Good morning again guys,
In another thread i posted about having my FC vert for sale. It sat for several years and wouldnt start, the MAF got seized and corroded badly with water. A friend let me use his S5 NA Mass air flow meter so i could get it started make sure the engine runs. Was wondering if anyone knows if I could use this set up, and what the differences may be/ concerns. Im more concerned about running lean. I had a emanage ultimate started having communication problems and other problems so i removed it and went back to stock. I installed the stock 550 back into the primaries trying to get it to start before finding the MAF was toast, I have a 255 walbro intank pump, and SARD fuel pressure regulator that ups fuel pressure with boost, also I left the 800cc injectors in the secondaries- so really if I still had the correct MAF in theory i should be running rich, but wondering how the s5 NA MAF may affect that. Thanks for any help guys.

 

Sorry all second hand account, but had a buddy with s5 t2 and he got his car to run off of s5 na. But said it does lean with it.

honestly.... why not just buy the s4 t2 maf? They’re dirt cheap. ~$30

 

The mafs are all calibrated way differently especially so s4 vs s5 ones a cone and ones a flapper

source the correct maf

 

Im sorry I realized im running an s4 na mass air flow, not the hot wire s5. If i remember correctly dont you want the maf to match the ecu, i ask because im running the vert ECU and was wondering if i should use the vert airflow meter or source a turbo. Thanks guys

 

Bottom line, get the air flow meter (AFM) that matches the ECU series (S4 or S5) AND engine type (NA or turbo) that you're using. So for example if you're running an S4NA ECU with an S4 NA motor, you should get a S4NA AFM which is what that S4NA ECU is calibrated for.

Now if you're trying to run a turbo engine (S4 or S5) with a stock ECU & AFM made for an NA engine (S4 or S5), that's a whole 'nother level of stupid. Don't do it.

FYI, none of the FC AFMs were of the "hot wire" variety mass airflow (MAF) sensors. The S4 & S5 FCs used a direct measurement of physical airflow with a variable resistor - S4's used a flapper valve design, while the S5's used a sliding cone design to move the variable resistor.

 

Pete_89T2, thanks for the input, i visible saw a s5 MAF and found that was not what i was running, and looking at the shape thought it was a hot wire i apologize. As for AFM that matches the ECU, the vert ECUs were said to be able to run boost- please research. So would a turbo MAF work with a vert n318, or would i be looking more at a n318 MAF for a vert. If the vert ecu can run a boosted t2 s4 engine would there be a difference between the NA vert s4 MAF and the turbo vert s4 MAF. I suspect im looking for the vert MAF. if needed ill try to find a turbo one, i have 2 more turbo ecus laying the garage if need be. just trying to get some help dont need the insults. Thanks Pete.

 

Didn't mean it as an insult, but you really don't want to run a ECU & AFM meant for an NA engine on a turbo engine. If you think about it, the reasons should be pretty obvious - a turbo needs more fuel, needs to runs larger FI's, has different timing maps, etc.... It might actually start & run/idle OK for you, but will probably run like crap and end up blowing up on you if run it under load & boost.

As for the bolded statement above, I don't believe that is true for verts sold in the US - all verts sold in the US were NA, and all of them had ECUs designed/coded for NA use only. Mazda had distinct part #'s for each ECU version - the FC3SPro website has a good reference on ECU part #'s here. FC3S Pro v2.0: FAQ, ECU part numbers

The idea that vert ECUs can run boost probably came about from the fact that all verts sold in Japan were turbos, and perhaps from the unverifiable footnote in the website above. Also, think about that one - how crappy do you think an NA engine would run on an ECU designed/coded to run a turbo engine?
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I couldnt agree with you more, an NA ECU isnt gonna recognize a positive pressure, or a pressure above 1bar. but at the bottom of that website is a note

Note: The N338 '88 Convertible ECU can be used in place for an '87 or '88 Turbo ECU. This bit of information furnished by Donnie Peters of the now-defunct Sun Auto.

I just happen to have a 88 vert, and have run that ECU with a s4 turbo engine- i did have an emanage ultimate piggy backed in and controlling the injectors but **** happens and the emanage no longer is communicating so back to stock. I borrowed a friends s4 MAF because i couldnt get it started and idling without a MAF, and really it was just gonna be used to sell the car and drive it onto the trailer only- the buyer backed out and i've been fixing more and more and now that it idles and sounds great i was considering getting it to the point were a potential buyer could drive the car safely.

 

according to the Rtek guys, who have decoded the ecus,
Our research shows that the N338 is basically the same as an N326/N327. Contrary to popular believe it will not run a Turbo motor any better than an N326/327.

 

I was wrong, sorry figuring out how i set this car up 15years later. Looking through some of my stuff i noticed the vert n338 was stored away- i suspect i probable ran into problems or just didnt even try. Running a t2 ECU, probable try to track done the proper MAF, other problems im figuring out first