ECU Conversion - Hondata

[Bananahatch99]

Hey, i'm looking to swap over my OBD 2 ecu to an OBD1 ecu so i can put in a hondata setup --- what is involved and how much?. its for my 99 ek1 running a d16y4? also what are benefits of fitting hondata and can you gain more power output? cheers any help is apprciated :)

[Blaze]

Do you have any other modifications done to the car or is it stock?

From what everyone's been telling me, if you only have intake/header/exhaust done, it's optional to tune but you won't get the most of out of your mods without tune. That being said the difference should be about 5kw.

If you have modified the internals of your engine (which I'm assuming you haven't) then you will need a tune to get things working as they should.

If your car is stock. Don't bother. S300 is about $1000 plus $250 per hour on dyno. You'll end up spending a minimum of $1500 to get 3~5kw.

Have you done any other mods to your car? With the same amount of money as above ($1500) you could get a cat back exhaust and a coilover set and that would give you way more benefit than an ecu + tune. You could also get a really nice set of wheels.

Put simply, if I were you I would put that money elsewhere and not tune until I'd need to, which is what I'm doing since getting my header and exhaust finished.

[ECU-MAN]

Not to mention it will not be plug and play, you are going to have to make wiring modifications to the engine loom, change the distributor and IACV.

[Blaze]

ECU-MAN, why is it that you can't put an S300 in an OBDII ecu?

[ECU-MAN]

You can get an conversion harness for OBDIIA and OBDIIB to OBDI and then plug and play a Hondata S300 prepped ECU, no problems there

Here the problem is the P2K ECU. It does not use the standard OBDI, OBDIIA or OBDIIB wiring ECU pin outs nor does it use the "same" distributor as the regular D,B,H,F series engines. Although the distributors mentioned are physically different between engine families they are however electronically the same in regards to the CKP, CMP and TDC signals to the ECU. (this is why you can run S300 on H series engines).

The D16Y4 uses an optical distributor (not magnetic reductor type) that only provides CKP and TDC via logic IO. The D16Y4 utilises a 3 wire EACV where OBDI engines use the traditional 2 wire EACV and the injectors are configure for group batch firing not sequential, two injectors are wired to each other and fire simultaneously. With all this into account you can see why the ECU is different, some call it a bastard ECU because it is different however reality is this is a lower cost PGMFI system for a low end vehicle, the ECU's NEC CPU is a fax machine/printer CPU made to run a PGMFI system.

What do you have to do to convert to OBDI ? well some say there are harnesses available however I have not seen one for retail sale for some time now. You could make your own custom loom and wire in the distributor and injector wiring change EACV and ECU plugs or get an D16Y8 engine harness. Change the distributor and EACV (May need the entire intake manifold) and connect up the S300 ECU and tune.

[Dxs]

ECU-MAN, why is it that you can't put an S300 in an OBDII ecu?

you should search the internet to find your answers...

but basically, ECUs connect to sensors, and based on these sensors, like RPM, intake pressure, temp etc etc- it determines how long to spray the injectors and when to spark the spark plug.

ECU uses a reference table. Like at 3500rpm at X pressure spray injectors for X millisec:
http://www.xenocron.com/install/CromeGuide_files/image004.jpg

When you tune you change the values in the tables.

You can change the values in an OBD1 honda ecu by pulling the chip which has the values and replacing it with a new chip with your new values.
OBD2 honda ECUs are different design and no one knows how to replace the chip in them.

Hondata is just a Honda OEM OBD1 ecu, modified with an addition board that allows you to write to the chip on the fly and datalog.

If you have an obd1 ecu that is chippable, you can get a writable chip, get a chip writer, and play with the map and write one and then put it in the ecu.

Look at the moates or xenocron websites to see shit they sell.

[Bananahatch99]

28492 its currently got extractors, intake, exhaust, slightly bigger injectors? just looking for more power gains? what else could i try?

[skaterzac]

Hi ecu-man I need some help again!!!!
I have a 94-95 eg vti sedan it recently broke down and took it to the mechanic they worked out my ecu got damp and fried so he sourced another, he said the new ecu code didnt match because they were so hard to find (but apparently not according to eBay) anyway he said my car started ran fine but now my engine light is on/. I paid $580 thinking it would just be the engine light on and my car would be fixed! How wrong I am it now is the laggiest slowest piece of shit I don't even think the vtec kicks in it idles at lower and hits the limiter at about 6500 before it went to about 7200 and ran a lot better it is only stock but I think something's seriously wrong . Has he put a ecu from a non vtec in my car?? Please help

[ECU-MAN]

Hi skaterzac

I have replied to your PM.

[skaterzac]

Hi ecu-man thankyou for that ! Could I possibly grab some contact details to forward onto the mechanic ? He wants you to repair the ecu! I pm'd you but I don't know if it worked

[ECU-MAN]

best to keep PM'ing me and not hijack this guys thread

[Dxs]

ozhonda 2015 edition