Confused on P12 ECU swap.

[DAKOTADEMON7]

I've run across posts about swapping over to a P12 prelude ecm. I have been reading on it but the info leaves me still unclear Will it work in my 91 Accord with auto trans ? What part number do I need to look for ? There talking a 10 HP gain with a P12 ecm. Any info or good links would be a big help.

[H311RA151N]

I've run across posts about swapping over to a P12 prelude ecm. I have been reading on it but the info leaves me still unclear Will it work in my 91 Accord with auto trans ? What part number do I need to look for ? There talking a 10 HP gain with a P12 ecm. Any info or good links would be a big help.

http://www.cb7tuner.com/vbb/showthread.php?t=195890

Post #7

I remember creating a thread for this but its long gone now. Here goes the written proceedure:

Most Auto Ecus have a jumper at RP11 and have a blank space at RP12. Move RP11 to RP12 and you now have a Manual ECU. Here a closeup of the JDM Jumper configuration: Auto Jumpers


R96, C49 and R82 seem to be related to some Auto trans controls but can be left in place.

Some ECUs (Like the JDM P13-900) have resistors in both places. You can just remove both of them and replace RP12 with a jumper wire.

This applies to all ECUs that share the same board (P11, P12, P13, P14 and P39)

Read the thread for more info. Ghost is the shit. He never has bad info.

[DAKOTADEMON7]

http://www.cb7tuner.com/vbb/showthread.php?t=195890

Post #7



Read the thread for more info. Ghost is the shit. He never has bad info.

Thanks for the link. Rep given.

[dj_ender]

Or just find an auto P12...

[deevergote]

Exactly.

If you really want to get the full effect of the automatic Prelude, get the auto P12, the corresponding TCU, and the Prelude's automatic transmission (which I THINK is different from the Accord's... I know the Prelude S's manual transmission has slightly shorter gears than the Accord's.)

[H311RA151N]

I'd just rather learn to solder real well and go that route (which I have done personally). But that's just me. I'll do more work to save money if the outcome is the same.

Though I won't use a P12 due to it's inability to operate IAB's, I do look for them in the yards. Which when you find them you get what you get. There typically isn't any picking and choosing.

[DAKOTADEMON7]

Exactly.

If you really want to get the full effect of the automatic Prelude, get the auto P12, the corresponding TCU, and the Prelude's automatic transmission (which I THINK is different from the Accord's... I know the Prelude S's manual transmission has slightly shorter gears than the Accord's.)

I'm just looking to do the P12 ECM for a little extra power. If I'm going to swap trans, it's going to be a 5 speed.

[H311RA151N]

I'm just looking to do the P12 ECM for a little extra power. If I'm going to swap trans, it's going to be a 5 speed.

I made a write up on that. If you ever decide you want to. And your welcome for the help.

[DAKOTADEMON7]

I made a write up on that. If you ever decide you want to. And your welcome for the help.

That's cool. I try to find most my info using a Google search. Most the time it's good but sometimes it seems like you can only find half the info on a subject. I still have to do research on what would be the best 5 speed trans to swap for. I want to find out what trans has the best rear ratio and if there is one that comes with an LSD that don't cost a small fortune used. I think I'm going crossed eye from all the reading. Lol.

[H311RA151N]

That's cool. I try to find most my info using a Google search. Most the time it's good but sometimes it seems like you can only find half the info on a subject. I still have to do research on what would be the best 5 speed trans to swap for. I want to find out what trans has the best rear ratio and if there is one that comes with an LSD that don't cost a small fortune used. I think I'm going crossed eye from all the reading. Lol.

Depends on what you want as for which one(s) are "best". I want mpg so my long geared H2U5 does me just fine.

I Google search this site too. "CB7 _______" (what ever I'm looking for). It beats using the search function on the site.

Most LSD transmissions have a quite higher price tag. In fact I think it's safe to say all do. Even the automatics LSD's.

[DAKOTADEMON7]

Depends on what you want as for which one(s) are "best". I want mpg so my long geared H2U5 does me just fine.

I Google search this site too. "CB7 _______" (what ever I'm looking for). It beats using the search function on the site.

Most LSD transmissions have a quite higher price tag. In fact I think it's safe to say all do. Even the automatics LSD's.

I wouldn't mind a shorter gear. I mostly use my car for work and run around town. All short distance. I have a 2014 Nissan Versa Note for the long hauls.

[H311RA151N]

I wouldn't mind a shorter gear. I mostly use my car for work and run around town. All short distance. I have a 2014 Nissan Versa Note for the long hauls.

http://www.cb7tuner.com/vbb/showthread.php?t=203209

http://www.cb7tuner.com/vbb/showthread.php?t=37839

[Joey GT-R]

I know the Prelude S's manual transmission has slightly shorter gears than the Accord's.)

This is true. Each gear is just a hair shorter. Which now that I think about it, might cure my VTEC drop when I'm shifting the H....dumpster diving I shall go!

[DAKOTADEMON7]

http://www.cb7tuner.com/vbb/showthread.php?t=203209

http://www.cb7tuner.com/vbb/showthread.php?t=37839

Great info. You the man !

[H311RA151N]

This is true. Each gear is just a hair shorter. Which now that I think about it, might cure my VTEC drop when I'm shifting the H....dumpster diving I shall go!

Below is the M2L5 from the 92-96 Prelude S vs H2U5 (just for instance). Not even close to being worth swapping. The Si H23A1/M2S4 is a whole other story.