Unexplained Rich AF Ratio & MAF Placement

[Edub1]

I'm noticing that myself and a number of other peole are having problems with unexplained rich conditions and unstable WBO2 readings after going turbo. This includes those of us tuning our own ECUs and SAFC users. Seems like no amount of tuning gets rid of the problem.

I have heard the issue raised and I have verified that a hotwire MAF must have a smooth flow of air passing through it and that turbulant air or even noise can cause problems.

It would not suprize me to find out that most of us have a Z32 MAF real close to the turbo.

[Edub1]

Nobody has any input on this issue?

[WDRacing]

Not really anything new. The BOV should be placed on the cold pipe and returned to the hotside behind the MAF by atleast 6" with the return port angled toward the turbo.The MAF should be placed atleast 12" from the turbo itself. Also, the screens should not be removed from the MAF.

My N62 was placed about 20" away and I never had any issues with running rich.

[S13FX]

yah WD is correct. Also a bend in the pipe helps out. And there is plenty of room for differ position of maf placement. Also you don't need one of those huge filters at the end. I got my self a baby cone filter and it worked just fine.

You just basically have to get creative with. Remember no matter how you look at it, putting a turbo on a KA is a DIY affair.

[Chezedik]

I am about 14" and it is a problem for me. Just bought a Civic intake, and am going cold air and adding a few bends. That should fix it.

[Edub1]

Here is a repost from from the other thread

I was just re-designing my MAF and upon inspection I noticed that the hot wire in the Z32 is only a couple inches from the MAF inlet. With a pop charger filter like the Apexi mounted directly to the MAF there is no way in hell the air passing the wire is in laminar flow. In fact, I hit the filter with some compressed air and found that turbulent under hood air hitting the air filter is probably also hitting the wire and giving a false readout.So, I'm almost certain that the problem is not that the MAF is too close to the turbo but that the hot wire is way too close to the pop charger and that turbulent air is wreaking havok on the MAF readout.

What I did is left the MAF in the original location and to the MAF inlet I attached a 90* bend and took the air filter down into the fender. Now I should get a nice smooth laminar flow coming into the MAF instead of a bunch of swirling eddies.

I'm 99% sure this is the key - we shall see.

[Chezedik]

That is pretty much my plan. I intend to use the Civic intake to create a cold air style intake. And it cost me 14.51.

[Edub1]

Well, got the new intake on - didn't notice mutch difference but I'm sure it's better not to have the hot wire 2" from what is essentially open air. There is no way the Z32 will get a laminar air flow that way.

Anyway, I've decided to completely re-work my fuel maps with no closed loop. Hopefully this works but either way I'll probably go MegaSquirt before too long.

[Chezedik]

I am going to do mine tomorrow. I will let everyone know what happens.

[DRFT(kinda)]

Problem solved.

[Florida240sx]

Never had any problems with my car. Maf is preturbo. Safc II , placement is less than 12inches away...

[Edub1]

I think the problem is with this EC3 code or with ECCS ROM tuning in general. I'm going to go back to EC1 and give that a whirl. Seemed to work the best in the past.

[Chezedik]

Well, moving my MAF helps quite a bit. I am still running too rich, but I think I can lower fuel pressure and that will help. Last time I checked the fuel pressure was at 55psi with the Walbro, anyone else experience that?

[Edub1]

I never thought of that. What is the stock pressure? Doesn't the FPR return any excess to the tank though? Soon as the weather clears up I'm going to lower all my ttp min values by 90% and see what happens. I lowered them by 50% and got a decent cruise AF but it was rich under WOT. Stock fuel map though.

I'm just messing around till I get the MegaSquirt. Tuning half blind when there is a $400 MAP controlled stand alone out there is just plain irrational. I'll probably make more power, have better drivability and have a motor that lasts 5 times as long as a half a$$, hack ROM tune.

[Chezedik]

Stock pressure is supposed to be 43.5 (3Bar) at idle. Unfortunately, for some reason many people have found that the Walbro runs so much fuel that it increases pressure. So I would guess that an adjustable is the way to go. I have lots of other problems now, the car isn't giving me any control over fuel because I have too many CELs. IDK, but I need to get that fixed. I am only running 4psi but still I would like to have better control than 14.5:1.

[Edub1]

Just sell all the BS and get a MegaSquirt. The MSII will even allow you to select a MAF setup. Plus, with a WBO2 sensor the damn thing nearly tunes itself.

[S13FX]

The MSII is an awesome option, especially for the amount it costs. And supposedly the new MSIII coming should be able to work with our distributors too so that will make the installation much simpler.

There is another opetion Brian (WD) has shown me that I have been looking into. And it's called MSD Blaster EFI.

It's about 1200 dollars, comes with everything you need, even has a build in WB02 suppoer data logging and a lot of good features. It is very easily incorporated into the stock wiring harness, and uses all GM features.

http://www.msdignition.com/2007/blasterefi.html

I plan on using this on my next S13 project. Which I will plan on doing as soon as I move into my house. It will be called, "Project Fully Restore An S13 From Ground Up"

But more to come on that later on.

[The_Chosen_One]

The MSII is an awesome option, especially for the amount it costs. And supposedly the new MSIII coming should be able to work with our distributors too so that will make the installation much simpler.

MSI and MSII already work with the stock KA ignition. Theirs no such thing as MSIII. You must be confused with SMC3.0, Microsquirt, Spectre EMS.

Quote »There is another opetion Brian (WD) has shown me that I have been looking into. And it's called MSD Blaster EFI.[/quote]

MSD's ignition systems suck balls. Nascar cars have 2 of them in place incase 1 fails the 2nd system kicks in.

[Chezedik]

IDK if that is a reflection of the quality of the unit, they do that for sake of redundancy. When you build a million dollar rolling billboard, it reflects the quality level of it's sponsors (Tide, Sharpie, Busch, etc), and if that car fails, some of your stupider racegoers (i.e. NASCAR fans) will correlate that to the quality of the product.

While we all know it isn't true, they do not.

[Edub1]

The UltraMegaSquirt is still in development. It has a better processor and built in WBO2 controller. The MSII will hook up to a controller like the LC1 and will automatically generate VE tables based on the AF ratios you want.

You can also set tip in and decel fuel and it has an equation called Xtau that allows you to compensate for fuel that comes to rest on the manifold walls and how fast this evaporates.

It also will control an IACV stepper type or solenoid type as on the KA. It does work with our distributor - they have a wiring write up.

And check this out for slickness - it allows MAF + MAP operation so you can have the benefits of the MAF and control timing via MAP.

All for $400 assembled.

I'll be installing mine in the real near future.

[S13FX]

Thanks Edub,

The Ultra Mega Squirt is what I was referring to. A lot of forums I got to just simply refer to it as MS III, so I guess thats confusion on my part sorry .

[S13FX]

MSD's ignition systems suck balls. Nascar cars have 2 of them in place incase 1 fails the 2nd system kicks in.

Also I wasn't referring to their ignition system. I was referring to their new Stand alone called the Blaster EFI.

Thanks,Mike

[The_Chosen_One]

The UltraMegaSquirt is still in development. It has a better processor and built in WBO2 controller. The MSII will hook up to a controller like the LC1 and will automatically generate VE tables based on the AF ratios you want.

Ultra Megasquirt is a long way from reality. Ultra Megasquirt isn't their something building now. Ultra Megasquirt is all that stuff thats happening now the evolution of Megasquirt. As for processor thats still up in the air, they plan on upgrading to a dual core style processor in a yr or 2. As for built in controller, you can build it on the proto area of the megasquirt now. The Autotune feature that your refering to that automaticallys adjusts your VE table can be done on a narrowband sensor but is not recommended for over 4000rpms. Also SMC3.0 which is Megasquirt II but all surface mounted circuits, it will have the built in WBO2 controller as well as part GPIO.

Quote »You can also set tip in and decel fuel and it has an equation called Xtau that allows you to compensate for fuel that comes to rest on the manifold walls and how fast this evaporates.[/quote]XTAU is based on the code, its already in use with the MSII code 2.6 and up

Quote »It also will control an IACV stepper type or solenoid type as on the KA. It does work with our distributor - they have a wiring write up.[/quote]Thats already in effect, on MSI and MSII. For stepper motors it requires 4 jumpers underneath the board.

Quote »And check this out for slickness - it allows MAF + MAP operation so you can have the benefits of the MAF and control timing via MAP.[/quote]At the moment the code doesnt support both at the same time, its either MAP or MAF but at the moment only FORD MAF's are supported.

[The_Chosen_One]

Also I wasn't referring to their ignition system. I was referring to their new Stand alone called the Blaster EFI.

Thanks,Mike

I was refering to the brand

[Chezedik]

IDK, there are about a Million cars running them.

[Edub1]

All the features I reffered to are in refference to the MSII. I'm not aware that the MSII comes with a WBO2 sensor controller - I hope you are right.

Also, the MSII manual states that it can run both MAF & MAP together. I just read through it. Don't know how good it would work though - my Z32 MAF has been a real PITA.

Anyway, I'm just saying that for the money this thing can't be beat. I feel stupid for having even wasted time on ROM tuning.