confused about hondata - Honda Prelude Forum

rentien · 04-28-2004, 03:24 PM

so i'm getting a euro-R motor, but the euro-R ecu is OBD II (the motor is a 2000 accord motor) so i wanted to get it down to OBD I, and hondata it for a little more power, there will only be I/h/e on the car too, anyways does anyone know of any bad things about hondataing with p28 that would affect long term reliability? like no knock sensor or whatever, butterfly control does not matter because the euro-R manifold does not have butterflies...
someone inform me of this stuff i'm confused the heck out

joshmv · 04-28-2004, 03:32 PM

i was confused in your first sentence so don't feel bad

rentien · 04-28-2004, 03:38 PM

o yea... i just realized... the euro-R is from japan, and OBD II was a united states thing? does that mean the euro-R ECU will not be OBD II?? or am i being stupid and my head is making up stupid theories??

and and what i meant was... i thought that since the euro-R h22a motor was 2000 it came OBD II which is bad, so i wanted to get it hondata tuned with a OBD I ecu, p28 or p72... there are no butterflies in the IM, so control over those is not needed... does anyone knwo anything about this i was wondering if p28 is bad for a h22a in anyway also...

4thGenReady2Go · 04-28-2004, 05:13 PM

OBD II isn't bad, just not convenient when you have a 95 or earlier Prelude. You're not stupid, OBD does apply overseas as well, so yeah, your Euro-R H22 will be OBDII. I'm wondering, couldn't you just use one of those OBDII->OBDI conversion harnesses, retaining things like knock sensors etc? Someone more knowledgeable wanna take the ball?

DrSeus · 04-28-2004, 06:48 PM

The loss of the knock sensor is due to the P28 ECU which does not support it. The P72 does and it also supports the butterflies which you don't have anyway. If the loss of the ability to retard timing when knocking occurs is a concern, you can always get the J&S safeguard thing.

I believe those OBDII->OBDI conversion harness are used to adapt the main harness of an OBDII car to an OBDI ECU. Unless you have a 96 prelude, you'll be OBDI and the ECU should just plug right in. However you may have to play some wiring games with the engine harness connections to your main harness.

4thGenReady2Go · 04-28-2004, 07:00 PM

I might as well pipe in here, because I need to learn a bit about ecus. So, what, the OBDI h22s are P13? Which cars do the P28 and P72 ECUs come from?

MidNKight-lude · 04-28-2004, 07:46 PM

b18c and b16

4thGenReady2Go · 04-28-2004, 10:11 PM

so why/how would you use a P28 or P72 on an H22?

rentien · 04-29-2004, 03:23 AM

yea thats why i thought there might be an issue... cause they came from totally different cars p72 comes from integra type r? the b18c? and the p28 comes from some kinda civic i think... so i thought those were totally different...

does anyone think i should have the knock sensor for my euro-R since it has a higher compression ratio more prone to knock 11.0, and i'm only running on pump premium gas out here in cali (91)?

or get a chipped p72? i think they're more expensive though... does anyone know what a good average cost of the J&S safeguard is...?

or does anyone think that knock sensor is pointless?? i thoguht it was always a good thing to have to retard the timing incase i have problems with the little bit higher compression ratio... but then i've heard of higher ratios being run on the street so... 11.0 should be ok?

rentien · 04-29-2004, 09:29 PM

anyone in here know? has anyone hondataed before? do they know how important the knock sensor is? and whether or not a p72 would work for me, and not shoot a cel or something cause i don't have butterflies...?

buffmanextreem · 04-29-2004, 11:14 PM

Those ecu's are supported beacuase they all use the same sensors. The difference is pretty much the fuel maps and the timing. So what the hondata does is utilizes the stock sensors but you manually adjust the fuel and timing maps.

Just go with the p28 becuase it is much cheaper. If you are not going FI any time soon you really wont need the knock sensor if the motor is tuned right. Also you dont need the control for the secondaries.

If you are worried about knock just get a j&s safeguard. But my opinion is just go with the p28 you will not be disapointed

Hondata is an awesome unit!

rentien · 04-30-2004, 02:13 AM

ok thanx... i just wanted the knock sensor cause it came with the car... (so honda thinks it's needed?) and i care a lot about reliability.... thanx though

buffmanextreem · 04-30-2004, 01:48 PM

Like i said if you want to use the knock sensor just get the j&s safeguard. But with the mods that you have you probley wont even need it.