What can be changed under new ECU rule

[Bob Roth]

Effective 1/1/08: Change section 9.1.3.D.1.a.6 and add a new section 7 as follows:

6.<strike> Fuel injected cars may alter or replace the engine management computer, or ECU, provided that all modifications are done within the original OEM ECU housing. Only the stock (unmodified) OEM ECU connection to the wiring harness may be used. The allowance to modify the ECU in no way permits the addition of wiring, sensors, or piggybacked computers outside of the OEM ECU housing. The stock (unmodified) wiring harness must be used. The installation of a resistor is allowed between the sensor and the OEM wiring harness. Adjustable fuel pressure regulators are permitted.</strike>


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.

7. Wires and connectors in the engine wiring harness may be modified or replaced.


In other posts, I get a confusing mesage upon what this rule means. So that I can better understand, I have some examples that I would like a reply if they are acceptable under the proposed language. In your reply, please explain what rules language the reply was based upon.

1) Can someone add an Engine Management Computer to a fuel injected car (example &#39;76 alfa) that didn&#39;t have a computer? &#39;76 Alfa&#39;s have Mechanical fuel injection

2) In reconfiguring an engine management computor, is it acceptable to re-engineer one type of fuel injection (say L jetronic) to a different type modern sequential digital if that upgrade requires installing different type injectors, higher flow injectors, or higher flow or pressure fuel pumps etc?

3) A carburator and a mechanical injection pump computes fuel mixture upon mechanical means. Some fuel injection systems use a combination of mechanical and analog electronic means to compute fuel mixture. Distributors computes spark timing based upon mechanical means. Are any of these non digital devices considered "Engine Management Computers" under the proposed rules?

4) Under the wording of the rule, can I modify the engine head, intake manifold or other supporting hardware in order to create an engine management system different than the original? For example, if I have a single point injector in my 1991 ITB DX honda CRX, is it acceptble to modify the intake manifold and install 4 multipoint fuel injectors with my new computer?

5) If I have an air metering device (example Porsche 944 air box or a Rabbit CIS box), under this rule, can I upon adding an engine managment computer with means to control mixture leave these devices in place but disable them in a way that substantially reduces their induction pressure drop?

In reading the rule, I would think "No" for all questions. What does the committee say? If the committee cannot answer these questions in a clear and unamiguous way, this rule should not be approved.

[Greg Amy]

Keep in mind the over-riding rule here for everything is "if it doesn&#39;t say you can, then you cannot".


Can someone add an Engine Management Computer to a fuel injected car...that didn&#39;t have a computer?[/b]
No. The proposed rule states "altered or replaced" not "add".


...is it acceptable to re-engineer one type of fuel injection (say L jetronic) to a different type modern sequential digital if that upgrade requires installing different type injectors, higher flow injectors, or higher flow or pressure fuel pumps etc?[/b]
Nope. No where in the rules does it allow "different type injectors, higher flow injectors".


Are any of these non digital devices considered "Engine Management Computers" under the proposed rules?[/b]
An interesting concept.

Old adding machines are "computers", albeit mechanical ones. An abacus is also a "computer." Ergo, barring a clear definition of "computer" to specify electronic versions only, I&#39;d suggest anything that accepts inputs and changes outputs can be construed as a "computer" and thus able to be "altered or replaced".

For example, I know back in "the old days" Showroom Stock racers used to reprofile the metering pin/shaft in the CIS cars in order to improve the fuel mixture. That fuel metering device is decisively a "computer" in the mechanical sense of the word, in that it takes inputs (control pressure via the control pressure regulator, and airflow via the airflow flap) and controls the output of fuel to the injectors. While that was decisively illegal in Showroom Stock, I suggest it may be "legal" under these new rules.

But, though, that&#39;s to the strict literal interpretation of the words only, and I personally don&#39;t see it as the original intent. If handed to me on a protest, I&#39;d be hard-pressed to reject the idea, though...


Under the wording of the rule, can I modify the engine head, intake manifold or other supporting hardware in order to create an engine management system different than the original?[/b]
Nope, once again: no specifically allowed, ergo specifically disallowed.


If I have an air metering device (example Porsche 944 air box or a Rabbit CIS box), under this rule, can I upon adding an engine managment computer with means to control mixture leave these devices in place but disable them in a way that substantially reduces their induction pressure drop?[/b]
You cannot mechanically modify them, but you can reprogram your computer to ignore their inputs.

"If it doesn&#39;t say you can..."

Greg

[Bob Roth]

Good thoughts, I would agree.

[lateapex911]

No, to all. But perhaps "engine management computer" needs to be added to the Glossary.

[RSTPerformance]

5) If I have an air metering device (example Porsche 944 air box or a Rabbit CIS box), under this rule, can I upon adding an engine managment computer with means to control mixture leave these devices in place but disable them in a way that substantially reduces their induction pressure drop?
[/b]

Sure you can disable them... Why not?

The second part of the rule says Wires and connectors in the engine wiring harness may be modified.

Also the first part of the rule says that the engine management computer may be altered or replaced. Simply replace it with one where the wires don&#39;t have a place to connect ;) or better yet a place to connect but don&#39;t go anywhere (this is an alt approach incase the second part of the rule doesn&#39;t get approved).



For example, I know back in "the old days" Showroom Stock racers used to reprofile the metering pin/shaft in the CIS cars in order to improve the fuel mixture. That fuel metering device is decisively a "computer" in the mechanical sense of the word, in that it takes inputs (control pressure via the control pressure regulator, and airflow via the airflow flap) and controls the output of fuel to the injectors. While that was decisively illegal in Showroom Stock, I suggest it may be "legal" under these new rules.

You cannot mechanically modify them, but you can reprogram your computer to ignore their inputs.
[/b]

Greg two answers that seem to somewhat contradict the other answeres... wouldn&#39;t the reprofiling of the metering pin/shaft be a mechanical modification rather than a "reprogram" of the computer?


IMO a CIS car is run on mostly vaccume inputs via the entire engine... (The more air the more fuel). I see no reason why the entire engine in that case is not part of the computer system (as described by greg in his mechanical sense in the word), thus I see no reason why anything that may effect vaccume can not be altered, including all the things you mentioned. It is a stretch, but I like it.

Raymond "I wrote one of the three oposing letters" Blethen

[Eagle7]

Sure you can disable them... Why not?

Raymond "I wrote one of the three oposing letters" Blethen [/b]

Wait a minute there, grasshopper. You seemed to miss the key part of the question - "...disable them in a way that substantially reduces their induction pressure drop".

Nothing allows this. As a matter of fact, it&#39;s specifically disallowed - "Other existing sensors, excluding the stock air metering device, may be substituted for equivalent units".

[pfcs49]

alter the resistance of the sensor.