of these terribly expensive and unreliable old MAFs. If successfull, the car will behave perfectly fine. If your original MAFs are very old, chances are that they have value drifting or offsets which results in them delivering bad signals. Some drifts can be compensated with the oxygen sensor adaptation. Others may not. A modern MAF will show much less unreliability over the years. (new is alway better applies here)

There will be not be a power increase over original (but perfectly new) MAFs. If anyone thinks that changing the conversion characteristic might improve power, you can design your own curve and we can program that. But me, I'd stay with the factory values because I don't know what would happen otherwise. We can make it programmable even with Bluetooth - but now we're talking about MUCH higher cost (because development time).

Revtor: If you know how to re-program the ECU... we can do it your way. I just have no idea how to do that. With our solution and IF we can produce a connector, you can switch between original and modern mafs however you please. If anyone desires a TÜV certificate - that is really expensive, but doable (I don't have the time for that, tho).

Tomorrow evening I have a meeting with my friend who knows the project. We will see.
I'm honestly positively surprised of the initial feedback here. Still usure whether I could come out of this not loosing money (I'm already 2kEUR down, but that was fun, so I don't mind. Just wanted to know if it would work. Anything coming now, I'd like to not lose money (time is fine).

Dieter: for the wiring/crossover connector i did mean you will not see the crossover from the original connector to the new electronic as all can be hidden under the engine cover.

Anyone that can chime in on the question if the car uses the MAF at full throttle? , I did run the the car on Dyno a years back and result was not fully where I expected it to be so question is obviously if a MAF is not 100% anymore and that also then for me a good chance to try with new ones to see if that improves the power.

By the Way Pål Rønning is also interested to participate as he has one CSI and one B12 5,7 ( assume the Alpina also uses the same MAF as CSI )

Regards
Terje

Zitat von fuzzifikation;131808

A batch makes sense if I produce well over 100 units. That's A LOT. Otherwise we are looking at hand-soldering and programming - that will be expensive!

When I was talking about a batch I was thinking about 10 or maybe 20... Forget about selling a 100. That will never happen.

Zitat

Your question was: Why not convert the tables within the ECU. Sure. that would also work - but I do not have ANY clue as to how to do that.
If folks would prefer that - sure, that's also fine with me. I'll happily provide the data.

I do not know much about changing the fuel-to-air maps either, but Omega man 1969 at bimmerforums.com does. He is quite knowledgeable about chip tuning and has investigated the S70 DME and EML in detail and even offered to reprogram the maps to work with other MAFs. Of course, this approach would only make sense if it can reduce the costs of the electronics substantially because you'd loose drop-in compatibility with tuned chips.

Personally I'd prefer to find a company that rebuilds these MAFs. It's not exactly rocket science.