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Obd2 to Obd1

Posted: Wed Jul 08, 2009 3:53 am
by saxophonias
Description of the procedure, reasons for doing the swap, and necessary parts in order to complete the conversion.

Re: Obd2 to Obd1

Posted: Fri Aug 07, 2009 2:22 pm
by saxophonias
Very soon we are going to add everything is needed to perform the obdd1 swap in ej9 civics.
Let us begin with some general comments though.
As far as i can tell, (the more knowledgeable, please correct me where i am wrong) the obd2a/b ecus are more advanced and can control far more parameters than obd0 and obd1. They are faster, more refined and protect the engine better in case something goes wrong. Moreover they are far more sensitive to climatic and environmental changes (temperature, humidity, etc) fuel quality, a/f settings etc. And here is where i stand. I am under the impression that obd2 combos are always trying to achieve the stock settings resisting to power increase. Furthermore they are influenced greatly by weather conditions and all the things i mentioned above, which is very irritating as our cars don't perform the same everyday.

Personally i am under the impression that my car has shifts in performance very often. I am worrying about that and this is one of the main reasons i want to do the obd1 swap. Still what are the drawbacks to this?

Re: Obd2 to Obd1

Posted: Sat Aug 08, 2009 2:01 pm
by Dodo Bizar
About whether-sensitivity: have the same for each OBD.

Some things like inlet temperature are better measured since the OBD2 measurement is done by a different sensor on a different location, more to the front in the inlet tube, giving it faster reaction times.

But with using an OBD1 ECU you can still utilize the OBD2 sensor (which I did after first using the OBD1 sensor which is mounted in the intake manifold).

The real techniques of fuel and ignition mapping have not changed much between OBD1 and 2. It is more the error handling. When something goes wrong the OBD2 type ECU will try to safe the environment instead of your engine... some choices like that were made. Can't think of a good example, but most OBD0 and OBD1 controlled engines will run longer with errors compared to OBD2 controlled. At least this is my understanding of it all.

Re: Obd2 to Obd1

Posted: Sat Aug 08, 2009 2:54 pm
by saxophonias
So obd2 for safety and reliability right?
Is the obd1 the easiest to adapt to engine modifications?

Re: Obd2 to Obd1

Posted: Sat Aug 08, 2009 4:31 pm
by Dodo Bizar
OBD1 and OBD0 are both quite popular... for what I know I just can get nicer programs for the OBD1 systems. (I recommend eCtune ofcourse :) ).

Re: Obd2 to Obd1

Posted: Mon Aug 10, 2009 10:10 pm
by Law_
The only thing that can keep me on OBD II is the knock sensor that, with compression rate going up, removing some material from the gasket and from the natual compression of the Y8 head, is important ! knock can destroy an engine, and it is a far more important in countries that use 91 / 93 octanes gas. Our cars are OBDIIa right meaning they have already a knock sensor or not? Is it really necessary to change to OBD I or its just a matter of ECU Tuning?

Regards

Re: Obd2 to Obd1

Posted: Mon Aug 10, 2009 11:44 pm
by saxophonias
I think we don't have a knock sensor as standard despite being obd2. Joris can verify that.

Re: Obd2 to Obd1

Posted: Tue Aug 11, 2009 5:47 pm
by henrique b correia
i think only d16y8 have knock sensor,

Re: Obd2 to Obd1

Posted: Tue Aug 11, 2009 7:13 pm
by Dodo Bizar
Yup not all Honda's have knock sensors. Mostly the Japanese cars have them. OBD1 or OBD2, both are capable of controlling knock.

I experienced from very close by how an engine was blown having knock. Was a mini-me D15B2 with D16Y8 head I build. Normally they all use octane 95 and it goes well. I adviced to use 98 which is readily available over here. The ECU tuner of this car and I who drove it during testing didn't here the knock due to loud exhaust.

But within 100km it had melted away (it was extemely fast btw for a mini-me). Researched everything and finally the only thing that could have caused it (even though ignition was retarded!). What was the problem? Enough people had build this setup before but used stock cam gears, keeping dynamic compression just in range. I used a different gear and put it to the point were from my experience max hp could be found.

It was there... for a short while... sad picture when we opened up the block. Piston melted away completely to one side. All pistons showed detonation marks. Did this piston not die, within a few seconds another would have gone.

Ah well... people driving with knock sensor tell me those can be quite irritating since you feel the car controlling its ignition point while you want to drive constant speed.

Re: Obd2 to Obd1

Posted: Tue Aug 11, 2009 7:45 pm
by Law_
You are scaring me ! I want to keep my car alive. what do you reccomend? not to install an aftermarket cam, install a knock sensor? watch the knock noises?