TT

Why? The same Volvo uses Motronic with the MAF.

The whole point of my experiment. I couldn't see shelling out $1k+ for a MAF and ARC2 setup when Bosch already has the MAF working with Motronic.

I have an 86 944 (w/88 engine) and an 89 951. The money I dumped into the rebuild of the 944 would have bought a whole lot of power for the 951, but I love my 944, used the previous engine as a testing lab and have learned a lot that will be eventually applied to my 951. There is very little difference between the two as far as engine control goes.

That's why I've always been a Lotus fan; my next car will be an Esprit S4S.

Magnus, I would look at using a MAF from a Saab 9000 turbo if I did it again. It is the about the same size as the Volvo 750, but would have to flow more air (some have internal cooling fins others don't, about a 25% flow penalty if they do IIRC) and are made of metal instead of plastic. If you need some pinouts for the Bosch MAF just let me know. I currently have a push button for the hotwire burnoff, haven't gotten around to designing an timing circuit for it. The thermistor is available from Digikey.

Luke

TT,

That motronic is OLD and very SLOW.

Magnus

TT, I understand that the Saab 9000 turbo MAF can handle more flow since the Saab has more power, but will the Volvo MAF run out of its metering range one a 944 N/A? Have you had any problems with the Volvo MAF running out of range or limiting the air flow in any way?

Yes, the pinout would be nice! Do you have the pinout for both the volvo and saab maf?

Thanks for all your help!
//Magnus

TT

Pinout for the Bosch MAF from the Volvo is:

1 - Ground to engine
2 - Ground to DME
3 - MAF output (2-4.8V)
4 - Hotwire burnoff (Apply 5V for 1-2 seconds for burnoff)
5 - 12V Power
6 - Potentiometer on MAF

Apply power and ground and look for voltage on pin 3, blow on the element and you should see it fluctuate. As far as limiting the flow and running out of range, the two walk hand in hand. The MAF could limit the flow while still staying in range. That is why I would go with a less restrictive MAF if I were you. The Saab 9000 units looked have an identical connector, but I don't have any wiring diagrams for those.

As far as Motronic being slow and old, so are these cars. Motronic was designed to handle requirements up to a max of around 7000 rpm. Bosch could have clocked the processor at 12MHz but chose 6MHz for any number of reasons (16bit timer limit, EMI, etc.). The Motronic in 944s is a glorified tooth counter that does timing and injection calculations in its spare time and does it well.

SoloRacer

Doesn't the 968 use a MAF sensor as well? I saw one for sale a little while ago for around $100 and was considering buying it. If the 968 did use a MAF sensor would it make sense to buy this unit and put it on my 951? I already have APE stage 2 chips - would I be able to trade them in to APE and get their chips that can read the MAF sensor?

Magnus

Thanks TT, I'll guess the MAF hunting season at the local junk yard will begin on monday.
Just before I read your answer I found these Volvo wiring diagrams, Volvo 940 and Volvo 740. They both match your pinout so I guess most Bosch MAF's uses the same pinout, and since Saab also use Bosch that unit will also match.

//Magnus

instigator

what happened to this project?

Magnus are you on the dtmpower boards too? i recognize that name from over there.
Danno and i have been conversing about this kinda stuff (map sensors) but it looks like if we are to do this we are gonna have to visit radio shack more often, also i'm not a electronic buff but i want to get into the mix with this stuff

i really would like to resolve this maf or map or something other that the crap we have (though it seems to do the job for now)

ribs

*bump*

I am also very interested in doing the "ghetto MAF" kit. Finding a MAF to support the airflow (proper girth) for a modded 951 will leave me with few options for a donor MAF. Lets see, from a quick search on the internet, I found that '85 to '89 C4 vettes used a bosch MAF with the burn off thingie ( <a href="http://home.fuse.net/c4/MAF.htm" target="_blank">http://home.fuse.net/c4/MAF.htm</a> ), so this may have the proper diameter to support large airflow. The only other options I can think of are: 968 MAF, 928 MAF (if they made one...don't know), firebird/camaro (probably the same as the C4 MAF), turbo volvo/saab/audi, other SBC based MAF metered vehicles (cop cars, trucks, etc.), mustang, and what ever else.

Here is a thread I came across on somebody replacing a vein sensor with a volvo/saab MAF in their merkur XR4Ti: <a href="http://www.diy-efi.org/diy_efi/html_archives/archive_num_115/msg00056.html" target="_blank">http://www.diy-efi.org/diy_efi/html_archives/archive_num_115/msg00056.html</a> . This seems to be a common thing. I would just like to know more about how tt went about converting the voltages and where he found the information for different corresponding voltage ranges. TT, you still out there?

Huntley Racing

Just to be accurate an average 944 N/A makes 115-117 HP at the wheels stock. This is taking the roughly 10 cars we have dynoed stock. MAF kits makes 10-15 HP over stock which is listed on our web page. However they allow for other mods to be tuned in which further the ability of the car to make power.

James Bond

[quote]Originally posted by Huntley Racing:
<strong>Just to be accurate an average 944 N/A makes 115-117 HP at the wheels stock.</strong><hr></blockquote>

Just to be unambiguous, you are talking about detuned US spec cars aren't you?

I'd have thought the quickest way to a bit more power is to fit European pistons and DME. Euro spec cars make up to around 20bhp more than US N/A cars.

Mike.