Hey guy. I blew my AP1s engine a few months ago, and I'm getting ready to buy a new engine. I was planning on just getting a JDM engine from Hmotors, and calling it a day. But I started to look into the JDM swap and now I'm mostly just confused as all hell, and most of the posts I found on this topic are like 10 years old now.

So.
Should I be using my USD harness, ecu, and VTEC solenoid?/does that work with the JDM engine?

Do I need to remove the air pump or?? (Also I don't have to do emissions where I live.)

And lastly, I live in Colorado, so the highest octain gas I can get is 91. But we can normal run crappier gas because our air pressure is lower since my town is a little over 6,000ft above sea level. Would that be an issue since the JDM engines have a higher compression?

Any help would be greatly appreciated guys. Not sure what the best couse of action should be since every USDM engine I've found so far is crazy high mileage and/or way more expensive, but the car is my daily so I really don't wanna deal with the headache it looks like I'll be getting with the JDM engine. And obviously this is my first time dealing with anything this intensive... Thanks again guys.

 

The air is less dense at higher altitudes and thus less octane is required to prevent pre-detonation (that's all octane does). The USDM octane recommendation for our cars is 91 (warning to not go below than 87) which should be good for the JDM engine as well since the compression is only marginally higher and the ECU is designed to handle small variations. I don't know how the JDM engine gets a higher compression ratio but reducing the ratio is a common modification when fitting forced induction and could be done here if there is any concern.

-- Chuck