RX7HNski

I've got an 86 FC that I've had for 19 years, bought a refreshed 13b street port turbo and installed. What wires in the loom need to be connected to get a start up?? It turns over so that's a start but I have removed the factory inter cooler and turbo and have replaced with front mount int and T04Z. Will the factory computer allow start up with this set up??

insightful

even if you get it to start, nothing about that turbo size and a stock computer is a good idea, even if to just start the car.

i'm hoping you have bigger injectors, and anything much larger than stock 550cc is just going to flood the crap out of the engine and make it that much harder to start later.

RX7HNski

Do some damage?

insightful

that really depends on how far you try to go with it, yes it is easily possible to do damage with the stock ECU and its aggressive timing curves with such a large turbo. i'm more concerned about your fuel setup and flooding the engine.

RX7HNski

Ideas and directions would be great as I've only just installed? Any advice would be great.

insightful

well, my advice would be to read up about modifying an engine and about how to install and tune a standalone ECU, because that's what you need to do. that or pay a shop to do the fine touches on it for you, because you're at the point where people usually go very wrong if they aren't careful, those being the standalone installation and tuning as well as combing through the setup for potential issues.

RX7HNski

Cheers ??

insightful

i'm not trying to be a dick, but i get really tired of people not doing research before dumping a huge turbo on their car with a stock ECU.

what you're basically asking is for me to write out a 300 page book about how to design and setup your engine peripherals, teach you how to tune it and how to go over your fuel system and exhaust, check for intake leaks, install gauges, learn to datalog and read those logs. etc, etc, etc. the information is already out there without needing to say it over again and again, which i have time and time again.

in essence the stock computer doesn't control injector pulsewidth during cranking, it is a solid figure that is only modified by the engine temperature. even if you just want to just hear the engine run, starting with the stock ecu is already a bad idea.

RX7HNski

For starters, no I'm not asking you to list off every detail of what I should be running with what I have. I'm asking if the motor will start if it's connected to the stock ECU. I intend on starting it for a minute to make sure I have the wiring loom sorted as on the new motor all of the emissions have been capped off and I'm stuck with a crap load of plugs everywhere. Once I've made sure it will start I'll begin upgrading everything including the loom as it's perishing.

Secondly the question marks after me saying cheers are because I tried to add a thumbs up emoji which I've now worked out don't work on here so I wasn't being sarcastic.

Ive got a long way to go with this build which is going to involve removing the engine and drive train a few times but for now I'm just trying to work out what needs to be connected since the new motor is missing emissions and I'm left with plugs and pipes which I'm not sure where they should go/ be plugged off.

insightful

what size injectors are you running in the primary location?

RX7HNski

I'm not sure, whatever was in it when it was rebuilt by a rotary mechanic called REVS. The motor was a customers that he rebuilt and the customer skipped on him and never paid up, we never got into conversation about what turbo was being ran.

insightful

then honestly i can't give you an answer. if they are the stock 550cc injectors it should start but it may not hold an idle, if they are 720cc, it should start and idle, however may roughly. if they are larger than 720cc you will likely never get it started and wind up just dousing everything inside the engine with wet fuel.

the AFM can be hacked to get it idling decently, but that isn't quite a novice step and requires messing with the delicate internals of the airflow meter(AFM) which directly controls how much fuel the engine gets after it is started, otherwise something like an SAFC can technically do it, but it'd be a waste of investment since it would only be temporarily installed.

insightful

you could try though, but you may wind up just flooding the engine severely and need to pump in a supplemental oil to build compression back up for future starting tests.

the intake needs to be leak free and airflow meter installed, the crank sensor needs to be timed by installing it as per the factory manual, the coolant temp sender needs to be hooked up, the TPS as well and all your ignition wires to the proper plug positions, aside from those basic things, the ECU doesn't need much input to get the engine running. the intake temp sender is actually inside the AFM already(the one on the intake elbow is actually for cold start systems, however we use it on standalone cars since the AFM goes bye bye, the AFM temp sender is in a bad location anyways for performance).

RX7HNski

I haven't installed the AFM yet as I'm trying to work out how to mount it with the new inter pipe work. I'll keep everything you've said in mind as this is why I've joined the forum. I'm not new to owning RX7s but I'm new to modifying them. I'll probably run in all sorts of problems when it comes to the single turbo conversion on my FD.

insightful

understandable, and sorry if i seem short. i've been answering questions about modding FCs for nearly 2 decades and the whole drift kid fad kind of took the wind out of my sails.

RX7HNski

No drifting going on here, just wanted to up the anti in the power department because I got bored of the stock 13B with the little snail hanging off it. Your input is exactly what I was looking for. Correct me if I'm wrong but did you say you can get rid of the AFM?

insightful

no, the AFM is the single most important thing that needs to stay plugged into the ECU, it cannot be deleted even on a simplified setup. nor can it just be laying somewhere on a fender while you try to turn over the car, it needs to actively be measuring air going into the engine.

the airflow meter is like a measuring cup, it tells the ecu how much air is getting to the engine. without a measuring cup the ECU only has the RPMs to go by for a measuring method, so it just turns on the faucet at a steady flow. there is also a fuel pump switch inside the AFM, if nothing is going past the AFM then the pump will shut off immediately after the engine starts as the switch will constantly be open.

what you may remember is that i said standalones omit the AFM because it really is an old system, one that modern cars no longer use.

RX7HNski

I thought so, must have read your other post wrong lol. I'll go back and read it in a minute.

insightful

yeah, i get a bit edit happy, most of the time i'm not responding to someone who is immediately reading the messages.

RX7HNski

This is my FD that will be getting the single turbo conversion.

Aaron Cake

iTrader: (1)

At the minimum, all you need to start and run the engine is:

-AFM
-Boost/pressure sensor
-Idle mixture adjustment pot
-TPS
-CLT
-IAT
-CAS
-Coils
-Injectors

That will run the engine.

However as mentioned, with that turbo, you are into standalone territory.

On the stock ECU you can start and drive the car out of boost. No danger there. But the stock ECU has no way of handling the large turbo without a lot of hacking and add ons. Which is an old terrible way of doing things that was typical of modifying cars in the '80s and '90s before affordable standalone systems were common.

RX7HNski

Cheers man, like I said I'm not interested in driving it just want to start it to make sure all wiring is in order before I pull the engine out again and re do the engine bay and loom etc.

misterstyx69

iTrader: (142)

Pull the engine out anyways and go with a Stand alone.
That way you start fresh.
Put essentials on the engine that will support your goal..like the size of injectors,Turbo,wastegate etc..and then plug those parameters into the new ECU after you install the engine back into the bay.
I think you are doing things a little backwards and need to have the engine and it's support systems in place to guide you through the rest of your build.
The stand alone ECU will just about run anything you put at it,the thing is the engine needs to happily run in harmony with all it's essentials first..so Take a look at what others are running and that will give you a good idea as what you can start with or guide you to help you build up your engine.