mackstann

I have seen that a d16y8 can be swapped into a CRX, so the y5 should be possible too, since the only difference is the head / ecu / 5 wire o2 sensor (right?). But what I'm confused about is that I thought the y5 ecu would require OBDII.. is that right?

Ideally I would hunt down a CRX with a d16y8 already swapped in, and then just put my y5 head on it. But that brings me to the other big question -- which CRX to get. I am almost sure that I want an HF, but what year? I figure I might as well get a 90 or 91, but they are a little heavier than earlier ones. I don't care much about creature comforts, I just want a car that is as light as possible and doesn't look super old and can have my y5 swapped into it.

What do you think?

jlicrx

for what you want to do, the 88 CRX HF would be the best since it is the lightest - visually, it is hard to tell the differences between 88 and 91, which are relatively minor - finding one with a Y8 in it probably isn't going to help you much since most people when swapping the Y8 into the 88-91 CRX run the engine as OBD1 rather than OBD2 - you could also run the Y5 as OBD1 with OBD1 ECU - most people with Y8 use the EX P28 ECU which may run too rich for the Y5 (maybe not) - i don't know what other ECU you could use for OBD1, maybe the ECU from VX which is also VTEC, but it would probably not be too good with the Y5 - if you want to run it OBD2, just get a stock 88 HF, get a OBD0 to OBD2 conversion harness from Rywire and drop the Y5 in (you would need to make some minor changes) and put on a good exhaust system (HF exhaust is tiny) - unless you are looking strictly for fuel mileage, you would probably want to also get rid of the HF transmission (very long gears) and get a DX or Si transmission

jlicrx

i believe the Y5 has the EGR system on it, correct? - since the HF also has EGR system, it should be compatible

mackstann

Actually I don't know much of anything about egr on either car. I just found a little bit of info: http://www.hondacivicforum.com/m_233933/tm.htm including one guy who says it's only on automatics. I will have to take a look at my hx later.

Doesn't the 88 have that weird passive rear wheel steering thing?

Will a d16y8 transmission work? (edit: nm, forgot about cable/hydro)

Also, as for my goals with this -- I am looking basically for a balance of mpg and power. I like getting 30/40mpg city/hwy in my HX, but I like CRX's more than Civics, so I figure this would be an even better combination.

According to my half-ass calculations, assuming the HX is 2500lbs and the CRX is 1800lbs, and the y5 makes 115hp, then the 700 fewer lbs is roughly equivalent to increasing the hp on the HX to 160. I basically calculated each car's "hp per 2500lbs" with the y5:

(115 / 2500) x 2500 = 115
(115 / 1800) x 2500 = 160

I wonder what effect it will have on mpg...

jlicrx

yes, the 88 has different rear suspension - not a big deal as far as i am concerned (i have 88 HF), but if it worried you, just get the 89 HF - it only weighs 15lbs more than the 88 - you would be right that the HF with the Y5 would run like the HX with an engine with 160hp - still, 115hp in a CRX isn't a lot, but a lot more than a stock HF engine - we do a lot of DOHC ZC swaps in the 88-91 CRX/Civic cars and the 88-89 HF with the DOHC ZC and a DX transmission gets around 38-40mpg - the Y5 should be in the same ballpark

mackstann

I can't seem to find anything about odb0 to odb2 conversion (including at rywire), or odb2 crx's. I'm a little ignorant about this stuff. What all does the ECU hook up to? Just the engine basically? Then couldn't I just use a d16y8/5 engine wiring harness and hook it up to the hx ecu and call it a day? Or am I oversimplifying it?

edit: Ok.. I'm finding a little info now.
also http://hondaswap.com/civic-crx-ef/d1...eat-ecu-73783/