LugTronic for MK3

[Beran]

Anyone do this in ITB yet? It's basically the Megasquirt for the VW.
Although the rules seem to still require the MAF to be hooked up and functioning.
Any thoughts?
Anyone done this?
Thanks,
Beran

[Greg Amy]

Although the rules seem to still require the MAF to be hooked up and functioning.

Yes, and no. The MAF must still be in place, must remain unmodified, and all intake air must pass through it. However, in now way, shape, or form does it have to be 'functional'; you can simply tell your ECU to ignore it and use the MAP sensor. Or, since ECU wiring is effectively free, simply don't terminate the MAF wires to the ECU at all.

But, again, it must be there and all intake air must pass through it.

GA

[GTIspirit]

Wow, that Lugtronic is really expensive. For not so much more $$$$ there is the Bosch MS3 Sport:
http://www.bosch-motorsport.com/cont.../html/2953.htm

[jlinfert]

We have been doing MegaSquirt installs for several months now. 3 Mk 3s and on average we are seeing 6 to 8% increase in peak HP plus better fuel economy. (the Motronic 2.9 ECU goes VERY rich at wide open throttle)
I can't see spending the money on a Lugtronic unit when I can install AND tune an MS2 system on a customer's car for around $1600 (customer's cost)

[Beran]

Hmm - the rules state:
6. The engine management computer may be altered or replaced. A throttle position sensor and its wiring may be added or replaced. A MAP sensor and its wiring may be added. Other existing sensors, excluding the stock air metering device, may be substituted for equivalent units

but then:
Air cleaner assemblies may be modified, removed or replaced. Velocity stacks, ram air or cowl induction are not permitted unless fitted as original equipment. Air intake source shall be within the confines of the engine compartment or stock location. Air intake hoses, tubes, pipes, resonators, intake mufflers, housings, etc., located ahead of the carburetor/throttle body may be removed or substituted. On cars so equipped, the air metering/measuring device (i.e. air flow meter, air mass meter, MAF) must be operational and shall not be modified.

So - "Operational" seem to state that it has to be working/used?
Anyone else?

[Greg Amy]

So - "Operational" seem to state that it has to be working/used?

Think of it this way.

A vehicle's MAF is typically the main intake restriction, especially those with a flapper-type system (e.g. Mk1 Miata). As such, the rule is written such that you cannot remove the MAF and increase the amount of airflow going into the engine.

But, the rule was written specifically to allow such systems as Megasquirt, Haltech, and "piggyback" ECUs, many of which use TPS and MAP as their primary engine load input.

Thus, one can meet this rule very easily: install a TPS and MAP if not so equipped (specifically allowed), and if you wish leave all the wiring stock - even the inputs into the wiring harness/ECU - and simply program your ECU to ignore the MAF signal. Since ECUs are free, including programming, is completely free, it's not only legal to the letter but also to the spirit and intent of the rule.

While you may find the wording of the rules a bit awkward, I ssure you this was the specific intent of them. - GA

[bobqzzi]

Yes, and no. The MAF must still be in place, must remain unmodified, and all intake air must pass through it. However, in now way, shape, or form does it have to be 'functional'; you can simply tell your ECU to ignore it and use the MAP sensor. Or, since ECU wiring is effectively free, simply don't terminate the MAF wires to the ECU at all.

But, again, it must be there and all intake air must pass through it.

GA

The rules say:

6. The engine management computer may be altered or replaced. A throttle position sensor and its wiring may be added or replaced. A MAP sensor and its wiring may be added. Other existing sensors, excluding the stock air metering device, may be substituted for equivalent units

but then in the next section:

7c. Air cleaner assemblies may be modified, removed or replaced. Velocity stacks, ram air or cowl induction are not permitted unless fitted as original equipment. Air intake source shall be within the confines of the engine compartment or stock location. Air intake hoses, tubes, pipes, resonators, intake mufflers, housings, etc., located ahead of the carburetor/throttle body may be removed or substituted. On cars so equipped, the air metering/measuring device (i.e. air flow meter, air mass meter, MAF) must be operational and shall not be modified.

Sure seems like it needs to be "operating."

[Greg Amy]

Sure seems like it needs to be "operating."

Physically, yes. Electronically, no.

Think of it more simply: since the ECU and its programming are free, where do the rules say that the MAF has to be considered as part of that programming? Why can you not simply ignore its signal, effectively the same as cutting the wires?

This is no longer an issue of "if it doesn't say you can, then you cannot", as by making the ECU "free" it now reverts to the Roffe Theorem: "If it says you can, then you bloody well can!"

GA

[bobqzzi]

I agree that you could program the computer to ignore any input and be legal. But it does specifically say that it can't be altered and must be operating. It makes no distinction between physically and electrically; therefore, if it is not receving voltage and outputting a signal, it is not operating.

I'd agree that when the rule was written the intention probably did not include electrical operation, but intentions are meaningless. Only what is written matters. This needs to changed.

[Beran]

"Other existing sensors, excluding the stock air metering device, may be substituted for equivalent units"

The word "excluding" is specific to the MAF.

I understand what the intent was but the wording does not support it.
What you really want is the stock air flow meter to remain in place and to have all the intake air pass through it. Aside from requiring intake air to flow through, it does not have to perform any other function.

Beran

[Greg Amy]

Looks like you guys are screwed, then.

As a related aside, the ITAC chairman has an aftermarket ECU in his Miata, and his MAF is, by your definition, "not operational". In fact, it's even been spied in post-race Tech as electrically unplugged... Just sayin'...

[Beran]

Well then he is not legal to the letter ;-)

It is possible to use the stock air flow meter with a system like the megasquirt, lugtronic, or other. This is what the rules look like they were written for.
Until the rules are changed - this seems to be the legal way to run a programmable system.

[Eagle7]

It is possible to use the stock air flow meter with a system like the megasquirt, lugtronic, or other. This is what the rules look like they were written for.
Until the rules are changed - this seems to be the legal way to run a programmable system.

Then why the allowance to add a MAP sensor? I'm with tGA on this one.

[JoshS]

Guys, tGA is right about the intent. I was there when the rules were written -- the intent is that you can electrically disconnect your MAF but you can't alter its physical properties. You cannot improve your airflow at all with this allowance.

So you can ignore the signal, or even unplug it. Just don't mechanically modify it or move it.

If the rules fail to say this, maybe they could be reworded. But I personally think they are sufficient. Happy to hear suggestions though.

[Beran]

Hi Josh,
Thanks for the help.
Maybe a tech bulletin for the air flow issue and a clarification of what "Operational" means..... mechanical versus electrical.
My engine building likes to stay to the letter of the rules and was/is not comfortable with saying that it will be 100% legal if the air flow meter in not operating electrically.
It might be a total nit picking point... sorry.
Beran

[lateapex911]

I too was there at birth, LOL. The reason the MAF is excluded from substitution and or removal is, as others have stated, to make sure it's stays in the airflow and provides the same restriction as stock. If we didn't say "Operational" the flapper door would be fixed in the open position. Send the thing voltage if you like to be legal to the letter of the rules, but don't "listen" to what it is saying.....

Gerg and Josh have the correct take.

If the unit is getting voltage, and attempting to return a signal, however wrong that signal is, and however ignored that signal is, I consider it oerational.

[jlinfert]

Well then he is not legal to the letter ;-)

It is possible to use the stock air flow meter with a system like the megasquirt, lugtronic, or other. This is what the rules look like they were written for.
Until the rules are changed - this seems to be the legal way to run a programmable system.

Leave the sucker in.... leave it plugged in.... unplug the factory ecu and run the MS or Lugtronic on it's own harness. Perfectly legal as you are allowed to add to or modify the factory harness to run your aftermarket ECU.With a clean install it is hard to tell anything has even been done in the engine compartment.

[NATW]

"But, again, it must be there and all intake air must pass through it."


I don't agree with this statement, the rule clearly says that air intake hoses located ahead of the throttle body may be removed or substituted. Nothing says that all air must pass through the air mass meter. Even in vehicles using the air mass meter it would be legal to let extra air into the system after the air mass meter as long as it is before the throttle body.

I realize that this was not the intent when all this was discussed on this forum but that is what the rule says.

I think the wording about being "operational" is very confusing and should be changed. I also think that an air temperature sensor should be specifically allowed to permit conversion to a MAP system.

Nat Wentworth
ITB Volvo 142

[Eagle7]

"But, again, it must be there and all intake air must pass through it."

I don't agree with this statement, the rule clearly says that air intake hoses located ahead of the throttle body may be removed or substituted. Nothing says that all air must pass through the air mass meter. Even in vehicles using the air mass meter it would be legal to let extra air into the system after the air mass meter as long as it is before the throttle body.

4. All air entering the intake tract shall pass through the carburetor or fuel injection air inlet.

Now we can debate what an air inlet is.

[Beran]

I have to agree with Nat.
The wording "On cars so equipped, the air
metering/measuring device (i.e. air flow meter, air mass meter,
MAF) must be operational and shall not be modified."
Is confusing.
Add to that the sentence before the above:
"Air intake hoses, tubes, pipes, resonators, intake mufflers,
housings, etc., located ahead of the carburetor/throttle body
may be removed or substituted."

What is the intent?

Can I just hang my air flow meter (electrically plugged in) on my inner fender and not have any air flow go through it... Then hook a nice big air intake hose to my throttle body?