My sad civic

Hello all, happy and yet apprehensive to be here. I hoped I could figure it all out on my own, but alas, t'is hard. I have a Canadian 1997 civic si, with a d16y8 motor and a b4ra automatic transmission. I aspire to put an old td04l turbo on it and remove the reliability that made it such a good daily. However, I want to keep my automatic transmission. At least long enough to send it to the aether someday. I'm having trouble understanding parallel ecu setups, and would really love some advice from those who have done this before me. I'm still unsure on a lot of things, and honestly any advice would make me feel a lot better. My motor is out of the car, on a stand, mostly torn down and waiting to be fully cleaned and painted. I've never done any of it before, but at the same time, I want to do it all. I already have quite the pile of parts, and it only becomes more daunting as I realize I've dug quite the hole for myself. So here I am, paying for gold membership, hoping the forums will come to my aid and help me build a fun little street car and dip my toes in the worlds of engine building and tuning. I am also a level one apprentice, and I have a relatively firm grasp of the mechanical functions of everything. I just need some guidance.on the finer details, and the pro tips to keep it running for at least one summer. Thanks to anyone who bothers to read or reply. I look forward to learning more than I ever imagined.

What are the requirements for the install? Do you need to retain some type of emissions compliance? is a CEL ok? What ECU or ECUs are you considering?

I just want to be able to learn to tune it myself. I want to use the trans I already own, mostly cause I'm poor and secondarily cause it sounds fun to ruin one then tear it down after. I could care less about emissions or a cel, so no problems there. I am considering any aftermarket ecu, but I'd rather not have an antiquated hondata. Especially when the price seems close to a modern unit anyways. I've looked at the ecumaster det3, and I've looked at the haltech elite 550 or entry level link ecus, and even briefly researched speeduino. I don't have any real experience with any aftermarket ecu anyways so I don't really know what to look for past the basics. My only preference is availability of plug and play adapters as opposed to having to wire things in myself. That doesn't mean I won't wire it in myself, cause I can. I just would rather not have to. The difficult part for me is that they all seem like with the right setup they would get me where I want to go. Since I have no brand loyalty or specific experience whatever I choose to learn is equally new and exciting. Honestly, I have no real expectations. I am very flexible, because I know that I know very little in this regard. As they say, the more you know, the more you know you don't know.

The det3 is a significantly different device from a low IO ECU like a E550 or Speeduino. The det3 will let the stock ECU run the engine and you will be modifying from there. I do not believe it has direct fuel control so you would most likely need to add addittonal injector/s. This is an added complex that I would think is not desireable.

The current piggyback market isn't that great. You would most likely look at hardware like an AEM FIC or a Greddy eManage Ultimate. With the FIC, you would intercept the OEM Injectors, Tap the Crank sensor for RPM and add a MAP reference. Scale for changed injectors or just adding fuel for the increased MAP. If you needed ignition control, You could use the FIC. It would take just a little more wiring. If you could get away with retarding the total timing at the distributor a few degrees.

Now into standalone the standalone option. You can do a partial parallel or full parallel install. What is needed for the transmission to operate correctly should be the priority. I will give more info if the piggy back option doesnt work for you.

Yeah, even though it kind of sounds easier, I don't want to use a discontinued piggyback product if I don't have to. I'd much rather have a parallel ecu setup with a modern off the shelf standalone. I just don't know how to set that up. I had been imagining a partial parallel setup, as I'd rather not double up on sensors and wiring. However I am worried about keeping the integrity of the signals between them. I'm not really sure which signals I actually need so I'm not sure how hard it would be to setup sensors to be fully parallel.

These are all very valid points and things to consider when doing what you are. You can make the parallel ECU have a common sensor ground with the OEM ECU. With this, tapping the 0v and TPS signal only will still give you a proper TPS reading. The parallel ECU will not have the ability to offset for any deviation in the 5v reference. This will offset the voltage range up or down. Does it really matter, no. Should you keep it in mind, Yes. This is also important when it comes to the MAP sensor. Can you tap the MAP, yes. Would it be better to add your own, also yes. Trying to deal with a little variance in the MAP reading is not that desireable compared to the offset with the TPS.

Another issue is the two-wire temperature sensors. You cannot tap the OEM temperature input with a circuit on the parallel ECU that has a pull-up enabled. The OEM ecu is already doing this and the double pull-up will cause problems. Having the OEM ECU provide the pull-up is somewhat problematic. The value of the pull-up determines the scale of the two-wire temperature sensor. When you do not know that value, you might need to calibrate your own sensors.

Cam and Crank sensors: With port injection, it is nice to have them firing sequentially although it is not necessary. Depending on a few factors, you might get away with just tapping the crank sensor and having the ECU run batch fire and distributor fire. This would be the first option if keeping the CEL off is a priority. If not, tap both, or add a secondary cam trigger for the parallel ECU.