S5 Turbo II. N370 vs. N374. help
 

Hey guys. Been a very long time! I' m back in the game again and just picked up my first S5 Turbo II.. It's just a rolling chassis right now, but plan to get her back into her prime! My dilemma is it didnt come with a wiring harness or ecu. And have noticed N370 ecus aren't the easiest to come by.. Although I WILL hunt one down! But plan to buy a jdm engine/tranny. So, my question is, what's different about an N374 and a N370... and is there any way to make an N374 work on a usdm car?

And here's 2 pics of the car ;) already have another turbo hood that will be painted shortly.

Welcome back!

I don't know the particulars on N374s in USDM cars, but most people have all kinds of trouble with them. I seem to remember there being a problem getting the injectors to fire...but don't quote me on that.

^^thanks :)

i read that same thing... makes me wonder why the ecu will make the injectors fire differently when used with a usdm harness... I did notice Rtek does have an option to chip the N374 ecu.. so i wonder if they also cure the injector problem as well. I've read up on people using chipped N374's... so im curious who chips them.

^ So far as I know Amemiya and Knight Sport chip N374s

BTW, I've still got your old MS scoop

Gotcha gotcha... the typical suspects...lol.. ill have to dove deep onto all of this




And I figured as much... hahahahahah..... I saw someone posting a "want to buy" for one.. and someone commented to ask you..lol.. and when they had tried you wouldn't part with it.. lol.. glad to hear it! Did you finally ever install it? The lip that's on the car I just bought is an authentic Mazdaspeed piece :) so I still have SOME goodies..lol. also found the guy who bought my rollbar. Trying to buy that back.. lol.. he stopped responding.. oh well

the issue is likely the difference in wiring, because we have no pinouts translated into english to see where potential problems may occur. a simple input going to the ECU for pressure sensor or knock could tell the ECU to cut fuel to the rear rotor.

i have also run across the infamous N374 single rotor running condition which was quickly solved with an ECU swap to USDM.

i don't know about the N374 specifically, but i've been looking at the N3A1 FD vs the N3A7 JDM FD, and there are a few pins that are different, and the same should hold true for the N374.

so the N374, is JDM, and they didn't have AWS, so you should remove that wire. they also only have 1 of the two solenoids on the ACV, so that should be removed as well

because

in place of these the N374 has a speed limiter.

so its likely that either the N374 doesn't like 12V where the US harness gives it 12V, at the AWS and ACV pins, and then who knows what it wants for the speed limiter*

Somebody at Rtek must know, because they seem to have figured it out.

I also had same prob with N374. I was lucky enough and finally found a N370. I would also like to know exactly what they do to it to make them work.

Yeah, the person offered me a chunk of change for it but I wasn't tempted in the least to part with it. It's still orange but prepped for paint. It's on my turbo vert. Once I'm sure the mechanics are good on the car I'll focus on painting. Though if I start driving the car regularly I may take it to the bodyman who's going to do my painting and let him prep all my pieces for paint and have them in black primer. Black on black vert with some primer black pieces sounds a lot better than black on black vert with a red hood and an orange scoop :P

All that being said, yep it's on the car and I'm driving it to break in the engine, but am fighting some annoying electrical problems. I'd like the car to be a 3 season daily driver...once I get it reliable.

Here is the car from a few months ago with the rebuilt engine in and needing to be buttoned up. It drives fantastically till my efan kicks on. I believe I've narrowed it down to a failing modified S5 alternator. This weekend I may go junkyard diving for a Taurus alternator.
https://fbcdn-sphotos-f-a.akamaihd.n...74370314_o.jpg

A close friend moved to Japan and will be there for at least the next 7 months and probably longer if she decides to sign a longer contract with her employer. It is within the realms of possibility that if someone provides pin out I could get it translated through the friend.

I ran a 374 for 2 years in my s5 with no problems. They guy that bought it swapped everything into a vert and it drove for about another year until he took the motor apart to port it and go standalone.

edit: I almost forgot one important detail. I had no aws, acv, emissions, etc.

I also have the rear injector issue; however, it ran fine in my vert, while it had the na injectors installed. So now I have the issue of running no boost, or low boost on na ecu...smh. I do know someone with a n370, but he wants $250 and im like, "never gonna happen".

found this thread: https://www.rx7club.com/2nd-generati...4-help-518542/
this link:chips for sale 88-91 rx-7
So I will most likely order asap, and will let you guys know.

if you put the chip in there, and it fixes the running on one rotor problem, doesn't that mean the chip just defeats the speed limiter fuel cut?

Update: I tried to order today; However, the paypal account is down, the email doesn't exist, and their ebay account is also down. After looking on the paypal, it says, "last updated 2000". So it seems ill have to keep looking.....smh

I have a KS ROM tuned n374 in a s5 n/a car swapped to a jdm s5 t2 motor, seems to only run on one rotor for a few seconds only while warming up then goes away.

What can i try to remedy this?

I have all emissions bs hooked up can i disable all of the emissions bs without removing everything, cause i dont have a block off kit available?

(so the N374, is JDM, and they didn't have AWS, so you should remove that wire. they also only have 1 of the two solenoids on the ACV, so that should be removed as well)

AWS and ACV what is that again so new to turbo rx7s and i need to learn my abbreviations?

can these be disabled with removing the part, like taking off the electrical connections and letting the parts act as a block off?

i do have the part removed from the l.i.m and blocked off tho, i have the map, bov, and boost gauge vacuum lines t'd off the nipple below the bac valve could that be my problem?

Ive also removed the boost solenoid and blocked everything off.

car has develope a new problem idling down from 4k to 3k exhaust makes a sound like a mack truck coming to a stop sounds like a machine gun, and on the boost gauge i can see it too

sorry for the thread jack i just want to get to the bottom of this and not damage my motor.

I have a few japanese contacts what exactly would i ask for translated to english?

A n374 pinout of wiring? whats the proper terminology?