Miles,
First off, I’m going to give you the obligatory :search: emoticon. Don’t take it personally. All this info is out there, but I also understand it is frustrating to find it because it is mixed in with so much other bullshit. Years ago, we all found out this information by just asking about it and then later got jaded by having to repeat it over and over (thus the creation of the search emoticon).
You will need an engine stand. I believe that a lot of autoparts stores allow you to rent or borrow lifts but I have never had to do this. Although I’m far away from my friends with that stuff now, so when I pull my B17 in the next few weeks, I’ll let you know what I find.
You will need a nice big C clamp to compress the calipers in your Integra. Although frequently they will push in by hand. I suspect your Audi had the kind where there is a big + on the inside of the piston and you are actually supposed to twist (screw) it in to compress it down. I had a caliper like that vex me once.
What I mean by the transmission is that a hydro transmission comes with the engine you are looking at. Our cars use a cable transmission (cable actuates the clutch instead of a hydraulic line). I’m not saying you should use the one you currently have, but that you should buy a used cable transmission. There are two kinds, the one you have is referred to as a “long geared” transmission, but the ones that came on the 92-93 GS-R in the states and the one that came on B16 engines in Japan (and elsewhere) are “short geared”. You can look that stuff up, but a short geared is more appropriate for a B18C engine.
Doing an engine swap isn’t hard. I did them when I wasn’t much older than you. In my opinion they are much less difficult than rebuilding an engine. You just need to take your time and occasionally you will need someone to help you with stuff.
I would skip the GSR ECU and just get a chipped ECU from Xenocron. Just tell him that you have an OBD-1 B18C GSR engine and he will put the appropriate “basemap” on a chip for you. Later, if you decide to upgrade cams and all that good stuff, your tuner (at a Dyno) will be able to easily tap into that ECU to make you a new map for whatever mods you get.
The wiring plugs are different in your current car (OBD0) than in the GSR engine you would get (OBD1). But what you will do is take your existing harness and ONE PLUG AT A TIME switch it to the plugs that you will cut off of the engine harness that comes with the new engine. There are guides out there (FYI, I didn’t bother reading that one) but the last time I followed a guide like that it was a fucking disaster. It had me using the engine harness off of the new engine then swapping around all sorts of stuff in the engine bay and on the ECU and it was a mess. After it was all said and done, we broke out the wiring diagrams and realized if we had used the original harness in the car, we would have only had to change like 3 wires (this was a D16A1 1st gen integra engine into a 1st gen CRX SI) BTW.
Ok, now normally I wouldn’t condone this, and it is completely against the rules here, but if you do a google search for factory helms manuals and also put the word “spooner” in the search, you may stumble on a resource that will help you with the swap. The only reason I am pointing this out is because to do the wiring the best way, you will need the wiring diagrams from a honda factory service manual (Helms) and the current reprints from Helminc.com don’t include the wiring diagrams you need. You really should buy a real hard copy shop manual though. They are cheap ($46) and – take it from me – much easier to use when actually working on a car than a computer or printed sheets.
It isn’t that difficult. So when all the plugs are replaced on the engine, your car will be wired up exactly like it was before except you will have removed your injector resistor box (OBD1 injectors are a different type then your 90-91 OBD0 injectors) and maybe added a few wires (for VTEC and other stuff?) but all the plugs will correspond to the OBD0 pins on the ECU side. But, some of those pins aren’t in the right place for OBD1 and also the connectors on an OBD1 ecu are different than OBD0. At this point buy a OBD0 to OBD1 ecu conversion harness to make the changes on the ECU side. They cost like $100-$150. There are countless ways to convert to OBD1, but this makes the most sense to me. If I were you, I would search for OBD0 to OBD1 conversion and see what other people are doing/have done…
It sounds way more complicated than it is, but give yourself several days to do troubleshooting on the wiring after you are done. You will probably mis-wire at least one connector and will be going through every pin on the ecu and checking the continuity to the plug in the engine bay and banging your head against the wall. This is normal.
I think I answered all of your questions. Although I have some first hand experience with this kind of stuff, it has been a while since I’ve done any involved swaps like this with an OBD change, so I am sure I missed out some stuff and probably said a few things that are inaccurate. A good rule of thumb is don’t trust anybody on the internet unless they are also willing to come over and help you if you fuck up because of something they said. (and no, I won’t be coming over to help).
To answer your second question explicitly: for the most part, you won’t be able to use the connectors on your factory harness. Some stuff swaps over, but most doesn’t if I remember correctly.
