victor.m

So I currently have a 1994 Civic EX with a JDM D15B in there. It's an automatic so I'm thinking about soon doing an auto to manual conversion..I'll need a new 5-speed ECU anyways, so am I better off going with a P08 which is for the JDM D15B as opposed to a P28 which it currently has? Also, while I'm at it, what would be a good transmission to use and where can I get ahold of one apart from being lucky enough to find one at a salvage yard?

thanks in advance

crazyguy

p08 is the right ecu for your engine and p28 wont make your car run right cause air and fuel ratio is a bit off.. or get p28 ecu chipped and d16z6 is pretty good tranny for d series.

Dasfinc

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by victor.m &raquo;</TD></TR><TR><TD CLASS="quote">So I currently have a 1994 Civic EX with a JDM D15B in there. It's an automatic so I'm thinking about soon doing an auto to manual conversion..I'll need a new 5-speed ECU anyways, so am I better off going with a P08 which is for the JDM D15B as opposed to a P28 which it currently has? Also, while I'm at it, what would be a good transmission to use and where can I get ahold of one apart from being lucky enough to find one at a salvage yard?

thanks in advance</TD></TR></TABLE>

P28 does not activate the 2-stage Vtec that car has, so you are not getting the most out of that motor right now, let alone if you went manual.

if you are doing a manual swap anyways, I'd imagine you can just send your auto P28 to http://www.phearable.net and get it chipped for stick and with a P08 basemap for $100.

victor.m

Right so right now as I'm running with a P28 that means the engine is running a bit off? I'm not sure if it's been chipped, the swap was done before me and it seems like the ECU has been removed as one of the bolts to hold it in place is missing. How can I check if it's chipped?

So the d16z6 tranny would be fine? Would the p08 5spd ECU work just fine with that tranny?

Dasfinc, my D15B is the non-3-stage, but thanks. I'm sure about it because I only see 1 VTEC solenoid, unless I'm missing something. But thanks, I'll check out the chipping option..would be it just as good as getting a p08 5spd ECU?

crazyguy

to make sure if your p28 ecu is already being chipped. take ecu out and open the lid and see if u can spot a chipt and solder socket . ecu has nothing to do with tranny. ecu is for engine fuel/air and some sensors diagnose
http://www.phearable.net/
this guy is a pro i got mine from phearable.net too

JSPECSIR

the difference between a p28 and a p08 is a p28 uses a 4 wire o2 and the p08 uses a 1 wire o2. i use a p08 on my stock d16z6 in my 94 ex everyday. it runs the exact same as the p28 did.

Dasfinc

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by victor.m &raquo;</TD></TR><TR><TD CLASS="quote">Right so right now as I'm running with a P28 that means the engine is running a bit off? I'm not sure if it's been chipped, the swap was done before me and it seems like the ECU has been removed as one of the bolts to hold it in place is missing. How can I check if it's chipped?

So the d16z6 tranny would be fine? Would the p08 5spd ECU work just fine with that tranny?

Dasfinc, my D15B is the non-3-stage, but thanks. I'm sure about it because I only see 1 VTEC solenoid, unless I'm missing something. But thanks, I'll check out the chipping option..would be it just as good as getting a p08 5spd ECU?</TD></TR></TABLE>

Yes, it would run the same as a OEM P08 ECU.

I'm a bit confused, but to my understanding the D15B only comes in one style that has the multi-stage Vtec...

You sure you have a D15B?

victor.m

Humm so I suppose whoever swapped the engine converted the 1-wire O2 on the D15B to a 4-wire for the P28? Or are the O2 sensors interchangeable and he just used the p28 4-wire on the D15?

Gonna open it up tomorrow and see if its been chipped. Thanks guys.

Dasfinc

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by victor.m &raquo;</TD></TR><TR><TD CLASS="quote">Humm so I suppose whoever swapped the engine converted the 1-wire O2 on the D15B to a 4-wire for the P28? Or are the O2 sensors interchangeable and he just used the p28 4-wire on the D15?

Gonna open it up tomorrow and see if its been chipped. Thanks guys.</TD></TR></TABLE>

stock wiring is 4 wire, so i think the previous owner DIDN'T change it to a one wire O2.

You sure you don't have a Z6 or a Y8?

victor.m

Definitely a JDM D15B, here's a picture.



I had a bunch of people check out the pictures and tell me what it was so I could be sure. Seems like a JDM D15B? The "D" is a bit faded, but it's there.

95vxtealhatch

I'll chime in on this subject. I have a d15b, just like you. However im only using the shortblock with a z6 head. I'm running the p28 computer. I suggest you run the p08 since you have the d15b head.

Dasfinc

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by victor.m &raquo;</TD></TR><TR><TD CLASS="quote">Definitely a JDM D15B, here's a picture.



I had a bunch of people check out the pictures and tell me what it was so I could be sure. Seems like a JDM D15B? The "D" is a bit faded, but it's there.</TD></TR></TABLE>

Thats just the block, I'm like 99% certian D15B heads only come in one flavor.

I will try to find the pic that shows where you can tell what head you have.

There should be a "P08" or "P28" stamped on the head itself somewhere.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 95vxtealhatch &raquo;</TD></TR><TR><TD CLASS="quote">I'll chime in on this subject. I have a d15b, just like you. However im only using the shortblock with a z6 head. I'm running the p28 computer. I suggest you run the p08 since you have the d15b head.</TD></TR></TABLE>

*This is what I suspect he has as well*

suspendedHatch

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dasfinc &raquo;</TD></TR><TR><TD CLASS="quote">
Thats just the block, I'm like 99% certian D15B heads only come in one flavor.

I will try to find the pic that shows where you can tell what head you have.

There should be a "P08" or "P28" stamped on the head itself somewhere.

*This is what I suspect he has as well*</TD></TR></TABLE>

No... There is an OBD1 equivalent JDM D15B which has the same head as a Z6, and that's what he has. Your "2 stage VTEC" is the OBD2 equivalent JDM D15B which has the Y5/Y8 head with two VTEC solenoids (I'd say Y5 head cuz of the EGR but then people will think that the Y5 and Y8 heads are different). This motor is actually called "3 stage VTEC", the first stage being 12 valve mode, 2nd stage being 16 valve mode, and the third stage being your conventional SOHC VTEC.

This information has been around so long it blows my mind that people are so misinformed.

victor.m

Thanks, so yah I guess this is pretty much the same as a D16z6 but with 0.1L less displacement? Would the P08 ECU make a difference over the current P28 that's made for the D16z6? I'm gonna have to swap or chip the ECU anyways, so might as well know now so I can get a P08 5spd or something. I'd suppose having slightly smaller chambers the air/fuel ratio would be a bit diff. (no idea if what I said is correct)

Anyways, thanks guys. I know a bit about the 3-stage VTEC which was a mixture of VTEC and VTEC-E, read something about it, but def. not my engine. I appreciate all the input, and thanks suspendedHatch for that great info.

So the P08 is the right ECU for m y engine?

fryguy190

the tranny off of a z6 should be the same size. its a S20 tranny.

Bense

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by suspendedHatch &raquo;</TD></TR><TR><TD CLASS="quote">

No... There is an OBD1 equivalent JDM D15B which has the same head as a Z6, and that's what he has. Your "2 stage VTEC" is the OBD2 equivalent JDM D15B which has the Y5/Y8 head with two VTEC solenoids (I'd say Y5 head cuz of the EGR but then people will think that the Y5 and Y8 heads are different). This motor is actually called "3 stage VTEC", the first stage being 12 valve mode, 2nd stage being 16 valve mode, and the third stage being your conventional SOHC VTEC.

This information has been around so long it blows my mind that people are so misinformed.</TD></TR></TABLE>

yep.

for the nth time JDM D15B means nothing but "d-series 1.5 liter"

usdm d15z1 vtec-e = jdm d15b
usdm d15b7 nonvtec = jdm d15b


most of the time, when people say d15b, they are referring to the engine with the same d16z6 head. p08 is the engine code for this engine:
it is
75mm bore
84.5mm stroke
137mm rod (yes, it's a p28 d16z6 rod)
unique d-series crank with d16 sized rod journals
d15z1 block
sohc vtec head.

ever notice how d16z6's have p08 heads? that's why.

Dasfinc

Wow, never knew.

I knew the D15B was the 'jdm' equivalent of the Z6/Y8, didn't know it came in different flavors.

yea, by all means use a P28 then.

speedooo

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dasfinc &raquo;</TD></TR><TR><TD CLASS="quote">

P28 does not activate the 2-stage Vtec that car has, so you are not getting the most out of that motor right now, let alone if you went manual.

if you are doing a manual swap anyways, I'd imagine you can just send your auto P28 to http://www.phearable.net and get it chipped for stick and with a P08 basemap for $100.</TD></TR></TABLE>

wrong. obd2 d15b has 3 stage, uses the obd2a p2j ecu

Dasfinc

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by speedooo &raquo;</TD></TR><TR><TD CLASS="quote">

wrong. obd2 d15b has 3 stage, uses the obd2a p2j ecu</TD></TR></TABLE>

Buddy, it doesn't matter, I meant 3 stage, but he has an OBD1 D15B anyways which I now realize is a different animal.

Bense

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dasfinc &raquo;</TD></TR><TR><TD CLASS="quote">yea, by all means use a P28 then.</TD></TR></TABLE>

Technically, the p28 ecu is still not the correct ecu for the p08 d15b

notice that when I say p08 d15b, I am of course referring to the 1.5 liter with the d16z6 equivalent head. The one that has the d16 rods on the exclusive 84.5mm stroke crank.

the p08 ecu has different timing values than the p28 ecu. If you were to ask someone on pgmfi.org, or an experienced tuner, he would tell you to get the p08 ecu.

If you were to ask the 1992-2000 civic forum on honda-tech, they would tell you to use the p28 ecu.

I am going to tell you that the best option is going to be to send your p05/p06/p28 obd1 ecu to someone that can "chip your ecu" and have them make you a p08 chip. This will be much easier than finding the p08 ecu.

There's no such term as "2-stage" All this does is add to the multiple levels of confusion that this thread is causing. I know what you mean by 2-stage, but most people aren't going to and it will just confuse them.

Also, in japan, a ZC is just a d16.
Yes, not every JDM ZC is a DOHC

JDM version of our d16a6 = zc
jdm version of our d16y7 = zc
jdm dohc 1.6 liter 75mm bore that people swap into civics = ZC

Relic1

ALL about the D15B - http://asia.vtec.net/article/d15b/

the fuel/ign mapping inside the P28 and P08 are smiler to the point of being swappable if you really want to.
The P28/D15B combo will result in slightly less power and slightly poorer fuel mileage.
The P08/Z6 combo will run slightly leaner than with the P28. Also P08/Z6 combo may also develop a slight knock over time if pushed hard due to the ignition mapping differences.

by hard I mean track conditions most of it's life.

OP, do the auto--&gt;manual swap,
If you have an Auto P08, open the back case of the ECU, remove RP18 and replace it with a 1.4kohm resistor. This will convert the ECU to manual trans.

BlueCrxNC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Relic1 &raquo;</TD></TR><TR><TD CLASS="quote">
OP, do the auto--&gt;manual swap,
If you have an Auto P08, open the back case of the ECU, remove RP18 and replace it with a 1.4kohm resistor. This will convert the ECU to manual trans.</TD></TR></TABLE>

Not arguing:
The Forums/WIKI on PGMFI.org show two ways of Auto-&gt;Manual P08 Conversion.
OEM Manual ECU's leave RP17 Empty and put a 0 ohm resistor (jumper works as well) at RP18. I've done the above to all my P08's.

JSPECSIR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BlueCrxNC &raquo;</TD></TR><TR><TD CLASS="quote">

Not arguing:
The Forums/WIKI on PGMFI.org show two ways of Auto-&gt;Manual P08 Conversion.
OEM Manual ECU's leave RP17 Empty and put a 0 ohm resistor (jumper works as well) at RP18. I've done the above to all my P08's.</TD></TR></TABLE> thats what i did to mine as well. it was an auto ecu.

Relic1

I think (with JDM ECUs) as long as it's less than 1.5k it will set to manual. All though I have not had any time to play with it and see how far you can go before the ECU gets finicky.

USDM ECUs are so much easier.