I'm going to put my JDM RHD FD 13B-REW engine back together as soon as I get all the required engine Internal parts I'm waiting on and would like to run the absoute minimum amount of Crap in and around the engine Especially Harness wise (im keeping the A/C). It will be oil pump deleted and single turbo'ed, intercooler upgrade as well as a few other items. All that emissions crap will also go by the way side. What can I delete, block off, cut and discard off this thing?

BTW, it's a 1999 JDM RX-7

 

Cas x2
tps
Injector x4
Water temp x2
Air temp
ground terminal (consolidated)
knock (optional)

That's all that's needed in the harness. The lack of iac can be tuned out very easily. With that in mind, delete the associated parts that are no longer supported by the trimmed down harness.

 

I had to look twice at that.

The above listed is the stuff that is needed. Whereas the question was:

"What can be removed."

Perhaps elsewhere you have mentioned what aftermarket ecu you are planning to use.

The stock ecu will go nuts if you remove even a few items (such as the OMP).

Depending on the built-in programing flexibility of the ECU you will have greater success with the deletions.

When you say "remove the oil pump", I'd take it you rather mean the oil metering pump (OMP).

 

Probably going with an Apexi and yes I ment the oil metering pump.

 

You'd want to go through the many (many) threads discussing tuning the APEXI.

 

Here is a place to start:

https://www.rx7club.com/3rd-generati...-turbo-749702/

 

Mind you most of the discussion is for LHD S6 cars (Versions 1~3).

You may wish the search the laujesse download for the Updated FSM for Version 4 cars which shows the vacuum diagram for Version 4 (and largely later) cars.

As apposed to deleting the "rat's nest" you will be deleting the "rat box".

While you are at it, you'd need to download the Version 5 wiring diagrams suitable for 1999 cars.

You might want to grab a used 1999 "emssions harness" (aka Engine Harness) for $100 and practice you deletions on it.

Reusing a 25 year old harness is not likely the best course of action, so you may want to plan to have a custom harness built, or search out a ready made aftermarket alternative.

Bear in mind that there are only a limited amount of Version4 plus cars in North America, so collective experince in downsizing an S8 engine bay is more limited.

But the basic removals will be similar to that for S6.

 

stating only whats required is the same as listing what can be removed. it makes for a much shorter list

 

ok, how can i change the thread title?

 

i was responding to redbul

 

https://www.rx7club.com/power-fc-for...aster-1167351/

 

I would add wideband O2 to that list, although it may not necessarily live in the main 'engine' harness you should plan to have one on any modified car.

I would keep either the Idle valve or the thermowax valve too. Personally I removed the thermowax valve to simplify the coolant routing and kept the idle valve, and my ECU keeps the car idling nicely even if I want to run the car when there's snow on the ground. If you're modifying a factory harness, be careful of the power wire feeding the idle solenoid because it's daisy-chained with some of the other solenoids you'll probably remove. If you don't know what daisy-chained means for wires, just follow the power wire from the idle solenoid very carefully and know exactly where it connects before you cut any of the emissions or turbo control solenoid connectors off.

You'll probably want a boost control solenoid, and the ECU usually triggers the cooling fans so find that wire in the harness and be sure not to remove it. Again it may not go to the traditional 'engine' harness near the coolant sensor wires or throttle position sensor wires but it connects to the factory ECU so you should be aware of it.

If you're going to get a standalone ECU, I would get something that can protect the engine if the wideband O2 sensor detects that the engine is running too lean in boost. I don't think the PowerFC can do that without the Xavier Borg add-on module. Fuel system problems are very common in modified cars, and the cost of a rebuild is higher than the cost of a good ECU and good tuning. I would add an oil temperature/pressure sensor, and fuel pressure sensor. You can run a car without them, but it's better to have the data and know how well the important systems on the car are working.