Swap questions & opinions - Honda Prelude Forum

cifer6425 · 03-15-2003, 10:58 PM

I am looking at doing the H22 swap. I just have a few final questions.

First off what is a good ECU to run? I currently have the H23 ECU. I know hondata.com is a good place. Should buy an ECU from a VTEC or should I get on thatâ€™s been reprogrammed?

Whatâ€™s the difference between the JDM H22 and the USDM H22? I know the JDM will have a few extra ponies. Do they share the same engine code? If I go with the JDM engine I will have to rewire the distributor? Someone said its just changing two wires. How hard is this to do and what two wires are they?

Most places say the wiring harness is cut around the firewall. What did you all use to get from the firewall to the ECU?

Thanks for the time.

Zimmlude · 03-16-2003, 02:17 AM

Hey,

I have been researching this for a long time and just ordered my engine. I also have an H23. First thing to do is read the write-ups in the FAQ's. They are of tremendous help.

As far as the ECU, there are many options. I am going with a stock JDM P13 as I don't want to get crazy. You can get a rechipped P72 or a P28. It is completely your choice, look on www.hondata.com for info on this.

The difference between the JDM and USDM H22's is the CR (compression ratio). The USDM has a CR of 10:1 while the JDM has one of 10.6:1. This is where the extra hp comes from.

As far as the wiring harness, the JDM one is only good for plugs and some extra wire. Since the engine is JDM, all the plugs to the main harness are on the USDM drivers side. What most people do is use thier USDM H23 harness and add the extra plugs/wires. There are only three total wires to add to the H23 and some 4th gens are prewired for VTEC (mine is

). The two wires to add are the VTEC solenoid and the VTEC oil pressure switch. The solenoid is one wire (Green/Yellow) and, if prewired, will be in a dead-end plug on the passenger side shock tower near the intake filter. The other two are the positive and groud for the Oil pressure sensor. They are Light Blue and Black/something. The light blue wire is the only one you need to find for prewired. It is located in the main engine harness plug right next to the underhood fusebox. If you look on the firewall side of the plug you will see it come into the plug but none comming out the other side of the plug. The groung can just be attached to any bare metal on the engine block.

The distributor from your H23 will bolt directly to the H22. The problem with the JDM distributor is that it has an internal coil while the USDM has and external coil. Just pull the JDM one off and sell it and use your USDM one.

As far as where to buy it I have heard absolutly nothing but good things about www.hmotorsonline.com That is where I ordered mine from. Talk to Steve, he is cool.

Good luck on the swap

Layter

cifer6425 · 03-16-2003, 08:29 AM

Thanks man,
i think i will be ordering from Hmotors also. what year is your lude? mine is a 94. what do you look for to see if its prewired for Vtec?

thanks again.

red92s · 03-16-2003, 08:44 AM

If the search feature wasn't acting goofy, I'd tell you to use it. Since you can't, there is lots of good info in the FAQ. The H22 walkthrough seems to be down for some reason though, but I'm trying to correct the problem.

cifer6425 · 03-16-2003, 09:49 AM

thanks red,
i ve been using the search, or trying too.

red92s · 03-16-2003, 09:56 AM

http://www.preludeonline.com/showthr...&highlight=JDM

Zimmlude · 03-16-2003, 06:48 PM

Hey red92s,

The problem with the link to the walkthrough is the link. The hyperlink links to http://www.preludeonline.com/showth...&threadid=99723

The three dots shouldn't be there, it should link to this:

http://www.preludeonline.com/showthr...threadid=99723

HTH

Zimmlude · 03-16-2003, 06:50 PM

Quote:

Originally posted by cifer6425
Thanks man,
i think i will be ordering from Hmotors also. what year is your lude? mine is a 94. what do you look for to see if its prewired for Vtec?

thanks again.

Hey,

Glad I could help. I think I described how to find the wires. My car is a '95. There is also a good FAQ on it.

Good luck

cifer6425 · 03-17-2003, 08:23 PM

What the advantes of using diffrent ECU's? i know if i keep my stock ECU i will not have VTEC. having a VTEC is the big advantage. but can you not get an GSR ecu?

Zimmlude · 03-17-2003, 08:36 PM

The different ECU's are used because they can be remapped and give some good gains in HP. I personally think Honda does a great job and don't want to mess with it. I am going to be running a P13 (the ECU designed for the H22). I will be getting a Spoon chip put in to adjust the maps. There is NO point in swapping in the engine if you don't use the proper ECU. If you use an Si ECU the engine will run but will act like your current engine if not slower.

Check out www.hondata.com they have some info on their ECU programs.