HKS S-AFR, Apexi S-AFC, S-AFCII- Why wont they work?

[KyRaceFan]

Ive done quite a bit of searching, and have read alot of the threads on the install diffuculties of a piggyback fuel tuning device on my mazdaspeed protege.
I'm a little confused as to WHY exactly nothing seems to work.
I hear people say its a wiring issue, others say its the ECU, nothing ive read is very clear.

The car tunes fuel by a hotwire MAF, this much i know. There also is no MAP sensor correct?
Well if it tunes fuel by the MAF signal only, then what is the big issue with the car. Does the ECU reject or ignore the signal? I dont see how it could sense it overrides the signal that should be given, and gives it its own, and if it were just ignoring it, does the car just run off some sort of funky base map?

My next major mod plan after a downpipe is a piggyback fuel computer, and then some 450cc injectors, so i can safely run more boost, without fear of detonation.
Timings still a concern, but for a mostly stock setup, it shouldnt be too bad.

So help me out, and give me, and everyone else who wants to know, some insight as to why exactly the S-AFC, S-AFCII, and HKS Super AFR are so diffucult.

Thanks

 

[KyRaceFan]

Bump...


Someone has to have good info about why none of these simple fuel tuning computers do not work on the Mazdaspeed protege.

 

[blacksp20]

Ky,

I have always wondered why some type of fuel interceptor wouldn't work with our mazda's either.

A friend of mine who was visiting from out of state looked at my car for the first time a few weeks ago and informed me that my car (Australian Mazda SP20) DID have a MAP sensor as well as the MAF sensor and though that was very strange. He pointed to a small black cube with a grey tube coming out the bottom that was mounted to the cenre of the firewall and told me it was a MAP sensor. He knows a lot about cars, having converted many a Datsun 510 and working at a local Ford dealership, so I don't doubt his knowledge.

Maybe someone else could explain what the sensor is if it isn't a MAP. This could be why the S-AFC etc. will not work. It may also have something to do with the learning capabilities of the MP5 computer.

Hope this helps

 

[KyRaceFan]

Another question, is this an MSP only issue, or a trend among other proteges? Do these tuning devices work on on p5's, mp3's and regular proteges.

 

[BinaryRotary]

One word. EECV. Heres where it gets confusing. You can hook up any kind of piggyback and have it work, but it doesnt work correctly. The factory ECU is not consistent at the point where it goes into open loop. Being that it is very inconsistent at varying points, its hard to keep the car tuned properly, almost impossible.

 

[KyRaceFan]

Wouldnt a piggyback disable the open loop feature and tell the ECU what to do and when to do it,.?
Plus, since its modifying the signal the same way, everytime, the ECU should go into open loop at the same time.

 

[BinaryRotary]

Plus, since its modifying the signal the same way, everytime, the ECU should go into open loop at the same time.

See, thats the killer, it won't go open loop consistently.

 

[BinaryRotary]

See, thats the killer, it won't go open loop consistently.

It changes constantly depending on different factors.

 

[KyRaceFan]

I'm starting to understand now, thanks for the input.

 

[aftershock63]

What about getting a JDM OBD I ecu and hooking it up. Or even this; when did the 2.0L start getting put into the proteges? Was it OBDI???? I think this would be a good answer

 

[BinaryRotary]

You'd have to change the harrness and who knows what else.

 

[blacksp20]

sorry to bring this topic back from the dead but....

using an OBD-I computer was discussed..... will the AFC's work with the OBD-I or not.
I am an aussie MAzda owner and have the OBD-I ecu in my protege. any ideas if they will work or will they still have the same probs as with an OBD-II ecu?

 

[70]

There is more to it than this.
I don't why I missed this thread the first time around, but the ECU controls fuel based on the first O2 sensor, not strictly the MAF. The MAF also runs a specific voltage at specific points while the key is in and "off", "on" and "start" postion. It is not a fixed step up in voltage.

The S-AFC and others like it cannot deal with the change as it is trying to run what it wants. The car will not start if the ECU doesn't see the specific voltages. Hence why they do not work.

The E-Manage can work, however you need a voltage clamp on the first O2 sensor, otherwise the ECU will learn around it.

The only piggy that I have seen work is the MPI Tuner. How it gets around the issues presented with the other piggies is beyond me. The company will not disclose. However it works well with the MSP I hear and other turbo Proteges.

The closed/open loop switch also presents a problem because the car will go to a fixed table in open loop (or is closed, I forget). Anyway, at a specific load, or rpm, or throttle postion, or a combination of all three it will go into open loop and follow a specific table that, as far as I know, cannot be changed. The ECU only monitors a few choice sensors at that point and doesn't really use them to base fuel or timing.

In closed loop the ECU checks a number of sensors, however bases most of the fueling off of the first O2 sensor. The stock ECU can pull up to 20% (iirc) and can add up to 15% if needed...

That is a pretty big range. The ECU is no slacker for sure, it just makes tuning with a piggy or other thing a PITA.

As for OBDI cars, I'm not sure how the difference will effect any specific piggy option.

 

[thewrench]

The E-Manage can work, however you need a voltage clamp on the first O2 sensor, otherwise the ECU will learn around it.

OK, this has never been answered for me. On a NA car, do you need the clamp. If so then how does it work, since the clamp as far as I know, works as a boost switch. I know of at least one person trying to run an Emanage on here NA, but this still hasn't really been addressed. Also, does this mean on a MSP, that out of boost the ECU will learn around the Emanage, so that the Emanage is only good for adjustments in boost?

 

[steelie03]

Is a voltage clamp all that is needed to make the E-manage work proplerly? I am buying the GReddy Profec e-01 boost controller soon and was thinking serioiusly about buying the E-manage soon after in order to tune everything out properly for a higher boost level.

 

[70]

OK, this has never been answered for me. On a NA car, do you need the clamp. If so then how does it work, since the clamp as far as I know, works as a boost switch. I know of at least one person trying to run an Emanage on here NA, but this still hasn't really been addressed. Also, does this mean on a MSP, that out of boost the ECU will learn around the Emanage, so that the Emanage is only good for adjustments in boost?

There are two voltage clamps that I know of. The one from Flyin' Miata is a boost switch.

The other one is from Essential Speed, I think I don't know for sure, but it works differently.

Depending on how the other voltage clamp works, you might be able to run the E-manage on an NA car...

 

[70]

Is a voltage clamp all that is needed to make the E-manage work proplerly? I am buying the GReddy Profec e-01 boost controller soon and was thinking serioiusly about buying the E-manage soon after in order to tune everything out properly for a higher boost level.

As far as I know...

This has been covered in the engine management area a bit...