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Ian P

DE+T neo base maps

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Hi guys, first post - hope one of you can help- I've done a DE+ T conversion, topmount t5,greddy intake, 440cc injectors, big fmic,3" exhaust--as it's  an auto so I have  sourced a gtt neo ecu and modified with a nistune type 4 board but I need base maps to get it to fire up - anyone know where I could get some from- 

Thanks guys

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You will also have bigger issues than merely this, your auto is going to be in a world of hurt unless you wired the standalone TCU into the loom of the GTT ECU that you have.

To get this working you will need to teach yourself wiring and tuning if you haven't already, or be prepared to spend on hundreds of hours of someone else's labor as they figure it out while not wanting to 😛

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2 hours ago, Ian P said:

it's  an auto

 

19 minutes ago, Kinkstaah said:

your auto is going to be in a world of hurt unless you wired the standalone TCU into the loom of the GTT ECU that you have

Ha. I skipped right over that part. Kinks is correct. GTT ECU is not going to run the N/A auto. Also will not run the GTT auto in the NA body unless the loom is also properly swapped in.

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19 minutes ago, Kinkstaah said:

You will also have bigger issues than merely this, your auto is going to be in a world of hurt

And there are many posts on this subject previously, But Greg's 7 pages are must read.

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Oh yeah the ecu is from a neo gtt auto - the info over wiring that I've seen is that the only difference in the harness is the n/a has no boost sensor wiring which I have added- thanks guys I will just have to buy the nistune license and download rom packs - I expect a steep learning curve ahead!

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46 minutes ago, Ian P said:

the info over wiring that I've seen is that the only difference in the harness is the n/a has no boost sensor wiring which I have added

No. That's the only difference in the engine wiring.

Re-read what has been said above. But for clarity:

  • The NA auto cars have a separate TCU. The tranny loom is wired to that TCU.
  • The turbo cars have the TCU in the ECU. All the tranny TCU wiring reports to the ECU plug.

Only, when you plug your ECU into the ECU loom plug......where are the tranny wires? Still on the other side of the car connected to a TCU that is not connected to the ECU. The turbo ECU does not want to talk to the remote TCU. It only wants to talk to the TCU that it has inside itself.

 

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I think FROM MEMORY (which is 7+ years old a memory now, maybe longer) you CAN snip the wires from the gearbox TO the TCU, and connect them to the corresponding pin on the GTT Engine ecu. I know it is documented on the workshop manuals as to what the pins on the TCU are *for* and there is a corresponding pin on the Engine ECU.

I noticed this when I was removing the OEM TCU and wiring it into an aftermarket gearbox ECU. I never tried it myself, as I had an aftermarket ECU running the engine anyway.

Yes, my fix for this at the time was run a standalone engine ECU for the GTT motor, and run a seperate gearbox ECU to run the gearbox, as the car sat around for 3 years outside of my control while it took specialized JDM workshops to... not... look at the manual and figure it out.

Then there's the issue of the fact the NA gearbox is a piece of shit. The GTT gearbox when built up isn't exactly daily friendly either or performance friendly. Spend 10K+ on that.

To get this absolutely clear, you won't have a nice, working enjoyable car unless you do the equivalent of an engine/gearbox swap, because that is what you will be doing.

And why go to that effort.. for a NA+T and a... N/A auto box?

Return everything not bought yet.
Sell car.
Buy 86. Add turbo.

Posting here for future googler's reasons.

There is no cheap way to a R34 GTT via a NA+T given the price differences. There never was, but there still isn't now.

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You could just try and sell the auto ECU, keep the Nistune and put it in a GTT manual ECU. That will allow the existing NA TCU and wiring to run the gearbox. That's what I've got on my NA+t and is 'almost' plug and play. It won't be a GTT but it'll get you to the next step of sorting out the map.

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18 minutes ago, DatsunBanana said:

That will allow the existing NA TCU and wiring to run the gearbox.

How is your TCU doing a good job of running the tranny when it is not communicating with the ECU? The TCU and ECU need to talk to each other and usually get quite shitty when they can't. The auto ECUs know how to talk to the TCU, but the manual ECUs are autistic and refuse to communicate.

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As above, I would have thought the TCU will get stuck in 3rd/limp mode, because it expects things that it isn't getting. If you can supply what it was getting it'll answer a lot of google searches on this one.

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When I did this few years back I read everything I could find on the subject including the thread here for example:

 
I was happy to give it a go based on Dan666's experience but only after I checked out EC-11,12,13,14 and AT-8,9 in the workshop manual for myself. As I understand it, the required signals will still be connected between the manual GTT ECU and the existing separate TCU via the GT loom (e.g. pin 29 speed signal and pin 37 throttle opening signal). I'd suggest to anyone planning this swap to look at those pages and get an idea of the similarities and differences. Apart from that I can only speak from experience - I swapped in the manual GTT ECU and it's been fine on my NA+t.

I said 'almost' plug and play because there will be errors related to traction control and boost sensor which aren't physically there on a GT. But those were easy enough to workaround - I fed suitable voltages to the correct pins on the ECU via diodes to stop the check engine light coming on.

Pin 104 signal has different purposes between GT/GTT ECUs so a GTT ECU won't control the GT inlet manifold valve if that's still fitted. Little bit of info on page EC-44 for anyone interested.

The signals for A/T position indicator dash lights are not present on the manual GT ECU. Mine never worked before I did the conversion so I can't say for sure what will happen to those but I don't see why they wouldn't get the signals from the existing GT TCU.

Pin 79 is an interesting one. Looking at page EC-18, that signal relates to malfunction detection. For GTT it relates to TCS/ABS e.g. 'Malfunction (open/short circuit, etc.) is detected in multiplex communication line between engine and TCS/ABS'. And for GT it's different: Malfunction (open circuit, short circuit, etc.) is detected in multiplex communication line between ECM and TCM. [RB25DE). That difference hasn't caused any issues for me in the past 4 years as a daily driver.

For anyone Googling for answers I'd say some of us have had success and some haven't. It's inconclusive. But for the OP who's invested in this already, a manual GTT ECU can work and might be worth a try compared to the GTT auto ECU which will be a pain for the reasons already pointed out.

 

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Quality post. ^

This is a good reason why I say NA Skylines are only suitable for LS3 conversions. If you're going to have to go through bullshit to try to get 30 year old tech working, you might as well just strip it all out and make a 5 year old BIG V8 work.

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1 hour ago, GTSBoy said:

Quality post. ^

This is a good reason why I say NA Skylines are only suitable for LS3 conversions. If you're going to have to go through bullshit to try to get 30 year old tech working, you might as well just strip it all out and make a 5 year old BIG V8 work.

Tbh having done both the only tricky part really is the auto. It makes more sense to throw a manual in.

Making the BIG V8 work is a lot more work outside of the drivetrain. That part is the easy part!

The post a couple above is very accurate. Looking at the diagrams back to back you realise its a lot simpler than people make it seem (my memory is hazy now, many years and setups ago).

The problem is the inertia of getting someone to actually look at it. The bias of "Oh, a R34???? oh... it's N/A... oh... it's auto.. yeah okay... back of the line" is VERY real.

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1 hour ago, Kinkstaah said:

The problem is the inertia of getting someone to actually look at it. The bias of "Oh, a R34???? oh... it's N/A... oh... it's auto.. yeah okay... back of the line" is VERY real.

Yeah, well if I owned one I don't think I could overcome the inertia required to do it myself. I only went 25Neo in my R32 because it was actually quite trivial - having had the original auto box banished many years before and being mostly just a case of swapping the looms.

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