Question about Suby ECU in a swap Options

[jasons]

I know its possible to swap an NA EJ25 SOHC using the factory ECU. Renegade sells a "Speed Sensor" kit. I think it bolts to the output of the transaxle. Is this required or optional?

I'm trying to understand the ins and outs of these swaps because I think they are interesting. I know a swapper could go aftermarket, Link or Stinger or whatever. I'm curious how much work it is to go with the factory ECU.

BTW, I've looked at most of the threads that are relevant. None of them really give a play by play on using the factory ECU. Just intimidating pictures with lots of wires.

[charliew]

Time is money. You can buy a already enginered engine management unit and spend your time at your job making money to pay for it. Most people are better at their job than hotrodding. The speed sensor seems to be a failsafe part of the suby ecu. Most subys will run awhile after resetting the ecu then set a code and go into limp home mode or stop completely. It doesn't seem to need exact speed, just a feedback to say the car is moving.

You can use the suby ecu if you do a lot of learning yourself. The suby ecu, at least the 02 up ones are very smart, they learn. That also makes them a little tricky to reprogram. If there is a open ecu program for the na cars that is the way to go.

Probably this is not the highest tech site to learn about suby ecu's and reprogramming. The nasioc site is a good place to learn as many people have swapped motors and drivelines from one style suby to the other. There are also other swaps on their forums.

Also Subbug's I think ad., Paul Moran has a na suby that he is running megasquirt on and I'm pretty sure that is the most cost effictive standalone ecu available.

Again the already engineered ecu's are by far the quickest and simplest way to go. If you later go turbo I don't know if the ecu connectors are the same on na and turbo ecu's on the subys.

A jdm motor will be the cheapest but the hardest to get replacement parts for. Also the jdm runs a higher compression and more stock timing for higher octane fuel in japan. The jdm ecu will probably see a detonation event and shut the timing back to stop it, it may still run fine with retarded timing, I don't know. I bought a jdm tt 96 motor and tranny with low mileage with everything even the fuel pump from jhot. Because most of the hop up info is on the 02 up wrx/04sti I am going to use it with a 02 wrx ecu and sensors but it is still tricky as the sensor feedback is different so none of it is simple. The higher compression means I will just be able to run less boost. It does have hyd. lifters which if their not sticking will be kinda neat. It will still rev to 7k. Stock in japan it's 260 hp. Keep in mind that time ages connectors and they get brittle. A jdm connector that breaks might be a real pain to replace easily.

I think without a experienced person at yourside you will spend more time on the wiring and ecu than all the other conversion stuff on the 914.

There is already a conversion going nearly complete with a drive by wire immobilizer sti motor. He totaled his sti and kept the parts.