PDA

View Full Version : How to run a MAF with Stack Injection



Coyote 5.0
09-22-2014, 04:50 AM
Hi Guy's I'm new to the forum and looking for some answers to a problem I have.

First I'll give you quick insight into what I am doing and what I would like to do.

I have a current build under way where I'm fitting a Ford 5.0 Coyote and 6R80 transmission into a 1970 XW Falcon. (Australian 1970 Muscle car) Fitment of the engine and transmission is not a problem as I will be replacing the entire front end with a rack & pinion IFS setup. There maybe some work required on the transmission tunnel to fit the 6 speed tranny because of the size of the bellhousing but that'snot a real concern because the body is having a full rust restoration and it's down to just the bar shell. The engine and tranny have all the factory PCM and controllers with harness so it won't be hard to get the engine fired once it's fitted.

What I want to do and that's where all the wizards on here can hopefully help. I want to run 8 stack efi injection. That's problem No 1. The Ford PCM requires the MAF sensor to function. Easy fix I hear you say why not just go an aftermarket ECU. Yes it is easy I could do that as the new intake has a ECU that has been developed specifically for this intake and has full control of the VVT on the Coyote camshafts as well. If I go down this path it creates problem No. 2 which is the biggest problem. I cannot control the 6R80 auto because the aftermarket ECU does not have the ability and the manufactures have no intention of writing code not now or ever was the response I received when I asked the question.

I have made inquiries with every stand alone Tranmission Controller manufacturer that I can find on google. They all say they are working on it but don't have an a Unit that has the intelligence programming required to run this transmission. Best case scenario is possibly 6 months others say could be years away. One mob even make the OEM controllers for Ford but have no plans of releasing anything the the aftermarket community.

There are some work arounds like build a plenum to fit over the stacks and fit a MAF throttle body to it. I don't see this as an option because not only would it look but ugly it defeats the purpose of the free flowing stack injection.

Could drop the auto and go manual. That's not really financially smart thing to do due to the costs involved.

Drop the idea of the stack injection all together.

Or wait till somebody makes a controller.

So now I can show my complete newbie status when it comes to EFI systems. I have been thinking about it I have an idea. And I'm just throwing it out there. Maybe fit a MAF inside one of the intake stacks.

My questions are

If I could find a MAF to fit in one of the intakes stacks would it work correctly?
How would I find the right size MAF?
If it did and I used the Factory PCM would I be able to alter the appropriate tables using SCT or inequivalent software?

Go easy on me as I said I am a newbie :innocent2:

fastacton
09-22-2014, 05:05 AM
What happens if the factory PCM doesn't get a MAF signal? I know it's not the same, but the 4.6 in my old T-bird ran good when I disconnected the MAF (and much better than it did with a bad MAF). Does it affect shifting? If not, maybe you could use the factory PCM to control only the transmission and piggyback the aftermarket ECU to control the injection?

Coyote 5.0
09-22-2014, 06:42 AM
What happens if the factory PCM doesn't get a MAF signal? I know it's not the same, but the 4.6 in my old T-bird ran good when I disconnected the MAF (and much better than it did with a bad MAF). Does it affect shifting? If not, maybe you could use the factory PCM to control only the transmission and piggyback the aftermarket ECU to control the injection?

From what I can gather the new Coyote PCM needs the MAF signal. Ford Racing wanted to use the intake system that I want to use but even they couldn't get the PCM to run without a MAF. I don't know if they tried putting a MAF on the stacks though or if its even possible. I would think the PCM uses the MAF to calculate torque control on the transmission. Like I said I'm a newbie but I have a basic understanding. That's why I think a simple piggy back may not work in my application.

The engine will run with any ECU with a MAP sensor or density the Auto is the issue because it needs the PCM for the intelligence and programming.

That's why I thought If a MAF could be installed inside one of the stacks to send a signal back to the PCM might work. I have no idea of how to work out what size MAF would work or if it's even possible. The Motec has the hardware to run the auto but not the software which is unlikely to happen even though there would be a market for it in the hot rod and custom community. This engine is a very popular conversion over in the states and eventually over here.

steveo
09-22-2014, 07:51 AM
i can't imagine that it'd be difficult to piggyback the stock ecu and this other ecu to provide all functionality you require, and that's the solution i'd go for.

there has to be a way.

ideally, tune around that behavior somehow.

if it requires a maf signal? hell, just generate a fake one

i cant imagine that much MAF influence on transmission behavior, but if there is any.. im sure you can figure out an appropriate maf signal.

all the same if that stock ecm is tunable and you want to use it (not sure about ford tuning?) and it needs a maf, finding a maf the size of one of your stacks may be damn near impossible.. but if you can, should just be a matter of dividing the maf table by 8 and seeing how she goes.

delcowizzid
09-22-2014, 08:11 AM
theres a guy on pcmhacking.net just started controlling an older ford box with modified delco holden vr auto code thats about to be released for free.its also been controlling a toyota 1UZfe auto trans as well

Coyote 5.0
09-22-2014, 09:58 AM
i can't imagine that it'd be difficult to piggyback the stock ecu and this other ecu to provide all functionality you require, and that's the solution i'd go for.

there has to be a way.

ideally, tune around that behavior somehow.

if it requires a maf signal? hell, just generate a fake one

i cant imagine that much MAF influence on transmission behavior, but if there is any.. im sure you can figure out an appropriate maf signal.

all the same if that stock ecm is tunable and you want to use it (not sure about ford tuning?) and it needs a maf, finding a maf the size of one of your stacks may be damn near impossible.. but if you can, should just be a matter of dividing the maf table by 8 and seeing how she goes.

The SCT tuning software can alter a lot of parameters so I'm assuming MAF is one. I'm not a tuner so I don't know. I can certainly look into that side of it as well as a piggyback solution.

I have to agree finding a maf small enough to fit inside a stack will prove to be near imposssible. Maybe some efi motorbikes have a maf setup

steveo
09-22-2014, 05:46 PM
i work at a bike shop, i've never seen a bike with a maf. most of them are ITB with stacks too.


I'm not a tuner so I don't know

well there's one way to learn

buddrow
09-22-2014, 06:25 PM
On the Ford"ZF" 6R80, the controller is part of the valvebody. This Mechatronic unit gets engine info via CAN communication. The MAF is used for shift timing/feel, torque management, among other things. So, with that being said, you will have to use an engine controller compatible with the trans in order for the trans to operate, regardless of if you have a MAF or not.

I am currently building a trans controller for the 4/5 speed autos from GM/Ford/Chrysler but no plans on operating the mechatronic units as of yet.

Buddrow